WO2024000163A1 - 极片、电极组件、电池单体、电池和用电设备 - Google Patents

极片、电极组件、电池单体、电池和用电设备 Download PDF

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Publication number
WO2024000163A1
WO2024000163A1 PCT/CN2022/101919 CN2022101919W WO2024000163A1 WO 2024000163 A1 WO2024000163 A1 WO 2024000163A1 CN 2022101919 W CN2022101919 W CN 2022101919W WO 2024000163 A1 WO2024000163 A1 WO 2024000163A1
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WO
WIPO (PCT)
Prior art keywords
protective layer
area
pole piece
battery
active material
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/CN2022/101919
Other languages
English (en)
French (fr)
Inventor
常雯
付成华
叶永煌
郭锁刚
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/CN2022/101919 priority Critical patent/WO2024000163A1/zh
Priority to EP22948285.6A priority patent/EP4510205A4/en
Priority to CN202280067390.7A priority patent/CN118043988A/zh
Publication of WO2024000163A1 publication Critical patent/WO2024000163A1/zh
Priority to US18/947,581 priority patent/US20250070276A1/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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/667—Composites in the form of layers, e.g. coatings
    • 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
    • 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
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/586—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries inside the batteries, e.g. incorrect connections of electrodes
    • 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

Definitions

  • This application relates to the field of battery technology, and in particular to a pole piece, electrode assembly, battery cell, battery and electrical equipment.
  • embodiments of the present application provide a pole piece, electrode assembly, battery cell, battery and electrical equipment, which can avoid battery short circuit caused by burrs on the current collector piercing the isolation film, thereby improving the battery performance. Safety performance.
  • a pole piece including: a current collector, the current collector includes a first region, a second region and a pole ear arranged sequentially along a first direction, the first region is coated with an active material layer , the second area is not coated with an active material layer; a protective layer, the protective layer at least covers the edge of the second area close to the tab, and extends beyond the second area close to the tab in the first direction. Describe the edge of the extreme ear.
  • the current collector includes a first region coated with active material, a second region not coated with active material, and a tab.
  • a protective layer is provided on the second area that is not coated with active material. Further, the protective layer covers at least an edge portion of the second area close to the tab and extends beyond the edge.
  • the protective layer covers part of the tab.
  • the direction of the burrs on the second area of the current collector is uncertain.
  • the protective layer In order to completely prevent the burrs from being exposed, the protective layer must extend beyond the second area and be close to the edge of the tab.
  • the second area is connected to the tab, and beyond the second area is close to the edge of the tab, that is, the protective layer must cover part of the tab, but not all of the tab.
  • the protective layer completely covers the second area.
  • the protective layer covers at least the edge of the second area close to the tab, that is, the protective layer can cover part of the second area, or cover the entire second area. Making the protective layer cover the entire second area can improve the protective effect of preventing burrs from being generated or exposed, and further improve the safety performance of the battery.
  • the protective layer borders the active material layer at a connection between the first region and the second region.
  • the first region and the second region of the current collector are connected.
  • the first area is entirely coated with the active material layer, and the second area is entirely covered with the protective layer.
  • Making the protective layer and the active material layer border each other at the connection between the first area and the second area ensures that the protective layer completely covers the second area.
  • the protective layer has a non-porous structure.
  • the protective layer completely covers the second area and extends beyond the edge of the second area close to the tab.
  • the active material includes a main body region and a thinned region arranged along the first direction, the thickness of the thinned region is smaller than the thickness of the main body region, and the protective layer also covers the Thinning area.
  • the size of the thinned area does not exceed 10 mm.
  • a thinning area is provided on the side of the first area close to the second area, and the active material layer here is thinned. If the thinned area is too long, the energy density of the battery will be reduced. Keeping the size of the thinned area no more than 10mm can maintain the normal function of the thinned area without reducing the energy density of the battery.
  • the protective layer covering the thinned area has a microporous structure.
  • the active material is thinned in the thinned area, but the active material still exists in the thinned area.
  • the thickness of the protective layer covering the thinned area does not exceed the thickness difference between the main body area and the thinned area.
  • the thickness of the protective layer covering the thinned area does not exceed the thickness difference between the main body area and the thinned area. That is, the protective layer covers the thinned area but does not exceed the thinned area. This will not affect the volume energy of the battery. density.
  • the ratio of the size of the second area not covered by the protective layer to the size of the second area does not exceed 1:6.
  • the protective layer at least covers the edge of the second region close to the tab and beyond the edge, that is, the protective layer partially covers the second region, which can reduce production costs.
  • the ratio of the size of the second area not covered by the protective layer in the first direction to the size of the second area cannot exceed 1:6. If the ratio exceeds 1:6, on the one hand, the exposed current collector is facing the active material of the other pole piece, and if the isolation film is wrinkled, the exposed current collector that is too long may directly overlap with the other pole piece, which will cause Risk of short circuit; on the other hand, if the protective layer covers too little area of the current collector, the connection between the protective layer and the current collector will be weak, reducing the effectiveness of the protective layer in protecting the current collector.
  • the protective layer also covers the first area.
  • the first area is coated with an active material layer
  • the second area is not coated with an active material layer.
  • the second area is covered by a protective layer near the edge of the tab, and in the first direction, the protective layer extends beyond the edge of the second area near the tab.
  • the protective layer can cover the first area, that is, the protective layer is arranged on the first area and the second area of the current collector, and extends beyond the second area close to the pole.
  • the edge of the ear; the active material layer is coated on the protective layer and coincides with the projection of the first region of the current collector in the thickness direction.
  • the protective layer covering the first region has a porous structure.
  • the protective layer covers the first region and the second region of the current collector, and the active material layer is coated on the protective layer.
  • the protective layer covering the first area is arranged into a porous structure, so as not to affect the connection between the active material layer and the current collector, thus ensuring the normal electrochemical reaction of the battery.
  • the thickness of the protective layer is no greater than the thickness of the active material layer.
  • the thickness of the protective layer is too thick, the volumetric energy density of the battery will be reduced.
  • the protective layer can protect the safety of the battery without reducing the volumetric energy density of the battery.
  • the size of the second area is 0.5-3 mm.
  • the size of the second area in the first direction, if the size of the second area is too large, it will occupy too much current collector area, causing the battery energy density to decrease; if the size of the second area is too small, the connection between the protective layer and the second area will be increased. Difficulty. Keeping the size of the second area in the first direction at 0.5-3 mm can reduce production difficulty without occupying more active material areas.
  • the size of the current collector, the active material layer and the protective layer are the same, and the second direction is perpendicular to the first direction.
  • the protective layer at least covers the edge of the second region close to the tab and extends beyond the edge in the first direction.
  • the size of the current collector, the active material layer and the protective layer are made the same, and the protective layer can completely cover the burrs on the current collector, thereby improving the safety performance of the battery.
  • the protective layer in the second direction, a plurality of the current collectors are arranged at intervals, the protective layer is continuous in the second direction, and the size of the protective layer in the second direction
  • the second direction is perpendicular to the first direction and is the same as the overall size of a plurality of the current collectors and the spacing between a plurality of the current collectors.
  • the protective layer when multiple current collectors are spaced apart to form the pole piece of the battery, the protective layer is continuous in the pole piece. That is to say, the protective layer not only covers the edges of the second regions of different current collectors close to the tabs, but also covers the intervals between multiple current collectors. In the second direction, by making the total size of the protective layer and all current collectors and the intervals between all current collectors the same, the protective layer can completely cover the burrs on the current collector, thereby improving the safety performance of the battery.
  • the active material layer and the protective layer are provided on two opposite surfaces of the current collector.
  • the active material layer and the protective layer are arranged on two opposite sides of the current collector, which can increase the volumetric energy density of the battery.
  • the protective layer and the current collector are connected through bonding or thermal bonding.
  • the protective layer is connected to the current collector through bonding or thermal bonding. This connection method is simple and can be widely used in the production process.
  • the material of the protective layer is polypropylene, polyamide or epoxy resin.
  • the protective layer made of polypropylene, polyamide or epoxy resin can not only ensure the normal protective effect of the protective layer, but also reduce the production cost, which is beneficial to application in large-scale production.
  • an electrode assembly including the pole piece in the above embodiment.
  • a battery cell including the electrode assembly in the above embodiment; a case having an opening for accommodating the electrode assembly; and an end cover for closing the opening.
  • a battery including the battery cell in the above embodiment.
  • an electrical device including the battery in the above embodiment, where the battery is used to provide electrical energy.
  • Figure 1 is a schematic structural diagram of a vehicle according to an embodiment of the present application.
  • Figure 2 is an exploded structural diagram of a battery according to an embodiment of the present application.
  • Figure 3 is a schematic diagram of a battery cell according to an embodiment of the present application.
  • Figure 4 is a schematic structural diagram of a pole piece according to an embodiment of the present application.
  • Figure 5 is a left view of Figure 4.
  • Figure 6 is a schematic structural diagram of a pole piece according to another embodiment of the present application.
  • Figure 7 is a left view of Figure 6;
  • Figure 8 is a left side view of a schematic structural diagram of a pole piece according to another embodiment of the present application.
  • Figure 9 is a schematic structural diagram of a pole piece according to another embodiment of the present application.
  • Figure 10 is a left view of Figure 9;
  • Figure 11 is a schematic structural diagram of a pole piece according to another embodiment of the present application.
  • Vehicle 1 battery 2, battery cell 3;
  • Controller 11 motor 12, box 20, electrode assembly 31, housing 32, electrode terminal 33, connecting member 34, pressure relief mechanism 35, current collector 36, protective layer 38;
  • Active material layer 3611 main body area 3612, thinning area 3613, first direction X, second direction Y.
  • an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application.
  • the appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.
  • multiple refers to more than two (including two).
  • multiple groups refers to two or more groups (including two groups), and “multiple pieces” refers to It is more than two pieces (including two pieces).
  • the battery cells may include lithium metal secondary batteries, sodium metal batteries, magnesium metal batteries, etc., which are not limited in the embodiments of this application.
  • the battery cell may be in the shape of a cylinder, a flat body, or other shapes, and the embodiments of the present application are not limited to this.
  • Battery cells are generally divided into three types according to packaging methods: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application are not limited to this. For convenience of explanation, the following embodiments take a lithium metal battery as an example.
  • the battery mentioned in the embodiments of this application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in this application may include a battery module or a battery pack.
  • Batteries generally include a box for packaging one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.
  • a protective layer is provided on the non-tab portion of the current collector, and the protective layer at least covers the edge of the non-tab portion close to the tab and extends beyond the edge. This can effectively prevent the generation and exposure of burrs, thereby improving the safety performance of the battery.
  • the pole piece described in the embodiment of this application may be a positive pole piece or a negative pole piece.
  • the pole pieces described in the embodiments of this application are suitable for electrode assemblies, battery cells, batteries, and electrical equipment using batteries.
  • Power-consuming 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, etc.
  • spacecraft include aircraft, rockets, space shuttles, spaceships, etc.
  • electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric ship 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, planers and more.
  • Electric drills Electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, planers and more.
  • the following embodiments take the electric device as a vehicle as an example.
  • FIG. 1 is a schematic structural diagram of a vehicle 1 provided by an embodiment of the present application.
  • a battery 2 is provided inside the vehicle 1 , and the battery 2 can be provided at the bottom, head, or tail of the vehicle 1 .
  • the battery 2 may be used to power the vehicle 1 , for example, the battery 2 may be used as an operating power source for the vehicle 1 .
  • the vehicle 1 may also include a controller 11 and a motor 12.
  • the controller 11 is used to control the battery 2 to provide power to the motor 12, for example, for starting, navigating and driving the vehicle 1 to meet its power requirements.
  • the battery 2 can not only be used as the operating power source of the vehicle 1, but also can be used as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.
  • FIG. 2 is an exploded schematic diagram of the battery 2 provided by an embodiment of the present application.
  • the battery 2 includes a box 20 and a battery cell 3 .
  • the battery cell 3 is accommodated in the box 20 .
  • the box 20 is used to accommodate the battery cells 3 .
  • the box 20 can be of various structures.
  • the box body 20 may include a first box body part 201 and a second box body part 202.
  • the first box body part 201 and the second box body part 202 cover each other.
  • the first box body part 201 and the second box body part 202 cover each other.
  • the two box parts 202 jointly define an accommodation space 203 for accommodating the battery cells 3 .
  • the second box part 202 may be a hollow structure with one end open, and the first box part 201 is a plate-like structure.
  • the first box part 201 covers the open side of the second box part 202 to form a receiving space 203
  • the box 20; the first box part 201 and the second box part 202 can also be a hollow structure with one side open, and the open side of the first box part 201 is covered with the open side of the second box part 202 , to form the box 20 with the accommodation space 203 .
  • the first box part 201 and the second box part 202 can be in various shapes, such as cylinder, rectangular parallelepiped, etc.
  • a sealing member may also be provided between the first box part 201 and the second box part 202, such as sealant, sealing ring, etc. .
  • the first box part 201 can also be called an upper box cover, and the second box part 202 can also be called a lower box.
  • the battery 2 has a plurality of battery cells 3 .
  • Multiple battery cells 3 can be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that multiple battery cells 3 are connected in series and in parallel.
  • Multiple battery cells 3 can be directly connected in series or in parallel or mixed together, and then the whole composed of multiple battery cells 3 can be accommodated in the box 20 ; of course, multiple battery cells 3 can also be connected in series first. They may be connected in parallel or mixed to form a battery module (not shown in the figure), and multiple battery modules may be connected in series, parallel or mixed to form a whole, and be accommodated in the box 20 .
  • the plurality of battery cells 3 in the battery module can be electrically connected through bus components to achieve parallel, series or mixed connection of the multiple battery cells 3 in the battery module.
  • FIG. 3 it is a schematic structural diagram of a battery cell 3 according to an embodiment of the present application.
  • the battery cell 3 includes one or more electrode assemblies 31 , a casing 321 and an end cap 322 .
  • Housing 321 and end cap 322 form housing or battery case 32 .
  • the wall of the casing 321 and the end cover 322 are both called the wall of the battery cell 3.
  • the wall of the casing 321 includes a bottom wall and four side walls.
  • the housing 321 is determined according to the combined shape of one or more electrode assemblies 31.
  • the housing 321 can be a hollow rectangular parallelepiped, a cube, or a cylinder, and one surface of the housing 321 has an opening to accommodate one or more electrodes.
  • Component 31 may be placed within housing 321.
  • the housing 321 is a hollow rectangular parallelepiped or a cube
  • one of the planes of the housing 321 is an opening surface, that is, the plane does not have a wall so that the inside and outside of the housing 321 are connected.
  • the housing 321 can be a hollow cylinder
  • the end surface of the housing 321 is an open surface, that is, the end surface does not have a wall so that the inside and outside of the housing 321 are connected.
  • the end cap 322 covers the opening and is connected with the housing 321 to form a closed cavity in which the electrode assembly 31 is placed.
  • the housing 321 is filled with electrolyte, such as electrolyte solution.
  • the battery cell 3 may also include two electrode terminals 33 , and the two electrode terminals 33 may be provided on the end cap 322 .
  • the end cap 322 is usually in the shape of a flat plate, and two electrode terminals 33 are fixed on the flat surface of the end cap 322.
  • the two electrode terminals 33 are respectively a positive electrode terminal 331 and a negative electrode terminal 332.
  • Each electrode terminal 33 is provided with a corresponding connecting member 34, which may also be called a current collecting member 34, which is located between the end cover 322 and the electrode assembly 31 and is used to electrically connect the electrode assembly 31 and the electrode terminal 33.
  • the electrode assembly 31 can be provided as a single or multiple electrode components according to actual usage requirements. As shown in FIG. 3 , the battery cell 3 is provided with four independent electrode assemblies 31 .
  • the battery cell 3 may also be provided with a pressure relief mechanism 35 .
  • the pressure relief mechanism 35 is used to be activated when the internal pressure or temperature of the battery cell 3 reaches a threshold value to relieve the internal pressure or temperature.
  • the pressure relief mechanism 35 can be any possible pressure relief structure, which is not limited in the embodiments of the present application.
  • the pressure relief mechanism 35 may be a temperature-sensitive pressure relief mechanism configured to melt when the internal temperature of the battery cell 3 provided with the pressure relief mechanism 35 reaches a threshold value; and/or the pressure relief mechanism 35 may be a pressure-sensitive pressure relief mechanism configured to rupture when the internal air pressure of the battery cell 3 provided with the pressure relief mechanism 35 reaches a threshold value.
  • FIG 4 is a schematic structural diagram of a pole piece according to an embodiment of the present application.
  • the pole piece 311 includes a current collector 36.
  • the current collector 36 includes a first region 361, a second region 362 and a pole tab 363 arranged sequentially along the first direction X.
  • the first region 361 is coated with an active material layer 3611, and the second region 362 is not coated with the active material layer 3611; the protective layer 38, the protective layer 38 at least covers the edge of the second area 362 close to the tab 363, and extends beyond the edge of the second area 362 close to the tab 363 in the first direction X.
  • the current collector 36 refers to a component that collects current.
  • battery 2 it mainly refers to metal foil, such as copper foil, aluminum foil, etc.
  • the function of the current collector 36 is to collect the current newly generated by the active material of the battery 2 so as to form a larger current for external output. Therefore, the current collector 36 is generally made of a metal material whose internal resistance should be as small as possible.
  • the active material layer 3611 refers to a material that can participate in the flow reaction in the battery 2 .
  • Flow reactions are oxidation and reduction reactions. Oxidation reactions refer to chemical reactions that lose electrons; reduction reactions refer to chemical reactions that gain electrons.
  • the active material layer 3611 participates in a flow reaction, that is, when the active material on one electrode loses electrons, the active material on the other electrode obtains electrons at the same time. During the process of losing and gaining electrons, electrons flow, that is, electric current.
  • the current collector 36 includes a first region 361 coated with active material, a second region 362 not coated with active material, and tabs 363 .
  • a protective layer 38 is provided on the second region 362 that is not coated with active material, wherein the protective layer 38 covers at least an edge portion of the second region 362 and extends beyond the edge.
  • the protective layer 38 covers part of the tab 363 .
  • burrs refer to residual chips and very fine fibers appearing on the surface of the metal current collector 38. The more burrs there are, the greater the risk of the isolation membrane being punctured, and the lower the safety factor of the battery 2.
  • the direction of the burrs on the second region 362 of the current collector 36 is uncertain.
  • the protective layer 38 In order to completely prevent the burrs from being exposed, the protective layer 38 must be extended beyond the second region 362 and close to the edge of the tab 363 .
  • the second area 362 and the tab 363 are connected, and beyond the second area 362 is close to the edge of 363 , that is, the protective layer 38 must cover part of the tab 363 , but cannot cover all of the tab 363 .
  • the protective layer 38 By limiting the position of the protective layer 38 to cover part of the tab 363 , that is, the protective layer 38 does not cover all of the tab 363 , while ensuring the safety of the battery 2 , it also ensures the normal overcurrent capability and welding of the tab 363 capability, thereby ensuring the normal function of battery 2.
  • FIG. 5 is a left side view of FIG. 4 . As shown in FIG. 5 , the protective layer 38 completely covers the second area 362 .
  • the current collector 36 is composed of a first region 361, a second region 362 and a tab 363.
  • the first area 361 is coated with the active material layer 3611, and the second area 362 is not coated with the active material layer 3611.
  • the protective layer 38 is provided on the second area 362 where the active material layer 3611 is not coated.
  • the protective layer 38 at least covers the edge of the second region 362 close to the tab 363 , that is, the protective layer 38 can cover part of the second region 362 , or cover the entire second region 362 .
  • the protective layer 38 completely covers the second area 362, which can improve the protective effect of preventing burrs from being generated or exposed, and further improve the effect of the protective layer 38 in protecting the safety performance of the battery 2.
  • the protective layer 38 borders the active material layer 3611 at the connection between the first region 361 and the second region 362 .
  • the first region 361 and the second region 362 of the current collector 36 are connected, the second region 362 is entirely covered by the protective layer 38, and the first region 361 is entirely coated by the active material layer 3611, that is, the protective layer 361 and the active material Layer 3611 The two are connected but do not intersect.
  • the protective layer 38 and the active material layer 3611 are bordered at the connection between the first area 361 and the second area 362, which ensures that the protective layer 361 completely covers the second area 362, but does not occupy the active material layer 3611.
  • the area of the first area is 361.
  • the protective layer 38 has a non-porous structure.
  • the protective layer 38 completely covers the second area 361 and extends beyond the second area 362 close to the edge of the tab 363.
  • the active material layer 3611 is not coated on the second region 362. Therefore, the protective layer 38 on the second region 362 cannot have ions or electrons migrating.
  • the sealing and protective effects of the protective layer 38 can be increased.
  • FIG. 6 is a schematic structural diagram of a pole piece according to another embodiment of the present application
  • FIG. 7 is a left view of FIG. 6
  • the active material layer 3611 includes a main body area 3612 and a thinned area 3613 arranged along the first direction District 3613.
  • the thinned area 3613 is produced by thinning the edge of the active material layer 3611 during the processing of the pole piece 311.
  • the thinned area 3613 can avoid problems such as thick edges and bulging at the edge of the current collector 36 coated with the active material layer 3611 .
  • providing the thinned area 3613 on the active material layer 3611 can avoid problems such as thick edges and bulges in the active material layer 3611, thereby improving the quality of the pole piece 311.
  • the protective layer 38 it is difficult to make the protective layer 38 exactly border the active material layer 3611 at the connection between the first region 361 and the second region 362.
  • Making the protective layer 38 partially or completely cover the thinned area 3613, that is, the protective layer 38 and the active material layer 3611 partially overlap, can reduce the processing difficulty of setting the protective layer 38 during the production process.
  • the size of the thinned area 3613 does not exceed 10 mm.
  • a thinning area 3613 is provided at an edge of the first area 361 close to the second area 362 to thin the active material layer 3611 there. If the length of the thinned area 3613 is too long, that is, the overall mass of the active material is reduced, the energy density of the battery 2 will be reduced.
  • the energy density of the battery 2 refers to the ratio of the energy that can be charged to the mass or volume of the energy storage medium for a given electrochemical energy storage device.
  • the ratio of the energy that can be charged to the mass of the energy storage medium is the mass energy density, in units of W ⁇ h/kg; the ratio of the energy that can be charged to the volume of the energy storage medium is the volumetric energy density, in units of W ⁇ hour/liter, the energy storage medium is the active substance.
  • the size of the thinned area 3613 in the first direction 2 energy density is the size of the thinned area 3613 in the first direction 2 energy density.
  • the protective layer 38 covering the thinned area 3613 has a microporous structure.
  • Micropores refer to the holes on the protective layer 38 covering the thinned area 3613 as micropores.
  • micropores are holes with a diameter less than 2 nm, that is, there are holes with a diameter less than 2 nm on the protective layer 38 covering the thinned area 3613.
  • the thinned area 3613 is to thin the active material layer 3611 here, but active material still exists in it.
  • the protective layer 38 covering the thinned area 3613 to have a microporous structure, it can be ensured that the thinned area 3613 maintains normal electrochemical reactions and migration of metal ions and batteries.
  • the thickness of the protective layer 38 covering the thinned area 3613 does not exceed the thickness difference between the main body area 3612 and the thinned area 3613.
  • the protective layer 38 provided at the thinned area 3613 must partially or completely cover the thinned area 3613, but must not exceed the edge of the thinned area 3613 close to the first area 361.
  • the thickness of the protective layer 38 covering the thinned area 3613 does not exceed the thickness difference between the main body area 3612 and the thinned area 3613, that is, the protective layer 38 covers the thinned area 3613 but does not exceed the thinned area 3613 and is close to the first area.
  • Figure 8 is a left side view of a schematic structural diagram of a pole piece according to another embodiment of the present application. As shown in FIG. 8 , the ratio of the size D1 of the second area 362 not covered by the protective layer 38 to the size of the second area 362 does not exceed 1:6.
  • the protective layer 38 only needs to cover the edge of the second area 362 close to the tab 363 and beyond the edge. That is, the protective layer 38 can completely cover the second area 3612 or partially cover the second area 362 . When the protective layer 38 partially covers the second area 362, the production cost of the protective layer 38 can be reduced. However, the size D1 of the second area 362 not covered by the protective layer 38 must be set appropriately, because the active material layer 3611 is not coated at D1 on the second area 362, and the protective layer 38 is not provided. This area is a directly exposed current collector. 36. On the one hand, the exposed current collector 36 is facing the active material of the other pole piece 311.
  • the isolation film is wrinkled, the exposed current collector 36 that is too long will cause this part of the exposed current collector 36 to directly overlap with the other pole piece. connection, and there is a risk of short circuit; on the other hand, if the size D1 of the second area 362 not covered by the protective layer 38 is too large, the size of the second area 362 covered by the protective layer 38 will become smaller, that is, the protective layer The connection area between 38 and the second area 362 is small, which will result in a weak connection between the protective layer 38 and the current collector 36 and reduce the protective effect of the protective layer 38 on the current collector 36 .
  • the ratio of the size D1 of the second area 362 not covered by the protective layer 38 to the size of the second area 362 is controlled within 1:6. In this way, on the one hand, the production cost of the protective film 38 can be reduced, and on the other hand, the connection effect between the protective layer 38 and the current collector 36 can be enhanced.
  • FIG. 9 is a schematic structural diagram of a pole piece according to another embodiment of the present application
  • FIG. 10 is a left view of FIG. 9
  • the protective layer 38 also covers the first area 361 .
  • the first area 361 is coated with an active material layer 3611, and the second area 361 is not coated with an active material.
  • the edge of the second area 361 close to the tab 363 is covered by the protective layer 38 , and in the first direction X, the protective layer 38 extends beyond the edge of the second area close to the tab 363 .
  • the protective layer 38 can also cover the first region 361 .
  • the protective layer 38 also covers the first region 361 , that is, the protective layer 38 is disposed on both the first region 361 and the second region 362 of the current collector 36 , and extends beyond the second region 362 close to the edge of the tab 363 .
  • the active material layer 3611 is coated on the protective layer 38 , the protective layer 38 is directly connected to the current collector 36 , and the active material layer 3611 overlaps the first region 361 in the thickness direction.
  • the protective layer 38 covering the first region 361 has a porous structure.
  • the protective layer 38 is directly connected to the current collector 36 and covers the first area 361 and the second area 362 of the current collector 36 .
  • the active material layer 3611 is coated on the protective layer 38 .
  • the protective layer 38 covering the first region 361 needs to be provided with a porous structure.
  • the protective layer 38 covering the first region 361 is provided with a porous structure, so as not to affect the connection between the active material layer 3611 and the current collector 36, thus ensuring the normal electrochemical reaction of the battery 2.
  • the thickness of the protective layer 38 is no greater than the thickness of the active material layer 3611.
  • the volumetric energy density of a battery with a thicker protective layer 38 will be lower than that of a battery 2 with a thinner protective layer 38 .
  • the protective layer 38 can protect the safety of the battery 2 without reducing the volumetric energy density of the battery 2 .
  • the size of the second area 362 is 0.5-3 mm.
  • the second area 362 is not coated with active material, and the second area 362 is mainly used to connect with the protective layer 38 .
  • the area of the current collector 36 causes the energy density of the battery 2 to decrease.
  • the size of the current collector 36 , the active material layer 3611 and the protective layer 38 are the same, and the second direction Y is perpendicular to the first direction X.
  • a certain part of the current collector 36 will be die-cut along a certain edge of the current collector 36.
  • the edge of the second area 362 close to the tab 363 is die-cut.
  • the die-cutting area may be a wide tab area in which only the tab 363 is die-cut, and other current collectors 36 connected to the die-cut area are Areas do not require die cutting.
  • a protective layer 38 is provided on the second region 362 of the current collector 36; when die-cutting non-lugs, the protective layer 38 that does not cover the current collector 36 is die-cut; when die-cutting the tabs 363, die-cutting on the current collector 36 covered by the protective layer 38 .
  • the protective layer 38 should be provided on all areas of the current collector 36 that need to be die-cut.
  • this application has no special limitation on the time when the protective layer 38 is provided during the processing of the pole piece 311.
  • the protective layer 38 can be provided before the current collector 36 is die-cut, and directly acts on the protective layer 36 when the current collector 36 is die-cut; or it can be provided after the current collector 36 is die-cut, and can be changed according to production needs during the actual production process.
  • the protective layer 38 at least covers the edge of the second region 362 close to the tab 363 and extends beyond the edge in the first direction X.
  • the sizes of the current collector 36 , the active material layer 3611 and the protective layer 38 are made the same.
  • the protective layer 38 can completely cover the burrs on the current collector 36 , thereby improving the protection effect on the safety performance of the battery 2 .
  • Figure 11 is a schematic structural diagram of a pole piece according to another embodiment of the present application.
  • a plurality of current collectors 36 are arranged at intervals, the protective layer 38 is continuous in the second direction Y, and the size of the protective layer 38 in the second direction Y is consistent with the plurality of current collectors 36 .
  • the total size of the current collector 36 and the gaps 364 between the plurality of current collectors 36 is the same, and the second direction Y is perpendicular to the first direction X.
  • the protective layer 38 is continuously and uninterruptedly distributed in the pole piece 311 . That is to say, the protective layer 38 not only covers the edges of the second regions 362 of different current collectors 36 close to the tabs 363 , but also covers the intervals 364 between the plurality of current collectors 36 . Without the current collector 36, that is, the gap 364 without the active material layer 3611 can be used as a cutting place for the pole pieces 311 of the stacked battery cells 3, which can avoid burrs on the cutting edge; it can also be used as a rolled type. The corners of the battery cells 3 can prevent powder from falling off at the corners to produce particles, thereby damaging the safety of the battery cells 3, or avoid the risk of lithium precipitation at the corners.
  • the total size of the protective layer 38 and all current collectors 36 and the intervals 341 between all current collectors 36 is made the same, so that the protective layer 38 can completely cover the burrs on the current collector 36, and thus Improve the safety performance of battery 2.
  • the active material layer 3611 and the protective layer 38 are provided on two opposite surfaces of the current collector 36 .
  • arranging the active material layer 3611 on the two opposite surfaces of the current collector 36 can improve the energy density of the battery 2; arranging the protective layer 38 on the two opposite surfaces of the current collector 36 can further improve the safety of the battery 2. performance.
  • the protective layer 38 and the current collector 36 are connected through bonding or thermal bonding.
  • the protective layer 38 is connected to the current collector 36 through bonding or thermal bonding. This connection method is simple and can be widely used in the production process.
  • the material of the protective layer 38 is polypropylene, polyamide or epoxy resin.
  • Polypropylene is a thermoplastic synthetic resin polymer with excellent properties, produced through the addition polymerization reaction of propylene.
  • the protective layer 38 prepared using polypropylene as raw material is resistant to corrosion by a variety of organic solvents, and has chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and good high wear-resistance processing properties. wait.
  • the protective layer 38 prepared using polyamide or epoxy resin as raw material also has better performance.
  • the price of these three products is suitable, which is conducive to their application in large-scale production.
  • the protective layer 38 made of polypropylene, polyamide or epoxy resin can not only ensure that the protective layer 38 can properly protect the safety of the battery 2, but also reduce production costs, which is beneficial to application in mass production.
  • the embodiment of the present application also provides an electrode assembly 31, including the pole piece 311 in the previous embodiment.
  • the embodiment of the present application also provides a battery cell 3, which includes the battery assembly 31 in the previous embodiment; a housing 321 with an opening for accommodating the electrode assembly 31; and an end cover 322 for closing the opening.
  • the embodiment of the present application also provides a battery 2, including the battery cell 3 in the previous embodiment.
  • the embodiment of the present application also provides an electrical device, including the battery 2 in the previous embodiment, and the battery 2 is used to provide electric energy.
  • Comparative Example 1 a positive electrode piece, the two opposite surfaces of the current collector are coated with active material layers. After die-cutting, except for the tabs, 1.5 mm of the current collector is retained on the die-cut edge.
  • Embodiment 1 is a positive electrode plate.
  • the active material layer and the protective layer are arranged on two opposite surfaces of the current collector. Except for the tabs, a 1.5mm width area is left on the die-cut edge of the second area to be covered by a protective layer, and the protective layer extends beyond the edge of the second area close to the tabs by 1.5mm.
  • the thickness of the protective layer is the same as the thickness of the active material layer on the same side. .
  • Embodiment 2 is a positive electrode plate, the active material layer and the protective layer are arranged on two opposite surfaces of the current collector.
  • the tab there is a 1.5mm width area left on the die-cut edge of the second area, which is covered by a protective layer.
  • the protective layer extends 1.5mm beyond the edge of the second area close to the tab, and the 5mm thinned area is also covered by the protective layer.
  • the thickness of the layer is the same as the thickness of the active material layer on the same side.
  • Embodiment 3 is a positive electrode plate, the active material layer and the protective layer are arranged on two opposite surfaces of the current collector. Except for the tab, the rest of the current collector is covered by a protective layer. The local porous area of the protective layer is covered with active material. The protective layer extends 1.5mm beyond the edge of the second area close to the tab. The thickness of the protective layer is the same as the thickness of the active material layer on the same side.
  • the positive electrode plates, negative electrode plates and separators of the above comparative examples and examples are assembled into batteries.
  • the structure of the battery is designed such that the edge of the active material layer of the negative electrode plate in width is higher than that of the corresponding positive electrode mold. Structure that cuts the edge of the current collector. Hi-pot testing was performed on these batteries at 25°C to detect whether there were burrs piercing the separator and battery ignition. The test results are shown in Table 1.
  • the pole piece provided by the embodiment of the present application can effectively reduce the probability of burrs piercing the separator and the probability of battery ignition, thereby improving the safety performance of the battery.

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Abstract

本申请实施例提供一种极片(311)、电极组件(31)、电池单体(3)、电池(2)和用电设备。该极片(311)包括：集流体(36)，集流体(36)包括沿第一方向(X)依次设置的第一区域(361)、第二区域(362)和极耳(363)，第一区域(361)涂覆有活性物质层(3611)，第二区域(362)未涂覆有活性物质层(3611)；保护层(38)，保护层(38)至少覆盖第二区域(362)靠近极耳(363)的边缘，且在第一方向(X)上超出第二区域(362)靠近极耳(363)的边缘。本申请实施例提供的技术方案可以避免因集流体上的毛刺刺穿隔离膜而导致的电池短路，进而提高电池的安全性能。

Description

极片、电极组件、电池单体、电池和用电设备 技术领域
本申请涉及电池技术领域，特别是涉及一种极片、电极组件、电池单体、电池和用电设备。
背景技术
随着环境污染的日益加剧，新能源产业越来越受到人们的关注。在新能源产业中，电池技术是关乎其发展的一项重要因素。
在电池技术的发展中，如何提高电池的安全性能，是电池技术中一个亟待解决的技术问题。
发明内容
鉴于上述问题，本申请实施例提供了一种极片、电极组件、电池单体、电池和用电设备，可以避免因集流体上的毛刺刺穿隔离膜而导致的电池短路，进而提高电池的安全性能。
第一方面，提供了一种极片，包括：集流体，所述集流体包括沿第一方向依次设置的第一区域、第二区域和极耳，所述第一区域涂覆有活性物质层，所述第二区域未涂覆有活性物质层；保护层，所述保护层至少覆盖所述第二区域靠近所述极耳的边缘，且在所述第一方向上超出第二区域靠近所述极耳的边缘。
本申请实施例中，集流体包括涂覆有活性物质的第一区域、未涂覆活性物质的第二区域和极耳。在未涂覆活性物质的第二区域上设置保护层，进一步地，保护层至少覆盖第二区域靠近极耳的边缘部分且超出该边缘。通过设置保护层，并使保护层覆盖且超出第二区域靠近极耳的边缘部分，可以在对集流体加工时作用到保护层，从而防止毛刺的产生；或者是直接将集流体的该边缘上的毛刺覆盖住，防止毛刺外露，避免因毛刺刺穿隔离膜而导致的电池短路，进而提高电池的安全性能。
在一种可能的实施方式中，所述保护层覆盖所述极耳的部分区域。
本申请实施例中，集流体的第二区域上的毛刺方向不定，为了全面防止毛刺外露，必须要使保护层超出第二区域靠近极耳的边缘。而第二区域和极耳是相连的，超过第二区域靠近极耳的边缘，即保护层肯定要覆盖部分极耳，但不能覆盖全部极耳。通过将保护层的位置设置为覆盖极耳的部分区域，即保护层不覆盖全部极耳，在保证了电池安全性能的同时，也保证了极耳正常的过流能力和焊接能力，从而保证了电池的正常功能。
在一种可能的实施方式中，所述保护层完全覆盖所述第二区域。
本申请实施例中，保护层是至少覆盖第二区域靠近极耳的边缘，也就是保护层可以覆盖部分第二区域，或，覆盖全部第二区域。使保护层覆盖全部第二区域，可提高防止毛刺产生或外露的保护效果，进一步提高电池的安全性能。
在一种可能的实施方式中，所述保护层在所述第一区域和所述第二区域的连接处与所述活性物质层接壤。
本申请实施例中，集流体的第一区域和第二区域是相连的。第一区域上全部被活性物质层涂覆，第二区域上全部被保护层覆盖。使保护层和活性物质层在第一区域和第二区域的连接处接壤，即保证了保护层完全覆盖第二区域。
在一种可能的实施方式中，所述保护层为无孔结构。
本申请实施例中，为了全方位预防毛刺的产生及外露，使保护层完全覆盖第二区域且超出第二区域靠近极耳的边缘。通过将该完全覆盖第二区域且超出第二区域靠近极耳的边缘的保护层的结构设置为无孔结构，可以增加保护层的密闭、保护效果。
在一种可能的实施方式中，所述活性物质包括沿第一方向设置的主体区和削薄区，所述削薄区的厚度小于所述主体区的厚度，所述保护层还覆盖所述削薄区。
本申请实施例中，在极片的加工过程中，通过将活性物质层的边缘削薄，产生削薄区，可以避免极片产生厚边、鼓边等问题。使保护层覆盖削薄区，即保护层与活性物质层有部分重合，可降低生产过程中设置保护层的难度。
在一种可能的实施方式中，在所述第一方向上，所述削薄区的尺寸不超过10mm。
本申请实施例中，为避免极片产生厚边、鼓边等问题，在第一区域靠近第 二区域的一侧设置削薄区，将此处的活性物质层削薄。若削薄区的区域过长，则会降低电池的能量密度。使削薄区的尺寸不超过10mm，既可以保持削薄区的正常功能，也可以不降低电池的能量密度。
在一种可能的实施方式中，覆盖所述削薄区的所述保护层为微孔结构。
本申请实施例中，削薄区是将活性物质削薄，但其还是有活性物质存在。通过将覆盖削薄区处的保护层设置为有微孔结构，可以保证削薄区维持正常的电化学反应和金属离子、电子的迁移。
在一种可能的实施方式中，覆盖所述削薄区的所述保护层的厚度不超过所述主体区与所述削薄区的厚度差。
本申请实施例中，使覆盖削薄区的保护层的厚度不超过主体区与削薄区的厚度差，即保护层覆盖削薄区但不超过削薄区，这样可以不影响电池的体积能量密度。
在一种可能的实施方式中，在所述第一方向上，未被所述保护层覆盖的所述第二区域的尺寸，与所述第二区域的尺寸的比值不超过1:6。
本申请实施例中，保护层至少覆盖第二区域靠近极耳的边缘且超过该边缘，即保护层部分覆盖第二区域，这样可降低生产成本。但未被保护层覆盖的第二区域在第一方向的尺寸，与第二区域的尺寸的比值不能超过1:6。若比值超过1:6，一方面，裸露的集流体正对着另一极片的活性物质，隔离膜若发生褶皱，过长裸露的集流体或导致与另一极片直接搭接，进而发生短路风险；另一方面，若保护层覆盖集流体区域过少将导致保护层与集流体连接不牢，降低保护层保护集流体的效果。
在一种可能的实施方式中，所述保护层还覆盖所述第一区域。
本申请实施例中，第一区域涂覆有活性物质层，第二区域未涂覆活性物质。第二区域靠近极耳边缘被保护层覆盖，且在第一方向上，保护层超出第二区域靠近极耳的边缘。为进一步提高保护层对集流体上毛刺的预防和覆盖效果，可使保护层覆盖第一区域，也就是保护层设置在集流体的第一区域和第二区域上，且超出第二区域靠近极耳的边缘；活性物质层涂覆于保护层上，与集流体的第一区域在厚度方向上的投影重合。
在一种可能的实施方式中，覆盖第一区域的所述保护层为多孔结构。
本申请实施例中，保护层覆盖集流体的第一区域和第二区域，活性物质层涂覆于保护层上。将覆盖第一区域的保护层设置成多孔结构，这样可以不影响活性物 质层与集流体之间的连接，进而保证电池正常的电化学反应。
在一种可能的实施方式中，所述保护层的厚度不大于所述活性物质层的厚度。
本申请实施例中，若保护层的厚度过厚，则会降低电池的体积能量密度。通过将保护层的厚度设置为不大于活性物质层的厚度，保护层既可以保护电池的安全，又不降低电池的体积能量密度。
在一种可能的实施方式中，在所述第一方向上，所述第二区域的尺寸为0.5-3mm。
本申请实施例中，在第一方向上，第二区域的尺寸过大会占用过多的集流体面积，造成电池能量密度下降；第二区域尺寸过小，会增加保护层与第二区域的连接难度。将第二区域在第一方向上的尺寸保持在0.5-3mm，既可以降低生产难度，又不占用较多的活性物质区域。
在一种可能的实施方式中，在第二方向上，所述集流体、所述活性物质层与所述保护层的尺寸相同，所述第二方向垂直于所述第一方向。
本申请实施例中，保护层至少覆盖第二区域靠近极耳的边缘且在第一方向上超出该边缘。在第二方向上，使集流体、活性物质层和保护层的尺寸相同，保护层可以完全覆盖集流体上的毛刺，进而提高电池的安全性能。
在一种可能的实施方式中，在第二方向上，多个所述集流体间隔设置，所述保护层在所述第二方向上连续，所述保护层在所述第二方向上的尺寸与多个所述集流体以及多个所述集流体之间的所述间隔的总尺寸相同，所述第二方向垂直于所述第一方向。
本申请实施例中，当多个集流体间隔分布组成电池的极片时，保护层在该种极片中是连续的。也就是说，保护层不仅覆盖不同集流体的第二区域靠近极耳的边缘，还覆盖在多个集流体之间的间隔处。在第二方向上，使保护层与所有集流体以及所有集流体之间的间隔的总尺寸相同，保护层可以完全覆盖集流体上的毛刺，进而提高电池的安全性能。
在一种可能的实施方式中，所述活性物质层和所述保护层设置于所述集流体相对的两个面。
本申请实施例中，使活性物质层和保护层设置于集流体相对的两个面，可 提高电池的体积能量密度。
在一种可能的实施方式中，所述保护层与所述集流体通过粘接或热力贴合连接。
本申请实施例中，通过粘接或热力贴合使保护层与集流体连接，该连接方式简单，可在生产过程中广泛应用。
在一种可能的实施方式中，所述保护层的材料为聚丙烯、聚酰胺或环氧树脂。
本申请实施例中，采用聚丙烯、聚酰胺或环氧树脂所制作的保护层，在保证保护层正常保护效果的同时，可降低生产成本，有利于在大规模生产中应用。
第二方面，提供了一种电极组件，包括上述实施例中的极片。
第三方面，提供了一种电池单体，包括上述实施例中的电极组件；壳体，具有开口，用于容纳所述电极组件；端盖，用于封闭所述开口。
第四方面，提供了一种电池，包括上述实施例中的电池单体。
第五方面，提供了一种用电设备，包括上述实施例中的电池，所述电池用于提供电能。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本申请的一些实施例，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，还可以根据附图获得其他的附图。
图1是本申请一实施例的车辆的结构示意图；
图2是本申请一实施例的电池的分解结构示意图；
图3是本申请一实施例的电池单体的示意图；
图4是本申请一实施例的极片的结构示意图；
图5是图4的左视图；
图6是本申请另一实施例的极片的结构示意图；
图7是图6的左视图；
图8是本申请另一实施例的极片的结构示意图的左视图；
图9是本申请另一实施例的极片的结构示意图；
图10是图9的左视图；
图11是本申请另一实施例的极片的结构示意图；
附图标记说明：
车辆1，电池2，电池单体3；
控制器11，马达12，箱体20，电极组件31，外壳32，电极端子33，连接构件34，泄压机构35，集流体36，保护层38；
第一箱体部201，第二箱体部202，容纳空间203，极片311，壳体321，端盖322，正电极端子331，负电极端子332，第一区域361，第二区域362，极耳363，间隔364；
活性物质层3611，主体区3612，削薄区3613，第一方向X，第二方向Y。
具体实施方式
下面将结合附图对本申请技术方案的实施例进行详细的描述。以下实施例仅用于更加清楚地说明本申请的技术方案，因此只作为示例，而不能以此来限制本申请的保护范围。
除非另有定义，本文所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同；本文中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。
在本申请实施例的描述中，技术术语“第一”“第二”等仅用于区别不同对象，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量、特定顺序或主次关系。在本申请实施例的描述中，“多个”的含义是两个以上，除非另有明确具体的限定。
在本文中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。本领域技术人员显式地和隐式地理解的是，本文所描述的实施例可以与其它实施例相结合。
在本申请实施例的描述中，术语“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如A和/或B，可以表示：单独存在A，同时存在A 和B，单独存在B这三种情况。另外，本文中字符“/”，一般表示前后关联对象是一种“或”的关系。
在本申请实施例的描述中，术语“多个”指的是两个以上(包括两个)，同理，“多组”指的是两组以上(包括两组)，“多片”指的是两片以上(包括两片)。
在本申请实施例的描述中，技术术语“中心”“纵向”“横向”“长度”“宽度”“厚度”“上”“下”“前”“后”“左”“右”“竖直”“水平”“顶”“底”“内”“外”“顺时针”“逆时针”“轴向”“径向”“周向”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请实施例和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请实施例的限制。
在本申请实施例的描述中，除非另有明确的规定和限定，技术术语“安装”“相连”“连接”“固定”等术语应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或成一体；也可以是机械连接，也可以是电连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通或两个元件的相互作用关系。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请实施例中的具体含义。
本申请中，电池单体可以包括锂金属二次电池、钠金属电池或镁金属电池等，本申请实施例对此并不限定。电池单体可呈圆柱体、扁平体或其它形状等，本申请实施例对此也不限定。电池单体一般按封装的方式分成三种：柱形电池单体、方形电池单体和软包电池单体，本申请实施例对此也不限定。以下实施例为了方便说明，以锂金属电池为例进行说明。
本申请的实施例所提到的电池是指包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块。例如，本申请中所提到的电池可以包括电池模块或电池包等。电池一般包括用于封装一个或多个电池单体的箱体。箱体可以避免液体或其他异物影响电池单体的充电或放电。
现有电池中的集流体一般为金属铜或铝，在模切极耳时，裁剪金属材质的集流体总会有毛刺产生。而产生的毛刺极有可能在后续电池组装过程或电池使用过程中刺穿隔离膜，造成电池短路，进而对电池的安全性能造成影响。现有技术中虽然通 过减薄集流体厚度以及与绝缘物质结合等方式减少模切或裁切毛刺，但还是无法避免毛刺的产生。
为了解决上述问题，本申请实施例提供了一种技术方案。在集流体的非极耳部分设置保护层，并使该保护层至少覆盖靠近极耳的非极耳部分的边缘，且超出该边缘。这样可以有效防止毛刺的产生及外露，进而提高电池的安全性能。
本申请实施例描述的极片可以为正极极片，也可以为负极极片。本申请实施例描述的极片适用于电极组件、电池单体、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装置不做特殊限制。
以下实施例为了方便说明，以用电装置为车辆为例进行说明。
图1为本申请一实施例提供的车辆1的结构示意图。如图1所示，车辆1的内部设置有电池2，电池2可以设置在车辆1的底部或头部或尾部。电池2可以用于车辆1的供电，例如，电池2可以作为车辆1的操作电源。
车辆1还可以包括控制器11和马达12，控制器11用来控制电池2为马达12供电，例如，用于车辆1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2不仅仅可以作为车辆1的操作电源，还可以作为车辆1的驱动电源，代替或部分地代替燃油或天然气为车辆1提供驱动动力。
图2为本申请一实施例提供的电池2的爆炸示意图。如图2所示，电池2包括箱体20，电池单体3，电池单体3容纳于箱体20内。
箱体20用于容纳电池单体3。箱体20可以是多种结构。在一些实施例中，箱体20可以包括第一箱体部201和第二箱体部202，第一箱体部201与第二箱体部202相互盖合，第一箱体部201和第二箱体部202共同限定出用于容纳电池单体3的容纳空间203。第二箱体部202可以是一端开口的空心结构，第一箱体部201为板状结构， 第一箱体部201盖合于第二箱体部202的开口侧，以形成具有容纳空间203的箱体20；第一箱体部201和第二箱体部202也均可以是一侧开口的空心结构，第一箱体部201的开口侧盖合于第二箱体部202的开口侧，以形成具有容纳空间203的箱体20。当然，第一箱体部201和第二箱体部202可以是多种形状，比如，圆柱体、长方体等。
为提高第一箱体部201与第二箱体部202连接后的密封性，第一箱体部201与第二箱体部202之间也可以设置密封件，比如，密封胶、密封圈等。
假设第一箱体部201盖合于第二箱体部202的顶部，第一箱体部201亦可称之为上箱盖，第二箱体部202亦可称之为下箱体。
在电池2中，电池单体3为多个。多个电池单体3之间可串联或并联或混联，混联是指多个电池单体3中既有串联又有并联。多个电池单体3之间可直接串联或并联或混联在一起，再将多个电池单体3构成的整体容纳于箱体20内；当然，也可以是多个电池单体3先串联或并联或混联组成电池模块(图中未示出)，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20内。电池模块中的多个电池单体3之间可通过汇流部件实现电连接，以实现电池模块中的多个电池单体3的并联或串联或混联。
如图3所示，为本申请一个实施例的一种电池单体3的结构示意图，电池单体3包括一个或多个电极组件31、壳体321和端盖322。壳体321和端盖322形成外壳或电池盒32。壳体321的壁以及端盖322均称为电池单体3的壁，其中对于长方体型电池单体3，壳体321的壁包括底壁和四个侧壁。壳体321根据一个或多个电极组件31组合后的形状而定，例如，壳体321可以为中空的长方体或正方体或圆柱体，且壳体321的其中一个面具有开口以便一个或多个电极组件31可以放置于壳体321内。例如，当壳体321为中空的长方体或正方体时，壳体321的其中一个平面为开口面，即该平面不具有壁体而使得壳体321内外相通。当壳体321可以为中空的圆柱体时，壳体321的端面为开口面，即该端面不具有壁体而使得壳体321内外相通。端盖322覆盖开口并且与壳体321连接，以形成放置电极组件31的封闭的腔体。壳体321内填充有电解质，例如电解液。
该电池单体3还可以包括两个电极端子33，两个电极端子33可以设置在端盖322上。端盖322通常是平板形状，两个电极端子33固定在端盖322的平板面上，两个电极端子33分别为正电极端子331和负电极端子332。每个电极端子33各对应设 置一个连接构件34，或者也可以称为集流构件34，其位于端盖322与电极组件31之间，用于将电极组件31和电极端子33实现电连接。
在该电池单体3中，根据实际使用需求，电极组件31可设置为单个，或多个，如图3所示，电池单体3内设置有4个独立的电极组件31。
电池单体3上还可设置泄压机构35。泄压机构35用于电池单体3的内部压力或温度达到阈值时致动以泄放内部压力或温度。
泄压机构35可以为各种可能的泄压结构，本申请实施例对此并不限定。例如，泄压机构35可以为温敏泄压机构，温敏泄压机构被配置为在设有泄压机构35的电池单体3的内部温度达到阈值时能够熔化；和/或，泄压机构35可以为压敏泄压机构，压敏泄压机构被配置为在设有泄压机构35的电池单体3的内部气压达到阈值时能够破裂。
图4是本申请一实施例的极片的结构示意图。该极片311包括集流体36，集流体36包括沿第一方向X依次设置的第一区域361、第二区域362和极耳363，第一区域361涂覆有活性物质层3611，第二区域362未涂覆有活性物质层3611；保护层38，保护层38至少覆盖第二区域362靠近极耳363的边缘，且在第一方向X上超出第二区域362靠近极耳363的边缘。
本申请实施例中，集流体36是指汇集电流的部件。在电池2中，主要是指金属箔，如铜箔、铝箔等。集流体36的功能是将电池2活性物质新产生的电流汇集起来以便形成较大的电流对外输出，因此集流体36一般采用内阻应尽可能小的金属材料。
本申请实施例中，活性物质层3611是指在电池2中，能够参与成流反应的物质。成流反应就是氧化和还原反应，氧化反应是指失去电子的化学反应；还原反应在指得到电子的化学反应。活性物质层3611参与成流反应，即一个电极上的活性物质失去电子的同时，另一个电极上的活性物质同时得到电子，在电子的失去和得到过程中，电子产生流动，也就是电流。
上述方案中，集流体36包括涂覆有活性物质的第一区域361、未涂覆活性物质的第二区域362和极耳363。在未涂覆活性物质的第二区域362上设置保护层38，其中，保护层38至少覆盖第二区域362的边缘部分且超出该边缘。通过设置保护层38，并使保护层38覆盖且超出第二区域362靠近极耳363的边缘部分，可以在对集流体36加工时作用到保护层38上，防止毛刺的产生，或者是直接将集流体36的边缘上的毛 刺覆盖住，防止毛刺外露，避免因毛刺刺穿隔离膜而导致的电池2短路，进而提高电池2的安全性能。
可选地，保护层38覆盖极耳363的部分区域。
本申请实施例中，毛刺是指金属材质的集流体38表面出现的余屑和极细小的纤维，毛刺越多，隔离膜被刺穿的风险就越大，电池2的安全系数就越低。
上述方案中，集流体36的第二区域362上的毛刺方向不定，为了全面防止毛刺外露，必须要使保护层38超出第二区域362靠近极耳363的边缘。而第二区域362和极耳363是相连的，超过第二区域362靠近363的边缘，即保护层38肯定要覆盖部分极耳363，但不能覆盖全部极耳363。通过将保护层38的位置限定为覆盖极耳363的部分区域，即保护层38不覆盖全部极耳363，在保证了电池2安全的同时，也保证了极耳363正常的过流能力和焊接能力，从而保证了电池2的正常功能。
图5是图4的左视图。如图5所示，保护层38完全覆盖第二区域362。
本申请实施例中，集流体36由第一区域361、第二区域362和极耳363组成。第一区域361上涂覆有活性物质层3611，第二区域362上未涂覆有活性物质层3611。保护层38设置在未涂覆活性物质层3611的第二区域362上。保护层38至少覆盖第二区域362靠近极耳363的边缘，也就是保护层38可以覆盖部分第二区域362，或，覆盖全部第二区域362。
上述方案中，使保护层38完全覆盖第二区域362，可以提高防止毛刺产生或外露的保护效果，进一步提高保护层38保护电池2安全性能的效果。
可选地，保护层38在第一区域361和第二区域362的连接处与活性物质层3611接壤。
集流体36的第一区域361和第二区域362是相连的，第二区域362全部被保护层38覆盖，第一区域361上被活性物质层3611全部涂覆，即，保护层361和活性物质层3611二者相接但不相交。
上述方案中，使保护层38和活性物质层3611在第一区域361和第二区域362的连接处接壤，即保证了保护层361完全覆盖第二区域362，但不占用涂覆活性物质层3611的第一区域361面积。
可选地，保护层38为无孔结构。
为了全方位预防毛刺的产生及外露，使保护层38完全覆盖第二区域361且 超出第二区域362靠近极耳363的边缘。第二区域362上是未涂覆活性物质层3611，因此，第二区域362上的保护层38不能有离子或电子的迁移。
上述方案中，通过将完全覆盖第二区域362且超出第二区域362靠近极耳363的边缘的保护层38的结构设置为无孔结构，可以增加保护层38的密闭和保护效果。
图6是本申请另一实施例的极片的结构示意图，图7是图6的左视图。如图6和图7所示，活性物质层3611包括沿第一方向X设置的主体区3612和削薄区3613，削薄区3613的厚度小于主体区3612的厚度，保护层38还覆盖削薄区3613。
本申请实施例中，削薄区3613是在极片311的加工过程中，通过将活性物质层3611的边缘削薄所产生的。削薄区3613可以避免集流体36的涂覆活性材料层3611的边缘处产生厚边、鼓包等问题。
上述方案中，一方面，在活性物质层3611上设置削薄区3613，可避免活性物质层3611产生厚边、鼓包等问题，进而提高极片311的质量。另一方面，在实际加工过程中，使保护层38在第一区域361和第二区域362的连接处与活性物质层3611正好接壤有难度。使保护层38部分或全部覆盖削薄区3613，即保护层38与活性物质层3611有部分重合，可降低生产过程中设置保护层38的加工难度。
可选地，削薄区3613的尺寸不超过10mm。
为避免极片311产生厚边、鼓边等问题，在第一区域361靠近第二区域362的一侧边缘处设置削薄区3613，将此处的活性物质层3611削薄。若削薄区3613的长度过长，也就是活性物质的总体质量降低，则会降低电池2的能量密度。
本申请实施例中，电池2的能量密度是指对于给定的电化学储能装置，所能充入的能量与储能介质的质量或体积之比。所能充入的能量与储能介质的质量的比为质量能量密度，单位为瓦·时/千克；所能充入的能量与储能介质的体积的比为体积能量密度，单位为瓦·时/升，储能介质即活性物质。
上述方案中，在第一方向X上，使削薄区3613的尺寸不超过10mm，既可以保证削薄区3613能够预防极片311产生厚边、鼓边等问题的功能，也可以不降低电池2的能量密度。
可选地，覆盖削薄区3613的保护层38为微孔结构。
微孔是指覆盖削薄区3613处的保护层38上的孔为微孔。本申请实施例中，微孔是孔径小于2nm的孔，即覆盖削薄区3613处的保护层38上存在孔径小于2nm的 孔。
本申请实施例中，削薄区3613是将此处的活性物质层3611削薄，但其还是有活性物质存在的。通过将覆盖削薄区3613的保护层38设置为有微孔结构，可以保证削薄区3613维持正常的电化学反应和金属离子、电池的迁移。
可选地，覆盖削薄区3613的保护层38的厚度不超过主体区3612与削薄区3613的厚度差。
如前所述，若保护层38设置面积过大或过厚，则会降低电池2的体积能量密度。因此设置在削薄区3613处的保护层38既要部分覆盖或全部覆盖削薄区3613，又不能超过削薄区3613靠近第一区域361的边缘。
上述方案中，使覆盖削薄区3613的保护层38的厚度不超过主体区3612与削薄区3613的厚度差，即保护层38覆盖削薄区3613但不超过削薄区3613靠近第一区域361的边缘。这样可以不降低电池的体积能量密度。
图8是本申请另一实施例的极片的结构示意图的左视图。如图8所示，未被保护层38覆盖的第二区域362的尺寸D1，与第二区域362的尺寸的比值不超过1:6。
如前所述，保护层38只要覆盖第二区域362靠近极耳363的边缘且超过该边缘即可，也就是保护层38可以全部覆盖第二区域3612，也可以部分覆盖第二区域362。当保护层38部分覆盖第二区域362时，可降低保护层38的生产成本。但要合理设置未被保护层38覆盖的第二区域362的尺寸D1，因为第二区域362上D1处未涂覆活性物质层3611，也未设置保护层38，该区域是直接裸露的集流体36。一方面，裸露的集流体36正对着另一极片311的活性物质，隔离膜若发生皱褶，过长裸露的集流体36会导致该部分裸露的集流体36直接与另一极片搭接，进而有短路风险；另一方面，若未被保护层38覆盖的第二区域362尺寸D1过大，则被保护层38覆盖的第二区域362的尺寸就会变小，也就是保护层38与第二区域362的连接区域较小，这将导致保护层38与集流体36连接不牢，降低保护层38对集流体36的保护效果。
上述方案中，在第一方向X上，将未被保护层38覆盖的第二区域362的尺寸D1与第二区域362的尺寸的比控制在1：6内。这样一方面可以降低保护膜38的生产成本，另一方面可以加强保护层38与集流体36的连接效果。
图9是本申请另一实施例的极片的结构示意图，图10是图9的左视图。如图9和图10所示，可选地，保护层38还覆盖第一区域361。
第一区域361涂覆有活性物质层3611，第二区域361未涂覆活性物质。第二区域361靠近极耳363的边缘被保护层38覆盖，且在第一方向X上，保护层38超出第二区域靠近极耳363的边缘。为进一步提高保护层38对集流体36上毛刺的预防和覆盖效果，可以使保护层38也覆盖第一区域361。
上述方案中，使保护层38也覆盖第一区域361，即保护层38同时设置在集流体36的第一区域361和第二区域362上，且超出第二区域362靠近极耳363的边缘。活性物质层3611涂覆于保护层38上，保护层38与集流体36直接连接，且活性物质层3611与厚度方向上与第一区域361重合。
可选地，覆盖第一区域361的保护层38为多孔结构。
保护层38直接与集流体36连接，并覆盖集流体36的第一区域361和第二区域362。活性物质层3611涂覆于保护层38上。为了保证活性物质层3611与保护层38的正常连接，需将覆盖第一区域361处的保护层38设置为多孔结构。
上述方案中，将覆盖第一区域361的保护层38设置成多孔结构，这样可以不影响活性物质层3611与集流体36之间的连接，进而保证电池2正常的电化学反应。
可选地，保护层38的厚度不大于活性物质层3611的厚度。
在活性物质相同的情况下，相对于有较薄的保护层38的电池2，有保护层38的厚度较厚的电池的体积能量密度会变低。
上述方案中，通过将保护层38的厚度设置为不大于活性物质层3611的厚度，保护层38既可以保护电池2的安全，又不降低电池2的体积能量密度。
可选地，在第一方向X上，第二区域362的尺寸为0.5-3mm。
第二区域362上未涂覆有活性材料，第二区域362主要用来与保护层38连接。在第一方向X上，若第二区域362的尺寸过小，保护层38与第二区域362的难度就会增加；若第二区域362的尺寸过大，第二区域362就会占用过多的集流体36面积，造成电池2能量密度下降。
上述方案中，将第二区域362在第一方向X上的尺寸保持在0.5-3mm，既可以提高保护层38与集流体36之间的连接，又不占用较多的活性物质区域。
可选地，如图9所示，在第二方向Y上，集流体36、活性物质层3611与保护层38的尺寸相同，第二方向Y垂直于第一方向X。
在极片311实际加工过程中，会沿集流体36的某个边缘对集流体36的某 个部分进行模切。在本申请实施例中，即沿第二区域362靠近极耳363的边缘模切，该模切区可以是只模切极耳363的宽极耳区，与模切区相连的集流体36其他区域不需要模切。在模切前，在集流体36的第二区域362上设置保护层38；模切非极耳时，模切在不覆盖集流体36的保护层38上；模切极耳363时，模切在有保护层38覆盖的集流体36上。这样就可以预防因模切产生的毛刺产生或外露，进而提高电池2的安全性能。为了进一步提高保护层38对电池2的保护效果，应使集流体36上需要模切的区域都设置保护层38。
也就是说，本申请对保护层38在极片311加工过程中设置的时间无特别限制。保护层38可以在集流体36模切前设置，在模切集流体36时直接作用到保护层36；或者在集流体36模切后设置，在实际生产过程中，可根据生产需要进行变化。
上述方案中，保护层38至少覆盖第二区域362靠近极耳363的边缘且在第一方向X上超出该边缘。在第二方向Y上，使集流体36、活性物质层3611和保护层38的尺寸相同，保护层38可以完全覆盖集流体36上的毛刺，进而提高对电池2安全性能的保护效果。
图11是本申请另一实施例的极片的结构示意图。如图11所示，可选地，在第二方向Y上，多个集流体36间隔设置，保护层38在第二方向Y上连续，保护层38在第二方向Y上的尺寸与多个集流体36以及多个集流体36之间的间隔364的总尺寸相同，第二方向Y垂直于第一方向X。
当多个集流体36间隔分布组成电池单体3的极片311时，保护层38在该种极片311中是连续、不间断的分布的。也就是说，保护层38不仅覆盖不同集流体36的第二区域362靠近极耳363的边缘，还覆盖在多个集流体36之间的间隔364处。而没有集流体36设置，也就是没有设置活性物质层3611的间隔364处可以作为层叠电池单体3的极片311的裁切处，这样可以避免裁切边产生毛刺；也可以作为卷绕式电池单体3的拐角，进而可以避免拐角处掉粉以产生颗粒从而破坏电池单体3的安全，或是避免拐角处的析锂风险。
上述方案中，在第二方向Y上，使保护层38与所有集流体36以及所有集流体36之间的间隔341的总尺寸相同，这样保护层38可以完全覆盖集流体36上的毛刺，进而提高电池2的安全性能。
可选地，活性物质层3611和保护层38设置于集流体36相对的两个面。
上述方案中，使活性物质层3611设置于集流体36相对的两个面，可提高电池2的能量密度；使保护层38设置于集流体36相对的两个面，可进一步提高电池2的安全性能。
可选地，保护层38与集流体36通过粘接或热力贴合连接。
上述方案中，通过粘接或热力贴合使保护层38与集流体36连接，该连接方式简单，可在生产过程中广泛应用。
可选地，保护层38的材料为聚丙烯、聚酰胺或环氧树脂。
聚丙烯是丙烯通过加聚反应而成，一种性能优良的热塑性合成树脂的聚合物。本申请实施例中，使用聚丙烯为原材料制备的保护层38能耐多种有机溶剂的腐蚀，并且具有耐化学性、耐热性、电绝缘性、高强度机械性能和良好的高耐磨加工性能等。同样，使用聚酰胺或环氧树脂为原材料制备的保护层38也拥有较好的性能。并且这三者价格合适，有利于应用在大规模生产中。
上述方案中，采用聚丙烯、聚酰胺或环氧树脂所制作的保护层38，在保证保护层38正常保护电池2安全的同时，可降低生产成本，有利于在大规模生产中应用。
本申请实施例还提供了一种电极组件31，包括前述实施例中的极片311。
本申请实施例还提供了一种电池单体3，包括前述实施例中的电池组件31；壳体321，具有开口，用于容纳电极组件31；端盖322，用于封闭开口。
本申请实施例还提供了一种电池2，包括前述实施例中的电池单体3。
本申请实施例还提供了一种用电设备，包括前述实施例中的电池2，电池2用于提供电能。
对比例1
对比例1，一种正极极片，集流体相对的两个面都涂覆活性物质层，模切后除极耳外，其模切边缘保留1.5mm的集流体。
实施例1
实施例1，一种正极极片，活性物质层和保护层设置于集流体相对的两个面。除极耳外，第二区域模切边缘留有宽度1.5mm的区域被保护层覆盖，且保护层超出第二区域靠近极耳的边缘1.5mm，保护层的厚度与同侧活性物质层厚度相同。
实施例2
实施例2，一种正极极片，活性物质层和保护层设置于集流体相对的两个面。 除极耳外，第二区域模切边缘留有宽度1.5mm的区域被保护层覆盖，保护层超出第二区域靠近极耳的边缘1.5mm，且5mm的削薄区也被保护层覆盖，保护层的厚度与同侧活性物质层厚度相同。
实施例3
实施例3，一种正极极片，活性物质层和保护层设置于集流体相对的两个面。除极耳外，其余集流体被保护层覆盖，保护层局部多孔区域上覆盖活性物质，保护层超出第二区域靠近极耳的边缘1.5mm，保护层的厚度与同侧活性物质层厚度相同。
Hi-pot测试
将上述对比例和实施例的正极极片、负极极片和隔离膜组装成电池，在这些电池中，将电池的结构设计成负极极片的活性物质层在宽度上的边缘高于对应正极模切集流体边缘的结构。25℃下，对这些电池进行Hi-pot测试以检测是否有毛刺刺穿隔膜的情况与电池着火情况，测试结果如表1。
表1
组别 毛刺刺穿隔膜概率 着火失效概率
对比例1 75％ 98％
实施例1 1％ 1％
实施例2 1％ 1％
实施例3 1％ 1％
通过上述实施电池性能测试结果可知，本申请实施例提供的极片能够有效降低毛刺刺穿隔膜概率和电池着火概率，进而提高了电池的安全性能。
虽然已经参考优选实施例对本申请进行了描述，但在不脱离本申请的范围的情况下，可以对其进行各种改进并且可以用等效物替换其中的部件。尤其是，只要不存在结构冲突，各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例，而是包括落入权利要求的范围内的所有技术方案。

Claims (24)

  1. 一种极片(311)，其特征在于，包括：
    集流体(36)，所述集流体(36)包括沿第一方向(X)依次设置的第一区域(361)、第二区域(362)和极耳(363)，所述第一区域(361)涂覆有活性物质层(3611)，所述第二区域(362)未涂覆有活性物质层(3611)；
    保护层(38)，所述保护层(38)至少覆盖所述第二区域(362)靠近所述极耳(363)的边缘，且在所述第一方向(X)上超出所述第二区域(362)靠近所述极耳(363)的边缘。
  2. 根据权利要求1所述的极片(311)，其特征在于，所述保护层(38)覆盖所述极耳(363)的部分区域。
  3. 根据权利要求1或2所述的极片(311)，其特征在于，所述保护层(38)完全覆盖所述第二区域(362)。
  4. 根据权利要求3所述的极片(311)，其特征在于，所述保护层(38)在所述第一区域(361)和所述第二区域(362)的连接处与所述活性物质层(3611)接壤。
  5. 根据权利要求3或4所述的极片(311)，其特征在于，所述保护层(38)为无孔结构。
  6. 根据权利要求1或2所述的极片(311)，其特征在于，所述活性物质层(3611)包括沿所述第一方向(X)设置的主体区(3612)和削薄区(3613)，所述削薄区(3613)的厚度小于所述主体区(3612)的厚度，所述保护层(38)还覆盖所述削薄区(3613)。
  7. 根据权利要求6所述的极片(311)，其特征在于，在所述第一方向(X)上，所述削薄区(3613)的尺寸不超过10mm。
  8. 根据权利要求6或7所述的极片(311)，其特征在于，覆盖所述削薄区(3613)的所述保护层(38)为微孔结构。
  9. 根据权利要求6至8中任一项所述的极片(311)，其特征在于，覆盖所述削薄区(3613)的所述保护层(38)的厚度不超过所述主体区(3612)与所述削薄区(3613)的厚度差。
  10. 根据权利要求1或2所述的极片(311)，其特征在于，在所述第一方向(X)上，未被所述保护层(38)覆盖的所述第二区域(362)的尺寸，与所述第二区域(362)的尺寸的比值不超过1:6。
  11. 根据权利要求3所述的极片(311)，其特征在于，所述保护层(38)还覆盖所述第一区域(361)。
  12. 根据权利要求11所述的极片(311)，其特征在于，覆盖所述第一区域(361)的所述保护层(38)为多孔结构。
  13. 根据权利要求1至12中任一项所述的极片(311)，其特征在于，所述保护层(38)的厚度不大于所述活性物质层(3611)的厚度。
  14. 根据权利要求1至13中任一项所述的极片(311)，其特征在于，在所述第一方向(X)上，所述第二区域(362)的尺寸为0.5-3mm。
  15. 根据权利要求1至14中任一项所述的极片(311)，其特征在于，在所述第一方向(X)上，所述保护层(38)超出所述第二区域(362)靠近所述极耳(363)的边缘0.5-10mm。
  16. 根据权利要求1至15中任一项所述的极片(311)，其特征在于，在第二方向(Y)上，所述集流体(36)、所述活性物质层(3611)与所述保护层(38)的尺寸相同，所述第二方向(Y)垂直于所述第一方向(X)。
  17. 根据权利要求1至15中任一项所述的极片(311)，其特征在于，在第二方向(Y)上，多个所述集流体(36)间隔设置，所述保护层(38)在所述第二方向(Y)上连续，所述保护层(38)在所述第二方向(Y)上的尺寸与多个所述集流体(36)以及多个所述集流体(36)之间的所述间隔(364)的总尺寸相同，所述第二方向(Y)垂直于所述第一方向(X)。
  18. 根据权利要求1至17中任一项所述的极片(311)，其特征在于，所述活性物质层(3611)和所述保护层(38)设置于所述集流体(36)相对的两个面。
  19. 根据权利要求1至18中任一项所述的极片(311)，其特征在于，所述保护层(38)与所述集流体(36)通过粘接或热力贴合连接。
  20. 根据权利要求1至19中任一项所述的极片(311)，其特征在于，所述保护层(38)的材料为聚丙烯、聚酰胺或环氧树脂。
  21. 一种电极组件(31)，其特征在于，包括：
    如权利要求1至20中任一项所述的极片(311)。
  22. 一种电池单体(3)，其特征在于，包括：
    如权利要求21所述的电极组件(31)；
    壳体(321)，具有开口，用于容纳所述电极组件(31)；以及
    端盖(322)，用于封闭所述开口。
  23. 一种电池(2)，其特征在于，包括
    多个如权利要求22中所述的电池单体(3)。
  24. 一种用电设备，其特征在于，包括：
    如权利要求23所述的电池(2)，所述电池(2)用于提供电能。
PCT/CN2022/101919 2022-06-28 2022-06-28 极片、电极组件、电池单体、电池和用电设备 Ceased WO2024000163A1 (zh)

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EP22948285.6A EP4510205A4 (en) 2022-06-28 2022-06-28 ELECTRODE SHEET, ELECTRODE ASSEMBLY, BATTERY CELL, BATTERY AND ELECTRICAL DEVICE
CN202280067390.7A CN118043988A (zh) 2022-06-28 2022-06-28 极片、电极组件、电池单体、电池和用电设备
US18/947,581 US20250070276A1 (en) 2022-06-28 2024-11-14 Electrode plate, electrode assembly, battery cell, battery, and electric device

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