CN112993473B - A battery, a battery module, a battery pack and an electric vehicle - Google Patents

Abstract

The application provides a battery, a battery module and a battery pack. The battery includes a housing, the housing defines a housing cavity, and a plurality of battery core components are arranged in the housing cavity; each battery core component includes a polymer film bag, and is packaged in the polymer film bag The pole core and the first electrode and the second electrode that are electrically connected to the pole core and extend out of the polymer film bag for drawing current; the battery components are connected in series, and one of the two series battery components The first electrode of the cell assembly is plugged with the second electrode of another cell assembly. The battery provided by the present application has high battery capacity, fewer assembly processes, smaller internal resistance, and more stable battery performance.

Description

A battery, a battery module, a battery pack and an electric vehicle

technical field

The invention belongs to the field of batteries, and in particular relates to a battery, a battery module, a battery pack and an electric vehicle.

Background technique

With the continuous popularization of new energy vehicles, the requirements for the use of power batteries in new energy vehicles are becoming higher and higher. In particular, as users continue to increase the mileage requirements of new energy vehicles, the overall capacity of battery packs used in new energy vehicles needs to be continuously improved; at the same time, during the use of power battery packs, the internal resistance caused Internal friction and heating are required to be minimized.

Generally speaking, there is only one bare cell or multiple parallel-connected bare cells inside the battery casing, and the voltage of the entire battery cannot be increased by including a single bare cell or multiple parallel-connected cells. For example, the voltage of lithium titanate battery is 2.4 volts; the voltage of lithium iron phosphate battery is 3 .2 volts; the voltage of ternary battery is 3 .7 volts; the voltage of multi-polymer battery is 4 .3 volts . Therefore, when high voltage (high capacity) is required, a large number of batteries are connected in series to form a battery pack, and then the battery pack is assembled into a power battery pack; two adjacent batteries need to be powered through external power connectors. . This leads to more battery installation structures, which not only increases the cost, but also increases the overall weight; at the same time, the installation structure takes up more space inside the package, resulting in a reduction in the overall capacity of the power battery pack. The more batteries are arranged side by side, the more space is wasted . In addition, since multiple external power connectors need to be installed for power connection, the internal resistance increases, which increases the internal friction and heat generation of the power battery pack during use.

In order to solve the above technical problems, the related art provides an internal series battery pack, which includes a battery case and a plurality of pole groups arranged in a battery case, the plurality of pole groups are connected in series, and two adjacent pole groups separated by partitions. However, in this scheme, the partition is a metal partition, the housing is a plastic casing, and a sealing ring is provided between the metal partition and the plastic casing to realize how to seal the connection between the metal partition and the plastic partition to ensure The two chambers are completely isolated, but the sealing ring is soaked in the electrolyte for a long time and is prone to aging and failure. There is a risk of the electrolyte between the chambers communicating with each other, and the electrolyte is likely to occur due to the high potential difference. Decomposition, causing the battery to fail.

In addition, since the material of the positive tab is aluminum and the material of the negative tab is copper, how to achieve a more effective connection between the two tabs with different metal materials and the metal separator has become a problem that has not been considered in this solution.

Contents of the invention

The content of the present application aims to solve at least one of the technical problems existing in the prior art.

To this end, in the first aspect of the present application, a battery is provided, including: a casing and a plurality of cell assemblies, the casing defines an accommodation cavity, and the plurality of cell assemblies are located in the accommodation cavity wherein, a plurality of the cell assemblies are connected in series; the cell assembly includes a polymer film bag, a pole core encapsulated in the polymer film bag, and a polymer film electrically connected to the pole core and extending out of the polymer film The first electrode and the second electrode used to lead out the current outside the bag; the first electrode of one cell assembly in at least two series-connected cell assemblies is plugged with the second electrode of the other cell assembly.

In some embodiments of the present application, the first electrode of one cell assembly of the two series-connected cell assemblies is detachably plugged into the second electrode of the other cell assembly.

In some embodiments of the present application, the first electrode includes a first current drawing part and a first connecting part electrically connected to the first current drawing part, and the first current drawing part includes a first end and a first Two ends, the first end of the first current drawing part is connected to the pole core, the second end of the first current drawing part extends out of the polymer film bag and is connected to the first connecting part ;

The second electrode includes a second current drawing part and a second connection part electrically connected to the second current drawing part, the second current drawing part includes a first end and a second end, and the second current drawing part The first end of the part is connected to the pole core, and the second end of the second current lead-out part extends out of the polymer film bag and is connected to the second connection part;

The first connection portion of one of the two series-connected cell assemblies is inserted into the second connection portion of the other cell assembly.

In some embodiments of the present application, the first connecting part is provided with a first socket, and the second connecting part is provided with a first contact pin matched with the first socket. The cooperation of a pin and the first socket realizes series connection.

In some embodiments of the present application, the first electrode includes a first current extraction part, the first current extraction part includes a first end and a second end, and the first end of the first current extraction part is connected to the The pole core is connected, and the second end of the first current lead-out part extends out of the polymer film bag and is provided with a plug-in part;

The second electrode includes a second current lead-out part, the second current lead-out part includes a first end and a second end, the first end of the second current lead-out part is connected to the pole core, and the second The second end of the current lead-out part extends out of the polymer film bag and is provided with an insert that cooperates with the plug-in part;

The plug-in portion of the first electrode of one cell assembly in the two series-connected cell assemblies is inserted into the plug-in portion of the second electrode of the other cell assembly.

In some embodiments of the present application, the plug-in part is at least two first conductive sheets provided at the second end of the first current drawing part, and the plug-in part is provided at the second current drawing part. At least one second conductive sheet at the second end; the second conductive sheet of one of the two battery cell assemblies in series is inserted between the two first conductive sheets of the other battery assembly.

In some embodiments of the present application, the first conductive sheet is in interference fit with the two second conductive sheets.

In some embodiments of the present application, the first electrode further includes a first fixing part sleeved on the first current drawing part, and the first fixing part includes an inner surface facing the pole core, a back surface Facing the outer surface of the pole core and the circumferential surface connecting the inner surface and the outer surface facing the housing, the polymer film bag is sealed and connected to the circumferential surface of the first fixing part;

The second electrode also includes a second fixing portion sleeved on the second current drawing portion, the second fixing portion includes an inner surface facing the pole core, an outer surface facing away from the pole core, and The circumferential surface facing the casing connecting the inner surface and the outer surface, the polymer film bag is sealingly connected with the circumferential surface of the second fixing part.

In some embodiments of the present application, the plug-in part is a second socket provided on the first fixed part, the insert is a second pin provided on the second fixed part, and two electric cores The components are connected in series through the cooperation of the second pin and the second socket.

In some embodiments of the present application, the first fixing part is provided with a card slot, and the second fixing part is provided with a card matching with the card slot, or, the first fixing part is provided with There is a block, and the second fixing part is provided with a slot for matching with the block;

The first fixing portion of one cell assembly and the second fixing portion of the other cell assembly of the two series-connected cell assemblies are engaged with the clamping block through the engaging slot.

In some embodiments of the present application, the locking groove is located on the outer surface of the first fixing part, and the locking block is located on the outer surface of the second fixing part.

In some embodiments of the present application, the block is barb-shaped.

In some embodiments of the present application, the first fixing part and/or the second fixing part are insulating parts.

In some embodiments of the present application, the material of the first fixing part and/or the second fixing part includes polypropylene or polyethylene.

In some embodiments of the present application, the first current drawing part is integrally formed with the first fixing part; and/or the second current drawing part is integrally formed with the second fixing part.

In some embodiments of the present application, the battery further includes a liquid injection port, the liquid injection port is disposed on the first fixing portion and/or the second fixing portion, and the liquid injection port is in a sealed state.

In some embodiments of the present application, the pole core includes a receiving part, and at least part of the first electrode and/or at least part of the second electrode are respectively located in the receiving part.

In some embodiments of the present application, the pole core is "T"-shaped, and the two lower corners of the "T"-shaped pole core are respectively used to accommodate at least part of the first electrode and at least part of the second electrode.

In some embodiments of the present application, the pole core is provided with a first pole lug and a second pole lug for drawing current, and the first pole lug and the second pole lug are obtained from the Two lower corners protrude, one end of the first electrode located in the polymer film bag is connected to the first tab; one end of the second electrode located in the polymer film bag is connected to the second tab.

In some embodiments of the present application, a plurality of the cell assemblies are arranged along the first direction, the first electrode and the second electrode are respectively located at both ends of the cell assembly along the first direction, and two adjacent cell assemblies The first electrode of one cell assembly is plugged with the second electrode of the other cell assembly.

In some embodiments of the present application, the length direction of the cell assembly is along the first direction.

In some embodiments of the present application, the length of the battery is 400-2500 mm.

In some embodiments of the present application, one of the first electrode and the second electrode is an aluminum electrode, and the other is a copper electrode.

In some embodiments of the present application, the battery further includes a liquid injection port, the liquid injection port is located on the polymer film bag, and the liquid injection port is in a sealed state.

In some embodiments of the present application, the housing is a sealed housing.

In some embodiments of the present application, the polymer film bag includes a polypropylene bag or a polyethylene bag.

In a second aspect of the present application, a battery module is provided, including the battery in any one of the above implementation manners.

In a third aspect of the present application, a battery pack is provided, including the battery in any one of the above implementation manners or the above battery module.

In a third aspect of the present application, an electric vehicle is provided, including the above-mentioned battery pack.

Compared with the prior art, the present application has the following beneficial effects: firstly, connecting multiple pole cores in series in the battery case can increase the capacity of the battery, and at the same time, a single case is used to package multiple pole cores, reducing the need for a traditional pole core. The number of cores corresponds to the number of shells, which saves cost and weight; secondly, the pole cores are packaged in polymer film bags, and the adjacent two pole cores are isolated, so that the electrolyte will no longer be between adjacent polymer film bags Flow, will not affect each other, and will not be decomposed due to excessive potential difference, ensuring the safety and service life of the battery. Thirdly, this application uses a polymer film bag to seal the pole core, which can reduce the weight and cost of the entire battery compared to the common aluminum-plastic film; in addition, the pole cores are connected in series by plugging, which not only avoids the need for two different metal materials Soldering difficult problems, while reducing spot welding connection points, reducing internal resistance, improving battery performance and reducing costs.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Description of drawings

Fig. 1 is the schematic diagram of the battery structure provided by the present application;

FIG. 2 is a schematic structural diagram of a series connection of multiple battery cell assemblies inside the casing provided by the present application;

Fig. 3 is a structural schematic diagram of the polymer film bag, pole core and second electrode assembly of a cell assembly provided by the present application;

Fig. 4 is a structural schematic diagram of the polymer film bag, pole core and first electrode assembly of a cell assembly provided by the present application;

Fig. 5 is the schematic diagram of the enlarged structure of part B in Fig. 4;

Figure 6 is a top view of the cell assembly provided by the present application;

Figure 7 is a cross-sectional view of the cell assembly provided by the present application;

Figure 8 is an exploded view of the battery provided by this application;

FIG. 9 is a schematic structural diagram of a second electrode provided by the present application;

FIG. 10 is a schematic structural diagram of the first electrode provided by the present application;

Fig. 11 is a schematic structural view of opening a liquid injection port on the first fixing part provided by the present application;

Fig. 12 is a schematic structural diagram of yet another first electrode provided by the present application;

FIG. 13 is a schematic structural diagram of a second electrode provided in the present application.

reference sign

100. battery;

101, the shell body; 1011, the second cover plate; 1012, the first cover plate;

103. Cell assembly; 1031. Pole core; 1032. Second tab; 1033. First tab; 1034. Accommodating part

104, polymer film bag; 1041, opening; 1042, hot melting zone;

105. The second electrode; 1051. The second current lead-out part; 1052. The card slot; 1053. The second fixing part; 1054. The second pin;

106. First electrode; 1061. First current drawing part; 1062. Block; 1063. First fixing part; 1065. Second jack;

107. Liquid injection port; 1071. Blocking piece.

Detailed ways

Embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary, are only for explaining the present application, and should not be construed as limiting the present application.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Rear", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Axial", "Radial", "Circumferential" The orientation or positional relationship indicated by etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the application and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, use a specific Azimuth configuration and operation, therefore, should not be construed as limiting the application.

As shown in FIGS. 1-11 , the present application provides a battery 100 , including a casing, the casing defines a housing chamber, and a plurality of battery cell assemblies 103 are arranged in the housing chamber; each battery cell assembly 103 Comprising a polymer film bag 104, a pole core 1031 encapsulated in the polymer film bag 104, and a first electrode 106 and a second electrode 106 electrically connected to the pole core 1031 and extending out of the polymer film bag 104 for drawing current. The electrodes 105 and the cell assemblies 103 are connected in series, and the first electrode 106 of one cell assembly 103 of the two series cell assemblies 103 is plugged with the second electrode 105 of the other cell assembly 103 .

The pole core mentioned in this application is a pole core commonly used in the field of power batteries, and the battery cell assembly 103 is an integral part of the battery 100 shell, and cannot be understood as the battery 100 itself; the pole core can be a pole core formed by winding The core 1031 can also be a pole core 1031 made of laminated sheets; generally, the pole core 1031 includes at least a positive electrode sheet, a separator, a negative electrode sheet and an electrolyte, and the pole core 1031 generally refers to an incompletely sealed component. Therefore, the battery 100 mentioned in this application is a single battery, and it cannot be simply understood as a battery module or a battery pack because it includes a plurality of pole cores 1031 .

In this application, there may be one or more pole cores packaged in the polymer film bag of each cell assembly, and this application is not limited. Generally, if there are multiple pole cores, multiple pole cores are connected in parallel.

In this application, the polymer film bag 104 encapsulates the pole core 1031 so that the pole cores 1031 in series will not interfere with each other.

The polymer film bag 104 is used to isolate the pole cores 1031 connected in series. Compared with the background technology, the separator is used to isolate the pole cores 1031. The weight of the polymer film bag 104 is lighter, and the space inside the battery 100 is occupied. Less, the capacity of the battery 100 is higher.

In addition, the polymer film bag 104 is also easier to achieve sealing, the pole core 1031 is put into the polymer film bag 104, and the pole core 1031 can be sealed in the polymer film bag 104 by hot-melt sealing, as shown in Figure 8 As shown, the hot melting zone 1042 is formed by putting the pole core 1031 into the polymer film bag 104 and then sealing it. This sealing method does not need to use other sealing components, such as sealing rings. The sealing method is very simple and the operability is stronger. , The sealing stability is also higher.

In this application, when a plurality of cell assemblies 103 are connected in series, different cell assemblies 103 will have different voltages, which will cause the shell, such as an aluminum shell, to have a local potential too low, which will easily lead to lithium ions being embedded in the shell Inside the body, a lithium aluminum alloy is formed to corrode the aluminum shell, so in this embodiment, each pole core 1031 is individually packaged in a polymer film bag 104 to isolate the contact between the electrolyte and the shell.

In the prior art, in order to realize the series connection between the pole cores 1031, it is usually necessary to directly weld one positive tab of the two pole cores 1031 in series with the negative tab of the other pole core 1031. However, due to the difference between the positive tab and the negative tab The materials are different. The material of the positive tab is metal aluminum, and the material of the negative tab is metal copper. The welding between different metal materials is difficult, and the problem of virtual welding is prone to occur. The welding is unreliable and the internal resistance is large.

In order to solve the direct welding between different metal materials, the prior art also has a series connection between the pole core 1031 and the pole core 1031 through the pole core connector. The pole core connector includes a copper connection part and an aluminum connection part, and the copper connection part and the negative tab Welding, welding of the aluminum connection part and the positive tab, although this avoids the direct welding of the positive tab and the negative tab of different materials, but due to the existence of the pole core connector, it is easy to have a virtual weld and the solder joint is not firm, and this will also Increase the internal resistance of the battery by 100.

At the same time, the battery core assemblies 103 of the present application are directly plugged together, which can avoid the direct welding of two current lead-out parts of different materials, thereby avoiding the problems of virtual welding and weak solder joints during welding, and saving The pole core connector reduces the resistance of the entire battery 100 .

In this embodiment, the electrical properties of the first electrode 106 and the second electrode 105 are opposite, the first electrode 106 is a positive electrode, then the second electrode 105 is a negative electrode, or the first electrode 106 is a negative electrode, then the second electrode 105 is a positive electrode. The "first" and "second" of the first electrode 106 and the second electrode 105 are only used for name distinction, and are not used to limit the quantity. For example, the first electrode 106 and the second electrode 105 may contain one or more.

In some implementations, the first electrode 106 of one cell assembly 103 of the two series-connected cell assemblies 103 is detachably connected to the second electrode 105 of the other cell assembly 103 , thereby facilitating maintenance.

In some embodiments of the present application, the first electrode 106 includes the first current drawing part 1061 and a first connecting part (not shown in the figure) electrically connected to the first current drawing part 1061, and the first current drawing part 1061 includes a second One end and the second end, the first end of the first current drawing part 1061 is connected to the pole core 1031, and the second end of the first current drawing part 1061 extends out of the polymer film bag 104 and is connected to the first part connection; the second electrode 105 includes a second current drawing part 1051 and a second connecting part (not shown in the figure) electrically connected to the second current drawing part 1051, and the second current drawing part 1051 includes an opposite first end and the second end, the first end of the second current drawing part 1051 is connected to the pole core 1031, and the second end of the second current drawing part 1051 extends out of the polymer film bag 104 and is connected to the second part connection; the first connection portion of one cell assembly 103 of the at least two cell assemblies 103 is inserted into the second connection portion of the other cell assembly 103 .

In some specific examples of implementation, the first connection part is provided with a first socket, and the second connection part is provided with a first pin that matches the first socket, and the two cell assemblies are connected through the first socket. The cooperation of a pin and the first socket realizes series connection.

In the above embodiments, the insertion manner of the first connection part and the second connection is similar to the insertion manner of a plug and a socket.

In the above embodiments, there may be one or more first jacks, and one or more first pins.

It should be noted that, in order to ensure the safety of the battery 100, the first connection part and the second connection part are at least partially insulated, for example, in some embodiments, the outer surface of the first connection part is provided with an insulating layer, and the second connection part An insulating layer is provided on the outer surface except the first pin.

In some other embodiments, the first connecting part includes a first connecting part body, and a through hole (that is, a slot) is arranged in the first connecting part body, and a first conductive component is embedded in the through hole, and the first connecting part It includes a second connecting part body and a second conductive component (that is, a first pin) embedded in the first connecting part body and extending out of the second connecting part body. The second conductive part is inserted into the through hole and electrically connected with the first conductive part to realize the series connection of the two cell assemblies 103 , and the first connecting part body and the second connecting part body are insulators.

Likewise, the first current drawing part 1061 and the second current drawing part 1051 are only used to distinguish names, and are not limited to the number. In this application, since two adjacent cell assemblies 103 are located inside the same housing, the distance between the two cell assemblies 103 is greatly reduced. In terms of series connection, it simplifies the assembly process of the subsequent 100 packs of batteries; at the same time, it reduces the use of materials and reduces the weight. In addition, the two cell assemblies 103 are installed in the same casing, which greatly reduces the stability and firmness requirements of the connection between the cell assemblies 103 .

In one embodiment of the present application, as shown in FIGS. The first end of the first end is connected to the pole core 1031, and the second end of the first current drawing part 1061 extends out of the polymer film bag 104 and is provided with a plugging part;

The second electrode 105 includes a second current drawing part 1051, the second current drawing part 1051 includes a first end and a second end, the first end of the second current drawing part 1051 is connected to the pole core 1031, the second current drawing part 1051 The second end extends out of the polymer film bag 104 and is provided with an insert matched with the insertion part. The plug-in portion of the first electrode 106 of one cell assembly 103 of the two series-connected cell assemblies 103 is inserted into the plug-in portion of the second electrode 105 of the other cell assembly 103 .

In some specific implementations, as shown in FIG. 10 , the plug-in part is at least two first conductive sheets provided at the second end of the first current lead-out part 1061. For example, the two first conductive sheets face each other in the shape of " U" shape, the U-shaped opening is used for plugging.

In some specific implementation manners, as shown in FIG. 9 , the plug-in is at least one second conductive sheet provided at the second end of the second current drawing part 1051 .

The second conductive sheet of one cell assembly 103 of the two series-connected cell assemblies 103 is inserted between the two first conductive sheets of the other cell assembly 103 , that is, into a "U"-shaped opening.

In the above embodiment, there may be multiple first conductive sheets and multiple second conductive sheets, and each second conductive sheet is inserted between two first conductive sheets to achieve plug-in series connection.

In the above embodiment, by mating and inserting the first conductive sheet and the second conductive sheet, compared with direct welding, the contact area can be increased and the internal resistance can be reduced.

In order to make the insertion fit between the first current drawing part 1061 and the second current drawing part 1051 more stable, the first conductive sheet and the second conductive sheet are inserted with an interference fit.

For example, the distance between every two opposite first conductive sheets is 1.8mm, and the thickness of the second conductive sheet is about 2mm. Therefore, when the two are plugged together, the interference fit facilitates the conduction of electric current.

In one embodiment of the present application, in order to improve the stability of the entire battery 100 in series, as shown in FIG. 5 , FIG. 9 and FIG. 10 , the first electrode 106 includes a first A fixing portion 1063, the first fixing portion 1063 includes an inner surface facing the pole core 1031, an outer surface facing away from the pole core 1031, and a circumferential surface facing the casing connecting the inner surface and the outer surface, and the polymer film bag 104 is connected to the outer surface The circumferential surface of the first fixing portion 1063 is sealed and connected.

The second electrode 105 also includes a second fixing part 1053 sleeved on the second current drawing part 1051, and the second fixing part 1053 includes an inner side facing the pole core 1031 and an outer side facing away from the pole core 1031. The side surface and the circumferential surface facing the housing connecting the inner surface and the outer surface, the polymer film bag 104 is in sealing connection with the circumferential surface of the second fixing part 1053 .

In the above embodiment, the first fixing part 1063 can improve the strength of the first electrode 106, making the connection with the first tab 1033 more stable; the second fixing part 1053 can improve the strength of the second electrode 105, making it more stable with the The connection of the second tab 1032 is more stable.

In some embodiments, as shown in Figure 12, the first fixing part 1063 is provided with a second insertion hole 1065, which constitutes the insertion part; as shown in Figure 13, the second fixing part is provided with a second insertion hole 1065. pin 1054, which constitutes an insert; two cell assemblies are connected in series through the cooperation of the second pin 1054 and the second socket 1065.

There may be multiple second pins 1054 , and there may be multiple second sockets 1065 .

In order to further improve the stability of the insertion fit between the first current drawing part 1061 and the second current drawing part 1051, one of the first fixing part 1063 and the second fixing part 1053 is provided with a card slot 1052, The other is provided with a clamping block 1062 , and the first fixing portion 1063 of one cell assembly 103 and the second fixing portion 1053 of the other cell assembly 103 in the two series-connected cell assemblies 103 are snapped together through the slots 1052 and 1062 , so as to limit the first electrode 106 and the second electrode 105 .

FIG. 5 , FIG. 9 and FIG. 10 show that a clamping block 1062 is provided on the first fixing part 1063 , and a sub-clamping slot 1052 is provided on the second fixing part 1053 .

As shown in FIG. 12 and FIG. 13 , the locking block 1062 is disposed on the second fixing portion 1053 , and the locking slot 1052 is disposed on the first fixing portion 1063 .

The number of the card slot 1052 and the card block 1062 is not particularly limited, there may be one or more.

In order to simplify the manufacturing process, the clamping block 1062 can be integrally formed with the fixing portion provided with the clamping block 1062 , for example, in FIG. 5 , FIG. 9 and FIG. 10 , the clamping block 1062 can be integrally formed with the first fixing portion 1063 .

In some specific examples of the above-mentioned embodiments, the locking block 1062 can be a barb-shaped male insert that protrudes outward from the surface of the first fixing part 1063 or the second fixing part 1053, and is inserted into the card slot by plugging. 1052, so that the first electrode 106 and the second electrode 105 are not easily separated.

The block 1062 and the slot 1052 can be arranged on the circumferential surface of the fixing part, or on the outer side of the fixing part. In order to facilitate assembly, in some embodiments, the slot 1052 is located on the On the outer surface of the first fixing portion 1063 or the second fixing portion 1053 , the locking block 1062 is located on the outer surface of the first fixing portion 1063 or the second fixing portion 1053 provided with the locking block 1062 .

It should be noted that the “inner side” is the side facing the inside of the polymer film bag 104 , and the “outer side” is the side facing away from the polymer film bag 104 .

In order to avoid short circuit, the first fixing part 1063 and the second fixing part 1053 are insulators.

The first current drawing part 1061 and the first fixing part 1063 can be manufactured separately, and can also be integrally formed after being assembled together; the second current drawing part 1051 and the second fixing part 1053 can be manufactured separately, and then assembled together, can also be integrally formed , in order to simplify the manufacturing process, it is preferably integrally formed.

As shown in FIG. 8 , the materials of the first fixing part 1063 and the second fixing part 1053 can be the same or different. The material of molecular film bag 104 is identical; Polymer film bag 104 is provided with the opening 1041 that is used to lead out first electrode 106 and second electrode 105, and described polymer film bag 104 is with described first fixed part 1063 and second fixed part 1063. Part 1053 is hot-melt connected. The sealing method is relatively simple.

In this application, regarding the polymer film bag 104, the first fixing part 1063 and the second fixing part 1053 have a certain degree of insulation and electrolyte corrosion resistance, and it is sufficient not to react with the electrolyte. In some embodiments, Materials of the polymer film bag 104 , the first fixing part 1063 and the second fixing part 1053 may include polypropylene (PP) and polyethylene (PE).

It should be noted that, compared with the use of aluminum-plastic composite film for the polymer film, the use of PP or PE for the polymer film bag 104 can reduce the weight and cost of the entire battery 100. In addition, the aluminum-plastic composite film uses a layer between two layers of plastic film. Add a layer of aluminum foil, the burrs of the pole core 1031 will easily scratch the plastic film of the inner layer of the aluminum-plastic film, and form dents on the aluminum foil in the middle, and the electrolyte will accelerate corrosion after contacting these dents.

In some embodiments, the polymer film bag 104 has a certain degree of flexibility, which is convenient for forming the battery 100 and preventing punctures. The thickness of the polymer film bag 104 is preferably 80um-200um, of course, it can also be adjusted according to the actual situation.

In this application, when multiple cell assemblies 103 are connected in series, when the electrolytes in different cell assemblies 103 are connected, there is an internal short circuit problem; Potential difference (taking the lithium iron phosphate battery 100 as an example, the potential difference is about 4.0-7.6V), the electrolyte in it will decompose due to the large potential difference, which will affect the performance of the battery 100; Packaged in polymer film bag 104.

In some embodiments, the battery 100 further includes a liquid injection port 107, which is provided on the first fixing portion 1063 and/or the second fixing portion 1053, and the liquid injection port 107 is in a sealed state. 8 and 9 show that the liquid injection port 107 is disposed on the second fixing part 1053 .

The liquid injection port 107 is used for injecting electrolyte into each cell assembly 103 .

The liquid injection port 107 is in a sealed state after the electrolyte is injected, and is used to isolate the electrolyte between two adjacent cell assemblies 103 from communicating with each other. The blocking member 1071 is used to seal the liquid injection port 107 .

In some embodiments, the liquid injection port 107 is arranged on the polymer film bag 104 , so that the liquid injection port 107 corresponds to each polymer film bag 104 one by one.

The liquid injection port 107 can be all located on the first fixed part 1063, also can be located on the second fixed part 1053 entirely, can also be all located in the polymer film bag 104, or a part of liquid injection port 107 is located at the first fixed part. On the part 1063 , a part is provided on the second fixing part 1053 , and the other part is provided on the polymer film bag 104 .

In the field of power batteries 100, the consistency of working conditions of each battery 100 is very important, which directly affects the performance of the overall battery pack. Similarly, in this application, the consistency of the working conditions of each battery cell assembly 103 inside the battery 100 will also affect the overall performance of each battery 100 ; thus affecting the performance of the entire battery pack. Inside the battery 100 , the amount of electrolyte will affect the performance of the battery 100 , such as capacity and activity.

By providing a liquid injection port 107 on at least one of the first fixing part 1063, the second fixing part 1053 and the polymer film bag 104, the injection amount of the electrolyte in each cell assembly 103 can be precisely controlled, and can Effective realization and electrolyte infiltration.

In the prior art, the liquid injection port 107 is often arranged on the casing. When the number of liquid injection ports 107 increases, not only the processing difficulty of the casing is increased, but also the sealing performance of the liquid injection port 107 is greatly challenged. Once the electrolyte If leakage occurs, it will cause problems such as short circuit. In the present application, the liquid injection port 107 is arranged on at least one of the polymer film bag 104, the first fixing part 1063, and the second fixing part 1053, and then on the polymer film The casing is sleeved outside the bag 104, that is, the liquid injection port 107 is arranged inside the casing, and the casing plays a secondary sealing effect on the liquid injection port 107, and the sealing performance of the entire battery 100 is significantly improved; once one of the batteries If the electrolyte in the core assembly 103 leaks, and the other battery core assemblies 103 remain intact, there will still be no safety issues caused by the leakage of the electrolyte.

In addition, the liquid injection port 107 is opened on at least one of the polymer film bag 104, the first fixed part 1063, and the second fixed part 1053, and the liquid injection port 107 is not opened on the housing, and the sealing of the liquid injection port 107 is also Relatively simple, for example, on the polymer film bag 104, on the first fixing part 1063, on the second fixing part 1053, the liquid injection port 107 is set, when filling the liquid port, adopt hot-melt seal, can satisfy the requirement of the liquid injection port 107. Sealing requirements.

In some specific embodiments, the polymer film bag 104 includes a bag body and a protruding portion protruding outward from the bag body, the liquid injection port 107 is arranged on the protruding portion, and the opening is heat-sealed .

At least one of the polymer film bag 104 , the first electrode 106 , and the second electrode 105 is provided with a liquid injection port 107 , and the liquid injection port 107 may be one or multiple.

In this application, after the battery cell assembly 103 is injected, the liquid injection port 107 is in a sealed state. On the one hand, the electrolyte in the polymer film bag 104 will not flow out and come into contact with the casing, thereby causing an internal short circuit; On the one hand, the electrolyte will no longer flow between adjacent cell assemblies 103 , will not affect each other, and will not decompose due to excessive potential difference, ensuring the safety and service life of the battery 100 .

In the present application, the shape of the pole core 1031 can be various, it can be a regular geometric shape, and it can also be an irregular geometric shape, for example, it can be a square, a circle, a polygon, a triangle, or any shape, such as Shaped pole core 1031. It can be understood that the present application does not limit the shape of the pole core 1031 .

In some embodiments of the present application, the pole core 1031 includes a receiving portion 1034, and at least part of the first electrode 106 and/or at least part of the second electrode 105 are respectively located in the receiving portion 1034.

As shown in FIG. 8 , the receiving portion 1034 is a recessed area of the pole core 1031 .

It should be noted that the first electrode 106 and the second electrode 105 are partly located inside the polymer film bag 104 and partly located outside the polymer film bag 104 for the convenience of being connected in series. The electrodes located in the polymer film bag 104 are located in the accommodation portion 1034 .

The above embodiments can improve the space utilization rate of the battery 100 and increase the capacity of the battery 100 .

In the embodiment, the pole core 1031 is provided with a first pole lug 1033 and a second pole lug 1032 for drawing out current, and the first pole lug 1033 and the second pole lug 1032 are obtained from the T-shaped pole core 1031 respectively. The two lower corners extend out, and one end of the first electrode 106 located in the polymer film bag 104 is connected to the first tab 1033; the end of the second electrode 105 located in the polymer film bag 104 is connected to the second tab 1032 .

One of the first tab 1033 and the second tab 1032 is a positive tab, and the other is a negative tab.

At least part of the first electrode 106 is located in the receiving portion 1034. It can be understood that the receiving portion 1034 can only accommodate at least part of the first current drawing part 1061, or can accommodate at least part of the first current drawing part 1061 and at least part of the first fixing part. Section 1063.

At least part of the first electrode 106 is located in the accommodation part 1034. It can also be understood that the accommodation part 1034 can only accommodate at least part of the first current drawing part 1061, or can accommodate at least part of the first current drawing part 1061 and at least part of the first current drawing part 1061. connecting part.

2-11 show that one of the receiving parts 1034 accommodates part of the first current drawing part 1061 and part of the first fixing part 1063 .

At least part of the second electrode 105 is located in the accommodation part 1034. It can be understood that the accommodation part 1034 can only accommodate at least part of the second current drawing part 1051, or can accommodate at least part of the second current drawing part 1051 and at least part of the second fixing part. Section 1053.

At least part of the second electrode 105 is located in the accommodation part 1034. It can also be understood that the accommodation part 1034 can only accommodate at least part of the second current drawing part 1051, or can accommodate at least part of the second current drawing part 1051 and at least part of the first current drawing part. connecting part.

FIGS. 2-11 show that another receiving portion 1034 accommodates part of the second current drawing part 1051 and part of the second fixing part 1053 .

Arranging at least part of the first electrode 106 and at least part of the second electrode 105 in the accommodating part 1034 of the pole core 1031 can save the space wasted due to the separate arrangement of the first electrode 106 and the second electrode 105, and improve the space utilization rate in the casing , and further increase the capacity of the battery 100 .

In the prior art, for example in the application number CN201910544929.3, in order to improve the volume utilization rate of the battery pack 200, the size of the battery 100 is set to 400-2500mm. Since the battery 100 is too long, if only one pole core 1031 is set, the battery 100 The internal resistance is too high, the potential difference between the positive and negative terminals is too large, and the electrolyte cannot work normally. By adopting the technical solution of the present application, the battery 100 with the length of the battery 100 ranging from 400 to 2500 can be manufactured more conveniently, and at the same time, the internal resistance and the connection of structural parts will be reduced, and the cost will be further reduced.

As shown in FIG. 2 , in one embodiment of the present application, the cell assemblies 103 in the housing are arranged along the first direction, and the first electrodes 106 and the second electrodes 105 are respectively located along the first direction of the cell assemblies 103 . At both ends in one direction, the first electrode 106 of one cell assembly 103 of the two adjacent cell assemblies 103 is plugged with the second electrode 105 of the other cell assembly 103 .

In the present invention, it is preferred that the first tab 1033 and the second tab 1032 are separately arranged on opposite sides of the pole core 1031 along the first direction; all the cell assemblies 103 in the cell assembly 103 are arranged along the first direction The first direction is the length direction of the battery cell assembly 103, and also the length direction of the battery 100, that is, the "head-to-head" arrangement method is adopted. This arrangement method can more conveniently realize the cell assembly 103 in the battery 100 The pairwise series connection between them has a simple connection structure.

In addition, in this embodiment, on the premise that the capacity of the battery 100 is the same, through the arrangement positions of the first electrode 106 and the second electrode 105 and the arrangement direction of the battery cell assembly 103, it is relatively easy to obtain a battery with a longer length and a thinner battery. thin battery 100.

In the present application, the shape of the battery 100 can be various, it can be a regular geometric shape, it can also be an irregular geometric shape, for example, it can be a square, a circle, a polygon, a triangle, or it can be any shape, such as a special shape battery 100. It can be understood that, the present application does not limit the shape of the battery 100 . In one embodiment, the battery 100 is substantially cuboid, the battery 100 has a length L, a width H, and a thickness D, the length L of the battery 100 is greater than the width H, and the width H of the battery 100 is greater than the thickness D, wherein , the length of the battery 100 is 400-2500mm.

It should be noted that the substantially rectangular parallelepiped can be understood as that the battery 100 can be rectangular parallelepiped, square, or partially deformed, but roughly rectangular parallelepiped, square; Curved, but the overall shape is approximately cuboid or cube.

In the present application, the length L and width H of the battery 100 satisfy L/H=4˜21.

In this application, the shell is used to improve the strength of the battery 100 and ensure the safe use of the battery 100. It can be a plastic shell or a metal shell. When it is a metal shell, the heat dissipation performance is better, and the strength of the shell Higher, it can play a supporting role by itself.

In this application, one of the first electrode 106 and the second electrode 105 is an aluminum electrode, and the other is a copper electrode.

In a specific embodiment of the present application, one of the first current lead-out part 1061 and the second current lead-out part 1051 is an aluminum lead-out part, and the other is made of a copper lead-out part; the aluminum lead-out part is connected to the positive tab of the pole core 1031, The copper lead-out part is connected to the negative tab of the pole core 1031 .

Through the above technical solution, metals of different materials can be avoided from being welded to each other.

In this application, the housing is a sealed housing.

In one embodiment of the present application, as shown in FIG. 8, the housing includes a housing body 101, a first cover plate 1012 and a second cover plate 1011; the opposite ends of the housing body 101 are open respectively, and the first cover plate 1012 and the second cover plate 1011 respectively cover the opening.

In this embodiment, the housing body 101 , the first cover plate 1012 , and the second cover plate 1011 are sealed and connected together to define an accommodating space, and the cell assembly 103 is located in the accommodating space.

In this embodiment, a plurality of cell assemblies 103 are connected in series in the same casing so that the length of the battery 100 is longer, and the electrodes of the cell assemblies 103 are led out from both ends. In order to facilitate the extraction of current, the opening is along the first direction. The first cover plate 1012 and the second cover plate 1011 are respectively arranged on the openings along the first direction.

In the above embodiments, there are the following two methods for extracting the current.

The first type: the battery 100 includes a first electrode terminal and a second electrode terminal for drawing current; the first electrode terminal and the second electrode terminal are both arranged on the first cover plate 1012, and the first electrode terminal and the The first cover plate 1012 is insulated and connected, and the second electrode terminal is electrically connected to the second cover plate 1011;

Among the plurality of cell assemblies 103 connected in series, the first electrode 106 of one of the two cell assemblies 103 at the end is electrically connected to the first electrode terminal, and the second electrode 105 of the other cell assembly 103 It is electrically connected with the second cover plate 1011 .

In the above-mentioned embodiment, the housing body 101 is charged.

The second type: the first electrode terminal is set on the first cover plate 1012 and is insulated and connected to the first cover plate 1012; the second electrode terminal is set on the second cover plate 1011 and is insulated and connected to the second cover plate 1011;

Among the plurality of cell assemblies 103 connected in series, the first electrode 106 of one of the two cell assemblies 103 at the end is electrically connected to the first electrode terminal, and the second electrode 105 of the other cell assembly 103 It is electrically connected to the second electrode terminal.

In this embodiment, the housing is not charged.

One of the first electrode terminal and the second electrode terminal is a positive terminal, and the other is a negative terminal.

In this application, the battery 100 may be a lithium ion battery 100 .

In this application, the other structures of the battery 100 are the same as those in the prior art, such as explosion-proof valves, current interruption devices, etc., which will not be repeated here.

In another aspect of the present application, a battery module including the battery 100 of any one of the above embodiments is provided. With the battery module provided by the present application, the assembly process is less, and the cost of the battery 100 is lower.

The present application provides a battery pack, including the battery 100 in any of the above embodiments or the battery module provided above. With the battery pack provided by the present application, the assembly process is less, the cost of the battery 100 is lower, and the energy density of the battery pack is higher.

An electric vehicle includes the above-mentioned battery pack. Adopting the electric vehicle provided by the application, the battery life of the vehicle is high and the cost is low.

In the description of this application, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application in specific situations.

In the description of this specification, descriptions referring to the terms "embodiment", "specific embodiment", "example" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one aspect of the present application. In an embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present application. The scope of the application is defined by the claims and their equivalents.

Claims (27)

1. A battery is characterized by comprising a shell and a plurality of cell assemblies,

a containing cavity is defined in the shell, a plurality of battery cell assemblies are positioned in the containing cavity, and the battery cell assemblies are connected in series;

the battery cell assembly comprises a polymer film bag, a pole core packaged in the polymer film bag, and a first electrode and a second electrode which are electrically connected with the pole core and extend out of the polymer film bag to draw out current;

the first electrode of one cell module of the at least two cell modules connected in series is spliced with the second electrode of the other cell module, the at least two cell modules connected in series are arranged along a first direction, and the first electrode and the second electrode are respectively positioned at two ends of the cell module along the first direction;

the first electrode comprises a first fixing part, the second electrode comprises a second fixing part, the battery further comprises a liquid injection port, the liquid injection port is arranged on the first fixing part and/or the second fixing part, and the liquid injection port is in a sealing state.

2. The battery of claim 1, wherein the first electrode of one of the at least two series-connected cell assemblies is removable from the second electrode of the other cell assembly.

3. The battery of claim 1, wherein the battery is configured to provide a battery of a battery type,

the first electrode comprises a first current extraction part and a first connecting part electrically connected with the first current extraction part, the first current extraction part comprises a first end and a second end, the first end of the first current extraction part is connected with the pole core, and the second end of the first current extraction part extends out of the polymer film bag and is connected with the first connecting part;

the second electrode comprises a second current extraction part and a second connecting part electrically connected with the second current extraction part, the second current extraction part comprises a first end and a second end, the first end of the second current extraction part is connected with the pole core, and the second end of the second current extraction part extends out of the polymer film bag and is connected with the second connecting part;

the first connecting part of one cell assembly of the at least two cell assemblies connected in series is spliced with the second connecting part of the other cell assembly.

4. The battery of claim 3, wherein a first jack is provided on the first connection portion, a first pin is provided on the second connection portion to mate with the first jack, and the at least two cell assemblies are connected in series by the cooperation of the first pin and the first jack.

5. The battery of claim 1, wherein the first electrode comprises a first current lead-out portion comprising a first end and a second end, the first end of the first current lead-out portion being connected to the pole piece, the second end of the first current lead-out portion extending out of the polymeric film pouch and being provided with a plug portion;

the second electrode comprises a second current extraction part, the second current extraction part comprises a first end and a second end, the first end of the second current extraction part is connected with the pole core, and the second end of the second current extraction part extends out of the polymer film bag and is provided with an insert matched with the plug-in part;

the plug-in part of the first electrode of one cell assembly of the at least two cell assemblies connected in series is plugged in the plug-in part of the second electrode of the other cell assembly.

6. The battery of claim 5, wherein the plug portion is at least two first conductive tabs provided at the second end of the first current lead-out portion,

The plug-in is at least one second conductive sheet arranged at the second end of the second current extraction part;

the second conductive sheet of one of the at least two series-connected cell assemblies is inserted between the two first conductive sheets of the other cell assembly.

7. The battery of claim 6, wherein the two first conductive tabs are interference fit with the second conductive tab.

8. The battery according to claim 5, wherein the first fixing portion is sleeved on the first current lead-out portion, the first fixing portion includes an inner side surface facing the pole core, an outer side surface facing away from the pole core, and a circumferential surface facing the housing connecting the inner side surface and the outer side surface, and the polymer film pouch is in sealing connection with the circumferential surface of the first fixing portion;

the second fixing part is sleeved on the second current leading-out part, the second fixing part comprises an inner side surface facing the pole core, an outer side surface facing away from the pole core and a circumferential surface facing the shell and connecting the inner side surface and the outer side surface, and the polymer film bag is in sealing connection with the circumferential surface of the second fixing part.

9. The battery of claim 8, wherein the plug-in portion is a second jack provided on the first fixing portion, the plug-in portion is a second pin provided on the second fixing portion, and the at least two cell assemblies are connected in series by cooperation of the second pin and the second jack.

10. The battery according to claim 8 or 9, wherein the first fixing portion is provided with a clamping groove, the second fixing portion is provided with a clamping block matched with the clamping groove, or the first fixing portion is provided with a clamping block, and the second fixing portion is provided with a clamping groove matched with the clamping block;

the first fixing part of one cell assembly and the second fixing part of the other cell assembly of the at least two cell assemblies connected in series are clamped with the clamping block through the clamping groove.

11. The battery of claim 10, wherein the clamping groove is positioned on the outer side surface of the first fixing part, and the clamping block is positioned on the outer side surface of the second fixing part; or, the clamping groove is positioned on the outer side surface of the second fixing part, and the clamping block is positioned on the outer side surface of the first fixing part.

12. The battery of claim 10, wherein the latch is barb-shaped.

13. The battery of claim 10, wherein the first securing portion and/or the second securing portion is an insulating member.

14. The battery of claim 13, wherein the material of the first and/or second fixing portions comprises polypropylene or polyethylene.

15. The battery of claim 10, wherein the first current lead-out portion is integrally formed with the first fixing portion; and/or the second current leading-out part and the second fixing part are integrally formed.

16. The battery according to any one of claims 1-9, 11-15, wherein the electrode core comprises a receiving portion, and at least part of the first electrode and/or at least part of the second electrode are respectively located in the receiving portion.

17. The battery of claim 16 wherein said pole piece is "T" shaped with two lower corners of said "T" shaped pole piece for receiving at least a portion of said first electrode and at least a portion of said second electrode.

18. The battery of claim 17, wherein the electrode core is provided with a first electrode lug and a second electrode lug for leading out current, the first electrode lug and the second electrode lug respectively extend out from two lower corners of the T-shaped electrode core, and one end of the first electrode positioned in the polymer film bag is connected with the first electrode lug; one end of the second electrode, which is positioned in the polymer film bag, is connected with the second lug.

19. The battery of any one of claims 1-9, 11-15, wherein a plurality of the cell assemblies are arranged along a first direction, the first electrode and the second electrode are respectively positioned at two ends of the cell assemblies along the first direction, and the first electrode of one cell assembly of two adjacent cell assemblies is spliced with the second electrode of the other cell assembly.

20. The battery of claim 19, wherein the length direction of the cell assembly is along the first direction.

21. The battery of claim 20, wherein the battery is 400-2500 mm long.

22. The battery of any one of claims 1-9, 11-15, wherein one of the first electrode and the second electrode is an aluminum electrode and the other is a copper electrode.

23. The battery of claim 1, wherein the housing is a sealed housing.

24. The battery of claim 1, wherein the polymeric film pouch comprises a polypropylene pouch or a polyethylene pouch.

25. A battery module comprising a battery as claimed in any one of claims 1 to 24.

26. A battery pack comprising the battery according to any one of claims 1 to 24 or the battery module according to claim 25.

27. An electric vehicle comprising the battery pack of claim 26.