WO2023065184A1 - 电池单体、电池及用电设备 - Google Patents

电池单体、电池及用电设备 Download PDF

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Publication number
WO2023065184A1
WO2023065184A1 PCT/CN2021/125105 CN2021125105W WO2023065184A1 WO 2023065184 A1 WO2023065184 A1 WO 2023065184A1 CN 2021125105 W CN2021125105 W CN 2021125105W WO 2023065184 A1 WO2023065184 A1 WO 2023065184A1
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WO
WIPO (PCT)
Prior art keywords
winding
pole piece
welding
battery cell
section
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2021/125105
Other languages
English (en)
French (fr)
Inventor
孙东升
迟庆魁
谷慧
柴志生
朱广浩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Contemporary Amperex Technology Co Ltd
Original Assignee
Contemporary Amperex Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Contemporary Amperex Technology Co Ltd filed Critical Contemporary Amperex Technology Co Ltd
Priority to PCT/CN2021/125105 priority Critical patent/WO2023065184A1/zh
Priority to EP21960937.7A priority patent/EP4354637A4/en
Priority to JP2024505486A priority patent/JP7746534B2/ja
Priority to KR1020247001054A priority patent/KR20240018655A/ko
Priority to CN202180092104.8A priority patent/CN116830378B/zh
Publication of WO2023065184A1 publication Critical patent/WO2023065184A1/zh
Priority to US18/528,326 priority patent/US20240120624A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/536—Electrode connections inside a battery casing characterised by the method of fixing the leads to the electrodes, e.g. by welding
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0431—Cells with wound or folded electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/147—Lids or covers
    • H01M50/148—Lids or covers characterised by their shape
    • H01M50/152—Lids or covers characterised by their shape for cells having curved cross-section, e.g. round or elliptic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/538—Connection of several leads or tabs of wound or folded electrode stacks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • H01M50/547—Terminals characterised by the disposition of the terminals on the cells
    • H01M50/548—Terminals characterised by the disposition of the terminals on the cells on opposite sides of the cell
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present application relates to the technical field of batteries, in particular, to a battery cell, a battery and an electrical device.
  • Batteries are widely used in electronic equipment, such as mobile phones, laptop computers, battery cars, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools.
  • Embodiments of the present application provide a battery cell, a battery, and an electrical device, so as to improve the power performance of the battery.
  • the embodiment of the present application provides a battery cell, including an electrode assembly;
  • the electrode assembly includes a first pole piece, and one side of the width direction of the first pole piece is provided with a plurality of welding parts, the A plurality of welding parts are arranged at intervals along the length direction of the first pole piece;
  • the electrode assembly has a winding structure
  • the first pole piece includes a winding start end and a winding end end
  • one of the plurality of welding parts closest to the winding start end is a first welding part
  • the one of the plurality of welding parts closest to the winding end is a second welding part
  • the first pole piece includes a main body section
  • the main body section is from the first welding part close to the winding starting end to the edge of the second welding part near the winding end
  • the main body section is equally divided into a plurality of subsections with a length L, and the total length of the welding part of each subsection is not Less than 5%*L, where 200mm ⁇ L ⁇ 1200mm.
  • the existing current collecting member and the electrode assembly are welded by laser continuous linear welding or pulse spot welding, and the shape of the welding mark is X-shaped, ring-shaped, etc.
  • the shape of the welding mark is X-shaped, ring-shaped, etc.
  • the first pole piece is formed by The main body part defined by the first welding portion near the winding start end and the second welding portion near the winding end end is divided into a plurality of sub-sections of equal length, and the total length of the welding portion of each sub-section is not less than the length of the sub-section 5% to make the distribution of the welding part formed by welding the first pole piece and the current collecting member more reasonable, so as to reduce the internal resistance of the battery cell and meet the actual overcurrent demand, thereby improving the power performance of the battery cell.
  • the length of the sub-section is between 200mm and 1200mm, so that the winding length of the first pole piece meets the actual product requirements and the battery cell has a higher energy density.
  • the absolute value of the difference between the total lengths of the welded portions of any two subsections is less than or equal to 10mm.
  • the absolute value of the difference in the total length of the welded portion of any two sub-sections is controlled within 10mm, and the difference in the total length of the welded portion of each sub-section is reduced as much as possible, so that the distribution of the welded portion is more reasonable. It is beneficial to reduce the internal resistance of the battery cell, and make the difference in the overcurrent capacity of each sub-section small, so as to meet the actual overcurrent demand, thereby improving the power performance of the battery cell. Control the absolute value of the difference in the total length of the welding part of any two sub-sections within 10mm, which is equivalent to the error of the welding width of each sub-section within 10mm, allowing errors in the total length of welding between each sub-section, which can reduce welding difficulty.
  • the total lengths of the welding parts of any two subsections are the same.
  • the absolute value of the difference between the numbers of welds of any two subsections is less than or equal to 10.
  • the absolute value of the difference in the number of welds of any two sub-sections is controlled within 10, and the difference in the total length of the welds of each sub-section is reduced as much as possible, so that the distribution of welds is more reasonable, which is beneficial to
  • the internal resistance of the battery cell is reduced, so that the difference in the overcurrent capacity of each sub-section is small, and the actual overcurrent demand is met, thereby improving the power performance of the battery cell.
  • Controlling the absolute value of the difference in the number of welds between any two subsections within 10 means that the number of welds in each subsection can be different, allowing errors in the total length of welding between subsections, and reducing welding difficulty.
  • the number of welds of any two subsections is the same.
  • the difference in the total length of the welding parts of each sub-section is reduced as much as possible, so that the distribution of the welding parts is more reasonable, and it is beneficial to reduce the size of the battery cell.
  • the internal resistance makes the over-current capacity of each sub-section the same, which meets the actual over-current demand, thereby improving the power performance of the battery cell.
  • the first pole piece further includes a winding start section arranged continuously with the main body section, and the winding start section is from the winding start end to the winding start section. The edge of the first welded portion close to the winding starting end.
  • the winding starting section is from the winding starting end to the edge of the first welding part near the winding starting end, that is, the winding starting end and the edge of the first welding part close to the winding starting end define the coil
  • There is no welding part formed on the initial winding section and there is no welding relationship between the initial winding section and the current collecting member, which facilitates the welding of the current collecting member and the electrode terminal to output the electric energy of the battery cell.
  • the length of the winding start section is A, and A ⁇ L is satisfied.
  • the distance between the winding starting end and the first welding part is smaller than the length of the characteristic section, that is, the length of the winding starting section without the welding part is less than that with the welding part.
  • the subsection of the part, so that the length of the section without the welding part of the first pole piece will not be too long, so as to ensure the stable output of the electric energy of the battery cell.
  • the first pole piece further includes a winding ending section arranged continuously with the main body section, and the winding ending section is from the winding ending end to the first pole piece.
  • the edge of the second welded part is close to the end of the winding.
  • the winding ending section is defined from the winding ending end to the edge of the second welding part close to the winding ending end, that is, the winding ending end and the edge of the second welding part close to the winding ending end define the winding ending section , There is no welding part on the winding end section, and there is no welding relationship between the winding end section and the corresponding current collecting member, which facilitates the welding of the current collecting member and the electrode terminal to output the electric energy of the battery cell.
  • the length of the winding end section is B, which satisfies B ⁇ L.
  • the length of the winding end section is shorter than the length of the subsection, that is, the length of the winding start section without a welding part is shorter than the subsection with a welding part, so that The length of the section of the first pole piece without the welding portion is not too long, so as to ensure the stable output of the electric energy of the battery cell.
  • the number of welding parts of the turn near the center of the winding of the electrode assembly is smaller than that of the turn farther away from the winding center.
  • the length of the turn close to the winding center is smaller than the length of the turn far away from the winding center.
  • the number of welded parts formed in one round of the winding center of the wound electrode assembly is smaller than the number of welded parts of one round away from the winding center, so that the length of the first pole piece in each circle corresponds to the length of the first pole piece in each circle. Matching the number of welded parts with the total length of the welded parts can make the distribution of the welded parts more reasonable, reduce the internal resistance of the battery cell, meet the actual overcurrent demand, and improve the power performance of the battery cell.
  • the battery cell further includes a casing, an end cap assembly, and a current collecting member;
  • the casing is used to accommodate the electrode assembly, and the casing has an opening;
  • the end cover assembly includes an end cover and an electrode terminal, the end cover is used to cover the opening, the electrode terminal is installed on the end cover;
  • the current collecting member is located between the end cover and the electrode assembly and used to connect the tab part of the electrode assembly with the electrode terminal, the tab part is formed by winding the uncoated area of the first pole piece, at least a part of the current collecting member is connected to the electrode terminal
  • the tab portion is welded to form the plurality of welded portions.
  • At least a part of the current collecting member is welded to the lug part to form a plurality of welded parts, and along the length direction of the first pole piece, the first pole piece is formed from the first welded part close to the winding start end to the first pole piece close to the
  • the main body part defined by the second welding part at the winding end is divided into multiple subsections of equal length, and the total length of the welding part of each subsection is not less than 5% of the length of the subsection, so that the first pole piece and the current collector
  • the distribution of welded parts formed by component welding is more reasonable to reduce the internal resistance of the battery cell and meet the actual overcurrent demand, thereby improving the power performance of the battery cell.
  • the first pole piece further includes a winding starting section from the winding starting end to the edge of the first welding portion close to the winding starting end , the uncoated area of the main body section is wound to form a first part, the uncoated area of the winding start section is wound to form a second part, and the second part is located radially inside the first part
  • the current collecting member includes a first current collecting part and a second current collecting part arranged continuously in the radial direction, the first current collecting part is arranged opposite to the first part along the width direction of the first pole piece, And welded with the first part to form the plurality of welding parts, the second current collecting part is arranged opposite to the second part along the width direction of the first pole piece, and welded with the electrode terminal.
  • the uncoated area of the main body section is wound to form a first part welded to the first current collecting part of the current collecting member, so as to realize the electrical connection between the electrode assembly and the current collecting member.
  • the winding start section is defined from the winding start end to the edge of the first welded part near the winding start end, that is, the winding start end and the first welding part's edge near the winding start end define the winding start section, No welding part is formed on the winding start section, that is, there is no welding relationship between the second part formed by winding in the uncoated area of the winding start section and the current collecting member, and the second current collecting part opposite to the second part No welding mark is formed on the top, which is convenient for the current collecting member to be welded to the electrode terminal through the second current collecting part, so as to output the electric energy of the battery cell.
  • the first pole piece further includes a winding end section from the winding end to the edge of the second welding portion close to the winding end, so The uncoated area of the main body section is wound to form a first part, the uncoated area of the winding end section is wound to form a third part, and the third part is located radially outside the first part;
  • the current collecting member includes a first current collecting part and a third current collecting part arranged continuously in the radial direction, the first current collecting part is arranged opposite to the first part along the width direction of the first pole piece, and is opposite to the first pole piece.
  • the first part is welded to form the plurality of welding parts, and the third current collecting part is disposed opposite to the third part along the width direction of the first pole piece, and is welded to the electrode terminal.
  • the uncoated area of the main body section is wound to form a first part welded to the first current collecting part of the current collecting member, so as to realize the electrical connection between the electrode assembly and the current collecting member.
  • the winding end section is from the winding end to the edge of the second welding part near the winding end, that is, the winding end and the edge of the second welding part near the winding end define a winding end section, and the winding end section
  • No welding part is formed on the upper part, that is, there is no welding relationship between the third part formed by winding and the current collecting member in the uncoated area of the winding end section, and no welding mark is formed on the third current collecting part opposite to the third part , so that the current collecting member can be welded with the electrode terminal through the third current collecting part, so as to output the electric energy of the battery cell.
  • the embodiment of the present application provides a battery, including the battery provided in the embodiment of the first aspect.
  • the first pole piece of the battery cell is formed from the first welding part near the winding starting end to the second welding part near the winding ending end.
  • the defined body part is divided into a plurality of subsections of equal length, and the total length of the welding part of each subsection is not less than 5% of the length of the subsection, so that the distribution of the welding part formed by welding the first pole piece and the current collecting member It is more reasonable to reduce the internal resistance of the battery cell, which can meet the actual over-current demand, thereby improving the power performance of the battery.
  • an embodiment of the present application provides an electric device, including the battery provided in the embodiment of the second aspect.
  • the electrical equipment adopts the battery provided in the embodiment of the second aspect
  • the first pole piece of the battery cell is defined by the first welding part near the winding starting end and the second welding part near the winding ending end
  • the main body part is divided into a plurality of subsections of equal length, and the total length of the welding part of each subsection is not less than 5% of the length of the subsection, so that the distribution of the welding part formed by welding the first pole piece and the current collecting member is more accurate.
  • Reasonable in order to reduce the internal resistance of the battery, can meet the actual over-current demand, thereby improving the power performance of the battery.
  • Fig. 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • Fig. 2 is a schematic structural diagram of a battery provided by some embodiments of the present application.
  • Fig. 3 is an exploded view of a battery cell provided by some embodiments of the present application.
  • Fig. 4 is a schematic structural diagram of an electrode assembly provided by some embodiments of the present application.
  • Fig. 5 is an expanded view of the first pole piece provided by some embodiments of the present application.
  • Fig. 6 is a schematic diagram of the dimensions of the expanded state of the first pole piece provided by some embodiments of the present application.
  • Fig. 7 is a schematic structural diagram of an electrode assembly provided by another embodiment of the present application.
  • Fig. 8 is an expanded view of the first pole piece provided by other embodiments of the present application.
  • Fig. 9 is a schematic diagram of the dimensions of the unfolded state of the first pole piece provided by other embodiments of the present application.
  • Fig. 10 is an expanded view of the first pole piece provided by some other embodiments of the present application.
  • Fig. 11 is a schematic diagram of the dimensions of the unfolded state of the first pole piece provided by some other embodiments of the present application.
  • Fig. 12 is a schematic diagram of an electrode assembly of an electrode assembly provided in some other embodiments of the present application.
  • Fig. 13 is a schematic structural diagram of an electrode assembly provided in some further embodiments of the present application.
  • Fig. 14 is a schematic diagram of a welded current collecting member provided in some embodiments of the present application.
  • Fig. 15 is a schematic diagram of a welded current collecting member provided in another embodiment of the present application.
  • Fig. 16 is a schematic diagram of a welded current collecting member according to some other embodiments of the present application.
  • Icons 1000-vehicle; 100-battery; 10-box; 11-accommodating space; 12-first part; 13-second part; 20-battery unit; 21-housing; 211-opening; 22-electrode assembly ; 221-the first pole piece; 2211-coating area; 2212-uncoated area; 225-body section; 2251-subsection; 226-winding center hole; 226a-first area; 226b-second area; 226c-third area; 226d-fourth area; 226e-fifth area ;226f-the sixth region; 227a-the first ring; 227b-the second ring; 227c-the third ring; 227d-the fourth ring; 227e-the fifth ring; Section; 23-end cover assembly; 231-end cover; 232-electrode terminal; 24-current collecting member; 241-first current collecting part; 242-second current collecting part; Controller; 300-motor; X-the width direction of
  • the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship that is usually placed when the product of the application is used, or the orientation or positional relationship of this application.
  • Orientations or positional relationships commonly understood by those skilled in the art are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood For the limitation of this application.
  • the terms “first”, “second”, “third”, etc. are only used for distinguishing descriptions, and should not be construed as indicating or implying relative importance.
  • Power batteries are not only used in energy storage power systems such as hydraulic, thermal, wind and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric vehicles, as well as military equipment and aerospace and other fields . With the continuous expansion of power battery application fields, its market demand is also constantly expanding.
  • the battery cell includes a casing, an end cap assembly and an electrode assembly, and the end cap assembly is covered on the casing to provide a closed space for the electrode assembly and electrolyte, and the electric energy of the electrode assembly can pass through the end cap assembly
  • the electrode terminals are drawn out of the casing, wherein the electrode assembly is welded to the current collecting member through the tab, and the electrode terminal is electrically connected to the current collecting member to extract the electric energy of the battery.
  • the electrode assembly includes a pole piece, and the pole piece includes a coated area coated with an active material layer and an uncoated area not coated with an active material layer. The uncoated area of the pole piece is wound to form a tab part, and the current collecting member is welded to the tab part to form a plurality of welded parts.
  • the tab For the wound-type full-tab electrode assembly, the tab needs to be flattened and then welded to the current-collecting member.
  • the existing current-collecting member and electrode assembly are welded by laser continuous linear welding or pulse spot welding.
  • the shapes are X-shaped, ring and so on. After unfolding the pole piece, it will be found that along the length direction of the pole piece, some sections have relatively dense welds, some sections have relatively sparse welds, and the distribution of welds on the pole piece is uneven.
  • the effective welding length of the pole piece (that is, the total length of the welding part of this section) is not enough to match the length of the pole piece, so that the flow capacity between the pole piece and the current collecting member is poor , the internal resistance of the battery cell is large, which reduces the power performance of the battery cell.
  • the inventor has designed a battery cell after in-depth research.
  • the total length is not less than 5% of the length of the sub-section, so that the distribution of the welded part formed by welding the first pole piece and the current collecting member is more reasonable, so as to reduce the internal resistance of the battery cell and meet the actual overcurrent demand, Thereby improving the power performance of the battery cell.
  • Electrical devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and power tools, etc.
  • Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles;
  • spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.;
  • electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric boat toys and electric airplane toys, etc.;
  • electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, electric planers, and more.
  • the embodiment of the present application does not impose special limitations on the above electric equipment.
  • FIG. 1 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application.
  • the interior of the vehicle 1000 is provided with a battery 100 , and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000 .
  • the battery 100 can be used for power supply of the vehicle 1000 , for example, the battery 100 can be used as an operating power source of the vehicle 1000 .
  • the vehicle 1000 may further include a controller 200 and a motor 300 , the controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, for starting, navigating and running the vehicle 1000 .
  • the battery 100 can not only be used as an operating power source for the vehicle 1000 , but can also be used as a driving power source for the vehicle 1000 to provide driving power for the vehicle 1000 instead of or partially replacing fuel oil or natural gas.
  • FIG. 2 is a schematic structural diagram of a battery 100 provided by some embodiments of the present application.
  • the battery 100 includes a case 10 and battery cells 20 , and the battery cells 20 are accommodated in the case 10 .
  • the box body 10 is used to provide an accommodating space 11 for the battery cells 20 .
  • the box body 10 may include a first part 12 and a second part 13 , and the first part 12 and the second part 13 cover each other to define an accommodating space 11 for accommodating the battery cells 20 .
  • the connection between the first part 12 and the second part 13 can be sealed by a sealing member (not shown in the figure), and the sealing member can be a sealing ring, a sealant, or the like.
  • the first part 12 and the second part 13 can be in various shapes, such as cuboid, cylinder and so on.
  • the first part 12 is a hollow structure with one end open to accommodate the battery cell 20.
  • the second part 13 may also be a hollow structure with one side open and a battery cell 20.
  • the second part 13 The open side covers the open side of the first part 12 to form the box body 10 with a closed space.
  • the first part 12 may also be a hollow structure with one end open to accommodate the battery cell 20
  • the second part 13 is a plate-shaped structure, and the second part 13 covers the open side of the first part 12, then A box body 10 having a closed space is formed.
  • the battery 100 there may be one or a plurality of battery cells 20 . If there are multiple battery cells 20 , the multiple battery cells 20 may be connected in series, in parallel or in parallel.
  • the mixed connection means that the multiple battery cells 20 are both in series and in parallel.
  • a plurality of battery cells 20 can be directly connected in series, in parallel or mixed together, and then the whole composed of a plurality of battery cells 20 is housed in the box 10; of course, a plurality of battery cells 20 can also be connected in series first
  • a battery module is formed by connecting in parallel or in series, and multiple battery modules are connected in series or in parallel or in series to form a whole, and are accommodated in the box 10 .
  • the battery cell 20 may be in the form of a cylinder, a flat body, a cuboid or other shapes.
  • FIG. 2 exemplarily shows the case where the battery cell 20 is a cylinder.
  • the battery 100 may further include a confluence component (not shown in the figure), and multiple battery cells 20 may be electrically connected through the confluence component, so as to realize series connection, parallel connection or mixed connection of multiple battery cells 20 . couplet.
  • FIG. 3 is an exploded view of a battery cell 20 provided by some embodiments of the present application.
  • the battery cell 20 may include a case 21 , an electrode assembly 22 and an end cap assembly 23 .
  • the casing 21 has an opening 211 , the electrode assembly 22 is accommodated in the casing 21 , and the end cap assembly 23 is used to cover the opening 211 .
  • the housing 21 can be in various shapes, such as cylinder, cuboid and so on.
  • the shape of the casing 21 can be determined according to the specific shape of the electrode assembly 22 .
  • the shell 21 can be a cylindrical structure; if the electrode assembly 22 is a rectangular parallelepiped, the shell 21 can be a rectangular parallelepiped.
  • FIG. 3 exemplarily shows the case where the casing 21 and the electrode assembly 22 are cylinders.
  • the housing 21 may also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., which are not particularly limited in this embodiment of the present application.
  • the electrode assembly 22 may include a positive electrode sheet (not shown in the figure), a negative electrode sheet (not shown in the figure) and a separator (not shown in the figure).
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, and the positive electrode current collector that is not coated with the positive electrode active material layer protrudes from the positive electrode collector that has been coated with the positive electrode active material layer , the positive electrode current collector not coated with the positive electrode active material layer is used as the positive electrode tab.
  • the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector, and the negative electrode current collector that is not coated with the negative electrode active material layer protrudes from the negative electrode collector that has been coated with the negative electrode active material layer , the negative electrode current collector not coated with the negative electrode active material layer is used as the negative electrode tab.
  • the material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon.
  • the electrode assembly 22 may be a winding structure formed by winding a positive electrode sheet, a separator, and a negative electrode sheet.
  • the electrode assembly 22 also includes a positive electrode tab (not shown in the figure) and a negative electrode tab (not shown in the figure), which can be a positive electrode current collector that is not coated with a positive active material layer in the positive electrode sheet as the positive electrode tab, and can be a negative electrode sheet
  • the negative electrode current collector that is not coated with the negative electrode active material layer is used as the negative electrode tab.
  • the end cap assembly 23 is used to cover the opening 211 of the casing 21 to form a closed accommodating cavity (not shown in the figure), and the accommodating cavity is used to accommodate the electrode assembly 22 .
  • the holding chamber is also used to hold electrolyte, such as electrolytic solution.
  • the end cap assembly 23 is used to output the electric energy of the electrode assembly 22 , and the electrode terminal 232 in the end cap assembly 23 is used to electrically connect with the electrode assembly 22 , that is, the electrode terminal 232 is electrically connected to the tab of the electrode assembly 22 .
  • the end cover assembly 23 can also be one, and then two electrode terminals 232 can be arranged in the end cover assembly 23, and the two electrode terminals 232 are respectively used to connect with the positive electrode lug and the negative electrode of the electrode assembly 22.
  • the tabs are electrically connected, and the two electrode terminals 232 in the end cap assembly 23 are respectively a positive electrode terminal 232 and a negative electrode terminal 232 .
  • the electrode terminal 232 in one end cap assembly 23 may be a positive electrode terminal for electrical connection with the positive electrode lug of the electrode assembly 22; the electrode terminal 232 in the other end cap assembly 23 may be a negative electrode The terminal is used for electrical connection with the negative electrode sheet of the electrode assembly 22 .
  • Figure 4 is a schematic structural view of the electrode assembly 22 provided by some embodiments of the present application
  • Figure 5 is an expanded view of the first pole piece 221 provided by some embodiments of the present application
  • Figure 6 is Some embodiments of the present application provide a schematic diagram of the dimensions of the expanded state of the first pole piece.
  • the battery cell 20 includes an electrode assembly 22 .
  • the electrode assembly 22 includes a first pole piece 221, one side of the width direction X of the first pole piece is provided with a plurality of welding parts 222, and the plurality of welding parts 222 are arranged at intervals along the length direction Y of the first pole piece; the electrode assembly 22 is The winding structure, the first pole piece 221 includes a winding starting end 223 and a winding ending end 224, the one closest to the winding starting end 223 among the plurality of welding parts 222 is the first welding part 222a, among the plurality of welding parts 222 The one closest to the winding end 224 is the second welding portion 222b.
  • the first pole piece 221 includes a main body section 225.
  • the main body section 225 is from the edge of the first welding portion 222a near the winding starting end 223 to the second welding portion 222b.
  • the edge near the winding end 224, the main body section 225 is equally divided into a plurality of subsections 2251 of length L, and the total length of the welding part 222 of each subsection 2251 is not less than 5%*L, wherein, 200mm ⁇ L ⁇ 1200mm.
  • the first pole piece 221 includes a coated area 2211 coated with an active material layer and an uncoated area 2212 not coated with an active material layer.
  • the first pole piece 221 can be a positive pole piece or a negative pole piece, and the electrode assembly 22 also includes a second pole piece. If the first pole piece 221 is a positive pole piece, the coating area 2211 is coated with a positive electrode active material material, and the second pole piece The pole piece is a negative pole piece; if the first pole piece 221 is a negative pole piece, and the coating area 2211 is coated with a negative electrode active material, then the second pole piece is a positive pole piece.
  • the tabs of the electrode assembly 22 are wound electrode assemblies with all tabs, the tabs of the first pole piece 221 and the tabs of the second pole piece are respectively located at both ends of the electrode assembly 22 in the axial direction.
  • the winding starting end 223 means that when the first pole piece 221 is wound to form the electrode assembly 22, the winding starting end 223 is used as the winding starting point of the first pole piece 221. After the winding is completed, the winding starting end 223 is opposite to Other parts of the first pole piece 221 are located at the innermost side of the electrode assembly 22 .
  • the winding end 224 means that when the first pole piece 221 is wound to form the electrode assembly 22, the winding end 224 is used as the winding end of the first pole piece 221. After the winding is completed, the winding end 224 is opposite to Other parts of the first pole piece 221 are located on the outermost side of the electrode assembly 22 .
  • the length of the welding portion 222 refers to the distance between the edge of the welding portion 222 near the winding start end 223 and the edge near the winding end 224, that is, the welding portion 222 is The dimension in the longitudinal direction Y of the first pole piece.
  • the total length of the welded portion 222 of the subsection 2251 refers to the sum of the lengths of all the welded portions 222 located in the subsection 2251 .
  • Each subsection 2251 may include one or more welds 222, and in an embodiment where each subsection 2251 includes a plurality of welds 222, the plurality of welds 222 may be evenly spaced or non-uniformly spaced.
  • the length of the main body section 225 should not be less than the sum of the lengths of the two subsections 2251 , that is, the main section 225 is at least equally divided into two subsections 2251 .
  • the flattened tab of the first pole piece 221 of the electrode assembly 22 is divided radially into multiple areas surrounding the winding center of the electrode assembly 22, each area including at least one circle of the first pole piece 221.
  • Each region may include one or more subsections 2251, and each subsection 2251 may be wound at least once.
  • the lug portion of the first pole piece 221 is divided into six concentrically arranged areas, which are respectively defined as the first area from the inside to the outside. 226a, a second region 226b, a third region 226c, a fourth region 226d, a fifth region 226e and a sixth region 226f.
  • the six areas are respectively divided by the first ring 227 a , the second ring 227 b , the third ring 227 c , the fourth ring 227 d and the fifth ring 227 e shown by dotted lines, and each area includes a subsection 2251 .
  • the “from inside to outside” mentioned in this application is relative to the winding center of the electrode assembly 22 , and the one close to the winding center is located inside the one far from the winding center.
  • the discharge internal resistance of the battery within 0.1s is used as the ohmic resistance.
  • the size of the ohmic resistance affects the charging and discharging internal resistance and the charging and discharging overcurrent capability of the battery cell 20 .
  • the following tests were performed:
  • Test conditions the length of the sub-section is 800mm.
  • the test environment temperature is 25°C.
  • SOC state of charge, state of charge
  • the full-battery internal resistance of the battery cell 20 includes two parts: ohmic internal resistance and polarization internal resistance.
  • the DC internal resistance test (DCIR) is a method that considers and measures both resistances, also called dynamic internal resistance
  • Table 1 The test results of ohmic internal resistance and full battery internal resistance corresponding to different ratios of the total length of the welded part to the length of the subsection
  • the ohmic internal resistance of the battery cell 20 and the internal resistance of the full battery both increase with the subsection.
  • the increase of the ratio of the total length of the welded portion 222 of the segment 2251 to the length of the sub-segment 2251 gradually decreases; when the total length of the welded portion 222 of the sub-segment 2251 is greater than or equal to 5% of the length of the sub-segment 2251, the battery cell Both the ohmic internal resistance of the body 20 and the internal resistance of the full battery tend to be stable. Therefore, the total length of the welding portion 222 of the subsection 2251 in this application is not less than 5% of the length of the subsection 2251, so that the battery cell 20 has a relatively Small charge and discharge internal resistance and strong charge and discharge overcurrent capability.
  • the current collecting member 24 (shown in FIG. 3 ) and the electrode assembly 22 are welded by laser continuous linear welding or pulse spot welding, and the shape of the welding mark includes X shape, ring shape and the like.
  • the shape of the welding mark includes X shape, ring shape and the like.
  • the effective welding length of the pole piece (that is, the total length of the weld of this section) is not enough to match the length of the pole piece, so that the current flow capacity between the pole piece and the current collecting member 24 Poor, the internal resistance of the battery cell is large, which reduces the power performance of the battery cell 20.
  • a plurality of welded portions 222 arranged at intervals are formed in the length direction Y of the first pole piece, and along the length direction Y of the first pole piece,
  • the first pole piece 221 is divided into a plurality of equal-length sub-sections 2251 by the main body portion defined by the first welding portion 222a close to the winding starting end 223 and the second welding portion 222b close to the winding ending end 224, each sub-section 2251
  • the total length of the welding part 222 is not less than 5% of the length of the sub-section 2251, so that the distribution of the welding part 222 formed by welding the first pole piece 221 and the current collecting member 24 is more reasonable, so as to reduce the inner space of the battery cell 20.
  • each subsection 2251 ranges from 200mm to 1200mm, so that the winding length of the first pole piece 221 meets actual product requirements and the battery cell 20 has a higher energy density.
  • the absolute value of the difference between the total lengths of the welding portions 222 of any two subsections 2251 is less than or equal to 10 mm.
  • Fig. 5 define the length of each welding part 222 in a subsection in any two subsections 2251 to be L1, ..., Ln respectively, each in another subsection in any two subsections 2251
  • the lengths of the welding parts 222 are respectively H1, . . . , Hm, where n and m are both natural numbers greater than or equal to 1. Satisfied, -10mm ⁇ (L1+...+Ln)-(H1+...+Hm) ⁇ 10mm.
  • the absolute value of the difference in the total length of the welded portion 222 of any two subsections 2251 is controlled within 10mm, and the difference in the total length of the welded portion 222 of each subsection 2251 is reduced as much as possible, so that the distribution of the welded portion 222 is more reasonable. It is beneficial to reduce the internal resistance of the battery cell 20 , and make the difference in the overcurrent capacity of each sub-section 2251 small, so as to meet the actual overcurrent requirement, thereby improving the power performance of the battery cell 20 .
  • the total length of the welding portion 222 of any two subsections 2251 is the same.
  • the total lengths of the welded portions 222 of any two subsections 2251 are the same, which means that the difference between the total lengths of the welded portions 222 of any two subsections 2251 is zero.
  • the total length of the welded portion 222 of any two subsections 2251 is the same, and the total length of the welded portion 222 of each subsection 2251 has no difference, so that the distribution of the welded portion 222 is more reasonable, and the internal resistance of the battery cell 20 is reduced as much as possible. And the overcurrent capacity of each subsection 2251 is the same to meet the actual overcurrent requirement, thereby improving the power performance of the battery cell 20 .
  • the absolute value of the difference in the number of welds 222 of any two subsections 2251 is less than or equal to ten.
  • ⁇ 10 ⁇ n ⁇ m ⁇ 10 that is, the absolute value of the difference between the numbers of welded portions 222 of any two subsections 2251 is less than 10.
  • the absolute value of the difference in the number of welds 222 of any two subsections 2251 is controlled within 10, which is equivalent to the difference in the number of welds 222 of each subsection 2251, allowing errors in the total length of welding between each subsection 2251, It can reduce the difficulty of welding.
  • the number of welds 222 of any two subsections 2251 is the same.
  • the second region 226b, the third region 226c, the fourth region 226d, the fifth region 226e and the sixth region 226f each have a subsection 2251, the second region 226b, the third region 226c, the fourth region 226d, the fifth region 226e and the sixth region 226f have the same number of welded portions 222.
  • each sub-section 2251 have the same over-current capacity, which meets the actual over-current requirement, thereby improving the power performance of the battery cell 20 .
  • the first pole piece 221 further includes a winding start section 228 arranged continuously with the main body section 225, and the winding start section 228 starts from the winding start end. 223 to the edge of the first welding portion 222a close to the winding start end 223 .
  • the main body section 225 is arranged continuously with the winding start section 228 , which means that the winding start section 228 is directly connected with the main body section 225 .
  • the coil layer formed by winding the initial winding section 228 is located inside the coil layer formed by winding the main body section 225 .
  • the winding start section 228 is located in the first region 226 a, and the welding portion 222 is not provided.
  • the first pole piece 221 may only include the winding start section 228 and the main body section 225 . In other embodiments, the first pole piece 221 may only include the main body segment 225 .
  • the winding starting section 228 is defined from the winding starting end 223 to the edge near the winding starting end 223 of the first welding portion 222a, that is, the winding starting end 223 and the edge of the first welding portion 222a near the winding starting end 223 are defined.
  • the winding initial section 223 exceeds the first welding portion 222a, and the welding portion 222 is not formed on the winding initial section 228, and the winding initial section 228 is connected to the current collecting member 24 (Fig. 3) there is no welding relationship, the part of the current collecting member 24 (shown in FIG. 3 ) corresponding to the tab of the winding start section 228 is not welded, and can be used for welding with the electrode terminal 232 to output the battery The electric energy of monomer 20.
  • the length of the winding start section 228 may be different.
  • the length of the winding start section 228 is A, satisfying A ⁇ L.
  • the length of the winding start section 228 refers to the distance between the winding start end 223 and the edge of the first welding portion 222 a near the winding start end 223 when the first pole piece 221 is in the unfolded state.
  • the distance between the winding starting end 223 and the first welding portion 222a is smaller than the length of the subsection, that is, the length of the winding starting section 228 without the welding portion 222 is shorter than that with the welding section 228.
  • the length of the subsection 2251 of the part 222 is such that the length of the section of the first pole piece 221 without the welding part 222 will not be too long, so as to ensure the stable output of the electric energy of the battery cell 20 .
  • Figure 7 is a schematic structural view of the electrode assembly 22 provided by other embodiments of the present application
  • Figure 8 is an expanded view of the first pole piece 221 provided by other embodiments of the present application
  • 9 is a schematic diagram of the dimensions of the unfolded state of the first pole piece 221 provided in some other embodiments of the present application.
  • the first pole piece 221 further includes a winding end section 229 arranged continuously with the main body section 225, and the winding end section 229 is from the winding end 224 to the second welding portion 222b near the winding end 224 the edge of.
  • the main body section 225 and the winding ending section 229 are arranged continuously, which means that the winding ending section 229 is directly connected to the main section 225 .
  • the coil formed by the winding end section 229 is located outside the coil formed by the main body section 225 .
  • the winding end section 229 is located in the sixth area 226 f, and the welding portion 222 is not provided.
  • the first pole piece 221 may only include the winding tail section 229 and the main body section 225 . In other embodiments, as shown in FIG. 10 and FIG. 11 , the first pole piece 221 may include a winding start section 228 , a main body section 225 and a winding end section 229 connected in sequence.
  • the winding end section 229 is defined from the winding end 224 to the edge of the second welding portion 222b near the winding end 224, that is, the winding end 224 and the edge of the second welding portion 222b near the winding end 224 define a
  • the winding end section 229 in other words, the winding end section 224 exceeds the second welded portion 222b, the winding end section 229 does not form the welding portion 222, the winding end section 229 and the current collecting member 24 (shown in FIG. 3 ), there is no welding relationship between them, the part of the current collecting member 24 (shown in FIG. 3 ) corresponding to the lug of the winding end section 229 is not welded, and can be used for welding with the electrode terminal 232 to output the battery cell 20 electrical energy.
  • the length of the winding end section 229 can be different, and the length of the winding end section 229 should make the electrode assembly 22 meet the actual needs.
  • the length of the winding end section 229 is B, satisfying B ⁇ L.
  • the length of the winding ending section 229 refers to the distance between the winding ending end 224 and the edge of the second welding portion 222b near the winding ending end 224 .
  • the length of the winding end section 229 is shorter than the length of the subsection 2251, that is, the length of the winding start section 228 without the welding part 222 is shorter than that of the subsection 2251 provided with the welding part 222, So that the length of the section of the first pole piece 221 without the welding portion 222 is not too long, so as to ensure the stable output of electric energy of the battery cell 20 .
  • FIG. 12 is a schematic diagram of an electrode assembly 22 provided by some other embodiments of the present application
  • FIG. 13 is a schematic structural diagram of an electrode assembly 22 provided by some other embodiments of this application.
  • the number of welding portions 222 in the turn near the winding center of the electrode assembly 22 is smaller than the number of welding portions 222 in the turn away from the winding center.
  • the “in the two adjacent turns of the first pole piece 221 ” mentioned here may be in any two adjacent turns of the first pole piece 221 , and may also be in the two adjacent turns of the first pole piece 221 .
  • each area has a circle of first pole pieces 221, and in the first area 226a, each circle of first pole pieces 221 is provided with two welding portions 222; in the second area 226b , each round of the first pole piece 221 is provided with four welding parts 222; in the third area 226c, each round of the first pole piece 221 is provided with six welding parts 222; in the fourth area 226d, each round of the first
  • the pole piece 221 is provided with six welding portions 222; in the fifth region 226e, each circle of the first pole piece 221 is provided with six welding portions 222.
  • the welding portions 222 are radially distributed.
  • each area has a circle of first pole pieces 221.
  • part of the circle layer of the first pole piece 221 is provided with four welding parts 222, and part of the circle layer of the first pole piece 221 is provided with four welding parts 222.
  • each circle of the first pole piece 221 is provided with six welding parts 222; in the fourth area In 226d, each circle of the first pole piece 221 is provided with six welding portions 222; in the fifth area 226e, each circle of the first pole piece 221 is provided with six welding portions 222; in the sixth area 226f, part of the circle layer
  • the first pole piece 221 of the first pole piece 221 is provided with six welding portions 222
  • the first pole piece 221 of another part of the ring layer is provided with five welding portions 222 .
  • Some welding parts 222 are radially distributed, and some welding parts 222 are connected to form an arc segment around the winding center of the electrode assembly 22.
  • the arc segment is located in the sixth area 226f, and the arc segment connects two adjacent radial lines composed of welding parts 222. .
  • the number of welding portions 222 of any two adjacent turns of the first pole piece 221 may also be the same.
  • the length of the turn near the winding center is smaller than the length of the turn far away from the winding center.
  • the number of welding parts 222 formed in one circle of the winding center of the electrode assembly 22 is smaller than the number of welding parts 222 of one circle away from the winding center, so that the length of the first pole piece 221 of each circle is equal to the length of the first pole piece 221 of each circle.
  • the number of corresponding welding parts 222 matches the total length of the welding parts 222, which can make the distribution of the welding parts 222 more reasonable, so as to reduce the internal resistance of the battery cell 20, and can meet the actual overcurrent demand, thereby improving the battery cell. 20 power performance.
  • the battery cell 20 further includes a housing 21 , an end cap assembly 23 and a current collecting member 24 ;
  • the housing 21 is used to house the electrode assembly 22 ,
  • the housing 21 has an opening 211;
  • the end cover assembly 23 includes an end cover 231 and an electrode terminal 232, the end cover 231 is used to cover the opening 211, and the electrode terminal 232 is mounted on the end cover 231;
  • the current collecting member 24 is located between the end cover 231 and the electrode assembly 22, and is used to connect the tab part of the electrode assembly 22 and the electrode terminal 232, the tab part is formed by winding the uncoated area of the first pole piece 221, at least a part of the current collecting member 24 is welded to the tab part and A plurality of welded portions 222 are formed.
  • At least a part of the current collecting member 24 is welded to the lug portion to form a plurality of welded portions 222.
  • the first pole piece 221 is formed from the first welded portion 222a close to the winding start end 223 and the first welded portion 222a.
  • the main body portion defined by the second welding portion 222b close to the winding end 224 is divided into a plurality of subsections 2251 of equal length, and the total length of the welding portion 222 of each subsection 2251 is not less than 5% of the length of the subsection 2251, so that Make the distribution of the welding part 222 formed by welding the first pole piece 221 and the current collecting member 24 more reasonable, so as to reduce the internal resistance of the battery cell 20 and meet the actual overcurrent demand, thereby improving the power performance of the battery cell 20 .
  • FIG. 14 is a schematic diagram of a welded current collecting member 24 provided in some embodiments of the present application.
  • the first pole piece 221 further includes a winding starting section 228 from the winding starting end 223 to the edge of the first welding portion 222a close to the winding starting end 223, and the uncoated area of the main body section 225
  • the winding forms the first part 12 (not shown in the figure), and the uncoated area of the winding start section 228 is wound to form the second part 13 (not shown in the figure), and the second part 13 is located in the first part along the radial direction.
  • the current collecting member 24 includes a first collecting part 241 and a second collecting part 242 arranged continuously in the radial direction, and the first collecting part 241 is arranged opposite to the first part 12 along the width direction X of the first pole piece , and welded with the first part 12 to form a plurality of welded parts 222 , the second current collecting part 242 is disposed opposite to the second part 13 along the width direction X of the first pole piece, and welded with the electrode terminal 232 .
  • the width direction X of the first pole piece is consistent with the winding axis direction of the electrode assembly 22 . Since the uncoated area of the first pole piece 221 is used to form the lug of the first pole piece 221 , both the first portion 12 and the second portion 13 belong to the lug of the first pole piece 221 .
  • the second part 13 is located at the inner side of the first part 12 in the radial direction, and the part of the second part 13 may be located at the inner side of the first part 12, and the other part of the second part 13 is located on the same circumference as the part of the first part 12; All of the two parts 13 are located inside the first part 12 , and the first part 12 surrounds the outer periphery of the second part 13 .
  • the first current collecting portion 241 is opposite to the first part 12 along the width direction X of the first pole piece. It can be understood that along the width direction X of the first pole piece, the projection of the first part 12 on the current collecting member 24 is the same.
  • the current collecting parts 241 are at least partially overlapped, and the overlapping parts are welded to each other to form a plurality of welding parts 222 to realize the electrical connection between the electrode assembly 22 and the current collecting member 24 .
  • the second collecting portion 242 and the second collecting portion 242 are arranged continuously in the radial direction, and the winding starting section 228 is from the winding starting end 223 to the edge of the first welding portion 222a near the winding starting end 223, that is, the winding
  • the edge of the starting end 223 and the first welding portion 222a near the winding starting end 223 defines the winding starting section 228, and the welding section 222 is not formed on the winding starting section 228, that is, the uncoated part of the winding starting section 228
  • the portion 242 is welded to the electrode terminal 232 to output electric energy of the battery cell 20 .
  • FIG. 15 is a schematic diagram of a welded current collecting member 24 provided in another embodiment of the present application.
  • the first pole piece 221 further includes a winding end section 229 from the winding end 224 to the edge of the second welding portion 222b near the winding end section 229, and the uncoated area of the main body section 225 wraps
  • the first part 12 is wound around to form the first part 12, and the uncoated area of the winding end section 229 is wound to form a third part (not shown in the figure), and the third part is located on the outside of the first part 12 in the radial direction;
  • To the first collector part 241 and the third collector part 243 arranged continuously, the first collector part 241 and the first part 12 are arranged opposite to the width direction X of the first pole piece, and are welded with the first part 12 to form a plurality of
  • the welding part 222 the third current collecting part 243 and the third part are arranged opposite to each other along the width direction X of the first
  • both the first part 12 and the third part belong to the lug of the first pole piece 221 .
  • the third part is radially located on the outside of the first part 12. It can be that the part of the third part is located on the outside of the first part 12, and the other part of the third part is located on the same circumference as the part of the first part 12; it can also be the part of the third part All are located inside the first part 12 , and the third part surrounds the outer periphery of the first part 12 .
  • FIG. 16 is a schematic diagram of a welded current collecting member 24 provided in some other embodiments of the present application.
  • the implementation of the first pole piece 221 includes a winding start section 228, a main body section 225 and a winding end section 229.
  • the current collecting member 24 may include a second collecting portion 242 , a first collecting portion 241 and a third collecting portion 243 radially from the inside to the outside.
  • the first collector part 241 is welded to the first part 12, the second collector part 242 is arranged opposite to the second part 13 along the width direction X of the first pole piece, and the third collector part and the third part are arranged along the first pole piece.
  • the width direction X is opposite to each other, and the second current collecting portion 242 and the third current collecting portion 243 are welded to the electrode terminal 232 to output the electric energy of the battery cell 20 .
  • the electrode assembly 22 is electrically connected to the current collecting member 24 by welding the first current collecting part 241 and the first part 12, the third current collecting part 243 and the first current collecting part 241 are arranged continuously in the radial direction, and the winding end section 229 is The winding end 224 to the edge of the second welding portion 222b near the winding end 224, that is, the winding end 224 and the edge of the second welding portion 222b near the winding end 224 define a winding end section 229, No welding portion 222 is formed on the winding end section 229, that is, there is no welding relationship between the third part formed by winding the uncoated area of the winding end section 229 and the current collecting member 24, and the third part opposite to the third part No welding mark is formed on the current collecting portion 243 , which facilitates the welding of the current collecting member 24 to the electrode terminal 232 through the third current collecting portion 243 to output the electric energy of the battery cell 20 .
  • the embodiment of the present application provides a cylindrical battery, which includes a cylindrical casing 21, a cylindrical electrode assembly 22, a current collecting member 24, and an end cap assembly 23.
  • the electrode assembly 22 is accommodated in the casing, and the end cap 231 of the end cap assembly 23 Covering the opening 211 of the casing 21, the electrode assembly 22 includes a first pole piece 221, the first pole piece 221 includes a winding start end 223 and a winding end end 224, and among the plurality of welding parts 222 is closest to the winding start end 223
  • One of the plurality of welding parts 222 is the first welding part 222a, and the one closest to the winding end 224 among the plurality of welding parts 222 is the second welding part 222b.
  • the edge of the second welding portion 222b is close to the main body section 225 of the edge of the winding end 224, the main body section 225 is divided into a plurality of subsections 2251 with a length L, and the total length of the welding part 222 of each subsection 2251 is not Less than 5%*L, where 200mm ⁇ L ⁇ 1200mm.
  • the absolute value of the difference between the total lengths of welded portions 222 of any two subsections 2251 is less than or equal to 10mm, and the absolute value of the difference in the number of welded portions 222 of any two subsections 2251 is less than or equal to 10.
  • the first pole piece 221 also includes a winding start section 228 and a winding end section 229 arranged continuously with the main body section 225, and the winding start section 228 is wound from the winding start end 223 to the first welding portion 222a.
  • the winding ending section 229 is from the winding ending end 224 to the edge of the second welding part 222b close to the winding ending end 224, the length of the winding starting section 228 is A and the length of the winding ending section 229 is B, satisfying A ⁇ L, B ⁇ L.
  • the current collecting member 24 includes a second collecting part 242 , a first collecting part 241 and a third collecting part 243 arranged continuously from the inside to the outside in the radial direction.
  • the uncoated area of the main body section 225 is wound to form the first part 12, the uncoated area of the initial section 228 of the winding is wound to form the second section 13, and the uncoated area of the winding end section 229 is wound to form the third section.
  • the first collector part 241 is arranged opposite to the first part 12, and is welded with the first part 12 to form a plurality of welding parts 222, and the second collector part 242 is opposite to the second part 13 set and welded with the electrode terminal 232, the third current collecting part 243 is arranged opposite to the third part, and welded with the electrode terminal 232, so as to output the electric energy of the cylindrical battery.
  • the embodiment of the present application also provides a battery 100 , including the battery cell 20 provided in any of the above-mentioned embodiments.
  • the embodiment of the present application also provides an electric device, including the battery 100 provided in the above embodiment.

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Abstract

本申请提供了一种电池单体、电池及用电设备，涉及电池技术领域。电池单体包括电极组件；电极组件的第一极片的宽度方向的一侧设有多个焊接部，多个焊接部沿第一极片的长度方向间隔设置；第一极片包括卷绕起始端和卷绕收尾端，多个焊接部中最靠近卷绕起始端的一个为第一焊接部，多个焊接部中最靠近卷绕收尾端的一个为第二焊接部，第一极片包括从第一焊接部到第二焊接部的主体段，主体段等分为多个长度为L的子段，每个子段焊接部的总长度不小于5％*L，200mm≤L≤1200mm，以使第一极片和集流构件焊接形成的焊接部的分布更加合理，以减小电池单体的内阻，能够满足实际的过流需求，从而提高电池单体的功率性能。

Description

电池单体、电池及用电设备 技术领域
本申请涉及电池技术领域，具体而言，涉及一种电池单体、电池及用电设备。
背景技术
电池广泛应用与电子设备，例如手机、笔记本电脑、电瓶车、电动汽车、电动飞机、电动轮船、电动玩具汽车、电动玩具轮船、电动玩具飞机和电动工具等。
在电池技术的发展中，除了电池的安全性能以外，电池的功率性能也是不可忽视的问题，现有电池由于内阻大，导致电池的功率性能较低。因此，如何提升电池的功率性能成为电池技术领域亟待解决的问题。
发明内容
本申请实施例提供一种电池单体、电池及用电设备，以提升电池的功率性能。
第一方面，本申请实施例提供一种电池单体，包括电极组件；所述电极组件包括第一极片，所述第一极片的宽度方向的一侧设有多个焊接部，所述多个焊接部沿所述第一极片的长度方向间隔设置；
所述电极组件为卷绕结构，所述第一极片包括卷绕起始端和卷绕收尾端，所述多个焊接部中最靠近所述卷绕起始端的一个为第一焊接部，所述多个焊接部中最靠近所述卷绕收尾端的一个为第二焊接部，所述第一极片包括主体段，所述主体段从所述第一焊接部的靠近所述卷绕起始端的边缘到所述第二焊接部的靠近所述卷绕收尾端的边缘，所述主体段等分为多个长度为L的子段，每个所述子段的所述焊接部的总长度不小于5％*L，其中，200mm≤L≤1200mm。
上述技术方案中，现有集流构件和电极组件焊接采用激光连续线性焊接或脉冲点焊的方式，焊印的形状有X形、环形等。在将极片展开后会发现，沿极片的长度方向，有些区段的焊接部较密集，有些区段的焊接部较稀疏，焊接部在极片上的分布不均匀。对于焊接部较稀疏的区段，极片的有效焊接长度(即，该区段的焊接部的总长度)不足以匹配极片的长度，使得极片与集流构件之间的过流能力差，电池单体的内阻大，降低了电池单体的功率性能。在集流构件与第一极片的宽度方向的一侧焊接后，在第一极片的长度方向形成间隔布置的多个焊接部，沿第一极片的长度方向，将第一极片由靠近卷绕起始端的第一焊接部和靠近卷绕收尾端的第二焊接部限定出的主体部划分为等长的多个子段，每个子段的焊接部的总长度不小于子段的长度的5％，以使第一极片和集流构件焊接形成的焊接部的分布更加合理，以降低电池单体的内阻，能够满足实际的过流需求，从而提升电池单体的功率性能。子段的长度为200mm至1200mm之间，使得第一极片的卷绕长度满足实际产品需求和电池单体具有较高的能量密度。
在本申请第一方面的一些实施例中，任意两个所述子段的所述焊接部的总长度之差的绝对值小于或等于10mm。
上述技术方案中，将任意两个子段的焊接部的总长度之差的绝对值控制在10mm内，尽可能减小各个子段的焊接部的总长度的差异，使得焊接部的分布更加合理，有利于减小电池单体的内阻，且使各个子段的过流能力差异较小，满足实际的过流需求，从而提高电池单体的功率性能。将任意两个子段的焊接部的总长度之差的绝对值控制在10mm内，相当于各个子段的焊接宽度误差在10mm以，允许各个子段之间的焊接总长度存在误差，能够降低焊接难度。
在本申请第一方面的一些实施例中，任意两个所述子段的所述焊接部的总长度相同。
上述技术方案中，任意两个子段的焊接部的总长度相同，则各个子段的焊接部的总长度的没有差异，使得焊接部的分布更加合理，尽可能减小电池单体的内阻，且使各个子段的过流能力相同，满足实际的过流需求，从而提高电池单体的功率性能。
在本申请第一方面的一些实施例中，任意两个所述子段的所述焊接部的数量之差的绝对值小于或者等于10。
上述技术方案中，将任意两个子段的焊接部的数量之差的绝对值控制10以内，尽可能减小各个子段的焊接部的总长度的差异，使得焊接部的分布更加合理，有利于减小电池单体的内阻，使各个子段的过流能力差异较小，满足实际的过流需求，从而提高电池单体的功率性能。将任意两个子段的焊接部的数量之差的绝对值控制10以内，相当于各个子段的焊接部数量可以具有差异，允许各个子段之间的焊接总长度存在误差，能够降低焊接难度。
在本申请第一方面的一些实施例中，任意两个所述子段的所述焊接部的数量相同。
上述技术方案中，任意两个子段的焊接部的数量相同，则尽可能减小各个子段的焊接部的总长度的差异较小，使得焊接部的分布更加合理，有利于减小电池单体的内阻，使各个子段的过流能力相同，满足实际的过流需求，从而提高电池单体的功率性能。
在本申请第一方面的一些实施例中，所述第一极片还包括与所述主体段连续设置的卷绕起始段，所述卷绕起始段从所述卷绕起始端到所述第一焊接部的靠近所述卷绕起始端的边缘。
上述技术方案中，卷绕起始段从卷绕起始端到第一焊接部的靠近卷绕起始端的边缘，即卷绕起始端和第一焊接部的靠近卷绕起始端的边缘限定出卷绕起始段，卷绕起始段上未形成焊接部，卷绕起始段与集流构件之间没有焊接关系，方便集流构件与电极端子焊接，以输出电池单体的电能。
在本申请第一方面的一些实施例中，所述卷绕起始段的长度为A，满足A≤L。
上述技术方案中，沿第一极片的长度方向，卷绕起始端与第一焊接部之间的距离小于特征段的长度，即未设置焊接部的卷绕起始段的长度小于设置有焊接部的子段，以使第一极片没有焊接部的区段的长度不会太长，保证电池单体电能稳定输出。
在本申请第一方面的一些实施例中，所述第一极片还包括与所述主体段连续设置的卷绕收尾段，所述卷绕收尾段从所述卷绕收尾端到所述第二焊接部的靠近所述卷绕收尾端的边缘。
上述技术方案中，卷绕收尾段从卷绕收尾端到第二焊接部的靠近卷绕收尾端的边缘，即卷绕收尾端和第二焊接部的靠近卷绕收尾端的边缘限定出卷绕收尾段，卷绕收尾段上未设置焊接部，卷绕收尾段与对应的集流构件之间没有焊接关系，方便集流构件与电极端子焊接，以输出电池单体的电能。
在本申请第一方面的一些实施例中，所述卷绕收尾段的长度为B，满足B≤L。
上述技术方案中，沿第一极片的长度方向，卷绕收尾段的长度小于子段的长度，即未设置焊接部的卷绕起始段的长度小于设置有焊接部的子段，以使第一极片没有焊接部的区段的长度不会太长，保证电池单体电能稳定输出。
在本申请第一方面的一些实施例中，在相邻的两圈所述第一极片中，靠近所述电极组件的卷绕中心的一圈的所述焊接部数量小于远离所述卷绕中心的一圈的所述焊接部的数量。
上述技术方案中，对卷绕式电极组件而言，相邻的两圈第一极片中，靠近卷绕中心的一圈的长度小于远离卷绕中心的一圈的长度，焊接时，在靠近卷绕式电极组件的卷绕中心的一圈的形成焊接部数量小于远离卷绕中心的一圈的焊接部的数量，以使每圈第一极片的长度和每圈第一极片对应的焊接部的数量和焊接部的总长度匹配，能够使得焊接部的分布更加合理，以减小电池单体的内阻，能够满足实际的过流需求，从而提高电池单体的功率性能。
在本申请第一方面的一些实施例中，所述电池单体还包括壳体、端盖组件和集流构件；所述壳体用于容纳所述电极组件，所述壳体具有开口；所述端盖组件包括端盖和电极端子，所述端盖用于覆盖所述开口，所述电极端子安装于所述端盖上；所述集流构件位于所述端盖与所述电极组件之间，并用于连接所述电极组件的极耳部和所述电极端子，所述极耳部通过所述第一极片的未涂覆区域卷绕形成，所述集流构件的至少一部分与所述极耳部焊接并形成所述多个焊接部。
上述技术方案中，集流构件的至少一部分与极耳部焊接并形成多个焊接部，沿第一极片的长度方向，将第一极片由靠近卷绕起始端的第一焊接部和靠近卷绕收尾端的第二焊接部限定出的主体部划分为等长的多个子段，每个子段的焊接部的总长度不小于子段的长度的5％，以使第一极片和集流构件焊接形成的焊接部的分布更加合理，以减小电池单体的内阻，能够满足实际的过流需求，从而提高电池单体的功率性能。
在本申请第一方面的一些实施例中，所述第一极片还包括从所述卷绕起始端到所述第一焊接部的靠近所述卷绕起始端的边缘的卷绕起始段，所述主体段的未涂覆区域卷绕形成第一部分，所述卷绕起始段的未涂覆区域卷绕形成第二部分，所述第二部分沿径向位于所述第一部分的内侧；所述集流构件包括沿径向连续布置的第一集流部和第二集流部，所述第一集流部与所述第一部分沿所述第一极片的宽度方向相对设置，并与所述第一部分焊接以形成所述多个焊接部，所述第二集流部与所述第二部分沿所述第一极片的宽度方向相对设置，并与所述电极端子焊接。
上述技术方案中，主体段的未涂覆区域卷绕形成第一部分与集流构件的第一集流部焊接，实现电极组件与集流构件电连接。卷绕起始段从卷绕起始端到第一焊接部的靠近卷绕起始端的边缘，即卷绕起始端和第一焊接部的靠近卷绕起始端的边缘限定出卷绕起始段，卷绕起始段上未形成焊接部，即卷绕起始段的未涂覆区域卷绕形成的第二部分与集流构件之间没有焊接关系，与第二部分相对的第二集流部上未形成焊印，方便集流构件通过第二集流部与电极端子焊接，以输出电池单体的电能。
在本申请第一方面的一些实施例中，所述第一极片还包括从所述卷绕收尾端到所述第二焊接部的靠近所述卷绕收尾的边缘的卷绕收尾段，所述主体段的未涂覆区域卷绕形成第一部分，所述卷绕收尾段的未涂覆区域卷绕形成第三部分，所述第三部分沿径向位于所述第一部分的外侧；所述集流构件包括沿径向连续布置的第一集流部和第三集流部，所述第一集流部与所述第一部分沿所述第一极片的宽度方向相对设置，并与所述第一部分焊接以形成所述多个焊接部，所述第三集流部与所述第三部分沿所述第一极片的宽度方向相对设置，并与所述电极端子焊接。
上述技术方案中，主体段的未涂覆区域卷绕形成第一部分与集流构件的第一集流部焊接，实现电极组件与集流构件电连接。卷绕收尾段从卷绕收尾端到第二焊接部的靠近卷绕收尾端的边缘，即卷绕收尾端和第二焊接部的靠近卷绕收尾端的边缘限定出卷绕收尾段，卷绕收尾段上未形成焊接部，即卷绕收尾段的未涂覆区域卷绕形成的第三部分与集流构件之间没有焊接关系，则与第三部分相对的第三集流部上未形成焊印，方便集流构件通过第三集流部与电极端子焊接，以输出电池单体的电能。
第二方面，本申请实施例提供一种电池，包括第一方面实施例提供的电池。
上述技术方案中，包括了第一方面实施例提供的电池单体的电池，将电池单体的第一极片由靠近卷绕起始端的第一焊接部和靠近卷绕收尾端的第二焊接部限定出的主体部划分为等长的多个子段，每个子段的焊接部的总长度不小于子段的长度的5％，以使第一极片和集流构件焊接形成的焊接部的分布更加合理，以减小电池单体的内阻，能够满足实际的过流需求，从而提高电池的功率性能。
第三方面，本申请实施例提供一种用电设备，包括第二方面实施例提供的电池。
上述技术方案中，用电设备采用了第二方面实施例提供的电池，将电池单体的第一极片由靠近卷绕起始端的第一焊接部和靠近卷绕收尾端的第二焊接部限定出的主体部划分为等长的多个子段，每个子段的焊接部的总长度不小于子段的长度的5％，以使第一极片和集流构件焊接形成的焊接部的分布更加合理，以减小电池的内阻，能够满足实际的过流需求，从而提高电池的功率性能。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本申请的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1为本申请一些实施例提供的车辆的结构示意图；
图2为本申请一些实施例提供的电池的结构示意图；
图3为本申请一些实施例提供的电池单体的爆炸图；
图4为本申请一些实施例提供的电极组件的结构示意图；
图5为本申请一些实施例提供的第一极片的展开图；
图6为本申请一些实施例提供的第一极片的展开状态的尺寸示意图；
图7为本申请另一些实施例提供的电极组件的结构示意图；
图8为本申请另一些实施例提供的第一极片的展开图；
图9为本申请另一些实施例提供的第一极片的展开状态的尺寸示意图；
图10为本申请又一些实施例提供的第一极片的展开图；
图11为本申请又一些实施例提供的第一极片的展开状态的尺寸示意图；
图12为本申请又一些实施例提供的电极组件的电极组件的示意图；
图13为本申请再一些实施例提供的电极组件的结构示意图；
图14为本申请一些实施例提供焊接后的集流构件的示意图；
图15为本申请另一些实施例提供焊接后的集流构件的示意图；
图16为本申请又一些实施例提供焊接后的集流构件的示意图。
图标：1000-车辆；100-电池；10-箱体；11-容纳空间；12-第一部分；13-第二部分；20-电池单体；21-壳体；211-开口；22-电极组件；221-第一极片；2211-涂覆区域；2212-未涂覆区域；222-焊接部；222a-第一焊接部；222b-第二焊接部；223-卷绕起始端；224-卷绕收尾端；225-主体段；2251-子段；226-卷绕中心孔；226a-第一区域；226b-第二区域；226c-第三区域；226d-第四区域；226e-第五区域；226f-第六区域；227a-第一环；227b-第二环；227c-第三环；227d-第四环；227e-第五环；228-卷绕起始段；229-卷绕收尾段；23-端盖组件；231-端盖；232-电极端子；24-集流构件；241-第一集流部；242-第二集流部；243-第三集流部；200-控制器；300-马达；X-第一极片的宽度方向；Y-第一极片的长度方向。
具体实施方式
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目前，从市场形势的发展来看，动力电池的应用越加广泛。动力电池不仅被应用于水力、火力、风力和太阳能电站等储能电源系统，而且还被广泛应用于电动自行车、电动摩托车、电动汽车等电动交通工具，以及军事装备和航空航天等多个领域。随着动力电池应用领域的不断扩大，其市场的需求量也在不断地扩增。
发明人注意到，电池单体包括壳体、端盖组件和电极组件，端盖组件盖合于壳体上，为电极组件和电解液提供一个密闭的空间，电极组件的电能可通过端盖组件的电极端子引出至壳体外，其中，电极组件通过极耳与集流构件焊接，电极端子与集流构件电连接，以引出电池的电能。电极组件包括极片，极片包括涂覆有活性物质层的涂覆区域和未涂覆活性物质层的未涂覆区域。极片的未涂覆区卷绕形成极耳部，集流构件与极耳部焊接，形成多个焊接部。
对卷绕式的全极耳电极组件而言，需将极耳揉平后与集流构件焊接，现有集流构件和电极组件焊接采用激光连续线性焊接或脉冲点焊的方式，焊印的形状有X形、环形等。在将极片展开后会发现，沿极片的长度方向，有些区段的焊接部较密集，有些区段的焊接部较稀疏，焊接部在极片上的分布不均匀。对于焊接部较稀疏的区段，极片的有效焊接长度(即，该区段的焊接部的总长度)不足以匹配极片的长度，使得极片与集流构件之间的过流能力差，电池单体的内阻大，降低了电池单体的功率性能。
鉴于此，为了解决极片与集流构件的焊接位置的分布不合理，导致电池单体的内阻大、过流能力较弱的问题，发明人经过深入研究，设计了一种电池单体，通过将第一极片由靠近卷绕起始端的第一焊接部和靠近卷绕收尾端的第二焊接部限定出的主体部划分为等长的多个子段，并使每个子段的焊接部的总长度不小于子段的长度的5％，以使第一极片和集流构件焊接形成的焊接部的分布更加合理，以减小电池单体的内阻，能够满足实际的过流需求，从而提高电池单体的功率性能。
本申请实施例描述的技术方案适用于电池以及使用电池的用电设备。
用电设备可以是车辆、手机、便携式设备、笔记本电脑、轮船、航天器、电动玩具和电动工具等等。车辆可以是燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等；航天器包括飞机、火箭、航天飞机和宇宙飞船等等；电动玩具包括固定式或移动式的电动玩具，例如，游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等；电动工具包括金属切削电动工具、研磨电动工具、装配电动工具和铁道用电动工具，例如，电钻、电动砂轮机、电动扳手、电动螺丝刀、电锤、冲击电钻、混凝土振动器和电刨等等。本申请实施例对上述用电设备不做特殊限制。
以下实施例为了方便说明，以用电设备为车辆为例进行说明。
请参照图1，图1为本申请一些实施例提供的车辆1000的结构示意图。车辆1000的内部设置有电池100，电池100可以设置在车辆1000的底部或头部或尾部。电池100可以用于车辆1000的供电，例如，电池100可以作为车辆1000的操作电源。
车辆1000还可以包括控制器200和马达300，控制器200用来控制电池100为马达300供电，例如，用于车辆1000的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中，电池100不仅仅可以作为车辆1000的操作电源，还可以作为车辆1000的驱动电源，代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
请参照图2，图2为本申请一些实施例提供的电池100的结构示意图。电池100包括箱体10和电池单体20，电池单体20收容于箱体10内。
箱体10用于为电池单体20提供容纳空间11。在一些实施例中，箱体10可以包括第一部分12和第二部分13，第一部分12与第二部分13相互盖合，以限定出用于容纳电池单体20的容纳空间11。当然，第一部分12与第二部分13的连接处可通过密封件(图未示出)来实现密封，密封件可以是密封圈、密封胶等。
第一部分12和第二部分13可以是多种形状，比如，长方体、圆柱体等。第一部分12为一端开放的形成有容纳电池单体20的容纳部的空心结构，第二部分13也可以是一侧开放形成有容纳电池单体20的容纳部的空心结构，第二部分13的开放侧盖合于第一部分12的开放侧，则形成 具有密闭空间的箱体10。当然，也可以是第一部分12为一端开放的形成有容纳电池单体20的容纳部的空心结构，第二部分13为板状结构，第二部分13盖合于第一部分12的开放侧，则形成具有密闭空间的箱体10。
在电池100中，电池单体20可以是一个、也可以是多个。若电池单体20为多个，多个电池单体20之间可串联或并联或混联，混联是指多个电池单体20中既有串联又有并联。多个电池单体20之间可直接串联或并联或混联在一起，再将多个电池单体20构成的整体容纳于箱体10内；当然，也可以是多个电池单体20先串联或并联或混联组成电池模块，多个电池模块再串联或并联或混联形成一个整体，并容纳于箱体10内。电池单体20可呈圆柱体、扁平体、长方体或其它形状等。图2示例性的示出了电池单体20呈圆柱体的情况。
在一些实施例中，电池100还可以包括汇流部件(图未示出)，多个电池单体20之间可通过汇流部件实现电连接，以实现多个电池单体20的串联或并联或混联。
请参照图3，图3为本申请一些实施例提供的电池单体20的爆炸图。电池单体20可以包括壳体21、电极组件22和端盖组件23。壳体21具有开口211，电极组件22容纳于壳体21内，端盖组件23用于封盖于开口211。
壳体21可以是多种形状，比如，圆柱体、长方体等。壳体21的形状可根据电极组件22的具体形状来确定。比如，若电极组件22为圆柱体结构，壳体21则可选用为圆柱体结构；若电极组件22为长方体结构，壳体21则可选用长方体结构。图3示例性的示出了壳体21和电极组件22为圆柱体的情况。
壳体21的材质也可以是多种，比如，铜、铁、铝、不锈钢、铝合金等，本申请实施例对此不作特殊限制。
电极组件22可以包括正极片(图未示出)、负极片(图未示出)和隔离膜(图未示出)。
正极片包括正极集流体和正极活性物质层，正极活性物质层涂覆于正极集流体的表面，未涂敷正极活性物质层的正极集流体凸出于已涂覆正极活性物质层的正极集流体，未涂敷正极活性物质层的正极集流体作为正极极耳。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极片包括负极集流体和负极活性物质层，负极活性物质层涂覆于负极集流体的表面，未涂敷负极活性物质层的负极集流体凸出于已涂覆负极活性物质层的负极集流体，未涂敷负极活性物质层的负极集流体作为负极极耳。负极集流体的材料可以为铜，负极活性物质可以为碳或硅等。
电极组件22可以是由正极片、隔离膜和负极片通过卷绕形成的卷绕结构。电极组件22还包括正极极耳(图未示出)和负极极耳(图未示出)，可以是正极片中未涂覆正极活性物质层的正极集流体作为正极极耳，可以是负极片中未涂覆负极活性物质层的负极集流体作为负极极耳。
端盖组件23用于封盖壳体21的开口211，以形成一密闭的容纳腔(图未示出)，容纳腔用于容纳电极组件22。容纳腔还用于容纳电解质，例如电解液。端盖组件23作为输出电极组件22的电能的部件，端盖组件23中的电极端子232用于与电极组件22电连接，即电极端子232与电极组件22的极耳电连接。
需要说明的，壳体21的开口211可以是一个，也可以是两个。若壳体21的开口211为一个，端盖组件23也可以为一个，端盖组件23中则可设置两个电极端子232，两个电极端子232分别用于与电极组件22正极极耳和负极极耳电连接，端盖组件23中的两个电极端子232分别为正极电极端子232和负极电极端子232。如图3所示，若壳体21的开口211为两个，比如，两个开口211设置在壳体21相对的两侧，端盖组件23也可以为两个，两个端盖组件23分别盖合于壳体21的两个开口211处。在这种情况下，可以是一个端盖组件23中的电极端子232为正极电极端子，用于与电极组件22的正极极耳电连接；另一个端盖组件23中的电极端子232为负极电极端子，用于与电极组件22的负极片电连接。
请参照图4、图5、图6，图4为本申请一些实施例提供的电极组件22的结构示意图，图 5为本申请一些实施例提供的第一极片221的展开图，图6为本申请一些实施例提供的第一极片的展开状态的尺寸示意图。电池单体20包括电极组件22。电极组件22包括第一极片221，第一极片的宽度方向X的一侧设有多个焊接部222，多个焊接部222沿第一极片的长度方向Y间隔设置；电极组件22为卷绕结构，第一极片221包括卷绕起始端223和卷绕收尾端224，多个焊接部222中最靠近卷绕起始端223的一个为第一焊接部222a，多个焊接部222中最靠近卷绕收尾端224的一个为第二焊接部222b，第一极片221包括主体段225，主体段225从第一焊接部222a的靠近卷绕起始端223的边缘到第二焊接部222b的靠近卷绕收尾端224的边缘，主体段225等分为多个长度为L的子段2251，每个子段2251的焊接部222的总长度不小于5％*L，其中，200mm≤L≤1200mm。
沿第一极片的宽度方向X，第一极片221包括涂覆有活性物质层的涂覆区域2211和未涂覆活性物质层的未涂覆区域2212。第一极片221可以是正极片，也可以是负极片，电极组件22还包括第二极片，若是第一极片221为正极片，涂覆区域2211涂覆正极活性物质材料，则第二极片为负极片；若第一极片221为负极片，涂覆区域2211涂覆负极活性物质材料，则第二极片为正极片。在电极组件22的极耳为全极耳的卷绕式电极组件的实施例中，第一极片221的极耳和第二极片的极耳分别位于电极组件22的轴向的两端。
卷绕起始端223是指，在第一极片221卷绕形成电极组件22时，卷绕起始端223作为第一极片221的卷绕起点，在卷绕完成后，卷绕起始端223相对第一极片221的其他部位位于电极组件22的最内侧。
卷绕收尾端224是指，在第一极片221卷绕形成电极组件22时，卷绕收尾端224作为第一极片221的卷绕终点，在卷绕完成后，卷绕收尾端224相对第一极片221的其他部位位于电极组件22的最外侧。
在第一极片221处于展开状态时，焊接部222的长度是指，焊接部222靠近卷绕起始端223的边缘和靠近卷绕收尾端224的边缘之间的距离，即，焊接部222在第一极片的长度方向Y上的尺寸。子段2251的焊接部222的总长度是指，位于子段2251的全部焊接部222的长度的总和。
每个子段2251可以包括一个或者多个焊接部222，在每个子段2251包括多个焊接部222的实施例中，多个焊接部222可以均匀间隔布置，也可以是非均匀间隔布置。
主体段225的长度应不小于两个子段2251的长度之和，也就是说，主体段225至少等分为两个子段2251。
在实际焊接中将电极组件22的第一极片221的揉平后的极耳沿径向划分为环绕电极组件22的卷绕中心的多个区域，每个区域至少包括一圈第一极片221，每个区域可以包括一个或者多个子段2251，每个子段2251可以至少卷绕一圈。
示例性地，如图4所示，围绕电极组件22的卷绕中心孔226，将第一极片221的极耳部划分为同心布置的六个区域，从内至外分别定义为第一区域226a、第二区域226b、第三区域226c、第四区域226d、第五区域226e和第六区域226f。图4中，六个区域分别通过虚线示出的第一环227a、第二环227b、第三环227c、第四环227d和第五环227e划分，每个区域包含一个子段2251。
本申请中所述的“从内至外”是相对电极组件22的卷绕中心而言的，两者中靠近卷绕中心的一者位于远离卷绕中心的一者的内侧。
在电池单体验证中，将0.1s内电池的放电内阻作为欧姆电阻。欧姆电阻的大小影响电池单体20的充放电内阻和充放电过流能力。为了测试子段2251的焊接部222的总长度与子段2251的长度的比值对电池单体20的充放电内阻和充放电过流能力的影响，进行了如下测试：
测试条件：子段的长度为800mm。测试环境温度为25℃。SOC(state of charge，荷电状态)是指蓄电池使用一段时间或长期搁置不用后的剩余容量与其完全充电状态的容量的比值，常用百分数表示。其取值范围为0～1，当SOC＝0时表示电池放电完全，当SOC＝1时表示电池完全充满，本申请中以SOC＝0.5为例进行电池单体20的欧姆内阻和全电池内阻测试。为了获取电池单体20的全电池内阻，采DCIR(Direct Current Internal Resistance，直流内阻的测试)。电池单体20的 全电池内阻包括欧姆内阻和极化内阻两部分，直流内阻的测试(DCIR)是将两部分的电阻全部考虑并测量的方法，也称动态内阻。
表1 焊接部的总长度与子段的长度的不同比值对应的欧姆内阻和全电池内阻的测试结果
Figure PCTCN2021125105-appb-000001
由上述的测试结果可知，子段2251的焊接部222的总长度与子段2251的长度的比值在3％～5％时，电池单体20的欧姆内阻和全电池内阻均随着子段2251的焊接部222的总长度与子段2251的长度的比值的增大逐渐减小；子段2251的焊接部222的总长度与子段2251的长度的大于或者等于5％时，电池单体20的欧姆内阻和全电池内阻均趋于稳定，因此，本申请中子段2251的焊接部222的总长度不小于子段2251的长度的5％，以使电池单体20具有较小的充放电内阻和较强的充放电过流能力。
现有技术中，集流构件24(图3中示出)和电极组件22焊接采用激光连续线性焊接或脉冲点焊的方式，焊印的形状有X形、环形等。在将极片展开后会发现，沿极片的长度方向，有些区段的焊接部较密集，有些区段的焊接部较稀疏，焊接部在极片上的分布不均匀。对于焊接部较稀疏的区段，极片的有效焊接长度(即，该区段的焊接部的总长度)不足以匹配极片的长度，使得极片与集流构件24之间的过流能力差，电池单体的内阻大，降低了电池单体20的功率性能。在集流构件24与第一极片的宽度方向X的一侧焊接后，在第一极片的长度方向Y形成间隔布置的多个焊接部222，沿第一极片的长度方向Y，将第一极片221由靠近卷绕起始端223的第一焊接部222a和靠近卷绕收尾端224的第二焊接部222b限定出的主体部划分为等长的多个子段2251，每个子段2251的焊接部222的总长度不小于子段2251的长度的5％，以使第一极片221和集流构件24焊接形成的焊接部222的分布更加合理，以减小电池单体20的内阻，能够满足实际的过流需求，从而提高电池单体20的功率性能。每个子段2251的长度范围在200mm～1200mm之间，使得第一极片221的卷绕长度满足实际产品需求和电池单体20具有较高的能量密度。
请参照图5、图6，在一些实施例中，任意两个子段2251的焊接部222的总长度之差的绝对值小于或等于10mm。
在图5、图6中，定义任意两个子段2251中的一个子段中的各个焊接部222的长度分别为L1、……、Ln，任意两个子段2251中的另一个子段中的各个焊接部222的长度分别为H1、……、Hm，其中n和m均为大于或者等于1的自然数。满足，-10mm≤(L1+……+Ln)-(H1+……+Hm)≤10mm。
将任意两个子段2251的焊接部222的总长度之差的绝对值控制在10mm内，尽可能减小各个子段2251的焊接部222的总长度的差异，使得焊接部222的分布更加合理，有利于减小电池单体20的内阻，且使各个子段2251的过流能力差异较小，满足实际的过流需求，从而提高电池单体20的功率性能。将任意两个子段2251的焊接部222的总长度之差的绝对值控制在10mm内，相当于各个子段2251的焊接宽度误差在10mm以内，允许各个子段2251之间的焊接总长度存在误差，能够降低焊接难度。
在一些实施例中，任意两个子段2251的所述焊接部222的总长度相同。
任意两个子段2251的所述焊接部222的总长度相同，可以理解为，任意两个子段2251的焊接部222的总长度之差为零。
任意两个子段2251的焊接部222的总长度相同，则各个子段2251的焊接部222的总长度没有差异，使得焊接部222的分布更加合理，尽可能减小电池单体20的内阻，且使各个子段2251的过流能力相同，满足实际的过流需求，从而提高电池单体20的功率性能。
在一些实施例中，任意两个子段2251的焊接部222的数量之差的绝对值小于或者等于10。
在图5中，-10≤n-m≤10，即，任意两个子段2251的焊接部222的数量之差的绝对值小于10。
将任意两个子段2251的焊接部222的数量之差的绝对值控制在10以内，尽可能减小各个子段2251的焊接部减小电池单体20的内阻，使各个子段2251的过流能力差异较小，满足实际的过流需求，从而提高电池单体20的功率性能。将任意两个子段2251的焊接部222的数量之差的绝对值控制10以内，相当于各个子段2251的焊接部222数量可以具有差异，允许各个子段2251之间的焊接总长度存在误差，能够降低焊接难度。
在一些实施例中，任意两个子段2251的焊接部222的数量相同。
任意两个子段2251的所述焊接部222的数量相同，可以理解为，任意两个子段2251的焊接部222的数量之差为零，在图6中，n-m＝0。如图4所示，第二区域226b、第三区域226c、第四区域226d、第五区域226e和第六区域226f均具有一个子段2251，第二区域226b、第三区域226c、第四区域226d、第五区域226e和第六区域226f的焊接部222的数量相同。
任意两个子段2251的焊接部222的数量相同，则尽可能减小各个子段2251的焊接部222的总长度的差异较小，使得焊接部222的分布更加合理，有利于减小电池单体20的内阻，使各个子段2251的过流能力相同，满足实际的过流需求，从而提高电池单体20的功率性能。
请继续参见图4、图5、图6，在一些实施例中，第一极片221还包括与主体段225连续设置的卷绕起始段228，卷绕起始段228从卷绕起始端223到第一焊接部222a的靠近卷绕起始端223的边缘。
主体段225与卷绕起始段228连续设置，是指卷绕起始段228与主体段225直接连接。卷绕完成后，卷绕起始段228卷绕形成的圈层位于主体段225卷绕形成的圈层的内侧。如图4、图5、图6所示，卷绕起始段228位于第一区域226a，并未设置焊接部222。
在一些实施例中，第一极片221可以仅包括卷绕起始段228和主体段225。在另一些实施例中，第一极片221可以仅包括主体段225。
卷绕起始段228从卷绕起始端223到第一焊接部222a的靠近卷绕起始端223的边缘，即卷绕起始端223和第一焊接部222a的靠近卷绕起始端223的边缘限定出卷绕起始段228，换句话说，卷绕起始端223超出第一焊接部222a，卷绕起始段228上未形成焊接部222，卷绕起始段228与集流构件24(图3中示出)之间没有焊接关系，卷绕起始段228的极耳对应的集流构件24(图3中示出)的部分未焊接，可以用于与电极端子232焊接，以输出电池单体20的电能。
对不同的电池单体20而言，卷绕起始段228的长度可以不同。在一些实施例中，卷绕起始段228的长度为A，满足A≤L。
卷绕起始段228的长度是指，在第一极片221处于展开状态时，卷绕起始端223和第一焊接部222a靠近卷绕起始端223的边缘之间的距离。
沿第一极片的长度方向Y，卷绕起始端223与第一焊接部222a之间的距离小于子段的长度，即未设置焊接部222的卷绕起始段228的长度小于设置有焊接部222的子段2251的长度，以使第一极片221没有焊接部222的区段的长度不会太长，保证电池单体20电能稳定输出。
请参照图7、图8、图9，图7为本申请另一些实施例提供的电极组件22的结构示意图， 图8为本申请另一些实施例提供的第一极片221的展开图，图9为本申请另一些实施例提供的第一极片221的展开状态的尺寸示意图。在一些实施例中，第一极片221还包括与主体段225连续设置的卷绕收尾段229，卷绕收尾段229从卷绕收尾端224到第二焊接部222b的靠近卷绕收尾端224的边缘。
主体段225与卷绕收尾段229连续设置，是指卷绕收尾段229与主体段225直接连接。卷绕完成后，卷绕收尾段229卷绕形成的圈层位于主体段225卷绕形成的圈层的外侧。如图6、图7所示，卷绕收尾段229位于第六区域226f，并未设置焊接部222。
在一些实施例中，第一极片221可以仅包括卷绕收尾段229和主体段225。在另一些实施例中，如图10、图11所示，第一极片221可以包括依次连接的卷绕起始段228、主体段225和卷绕收尾段229。
卷绕收尾段229从卷绕收尾端224到第二焊接部222b的靠近卷绕收尾端224的边缘，即卷绕收尾端224和第二焊接部222b的靠近卷绕收尾端224的边缘限定出卷绕收尾段229，换句话说，卷绕收尾端224超出第二焊接部222b，卷绕收尾段229上未形成焊接部222，卷绕收尾段229与集流构件24(图3中示出)之间没有焊接关系，卷绕收尾段229的极耳部对应的集流构件24(图3中示出)的部分未焊接，可以用于与电极端子232焊接，以输出电池单体20的电能。
对不同的电池单体20而言，卷绕收尾段229的长度可以不同，卷绕收尾段229的长度应使电极组件22满足实际需。在一些实施例中，卷绕收尾段229的长度为B，满足B≤L。
在第一极片221处于展开状态时，卷绕收尾段229的长度是指，卷绕收尾端224和第二焊接部222b靠近卷绕收尾端224的边缘的距离。
沿第一极片的长度方向Y，卷绕收尾段229的长度小于子段2251的长度，即未设置焊接部222的卷绕起始段228的长度小于设置有焊接部222的子段2251，以使第一极片221没有焊接部222的区段的长度不会太长，保证电池单体20电能稳定输出。
请参照图12、图13，图12为本申请又一些实施例提供的电极组件22的示意图，图13为本申请再一些实施例提供的电极组件22的结构示意图。在一些实施例中，在相邻的两圈第一极片221中，靠近电极组件22的卷绕中心的一圈的焊接部222数量小于远离卷绕中心的一圈的焊接部222的数量。
这里所述的“在相邻的两圈第一极片221中”可以是任意相邻的两圈第一极片221中，也可以是部分相邻的两圈第一极片221中。
示例性地，如图12所示，每个区域具有一圈第一极片221，在第一区域226a内，每圈第一极片221设有两个焊接部222；在第二区域226b内，每圈第一极片221设有四个焊接部222；在第三区域226c、内，每圈第一极片221设有六个焊接部222；在第四区域226d内，每圈第一极片221设有六个焊接部222；在第五区域226e内，每圈第一极片221设有六个焊接部222。焊接部222呈放射状分布。
如图13所示，每个区域具有一圈第一极片221，在第二区域226b内，部分圈层第一极片221设有四个焊接部222，部分圈层第一极片221设有五个焊接部222，另一部分圈层第一极片221设有六个焊接部222；在第三区域226c内，每圈第一极片221设有六个焊接部222；在第四区域226d内，每圈第一极片221设有六个焊接部222；在第五区域226e内，每圈第一极片221设有六个焊接部222；在第六区域226f内，部分圈层的第一极片221设有六个焊接部222，另一部分圈层的第一极片221设有五个焊接部222。部分焊接部222呈放射状分布，部分焊接部222相连形成围绕电极组件22的卷绕中心的弧段，弧段位于第六区域226f，弧段连接其中相邻的两个由焊接部222组成的放射线。
在其他实施例中，任意相邻的两圈第一极片221的焊接部222的数量也可以相同。
对卷绕式电极组件22而言，相邻的两圈第一极片221中，靠近卷绕中心的一圈的长度小于远离卷绕中心的一圈的长度，焊接时，在靠近卷绕式电极组件22的卷绕中心的一圈的形成焊接部222数量小于远离卷绕中心的一圈的焊接部222的数量，以使每圈第一极片221的长度和每圈第 一极片221对应的焊接部222的数量和焊接部222的总长度匹配，能够使得焊接部222的分布更加合理，以减小电池单体20的内阻，能够满足实际的过流需求，从而提高电池单体20的功率性能。
请参照图3、图4、图5、图6，在一些实施例中，电池单体20还包括壳体21、端盖组件23和集流构件24；壳体21用于容纳电极组件22，壳体21具有开口211；端盖组件23包括端盖231和电极端子232，端盖231用于覆盖开口211，电极端子232安装于端盖231上；集流构件24位于端盖231与电极组件22之间，并用于连接电极组件22的极耳部和电极端子232，极耳部通过第一极片221的未涂覆区域卷绕形成，集流构件24的至少一部分与极耳部焊接并形成多个焊接部222。
集流构件24的至少一部分与极耳部焊接并形成多个焊接部222，沿第一极片的长度方向Y，将第一极片221由靠近卷绕起始端223的第一焊接部222a和靠近卷绕收尾端224的第二焊接部222b限定出的主体部划分为等长的多个子段2251，每个子段2251的焊接部222的总长度不小于子段2251的长度的5％，以使第一极片221和集流构件24焊接形成的焊接部222的分布更加合理，以减小电池单体20的内阻，能够满足实际的过流需求，从而提高电池单体20的功率性能。
请参照图14，图14为本申请一些实施例提供焊接后的集流构件24的示意图。在一些实施例中，第一极片221还包括从卷绕起始端223到第一焊接部222a的靠近卷绕起始端223的边缘的卷绕起始段228，主体段225的未涂覆区域卷绕形成第一部分12(图中未示出)，卷绕起始段228的未涂覆区域卷绕形成第二部分13(图中未示出)，第二部分13沿径向位于第一部分12的内侧；集流构件24包括沿径向连续布置的第一集流部241和第二集流部242，第一集流部241与第一部分12沿第一极片的宽度方向X相对设置，并与第一部分12焊接以形成多个焊接部222，第二集流部242与第二部分13沿第一极片的宽度方向X相对设置，并与电极端子232焊接。
在第一极片221处于卷绕状态时，第一极片的宽度方向X与电极组件22的卷绕轴线方向一致。由于第一极片221的未涂覆区用于形成第一极片221的极耳，因此，第一部分12和第二部分13均属于第一极片221的极耳。第二部分13沿径向位于第一部分12的内侧，可以是第二部分13的部分位于第一部分12的内侧，第二部分13的另一部分与第一部分12的部分位于同一圆周；也可以是第二部分13的全部位于第一部分12的内侧，第一部分12围设于第二部分13的外周。
第一集流部241与第一部分12沿第一极片的宽度方向X相对设置，可以理解为，沿第一极片的宽度方向X，第一部分12在集流构件24上的投影与第一集流部241至少部分重合，重合部分相互焊接，并形成多个焊接部222，实现电极组件22与集流构件24电连接。第二集流部242和第二集流部242沿径向连续布置，卷绕起始段228从卷绕起始端223到第一焊接部222a的靠近卷绕起始端223的边缘，即卷绕起始端223和第一焊接部222a的靠近卷绕起始端223的边缘限定出卷绕起始段228，卷绕起始段228上未形成焊接部222，即卷绕起始段228的未涂覆区域卷绕形成的第二部分13与集流构件24之间没有焊接关系，与第二部分13相对的第二集流部242上未形成焊印，方便集流构件24通过第二集流部242与电极端子232焊接，以输出电池单体20的电能。
请参照图15，图15为本申请另一些实施例提供焊接后的集流构件24的示意图。在一些实施例中，第一极片221还包括从卷绕收尾端224到第二焊接部222b的靠近卷绕收尾段229的边缘的卷绕收尾段229，主体段225的未涂覆区域卷绕形成第一部分12，卷绕收尾段229的未涂覆区域卷绕形成第三部分(图中未示出)，第三部分沿径向位于第一部分12的外侧；集流构件24包括沿径向连续布置的第一集流部241和第三集流部243，第一集流部241与第一部分12沿第一极片的宽度方向X相对设置，并与第一部分12焊接以形成多个焊接部222，第三集流部243与第三部分沿第一极片的宽度方向X相对设置，并与电极端子232焊接。
由于第一极片221的未涂覆区用于形成第一极片221的极耳，因此，第一部分12和第三部分均属于第一极片221的极耳。第三部分沿径向位于第一部分12的外侧，可以是第三部分的部分位于第一部分12的外侧，第三部分的另一部分与第一部分12的部分位于同一圆周；也可以是第三部分的全部位于第一部分12的内侧，第三部分围设于第一部分12的外周。
请参照图16，图16为本申请又一些实施例提供焊接后的集流构件24的示意图，在第一极片221包括卷绕起始段228、主体段225和卷绕收尾段229的实施例中，集流构件24可以包括沿径向从内至外的第二集流部242、第一集流部241和第三集流部243。第一集流部241与第一部分 12焊接，第二集流部242与第二部分13沿第一极片的宽度方向X相对布置，第三名集流部与第三部分沿第一极片的宽度方向X相对布置，第二集流部242和第三集流部243与电极端子232焊接，以输出电池单体20的电能。
通过第一集流部241和第一部分12焊接，实现电极组件22与集流构件24电连接，第三集流部243和第一集流部241沿径向连续布置，卷绕收尾段229从卷绕收尾端224到第二焊接部222b的靠近卷绕收尾端224的边缘，即卷绕收尾端224和第二焊接部222b的靠近卷绕收尾端224的边缘限定出卷绕收尾段229，卷绕收尾段229上未形成焊接部222，即卷绕收尾段229的未涂覆区域卷绕形成的第三部分与集流构件24之间没有焊接关系，与第三部分相对的第三集流部243上未形成焊印，方便集流构件24通过第三集流部243与电极端子232焊接，以输出电池单体20的电能。
本申请实施例提供一种圆柱电池，包括圆柱形的壳体21、圆柱电极组件22、集流构件24和端盖组件23，电极组件22容纳于外壳内，端盖组件23的端盖231封盖于壳体21的开口211，电极组件22包括第一极片221，第一极片221包括卷绕起始端223和卷绕收尾端224，多个焊接部222中最靠近卷绕起始端223的一个为第一焊接部222a，多个焊接部222中最靠近卷绕收尾端224的一个为第二焊接部222b，第一极片221包括从第一焊接部222a的靠近卷绕起始端223的边缘到第二焊接部222b的靠近卷绕收尾端224的边缘的主体段225，主体段225等分为多个长度为L的子段2251，每个子段2251的焊接部222的总长度不小于5％*L，其中，200mm≤L≤1200mm。任意两个子段2251的焊接部222的总长度之差的绝对值小于或等于10mm，任意两个子段2251的焊接部222的数量之差的绝对值小于或者等于10。第一极片221还包括与主体段225连续设置的卷绕起始段228和卷绕收尾段229，卷绕起始段228从卷绕起始端223到第一焊接部222a的靠近卷绕起始端223的边缘。卷绕收尾段229从卷绕收尾端224到第二焊接部222b的靠近卷绕收尾端224的边缘，卷绕起始段228的长度为A和卷绕收尾段229的长度为B，满足A≤L，B≤L。集流构件24包括沿径向从内向外连续布置的第二集流部242、第一集流部241和第三集流部243。主体段225的未涂覆区域卷绕形成第一部分12，卷绕起始段228的未涂覆区域卷绕形成第二部分13，卷绕收尾段229的未涂覆区域卷绕形成第三部分，沿第一极片的宽度方向X，第一集流部241与第一部分12相对设置，并与第一部分12焊接以形成多个焊接部222，第二集流部242与第二部分13相对设置，并与电极端子232焊接，第三集流部243与第三部分相对设置，并与电极端子232焊接，以使输出圆柱电池的电能。
本申请实施例还提供一种电池100，包括上述任意实施例提供电池单体20。
本申请实施例还提供一种用电设备，包括上述实施例提供的电池100。
以上仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (15)

  1. 一种电池单体，其中，包括：
    电极组件，包括第一极片，所述第一极片的宽度方向的一侧设有多个焊接部，所述多个焊接部沿所述第一极片的长度方向间隔设置；
    所述电极组件为卷绕结构，所述第一极片包括卷绕起始端和卷绕收尾端，所述多个焊接部中最靠近所述卷绕起始端的一个为第一焊接部，所述多个焊接部中最靠近所述卷绕收尾端的一个为第二焊接部，所述第一极片包括主体段，所述主体段从所述第一焊接部的靠近所述卷绕起始端的边缘到所述第二焊接部的靠近所述卷绕收尾端的边缘，所述主体段等分为多个长度为L的子段，每个所述子段的所述焊接部的总长度不小于5％*L，其中，200mm≤L≤1200mm。
  2. 根据权利要求1所述的电池单体，其中，任意两个所述子段的所述焊接部的总长度之差的绝对值小于或等于10mm。
  3. 根据权利要求1或2所述的电池单体，其中，任意两个所述子段的所述焊接部的总长度相同。
  4. 根据权利要求1-3中任一项所述的电池单体，其中，任意两个所述子段的所述焊接部的数量之差的绝对值小于或者等于10。
  5. 根据权利要求1-4任一项所述的电池单体，其中，任意两个所述子段的所述焊接部的数量相同。
  6. 根据权利要求1-5任一项所述的电池单体，其中，所述第一极片还包括与所述主体段连续设置的卷绕起始段，所述卷绕起始段从所述卷绕起始端到所述第一焊接部的靠近所述卷绕起始端的边缘。
  7. 根据权利要求6所述的电池单体，其中，所述卷绕起始段的长度为A，满足A≤L。
  8. 根据权利要求1-7任一项所述的电池单体，其中，所述第一极片还包括与所述主体段连续设置的卷绕收尾段，所述卷绕收尾段从所述卷绕收尾端到所述第二焊接部的靠近所述卷绕收尾端的边缘。
  9. 根据权利要求8所述的电池单体，其中，所述卷绕收尾段的长度为B，满足B≤L。
  10. 根据权利要求1-9任一项所述的电池单体，其中，在相邻的两圈所述第一极片中，靠近所述电极组件的卷绕中心的一圈的所述焊接部数量小于远离所述卷绕中心的一圈的所述焊接部的数量。
  11. 根据权利要求1-10任一项所述的电池单体，其中，所述电池单体还包括：
    壳体，用于容纳所述电极组件，所述壳体具有开口；
    端盖组件，包括端盖和电极端子，所述端盖用于覆盖所述开口，所述电极端子安装于所述端盖上；
    集流构件，位于所述端盖与所述电极组件之间，并用于连接所述电极组件的极耳部和所述电极端子，所述极耳部通过所述第一极片的未涂覆区域卷绕形成，所述集流构件的至少一部分与所述极耳部焊接并形成所述多个焊接部。
  12. 根据权利要求11所述的电池单体，其中，所述第一极片还包括从所述卷绕起始端到所述第一焊接部的靠近所述卷绕起始端的边缘的卷绕起始段，所述主体段的未涂覆区域卷绕形成第一部分，所述卷绕起始段的未涂覆区域卷绕形成第二部分，所述第二部分沿径向位于所述第一部分的内侧；
    所述集流构件包括沿径向连续布置的第一集流部和第二集流部，所述第一集流部与所述第一部分沿所述第一极片的宽度方向相对设置，并与所述第一部分焊接以形成所述多个焊接部，所述第二集流部与所述第二部分沿所述第一极片的宽度方向相对设置，并与所述电极端子焊接。
  13. 根据权利要求11或12所述的电池单体，其中，所述第一极片还包括从所述卷绕收尾端到所述第二焊接部的靠近所述卷绕收尾的边缘的卷绕收尾段，所述主体段的未涂覆区域卷绕形成第一部分，所述卷绕收尾段的未涂覆区域卷绕形成第三部分，所述第三部分沿径向位于所述第一部分的外侧；
    所述集流构件包括沿径向连续布置的第一集流部和第三集流部，所述第一集流部与所述第一部分沿所述第一极片的宽度方向相对设置，并与所述第一部分焊接以形成所述多个焊接部，所述第三集流部与所述第三部分沿所述第一极片的宽度方向相对设置，并与所述电极端子焊接。
  14. 一种电池，其中，包括根据权利要求1-13任一项所述的电池单体。
  15. 一种用电设备，其中，包括根据权利要求14所述的电池。
PCT/CN2021/125105 2021-10-20 2021-10-20 电池单体、电池及用电设备 Ceased WO2023065184A1 (zh)

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