Battery monomer, battery and electric device

Abstract

The utility model discloses a single battery, a battery and a power utilization device, the single battery comprises an electrode assembly, the electrode assembly comprises a plurality of pole pieces and an isolating membrane which are arranged in a laminated manner, the plurality of pole pieces at least comprise a first pole piece and a second pole piece which are positioned at two opposite ends in the lamination direction along the lamination direction, the second pole piece comprises a main body part and a pole lug, one side, deviating from the first pole piece, of the second pole piece is provided with a protection piece, and the protection piece covers at least one part of the main body part of the second pole piece and extends to at least one edge of the main body part. In the technical scheme of the embodiment of the invention, pole piece damage and the like caused by contact friction between the pressing claw and the second pole piece are avoided, so that ablation, fire breakout and the like of the isolating membrane are avoided, and the qualification rate of the electrode assembly is improved; and the protection piece can play a role in reinforcing the second pole piece, so that the strength of the edge of the second pole piece is improved, the edge of the pole piece is further prevented from being collided and damaged in the subsequent assembly process, and the qualified rate of the assembled single battery is improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] The energy density of stacked battery cells is high and the internal structure is relatively stable.

[0003] In actual production, the pressing claws of the stacking machine need to move outward in a direction parallel to the pole piece. At this time, they will rub against the surface of the pole piece, causing scratches on the pole piece and even damage to the isolation membrane, resulting in fire, etc., posing a safety risk. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, which can alleviate problems such as pole piece abrasion and isolation membrane damage that occur during the battery cell manufacturing process.

[0005] In the first aspect, the present application provides a battery cell, comprising: an electrode assembly, wherein the electrode assembly includes a plurality of pole pieces and an isolation membrane arranged in a stacked manner, wherein along the stacking direction, the plurality of pole pieces include at least a first pole piece and a second pole piece located at opposite ends in the stacking direction, and the second pole piece includes a main body and a pole ear, wherein a protective member is provided on a side of the second pole piece facing away from the first pole piece, and the protective member covers at least a portion of the main body and extends to at least one edge of the main body.

[0006] In the technical solution of the embodiment of the present application, a protective member is provided on the main body of the second pole piece of the electrode assembly to avoid contact and friction between the pressure claw and the second pole piece, thereby avoiding damage to the pole piece, thereby avoiding burning of the isolation membrane and catching fire, and improving the qualified rate of the electrode assembly; and because the protective member covers the main body and extends to the edge, the protective member can strengthen the second pole piece, improve the strength of the edge of the main body of the second pole piece, further avoid collision and damage to the edge of the pole piece during the subsequent assembly process, and improve the qualified rate of the battery cell after assembly.

[0007] In some embodiments, the main body of the second pole piece is square and has four corners, and a protective member is provided on the side of each corner away from the first pole piece. In the above technical solution, by providing pressure claws at the four corners of the second pole piece, the pressure claws can be separated from the second pole piece to avoid contact and friction between the pressure claws and the second pole piece, thereby avoiding damage to the pole piece, thereby avoiding ablation and fire of the isolation film, etc.; and the size of the protective member can be reduced, which is convenient for manufacturing and forming of the protective member.

[0008] In some embodiments, the main body of the second pole piece is square and the length dimension of the main body is L1, the minimum dimension of the protective member in the length direction of the second pole piece is L2, 0.1L1≤L2≤0.5L1. In the above technical solution, the protective member can effectively protect the second pole piece and avoid the protective member being too large to affect the arrangement of the protective member on the second pole piece.

[0009] In some embodiments, the main body of the second pole piece is square and the width of the main body is B1, the minimum dimension of the protective member in the width direction of the second pole piece is B2, 0.1B1≤B2≤0.5B1. In the above technical solution, the protective member can effectively protect the second pole piece and avoid the protective member being too large to affect the arrangement of the protective member on the second pole piece.

[0010] In some embodiments, the thickness of the main body of the second pole piece is H1, the maximum thickness of the protective member is H2, and 0.5H1≤H2≤2H1. In the above technical solution, the protective member can effectively protect the second pole piece without taking up too much space, thus avoiding the reduction of the energy density of the battery cell to a certain extent.

[0011] In some embodiments, the protective member includes at least one protective layer and a heat absorbing layer with heat absorption performance, the protective layer and the heat absorbing layer are arranged along the stacking direction of the electrode assembly, and a protective layer is provided on the side of the heat absorbing layer away from the second pole piece. In the above technical solution, when the pressing claw is withdrawn, even if the pressing claw and the protective member generate a certain amount of heat due to friction, the protective layer can transfer the heat to the heat absorbing layer, and the heat is absorbed by the heat absorbing layer, thereby reducing the temperature there, further avoiding the probability of the isolation film being ablated, and improving the reliability and qualification of the battery cell.

[0012] In some embodiments, the protective layer includes two layers, and the heat absorption layer is sandwiched between the two protective layers. In the above technical solution, the heat absorption layer is protected between the two protective layers, which can improve the stability of the overall structure, and to a certain extent avoid the heat absorption layer absorbing heat and causing phase change or deformation, which affects the reliability of the protection of the protective component, and at the same time avoid the heat absorption layer directly contacting the second pole piece to produce other adverse effects.

[0013] In some embodiments, the heat absorption layer is a paraffin layer. In the above technical solution, by using paraffin material, when the protective part rubs against the pressure claw, the heat absorption layer can absorb the heat generated by friction through phase change, thereby reducing the probability of heat transfer to the second pole piece, reducing the probability of the second pole piece being burned, and improving the reliability and qualification of the electrode assembly.

[0014] In some embodiments, the protective layer is a polyolefin layer. In the above technical solution, by using polyolefin materials, the protective layer can effectively protect the heat absorption layer. Polyolefin materials have good chemical stability and insulation properties, and the materials are easy to process and manufacture, which is convenient for large-scale manufacturing and use of protective parts.

[0015] In some embodiments, the protective member is bonded to the second pole piece. In the above technical solution, the protective member is fixedly connected to the second pole piece, the assembly process is simple, the assembly is convenient, the manufacturing difficulty is reduced, and the manufacturing cost is reduced.

[0016] In some embodiments, a rubber coating layer is provided on one side of the protective member facing the second pole piece. In the above technical solution, during the manufacturing process, a rubber coating layer can be preset on the protective member, and when the protective member is placed on the second pole piece, the rubber coating layer contacts the second pole piece, so that the protective member and the second pole piece can be bonded, and the connection is convenient.

[0017] In some embodiments, the material of the protective member includes one of polypropylene, polyethylene, and polyethylene terephthalate. In the above technical solution, by using the above materials, the protective member has good chemical stability and insulation, and is easy to process and manufacture, with low cost, which is convenient for large-scale manufacturing and use of the protective member.

[0018] In some embodiments, the side of the protective member facing away from the second pole piece is a smooth plane. In the above technical solution, the friction between the pressure claw and the protective member when the pressure claw is withdrawn can be reduced, the probability of wear of the protective member can be reduced, and the pressure claw can be easily withdrawn to reduce activity obstacles.

[0019] In some embodiments, the Shore hardness of the protective member is 30A-90A. In the above technical solution, the protective member can not only effectively protect the second pole piece, but also improve the qualified rate of the battery cell after assembly.

[0020] In a second aspect, the present application provides a battery, which includes the battery cell in the above embodiment.

[0021] In a third aspect, the present application provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0022] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0024] Figure 1 is a schematic diagram of an electrical device in the related art;

[0025] Figure 2 is a schematic diagram of a battery in the related art;

[0026] Figure 3 A schematic diagram of a battery cell provided for some embodiments of the present application;

[0027] Figure 4 A schematic diagram of the production and processing of battery cells in some embodiments of the present application;

[0028] Figure 5 A schematic diagram of an electrode assembly according to some embodiments of the present application;

[0029] Figure 6 Schematic diagrams of electrode assemblies of other embodiments of the present application;

[0030] Figure 7 A schematic diagram of a second pole piece of some embodiments of the present application;

[0031] Figure 8 Schematic diagram of protection elements according to some embodiments of the present application.

[0032] Reference numerals:

[0033] Battery 1000, power-consuming device 2000,

[0034] Battery cell 100, box body 200, first part 210, second part 220,

[0035] Shell 10, housing 11, end cover 12,

[0036] Electrode assembly 20, first pole piece 21, second pole piece 22, main body 221, pole ear 222, middle pole piece 23, isolation film 24, protective member 25, protective layer 251, heat absorption layer 252, glue coating layer 253,

[0037] Pressing claw 30. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0040] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0041] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0043] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0044] The term "plurality" used in the present application refers to two or more (including two).

[0045] In this application, a battery refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. Some batteries may include a casing for encapsulating one or more battery cells or multiple battery modules. The casing can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells. Of course, some batteries may not include the above-mentioned casing and are directly set in the battery installation compartment of the electrical device.

[0046] In the present application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries or magnesium-ion batteries, etc., and the embodiments of the present application do not limit this. Battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0047] For example, a battery cell may include a housing, an electrode assembly and an electrolyte, wherein the housing is used to contain the electrode assembly and the electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode body and a positive electrode ear, the positive electrode ear is led out from one end of the positive electrode body, most of the area of ​​the positive electrode ear is not coated with a positive electrode active material, and most of the area of ​​the positive electrode body is coated with a positive electrode active material. The negative electrode sheet includes a negative electrode body and a negative electrode ear, the negative electrode ear is led out from one end of the negative electrode body, most of the area of ​​the negative electrode ear is not coated with a negative electrode active material, and most of the area of ​​the negative electrode body is coated with a negative electrode active material.

[0048] In order to ensure that a large current can pass without melting, there are multiple positive electrode tabs stacked together, and there are multiple negative electrode tabs stacked together.

[0049] The material of the isolation film can be PP (polypropylene) or PE (polyethylene).

[0050] The battery cell may be provided with a pole or the like connected to the pole lug as the electrical connection part of the battery cell. In addition, the battery cell may have a pressure relief part. When the internal pressure of the battery cell is too high (for example, thermal runaway), the pressure relief part is used to release the internal substances of the battery cell (for example, gas, liquid, particulate matter, etc.) to reduce the internal pressure of the battery cell and avoid the internal pressure of the battery cell being too quickly pressurized, which may lead to dangerous accidents such as explosion of the battery cell. For example, the pressure relief part may be an explosion-proof valve, an explosion-proof plate, etc.

[0051] For example Figure 1 and Figure 2 As shown, in some electrical devices 2000, a battery 1000 is used for power supply. The battery 1000 includes a housing 200 and a battery cell 100. The housing 200 includes a first part 210 and a second part 220. Figure 3 As shown, the battery cell 100 includes a housing 10 and an electrode assembly 20, wherein the electrode assembly 20 includes a pole piece and a separator 24. Some electrode assemblies 20 are laminated, wherein the pole piece and the separator 24 are stacked. Figure 4 As shown, in the traditional actual production process, after the last layer of pole pieces are arranged, the pressure claw 30 of the laminating machine will press the pole pieces downward with a predetermined pressure, and then cover the isolation film 24 on the pole piece of the last layer, and finally remove the pressure claw 30, wherein the pressure claw 30 cannot be lifted upward, and lifting it will cause the outermost isolation film 24 to be lifted, and the isolation film 24 cannot achieve the protective effect, so the pressure claw 30 can only be pulled outward in a direction parallel to the pole piece and the isolation film 24, at which time the pressure claw 30 will generate heat by friction with the pole piece surface, causing the pole piece to be scratched, the isolation film 24 to be damaged, etc. In addition, some battery cells 100 perform a lithium replenishing process on the outermost negative pole piece. When the pressure claw 30 is pulled outward, it will generate heat by friction with the lithium layer on the surface of the outermost negative pole piece, which will cause the isolation film 24 to burn, or even catch fire, posing a safety risk.

[0052] To this end, the present application proposes a battery cell 100, such as Figure 3 and Figure 5 As shown, the battery cell 100 includes an electrode assembly 20, and the electrode assembly 20 includes a plurality of electrode sheets and an isolation membrane 24 arranged in a stacked manner. Along the stacking direction, the plurality of electrode sheets at least include a first electrode sheet 21 and a second electrode sheet 22 located at opposite ends in the stacking direction F1, and the second electrode sheet 22 includes a main body 221 and a pole ear 222, wherein a protective member 25 is provided on the side of the second electrode sheet 22 facing away from the first electrode sheet 21, and the protective member 25 covers at least a portion of the main body 221 of the second electrode sheet 22 and extends to at least one edge of the main body 221.

[0053] In the battery cell 100 of the above-mentioned structure, by providing a protective member 25 on the main body 221 of the second pole piece 22 of the electrode assembly 20, it is avoided that the pressure claw 30 contacts and rubs with the second pole piece 22 to cause damage to the pole piece, thereby avoiding burning and catching fire of the isolation membrane 24, thereby improving the qualified rate of the electrode assembly 20; and because the protective member 25 covers the main body 221 of the second pole piece 22 and extends to the edge, the protective member 25 can strengthen the main body 221 of the second pole piece 22, improve the strength at the edge of the main body 221 of the second pole piece 22, further avoid collision and damage to the edge of the pole piece during the subsequent assembly process, and improve the qualified rate of the battery cell 100 after assembly.

[0054] like Figure 1 As shown, the battery 1000 with the battery cell 100 disclosed in the embodiment of the present application can be used for, but not limited to, an electrical device 2000 such as a vehicle, a ship or an aircraft, and can enable a power system of the electrical device 2000 composed of the battery 1000 disclosed in the present application to ensure the safety and reliability of the electrical device 2000.

[0055] For example, the power-consuming device 2000 disclosed in the embodiment of the present application may be, but is not limited to, a vehicle, a mobile phone, a tablet, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The vehicle may be a fuel vehicle, a gas vehicle, a new energy vehicle, or a rail vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc.; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, etc.; the electric toy includes a fixed or mobile electric toy, such as a game console, an electric vehicle toy, an electric ship toy, and an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, etc.

[0056] Hereinafter, a battery cell 100 according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0057] like Figure 3-Figure 8 As shown, according to the battery cell 100 of the embodiment of the present application, it includes an electrode assembly 20, the electrode assembly 20 includes a plurality of pole pieces and an isolation membrane 24 arranged in a stacked manner, along the stacking direction F1, the plurality of pole pieces include at least a first pole piece 21 and a second pole piece 22 located at opposite ends in the stacking direction, the second pole piece 22 includes a main body 221 and a pole ear 222, wherein a protective member 25 is provided on the side of the second pole piece 22 facing away from the first pole piece 21, and the protective member 25 covers at least a portion of the main body 221 of the second pole piece 22 and extends to at least one edge of the main body 221 of the second pole piece 22.

[0058] The battery cell 100 includes a housing 10 and an electrode assembly 20. The housing 10 is used to accommodate the electrode assembly 20 and components such as electrolyte. The housing 10 may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite housing 10), or an aluminum-plastic film. As an example, the housing 10 may include a shell 11 and an end cap 12.

[0059] The battery cell 100 also includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0060] The electrode assembly 20 includes a positive electrode, a negative electrode and a separator 24. During the charge and discharge process of the battery cell 100, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode. The separator 24 is arranged between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting and allow active ions to pass through. The positive electrode can be a positive electrode sheet, and the negative electrode can be a negative electrode sheet. Multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and multiple positive electrode sheets and multiple negative electrode sheets are alternately stacked to form a laminated electrode assembly 20.

[0061] like Figure 5 As shown, there may be multiple isolation membranes, and an isolation membrane is provided between two adjacent pole pieces, such as Figure 6 As shown, the isolation membrane may be one, or a plurality of isolation membranes may be bent so that a portion of the isolation membrane is provided between two adjacent pole pieces.

[0062] In some examples, the electrode assembly 20 is a stacked structure, and the electrode assembly 20 includes two pole pieces, namely a first pole piece 21 and a second pole piece 22. The second pole piece 22 includes a main body 221 and a pole ear 222. The pole ear 222 is led out from one end of the main body 221. Most areas of the pole ear 222 are not coated with positive electrode active materials, and most areas of the main body 221 are coated with active materials.

[0063] The first pole piece 21 and the second pole piece 22 are arranged along the stacking direction, wherein a protective member 25 is further disposed on the outer side of the second pole piece 22 .

[0064] In some examples, such as Figure 3-Figure 6 As shown, the electrode assembly 20 is a laminated structure, and the electrode assembly 20 includes a plurality of pole pieces, and along the stacking direction F1, the plurality of pole pieces sequentially include a first pole piece 21, a plurality of intermediate pole pieces 23, and a second pole piece 22, and the first pole piece 21 and the second pole piece 22 are two pole pieces located at opposite ends in the stacking direction F1, wherein a protective member 25 is further provided on the outer side of the second pole piece 22. Here, the second pole piece 22 may be a negative pole piece.

[0065] It should be noted that here multiple pole pieces are arranged along the stacking direction F1, that is, during assembly, the first pole piece 21 is arranged at the bottom layer, and then multiple intermediate pole pieces 23 are arranged, and finally the second pole piece 22 is arranged. The second pole piece 22 is arranged at the top layer, and thus a protective member 25 is provided on the outside of the second pole piece 22.

[0066] Among them, the protective member 25 covers at least a portion of the main body 221 of the second pole piece 22 and extends to at least one edge of the main body 221 of the second pole piece 22. Here, the protective member 25 extending to the edge of the main body 221 means that the outer edge of the protective member 25 can be aligned with the edge of the main body 221 of the second pole piece 22.

[0067] Specifically, the protective member 25 can cover the entire main body 221 of the second pole piece 22. When the electrode assembly 20 of this design is assembled, after the second pole piece 22 covers the last layer of multiple pole pieces, the pressure claw 30 can be pressed on the protective member 25 to press the multiple pole pieces together. After the isolation membrane 24 covers the second pole piece 22, since the protective member 25 covers the entire main body 221 of the second pole piece 22, the pressure claw 30 can be pulled out from any direction without friction with the main body 221 of the second pole piece 22, thereby avoiding contact and friction between the pressure claw 30 and the second pole piece 22, which may cause damage to the pole piece.

[0068] The protective member 25 can also cover a portion of the main body 221 of the second pole piece 22, and the protective member 25 can extend along a direction to an edge of the main body 221 of the second pole piece 22. For example, the first edge and the second edge of the main body 221 are opposite to each other along the first direction F1. Along the first direction F1, the protective member 25 extends to the first edge of the main body 221 of the second pole piece 22, and is arranged at a distance from the second edge. When the electrode assembly 20 of this design is assembled, after the second pole piece 22 covers the last layer of multiple pole pieces, the pressure claw 30 is pressed on the protective member 25 to press the multiple pole pieces together. After the isolation membrane 24 covers the second pole piece 22, the pressure claw 30 can be withdrawn from the first edge side of the main body 221 along the first direction F1, so that the pressure claw 30 will not rub against the main body 221 of the second pole piece 22, thereby avoiding contact and friction between the pressure claw 30 and the second pole piece 22, resulting in damage to the pole piece.

[0069] The protective member 25 may also cover a portion of the main body 221 of the second pole piece 22, and the protective member 25 extends in multiple directions to the edges of the main body 221 of the second pole piece 22 in the corresponding directions. For example, the main body 221 has a first edge and a second edge opposite to each other along the first direction F1, and a third edge and a fourth edge opposite to each other along the third direction F3. The protective member 25 covers the main body 221. In this case, the protective member 25 may extend to the first edge and the third edge, and be spaced apart from the second edge and the fourth edge, or a protective member 25 may extend to the first edge and be spaced apart from the second edge. The second pole piece 22 is arranged at intervals, and another protective member 25 extends to the third edge and is arranged at intervals with the fourth edge; when the electrode assembly 20 of this design is assembled, after the second pole piece 22 covers the last layer of multiple pole pieces, the pressing claw 30 is pressed on the protective member 25 to press the multiple pole pieces together. After the isolation membrane 24 covers the second pole piece 22, the pressing claw 30 can be pulled out from the first edge side or the third edge side of the main body 221 along the first direction F1, so that the pressing claw 30 will not rub against the main body 221 of the second pole piece 22, thereby avoiding contact and friction between the pressing claw 30 and the second pole piece 22, thereby avoiding damage to the pole piece, etc.

[0070] In the above-mentioned embodiment, when the electrode assembly 20 is manufactured, when the pressing claw 30 performs the pressing action, the pressing claw 30 can be pressed on the protective member 25, and the multiple pole pieces are pressed by pressing the protective member 25. The pressing claw 30 will not directly contact the second pole piece 22, but the multiple pole pieces can be pressed by pressing the protective member 25. At the same time, when the pressing claw 30 is pulled out, in some embodiments, the pressing claw 30 is pulled out from one side of the main body 221, and in some embodiments, multiple pressing claws 30 are pulled out from multiple sides of the main body 221. Since the protective member 25 extends to the side edge, the probability of the pressing claw 30 contacting the second pole piece 22 during the withdrawal process can be avoided, and the pole piece damage caused by friction can be avoided to a certain extent, thereby avoiding the burning and fire of the isolation membrane 24.

[0071] According to the battery cell 100 of the embodiment of the present application, by providing a protective member 25 on the second pole piece 22 of the electrode assembly 20, it is avoided that the pressure claw 30 is in contact with the second pole piece 22 and causes the pole piece to be damaged, thereby avoiding burning and catching fire of the isolation membrane 24, thereby improving the qualified rate of the electrode assembly 20; and because the protective member 25 covers the second pole piece 22 and extends to the edge, the protective member 25 can strengthen the second pole piece 22, improve the strength at the edge of the second pole piece 22, further avoid collision and damage to the edge of the pole piece during the subsequent assembly process, and improve the qualified rate of the battery cell 100 after assembly.

[0072] like Figure 7 As shown, in some embodiments, the main body 221 of the second pole piece 22 is square and has four corners, and a protective member 25 is provided on a side of each corner facing away from the first pole piece 21 .

[0073] In some examples, in order to better press the pole piece, especially for some pole pieces with larger sizes, the pressing claws 30 can be pressed at the four corners of the pole piece. Figure 7 As shown, four protective members 25 are provided on the main body 221 of the second pole piece 22, and the four protective members 25 correspond to the four corners of the second pole piece 22 one by one, wherein the protective member 25 can cover the corners, each corner has two adjacent edges, and the protective member 25 can extend to the two edges of the corners. It should be noted that the corners here are the four corners of the second pole piece 22, and the specific size is not limited. The protective member 25 covers the corresponding corners, which may be part of the corner or completely cover the corner. Preferably, the size of the protective member 25 is larger than the size of the pressure claw 30 covering the second pole piece 22, so that the pressure claw 30 will not contact the second pole piece 22.

[0074] Therefore, when the electrode assembly 20 is manufactured, the pressure claws 30 are located at the four corners of the pole piece, so that the clamping action of multiple pole pieces can be realized. At this time, by setting the pressure claws 30 at the four corners of the second pole piece 22, the pressure claws 30 can be separated from the second pole piece 22, so as to avoid contact and friction between the pressure claws 30 and the second pole piece 22, which may cause damage to the pole piece, thereby avoiding burning and ignition of the isolation membrane 24; and the size of the protective component 25 can be reduced, which is convenient for the manufacturing and forming of the protective component 25.

[0075] like Figure 7 As shown, in some embodiments, the main body 221 of the second pole piece 22 is square, the length dimension of the main body 221 is L1, and the minimum dimension of the protective member 25 in the length direction F2 of the second pole piece 22 is L2, 0.1L1≤L2≤0.5L1.

[0076] like Figure 7 As shown, the main body 221 is rectangular, and the length dimension of the main body 221 is L1. In the length direction F2, the minimum dimension of the protective member 25 is L2. If the dimension of the protective member 25 in this direction is too small, the protective effect of the protective member 25 is poor, and it is difficult to effectively separate the pressing claw 30 from the second pole piece 22. If the dimension of the protective member 25 in this direction is too large, multiple protective members 25 are prone to overlap, and it is easy to cause waste of the protective member 25. For this reason, L2 is limited to between 0.1L1-0.5L1, and L2 can be any point value among 0.1L1, 0.2L1, 0.3L1, 0.4L1, and 0.5L1, or a range value between any two points.

[0077] Therefore, the protective member 25 can effectively protect the main body 221 of the second pole piece 22 , and can also prevent the protective member 25 from being too large to affect the arrangement of the protective member 25 on the second pole piece 22 .

[0078] like Figure 7 As shown, in some embodiments, the main body 221 of the second pole piece 22 is square and has a width dimension B1, and the minimum dimension of the protective member 25 in the width direction F3 of the second pole piece 22 is B2, 0.1B1≤B2≤0.5B1.

[0079] like Figure 7 As shown, the main body 221 is a rectangle, and the width dimension of the main body 221 is B1. In the width direction F3, the minimum dimension of the protective member 25 is B2. If the dimension of the protective member 25 in this direction is too small, the protective effect of the protective member 25 is poor, and it is difficult to effectively separate the pressing claw 30 from the second pole piece 22. If the dimension of the protective member 25 in this direction is too large, multiple protective members 25 are prone to overlap, and it is easy to cause waste of the protective member 25. For this reason, B2 is limited to between 0.1B1-0.5B1, and B2 can be any point value among 0.1B1, 0.2B1, 0.3B1, 0.4B1, and 0.5B1, or a range value between any two points.

[0080] Therefore, the protective member 25 can effectively protect the main body 221 of the second pole piece 22 , and can also prevent the protective member 25 from being too large to affect the arrangement of the protective member 25 on the second pole piece 22 .

[0081] Correspondingly, the second pole piece 22 may also be a square, and in this case, the length direction F2 of the second pole piece 22 may also be the width direction F3.

[0082] like Figure 5 and Figure 6 As shown, in some embodiments, the thickness of the main body 221 of the second pole piece 22 is H1, the maximum thickness of the protection member 25 is H2, and 0.5H1≤H2≤2H1.

[0083] The main body 221 of the second pole piece 22 has a thickness H1 , where the thickness here refers to the dimension in the stacking direction F1 .

[0084] If the thickness of the protective member 25 is too small, on the one hand, the protective member 25 that is too thin is difficult to manufacture and mold, and on the other hand, the protective member 25 that is too thin is difficult to effectively protect the second pole piece 22. If the thickness of the protective member 25 is too large, the protective member 25 that is too thick will protrude too much from the second pole piece 22, which will not only affect the assembly of the electrode assembly 20, but also occupy additional space in the battery cell 100, resulting in a decrease in energy density. For this reason, the thickness H2 of the protective member 25 can be limited to between 0.5H1-2H1, and H2 can be any point value among 0.5H1, 0.6H1, 0.7H1, 0.8H1, 0.9H1, 1H1, 1.1H1, 1.2H1, 1.3H1, 1.4H1, 1.5H1, 1.6H1, 1.7H1, 1.8H1, 1.9H1, and 2H1, or a range value between any two points.

[0085] Therefore, the protective member 25 can effectively protect the main body 221 of the second pole piece 22 without occupying too much space, thereby avoiding a reduction in the energy density of the battery cell 100 to a certain extent.

[0086] like Figure 8 As shown, in some embodiments, the protective member 25 includes at least one protective layer 251 and a heat absorption layer 252 having heat absorption properties. The protective layer 251 and the heat absorption layer 252 are arranged along the stacking direction F1 of the electrode assembly 20, and a protective layer 251 is provided on the side of the heat absorption layer 252 facing away from the second electrode sheet 22.

[0087] It can be understood that the protective layer 251 can be used to protect the heat absorption layer 252, and at the same time, the heat absorption layer 252 can be separated from the pressing claw 30. When the pressing claw 30 is withdrawn, even if the friction between the pressing claw 30 and the protective member 25 generates a certain amount of heat, the protective layer 251 can transfer the heat to the heat absorption layer 252, and the heat is absorbed by the heat absorption layer 252, thereby reducing the temperature there, further avoiding the probability of the isolation film 24 being burned, and improving the reliability and qualification of the battery cell 100.

[0088] like Figure 8 As shown, in some embodiments, the protective layer 251 includes two layers, and the heat absorption layer 252 is sandwiched between the two protective layers 251 .

[0089] The protective member 25 forms a three-layer sandwich structure, thereby protecting the heat absorption layer 252 between the two protective layers 251, which can improve the stability of the overall structure, and to a certain extent avoid the heat absorption layer 252 absorbing heat and causing phase change or deformation, which affects the protection reliability of the protective member 25, and at the same time avoid the heat absorption layer 252 from directly contacting the second pole piece 22 to produce other adverse effects.

[0090] In some embodiments, the heat absorption layer 252 is a paraffin layer. By using paraffin material, when the protective member 25 rubs against the pressure claw 30, the heat absorption layer 252 can absorb the heat generated by friction through phase change, thereby reducing the probability of heat transfer to the second pole piece 22, reducing the probability of the second pole piece 22 being burned, and improving the reliability and qualification of the electrode assembly 20.

[0091] In some embodiments, the protective layer 251 is a polyolefin layer. By using polyolefin materials, the protective layer 251 can effectively protect the heat absorption layer 252. The polyolefin material has good chemical stability and insulation properties, and the material is easy to process and manufacture, which is convenient for large-scale manufacturing and use of the protective part 25.

[0092] In some embodiments, the protective member 25 is bonded to the second pole piece 22, thereby achieving a fixed connection between the protective member 25 and the second pole piece 22, simplifying the assembly process, facilitating assembly and molding, reducing manufacturing difficulty, and reducing manufacturing costs.

[0093] like Figure 8 As shown, in some embodiments, a glue coating layer 253 is provided on a side of the protection member 25 facing the second pole piece 22 .

[0094] During the manufacturing process, a glue layer 253 can be preset on the protective member 25. When the protective member 25 is placed on the second pole piece 22, the glue layer 253 contacts the second pole piece 22, so that the protective member 25 and the second pole piece 22 can be bonded, and the connection is convenient.

[0095] Of course, the protection member 25 can also be bonded to the second pole piece 22 by adhesive.

[0096] In some embodiments, the material of the protection member 25 includes one of polypropylene, polyethylene, and polyethylene terephthalate.

[0097] The protective member 25 here can be a single-layer structural member, the protective member 25 is a polypropylene layer, or a polyethylene layer, or a polyethylene terephthalate layer. Of course, the protective member 25 can also be a multi-layer material member, in which case one layer of the protective member 25 is a polypropylene layer, or a polyethylene layer, or a polyethylene terephthalate layer.

[0098] By adopting the above materials, the protective member 25 has good chemical stability and insulation, and is easy to process and manufacture, with low cost, which facilitates large-scale manufacturing and use of the protective member 25.

[0099] like Figure 5 and Figure 6As shown, in some embodiments, the side of the protective member 25 facing away from the second pole piece 22 is a smooth plane, thereby reducing the friction between the pressure claw 30 and the protective member 25 when the pressure claw 30 is pulled out, reducing the probability of wear of the protective member 25, and facilitating the withdrawal of the pressure claw 30 and reducing movement obstacles.

[0100] In some embodiments, the protective member 25 has a Shore hardness of 30A-90A.

[0101] It is understandable that when the hardness of the protective member 25 is too low, it is difficult for the protective member 25 to play an effective protective role. When the pressure claw 30 is pulled out, there is a risk of deformation of the protective member 25, resulting in the second pole piece 22 still being worn. When the hardness of the protective member 25 is too high, after the electrode assembly 20 provided with the protective member 25 is put into the shell, the protective member 25 will collide with the outer shell 10 of the battery cell 100, thereby damaging the outer shell 10 or the electrode assembly 20. For this reason, the Shore hardness of the protective member 25 is limited to between 30A and 90A. The Shore hardness of the protective member 25 can be any point value among 30A, 40A, 50A, 60A, 70A, 80A, and 90A, or a range value between any two points.

[0102] Therefore, the protection member 25 can not only effectively protect the second pole piece 22 , but also improve the qualified rate of the battery cell 100 after assembly.

[0103] The battery 1000 according to the second aspect of the present application includes the battery cell 100 according to the first aspect of the present application. By adopting the battery cell 100, the manufacturing efficiency of the battery 1000 can be improved and the probability of unqualified products can be reduced.

[0104] The electric device 2000 according to the third embodiment of the present application includes the battery 1000 according to the second embodiment of the present application, and the battery 1000 is used to provide electric energy for the electric device 2000. Therefore, by using the above battery 1000, it is beneficial to improve the safety and reliability of the electric device 2000.

[0105] Alternatively, if Figure 1 As shown, when the battery 1000 is used in a vehicle, the battery 1000 can be arranged at the bottom, head, or tail of the vehicle. The battery 1000 can be used to power the vehicle, for example, the battery 1000 can be used as an operating power source for the vehicle. The vehicle can also include a controller and a motor, and the controller is used to control the battery 1000 to power the motor, for example, for starting, navigating, and driving the vehicle.

[0106] A battery 1000 and a vehicle having the same according to a specific embodiment of the present application will be described below with reference to the accompanying drawings.

[0107] like Figure 1As shown, the battery 1000 is disposed at the bottom of the vehicle, and as Figure 2 and Figure 3 As shown, the battery 1000 includes a box body 200 and a battery cell 100. The battery cell 100 includes a shell 10 and an electrode assembly 20. The electrode assembly 20 is a laminated type.

[0108] like Figure 5 , Figure 7 and Figure 8 As shown, the electrode assembly 20 includes a plurality of electrode sheets and an isolation membrane 24 arranged in a stacked manner. Along the stacking direction, the plurality of electrode sheets sequentially include a first electrode sheet 21, a plurality of intermediate electrode sheets 23 and a second electrode sheet 22. The plurality of intermediate electrode sheets 23 are located between the first electrode sheet 21 and the second electrode sheet 22. The second electrode sheet 22 includes a main body 221 and an electrode ear 222. The main body 221 is square and has four corners. A protective member 25 is provided on the side of each corner facing away from the intermediate electrode sheet 23.

[0109] In the length direction F2 of the main body 221 , the minimum dimension of each protection member 25 is L2 , the length dimension of the main body 221 is L1 , and 0.1L1≤L2≤0.5L1 .

[0110] In the width direction F3 of the main body 221 , the minimum dimension of each protection member 25 is B2 , the width dimension of the main body 221 is B1 , and 0.1B1≤B2≤0.5B1.

[0111] In the stacking direction F1 , the thickness of the main body 221 is H1 , the maximum thickness of the protection member 25 is H2 , and 0.5H1≤H2≤2H1.

[0112] The protective member 25 includes two protective layers 251 and a heat absorbing layer 252 . The heat absorbing layer 252 is disposed between the two protective layers 251 . The heat absorbing layer 252 is a paraffin layer, and the protective layer 251 is a polyolefin layer.

[0113] The protective member 25 also has a rubber coating layer 253 . The size of the rubber coating layer 253 may be slightly smaller than the sizes of other layers, or may be the same as the sizes of other layers. The protective member 25 is bonded to the second pole piece 22 via the rubber coating layer 253 .

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: An electrode assembly, the electrode assembly comprising a plurality of pole pieces and a separator arranged in a stacked manner, wherein along the stacking direction, the plurality of pole pieces at least comprise a first pole piece and a second pole piece located at opposite ends in the stacking direction, the second pole piece comprising a main body and a pole ear, A protective member is provided on a side of the second pole piece facing away from the first pole piece, and the protective member covers at least a portion of a main body of the second pole piece and extends to at least one edge of the main body.

2. The battery cell according to claim 1, characterized in that: The main body of the second pole piece is square and has four corners, and a protective member is respectively provided on a side of each corner away from the first pole piece.

3. The battery cell according to claim 2, characterized in that: The main body of the second pole piece is square and has a length dimension of L1. The minimum dimension of the protective member in the length direction of the second pole piece is L2, and 0.1L1≤L2≤0.5L1.

4. The battery cell according to claim 2, characterized in that: The main body of the second pole piece is square and has a width dimension of B1. The minimum dimension of the protective member in the width direction of the second pole piece is B2, and 0.1B1≤B2≤0.5B1.

5. The battery cell according to claim 1, characterized in that: The thickness of the main body of the second pole piece is H1, the maximum thickness of the protection member is H2, and 0.5H1≤H2≤2H1.

6. The battery cell according to claim 1, characterized in that: The protective member includes at least one protective layer and a heat absorbing layer with heat absorbing performance, the protective layer and the heat absorbing layer are arranged along the stacking direction of the electrode assembly, and a layer of the protective layer is provided on a side of the heat absorbing layer away from the second pole piece.

7. The battery cell according to claim 6, characterized in that: The protective layer includes two layers, and the heat absorption layer is sandwiched between the two protective layers.

8. The battery cell according to claim 6, characterized in that: The heat absorption layer is a paraffin layer; and / or the protective layer is a polyolefin layer.

9. The battery cell according to claim 1, characterized in that: The protective member is bonded to the second pole piece.

10. The battery cell according to claim 9, characterized in that: A rubber coating layer is provided on one side of the protective member facing the second pole piece.

11. The battery cell according to claim 1, characterized in that: The material of the protection piece includes one of polypropylene, polyethylene and polyethylene terephthalate.

12. The battery cell according to claim 1, characterized in that: A side of the protection member facing away from the second pole piece is a smooth plane.

13. The battery cell according to any one of claims 1 to 12, characterized in that: The Shore hardness of the protective member is 30A-90A.

14. A battery, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 13.

15. An electrical device, characterized in that: A battery according to claim 14, for providing electrical energy.

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