Battery cell, battery and electrical apparatus

Abstract

A battery cell (100), a battery (1000), and an electrical apparatus (2000). The battery cell (100) comprises: an electrode assembly (20), the electrode assembly (20) comprising, arranged in a stacked configuration, a plurality of electrode sheets and a separator. In the stacking direction, the plurality of electrode sheets at least comprise a first electrode sheet (21) and a second electrode sheet (22) which are located at two opposite ends in the stacking direction, the second electrode sheet (22) comprising a main body part (221) and tabs (222). The side of the second electrode sheet (22) facing away from the first electrode sheet (21) is provided with a protection member (25), the protection member (25) covering at least a portion of the main body part (221) of the second electrode sheet (22) and extending to at least one edge of the main body part (221).

Description

Battery cells, batteries and electrical devices Technical Field

[0001] This application relates to the field of batteries, specifically to a battery cell, a battery, and an electrical device. Background Technology

[0002] Stacked battery cells have higher energy density and relatively stable internal structure.

[0003] In actual production, the pressing claws of the stacking machine need to move outward in a direction parallel to the electrode sheet. At this time, they will rub against the surface of the electrode sheet, which may cause abrasions to the electrode sheet, or even damage to the separator, resulting in fire and other safety risks.

[0004] Summary of the Invention

[0005] In view of the above problems, this application provides a battery cell, a battery and an electrical device that can alleviate problems such as electrode scratches and separator damage that occur during the manufacturing process of the battery cell.

[0006] In a first aspect, this application provides a battery cell, comprising: an electrode assembly, the electrode assembly including a plurality of electrode sheets and a separator arranged in a stacked manner, wherein along the stacking direction, the plurality of electrode sheets include at least a first electrode sheet and a second electrode sheet located at opposite ends in the stacking direction, the second electrode sheet including a body portion and an electrode tab, wherein a protective member is provided on the side of the second electrode sheet opposite to the first electrode sheet, and the protective member covers at least a portion of the body portion and extends to at least one edge of the body portion.

[0007] In the technical solution of this application embodiment, by providing a protective component on the main body of the second electrode of the electrode assembly, the contact friction between the pressure claw and the second electrode is avoided, which may cause the electrode to break, thereby preventing the separator from burning or catching fire, and improving the pass rate of the electrode assembly. Moreover, since the protective component covers the main body and extends to the edge, the protective component can strengthen the second electrode, improve the strength at the edge of the main body of the second electrode, and further prevent the electrode edge from being bumped or broken during subsequent assembly, thereby improving the pass rate of the battery cell after assembly.

[0008] In some embodiments, the main body of the second electrode is square and has four corners, and a protective member is provided on the side of each corner opposite to the first electrode. In the above technical solution, by providing pressure claws at the four corners of the second electrode, the pressure claws can be separated from the second electrode, avoiding contact friction between the pressure claws and the second electrode that could cause electrode breakage, thereby preventing the separator from burning or catching fire; moreover, the size of the protective member can be reduced, making it easier to manufacture and form the protective member.

[0009] In some embodiments, the main body of the second electrode is square and its length is L1, and the minimum dimension of the protective member in the length direction of the second electrode is L2, where 0.1L1≤L2≤0.5L1. In the above technical solution, the protective member can effectively protect the second electrode while avoiding the protective member being too large and affecting its arrangement on the second electrode.

[0010] In some embodiments, the main body of the second electrode is square and the width of the main body is B1, and the minimum dimension of the protective member in the width direction of the second electrode is B2, where 0.1B1≤B2≤0.5B1. In the above technical solution, the protective member can effectively protect the second electrode while avoiding the protective member being too large and affecting its arrangement on the second electrode.

[0011] In some embodiments, the thickness of the main body of the second electrode is H1, and the maximum thickness of the protective member is H2, where 0.5H1≤H2≤2H1. In the above technical solution, the protective member can effectively protect the second electrode without occupying too much space, thus avoiding a reduction in the energy density of the battery cell to a certain extent.

[0012] In some embodiments, the protective element includes at least one protective layer and a heat-absorbing layer with heat-absorbing properties. The protective layer and the heat-absorbing layer are arranged along the stacking direction of the electrode assembly, and the protective layer is disposed on the side of the heat-absorbing layer opposite to the second electrode. In the above technical solution, even if the pressure claw generates a certain amount of heat due to friction between the pressure claw and the protective element when the pressure claw is withdrawn, the protective layer can transfer the heat to the heat-absorbing layer, which absorbs the heat, thereby reducing the temperature at that location. This further avoids the probability of the separator being burned, improving the reliability and qualification of the battery cell.

[0013] In some embodiments, the protective layer comprises two layers, with the heat-absorbing layer sandwiched between the two protective layers. In the above technical solution, protecting the heat-absorbing layer between the two protective layers can improve the stability of the overall structure, and to a certain extent avoid the heat-absorbing layer absorbing heat and undergoing phase changes or deformations that could affect the reliability of the protective component. It also avoids direct contact between the heat-absorbing layer and the second electrode, preventing other adverse effects.

[0014] In some embodiments, the heat-absorbing layer is a paraffin layer. In the above technical solution, by using paraffin material, when the protective component rubs against the pressure claw, the heat-absorbing layer can absorb the heat generated by friction through phase change, reducing the probability of heat being transferred to the second electrode, reducing the probability of the second electrode being burned, and improving the reliability and qualification of the electrode assembly.

[0015] 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-absorbing layer. Polyolefin materials have good chemical stability, insulation properties, and are easily processed and manufactured, facilitating the large-scale manufacturing and use of protective components.

[0016] In some embodiments, the protective component is bonded to the second electrode. This achieves a fixed connection between the protective component and the second electrode, simplifies the assembly process, facilitates assembly, reduces manufacturing difficulty, and lowers manufacturing costs.

[0017] In some embodiments, an adhesive layer is provided on the side of the protective component facing the second electrode. In the above technical solution, during the manufacturing process, an adhesive layer can be pre-formed on the protective component. When the protective component is placed on the second electrode, the adhesive layer contacts the second electrode, thereby achieving adhesion between the protective component and the second electrode, making the connection convenient.

[0018] In some embodiments, the material of the protective component includes one of polypropylene, polyethylene, and polyethylene terephthalate. In the above technical solution, by using the above materials, the protective component possesses good chemical stability, insulation properties, and is easy to process and manufacture, resulting in low cost and facilitating large-scale manufacturing and use.

[0019] In some embodiments, the side of the protective member facing away from the second electrode is a smooth plane. This reduces friction between the pressure claw and the protective member during extraction, lowers the probability of wear on the protective member, and facilitates extraction of the pressure claw while minimizing obstruction.

[0020] In some embodiments, the Shore hardness of the protective component is 30A-90A. In the above technical solution, the protective component can effectively protect the second electrode and improve the yield rate of the assembled battery cells.

[0021] Secondly, this application provides a battery that includes the battery cell described in the above embodiments.

[0022] Thirdly, this application provides an electrical device that includes the battery described in the above embodiments, the battery being used to provide electrical energy.

[0023] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0025] Figure 1 is a schematic diagram of an electrical device in the related technology;

[0026] Figure 2 is a schematic diagram of a battery in the related technology;

[0027] Figure 3 is a schematic diagram of a battery cell provided in some embodiments of this application;

[0028] Figure 4 is a schematic diagram of the production and processing of battery cells according to some embodiments of this application;

[0029] Figure 5 is a schematic diagram of electrode assemblies according to some embodiments of this application;

[0030] Figure 6 is a schematic diagram of electrode assemblies according to some other embodiments of this application;

[0031] Figure 7 is a schematic diagram of the second electrode sheet in some embodiments of this application;

[0032] Figure 8 is a schematic diagram of the protective element of some embodiments of this application.

[0033] Reference numerals: Battery 1000, Electrical device 2000, Battery cell 100, Housing 200, First part 210, Second part 220, Outer shell 10, Housing 11, End cap 12, Electrode assembly 20, First electrode 21, Second electrode 22, Main body 221, Electrode tab 222, Intermediate electrode 23, Separator 24, Protective component 25, Protective layer 251, Heat-absorbing layer 252, Adhesive layer 253, Claw 30. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0036] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0037] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0039] In the embodiments of this application, the same reference numerals denote 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 this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0040] In this application, "multiple" means two or more (including two).

[0041] In this application, a battery refers to a single physical module comprising one or more individual 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 housing for encapsulating one or more individual battery cells or multiple battery modules. The housing can prevent liquids or other foreign matter from affecting the charging or discharging of the individual battery cells. Of course, some batteries may not require the aforementioned housing and may be directly installed within the battery mounting compartment of the electrical device.

[0042] In this application, the battery cell 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 this application are not limited to these. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited to these. Battery cells are generally divided into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells, and the embodiments of this application are not limited to these.

[0043] For example, a battery cell may include a casing, electrode assembly, and electrolyte. The casing houses the electrode assembly and electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrode plates. The positive electrode includes a positive electrode body and a positive electrode tab. The positive electrode tab extends from one end of the positive electrode body, and most of the area of ​​the positive electrode tab is not coated with positive active material, while most of the area of ​​the positive electrode body is coated with positive active material. The negative electrode includes a negative electrode body and a negative electrode tab. The negative electrode tab extends from one end of the negative electrode body, and most of the area of ​​the negative electrode tab is not coated with negative active material, while most of the area of ​​the negative electrode body is coated with negative active material.

[0044] To ensure that a large current can pass through without melting, there are multiple positive electrode tabs stacked together, and there are multiple negative electrode tabs stacked together.

[0045] The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0046] A battery cell can be equipped with terminals or tabs that connect to the terminals, serving as the electrical connection points for the battery cell. Furthermore, the battery cell can have a pressure relief section. In the event of excessive internal pressure (such as thermal runaway), the pressure relief section releases substances (such as gases, liquids, or particulate matter) from inside the battery cell, reducing the internal pressure and preventing rapid pressurization that could lead to dangerous accidents such as battery cell explosion. For example, the pressure relief section can be an explosion-proof valve, an explosion-proof plate, etc.

[0047] For example, as shown in Figures 1 and 2, some electrical devices 2000 are powered by a battery 1000. 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. As shown in Figure 3, the battery cell 100 includes a housing 10 and an electrode assembly 20. The electrode assembly 20 includes an electrode sheet and a separator 24. Some electrode assemblies 20 are stacked, with the electrode sheet and separator 24 stacked in layers, as shown in Figure 4. In the traditional actual production process, after the last layer of electrode sheets is arranged, the pressing claw 30 of the stacking machine will press the electrode sheet downward with a predetermined pressure, and then cover the last layer of electrode sheets with the separator 24. Finally, the pressing claw 30 is removed. The pressing claw 30 cannot be lifted upward, as lifting it will cause the outermost separator 24 to be lifted, and the separator 24 will not achieve a protective effect. Therefore, the pressing claw 30 can only be pulled outward in a direction parallel to the electrode sheet and separator 24. At this time, the pressing claw 30 will generate heat by friction with the surface of the electrode sheet, resulting in electrode sheet abrasion and separator 24 damage. Furthermore, some battery cells 100 undergo lithium replenishment on the outermost negative electrode. When the claw 30 is pulled outward, it generates heat through friction with the lithium layer on the surface of the outermost negative electrode, which can cause the separator 24 to burn or even catch fire, posing a safety risk.

[0048] Therefore, this application proposes a battery cell 100, as shown in Figures 3 and 5. The battery cell 100 includes an electrode assembly 20, which includes a plurality of electrode sheets and a separator 24 arranged in a stacked manner. Along the stacking direction, the plurality of electrode sheets include at least a first electrode sheet 21 and a second electrode sheet 22 located at opposite ends in the stacking direction F1. The second electrode sheet 22 includes a main body portion 221 and an electrode tab 222. 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 portion 221 of the second electrode sheet 22 and extends to at least one edge of the main body portion 221.

[0049] In the battery cell 100 with the above-described structure, by providing a protective member 25 on the main body 221 of the second electrode 22 of the electrode assembly 20, the contact friction between the pressure claw 30 and the second electrode 22 is prevented from causing electrode breakage, thereby preventing the separator 24 from burning or catching fire, and improving the pass rate of the electrode assembly 20. Moreover, since the protective member 25 covers the main body 221 of the second electrode 22 and extends to the edge, the protective member 25 can strengthen the main body 221 of the second electrode 22, improve the strength at the edge of the main body 221 of the second electrode 22, and further prevent the electrode edge from being bumped or broken during subsequent assembly, thereby improving the pass rate of the battery cell 100 after assembly.

[0050] As shown in Figure 1, the battery 1000 with a battery cell 100 disclosed in this application embodiment can be used, but is not limited to, in electrical devices 2000 such as vehicles, ships or aircraft. The power system of the electrical device 2000 can be composed of the battery 1000 disclosed in this application to ensure the safety and reliability of the electrical device 2000.

[0051] For example, the electrical device 2000 disclosed in this application embodiment may be, but is not limited to, vehicles, mobile phones, tablets, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles may be fuel vehicles, natural gas vehicles, new energy vehicles, or rail vehicles; new energy vehicles may be pure electric vehicles, hybrid vehicles, or range-extended vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0052] Hereinafter, with reference to the accompanying drawings, a battery cell 100 according to an embodiment of the present application will be described.

[0053] As shown in Figures 3-8, the battery cell 100 according to an embodiment of this application includes an electrode assembly 20. The electrode assembly 20 includes a plurality of electrode sheets and a separator 24 arranged in a stacked manner. Along the stacking direction F1, the plurality of electrode sheets include at least a first electrode sheet 21 and a second electrode sheet 22 located at opposite ends in the stacking direction. The second electrode sheet 22 includes a main body portion 221 and an electrode tab 222. 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 portion 221 of the second electrode sheet 22 and extends to at least one edge of the main body portion 221 of the second electrode sheet 22.

[0054] The battery cell 100 includes a housing 10 and an electrode assembly 20. The housing 10 is used to house the electrode assembly 20 and components such as the electrolyte. The housing 10 can be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing 10), or an aluminum-plastic film, etc. As an example, the housing 10 may include a shell 11 and an end cap 12.

[0055] The battery cell 100 also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0056] The electrode assembly 20 includes a positive electrode, a negative electrode, and a separator 24. During the charging and discharging process of the battery cell 100, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator 24 is disposed between the positive and negative electrodes to prevent short circuits between the positive and negative electrodes while allowing 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 and negative electrode sheets can be provided respectively, and multiple positive and negative electrode sheets are alternately stacked to form a stacked electrode assembly 20.

[0057] As shown in Figure 5, there can be multiple separators, with one separator between two adjacent electrodes. As shown in Figure 6, there can be one separator, and multiple separators can be bent so that there is a portion of separator between two adjacent electrodes.

[0058] In some examples, the electrode assembly 20 is a stacked structure, which includes two electrodes, namely a first electrode 21 and a second electrode 22. The second electrode 22 includes a main body 221 and a tab 222. The tab 222 extends from one end of the main body 221. Most of the area of ​​the tab 222 is not coated with positive active material, while most of the area of ​​the main body 221 is coated with active material.

[0059] The first electrode 21 and the second electrode 22 are arranged along the stacking direction, and the outer side of the second electrode 22 is also provided with a protective element 25.

[0060] In some examples, as shown in Figures 3-6, the electrode assembly 20 has a stacked structure. The electrode assembly 20 includes multiple electrodes. Along the stacking direction F1, the multiple electrodes sequentially include a first electrode 21, multiple intermediate electrodes 23, and a second electrode 22. The first electrode 21 and the second electrode 22 are two electrodes located at opposite ends in the stacking direction F1. A protective element 25 is also provided on the outside of the second electrode 22. Here, the second electrode 22 can be a negative electrode.

[0061] It should be noted that multiple electrodes are arranged along the stacking direction F1. That is, during assembly, the first electrode 21 is arranged at the bottom layer, then multiple intermediate electrodes 23 are arranged, and finally the second electrode 22 is arranged at the top layer. Thus, a protective element 25 is set on the outside of the second electrode 22.

[0062] The protective member 25 covers at least a portion of the main body 221 of the second electrode 22 and extends to at least one edge of the main body 221 of the second electrode 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 electrode 22.

[0063] Specifically, the protective member 25 can cover the entire body 221 of the second electrode 22. When the electrode assembly 20 with this design is assembled, after the second electrode 22 covers the last layer of multiple electrodes, the clamping claw 30 can press on the protective member 25 to press the multiple electrodes together. After the separator 24 covers the second electrode 22, since the protective member 25 covers the entire body 221 of the second electrode 22, the clamping claw 30 can be pulled out from any direction without rubbing against the body 221 of the second electrode 22, thus avoiding contact friction between the clamping claw 30 and the second electrode 22, which could lead to electrode breakage.

[0064] The protective member 25 may also cover a portion of the main body 221 of the second electrode 22, and the protective member 25 may extend in one direction to one edge of the main body 221 of the second electrode 22. For example, the first edge and the second edge of the main body 221 are opposite each other in the first direction F1. In the first direction F1, the protective member 25 extends to the first edge of the main body 221 of the second electrode 22 and is spaced apart from the second edge. When the electrode assembly 20 with this design is assembled, after the second electrode 22 covers the last layer of multiple electrodes, the clamping claw 30 presses on the protective member 25 to press the multiple electrodes together. After the separator 24 covers the second electrode 22, the clamping claw 30 can be pulled out from the first edge side of the main body 221 in the first direction F1, so that the clamping claw 30 will not rub against the main body 221 of the second electrode 22, thus avoiding contact friction between the clamping claw 30 and the second electrode 22, which may cause the electrode to break.

[0065] The protective member 25 may also cover a portion of the main body 221 of the second electrode 22, and the protective member 25 extends in multiple directions to the edges of the main body 221 of the second electrode 22 in corresponding directions. For example, the main body 221 has a first edge and a second edge opposite to each other along a first direction F1, and a third edge and a fourth edge opposite to each other along a third direction F3. The protective member 25 covers the main body 221, and 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 single protective member 25 may extend to the first edge and be spaced apart from the second edge. The electrode assembly 20 is arranged with a gap, and another protective member 25 extends to the third edge and is spaced apart from the fourth edge. When the electrode assembly 20 with this design is assembled, after the second electrode 22 covers the last layer of multiple electrodes, the clamping claw 30 presses on the protective member 25 to press the multiple electrodes together. After the separator 24 covers the second electrode 22, the clamping 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 clamping claw 30 will not rub against the main body 221 of the second electrode 22, thus avoiding contact friction between the clamping claw 30 and the second electrode 22, which may cause electrode breakage.

[0066] In the above embodiments, when the clamping claw 30 performs a clamping action during the manufacturing of the electrode assembly 20, the clamping claw 30 can press onto the protective member 25. By clamping the protective member 25, multiple electrode sheets are clamped together. The clamping claw 30 will not directly contact the second electrode sheet 22, but multiple electrode sheets can be clamped together by clamping the protective member 25. At the same time, when the clamping claw 30 is pulled out, in some embodiments the clamping claw 30 is pulled out from one side of the main body 221, and in some embodiments multiple clamping claws 30 are pulled out from multiple sides of the main body 221. Since the protective member 25 extends to the edge of that side, the probability of the clamping claw 30 contacting the second electrode sheet 22 during the pulling process can be avoided to a certain extent, avoiding friction that could cause electrode sheet damage, and thus avoiding the burning or ignition of the separator 24.

[0067] According to the embodiments of this application, the battery cell 100, by providing a protective member 25 on the second electrode 22 of the electrode assembly 20, avoids the contact friction between the pressure claw 30 and the second electrode 22, which could lead to electrode breakage, thereby preventing the separator 24 from burning or catching fire, and improving the pass rate of the electrode assembly 20; moreover, since the protective member 25 covers the second electrode 22 and extends to the edge, the protective member 25 can strengthen the second electrode 22, improve the strength at the edge of the second electrode 22, and further prevent the electrode edge from being bumped or broken during subsequent assembly, thereby improving the pass rate of the battery cell 100 after assembly.

[0068] As shown in Figure 7, in some embodiments, the main body 221 of the second electrode 22 is square and has four corners, and a protective member 25 is provided on the side of each corner away from the first electrode 21.

[0069] In some examples, to better compress the electrode, especially for some larger electrodes, the pressure claws 30 can be pressed against the four corners of the electrode. For this purpose, as shown in Figure 7, four protective members 25 are provided on the main body 221 of the second electrode 22. The four protective members 25 correspond one-to-one with the four corners of the second electrode 22. The protective members 25 can cover the corners, each corner has two adjacent edges, and the protective members 25 can extend to the two edges of the corner. It should be noted that the corners here refer to the four corners of the second electrode 22. The specific size is not limited. The protective members 25 cover the corresponding corners. This can be covering part of the corner or completely covering the corner. Preferably, the size of the protective members 25 is larger than the size of the pressure claws 30 covering the second electrode 22, so that the pressure claws 30 will not come into contact with the second electrode 22.

[0070] Therefore, during the manufacturing of the electrode assembly 20, the clamping claws 30 are located at the four corners of the electrode sheet, which can realize the clamping action of multiple electrode sheets. At this time, by setting the clamping claws 30 at the four corners of the second electrode sheet 22, the clamping claws 30 and the second electrode sheet 22 can be separated, avoiding contact friction between the clamping claws 30 and the second electrode sheet 22, which may cause the electrode sheet to break, thereby avoiding the burning and fire of the separator 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.

[0071] As shown in Figure 7, in some embodiments, the main body 221 of the second electrode 22 is square, the length of the main body 221 is L1, and the minimum dimension of the protective member 25 in the length direction F2 of the second electrode 22 is L2, 0.1L1≤L2≤0.5L1.

[0072] As shown in Figure 7, the main body 221 is rectangular, and its length is L1. In this length direction F2, the minimum size of the protective member 25 is L2. If the size of the protective member 25 in this direction is too small, the protective effect of the protective member 25 will be poor, and it will be difficult to effectively separate the pressure claw 30 from the second pole piece 22. If the size of the protective member 25 in this direction is too large, multiple protective members 25 are likely to overlap, and it will be easy to waste the protective member 25. Therefore, L2 is limited to between 0.1L1 and 0.5L1. L2 can be any point value or a range between any two points from 0.1L1, 0.2L1, 0.3L1, 0.4L1, and 0.5L1.

[0073] Thus, the protective element 25 can effectively protect the main body 221 of the second electrode 22, and also prevent the protective element 25 from having too much impact on the arrangement of the protective element 25 on the second electrode 22.

[0074] As shown in Figure 7, in some embodiments, the main body 221 of the second electrode 22 is square and the width dimension of the main body 221 is B1, and the minimum dimension of the protective member 25 in the width direction F3 of the second electrode 22 is B2, 0.1B1≤B2≤0.5B1.

[0075] As shown in Figure 7, the main body 221 is rectangular, and its width is B1. In this width direction F3, the minimum size of the protective member 25 is B2. If the size of the protective member 25 in this direction is too small, the protective effect of the protective member 25 will be poor, and it will be difficult to effectively separate the pressure claw 30 from the second pole piece 22. If the size of the protective member 25 in this direction is too large, multiple protective members 25 are likely to overlap, and it will be easy to waste the protective member 25. Therefore, B2 is limited to between 0.1B1 and 0.5B1. B2 can be any value among 0.1B1, 0.2B1, 0.3B1, 0.4B1, and 0.5B1, or a range between any two points.

[0076] Thus, the protective element 25 can effectively protect the main body 221 of the second electrode 22, and also prevent the protective element 25 from having too much impact on the arrangement of the protective element 25 on the second electrode 22.

[0077] Correspondingly, the second electrode 22 can also be square, and in this case, the length direction F2 of the second electrode 22 can also be the width direction F3.

[0078] As shown in Figures 5 and 6, in some embodiments, the thickness of the main body 221 of the second electrode 22 is H1, and the maximum thickness of the protective member 25 is H2, where 0.5H1≤H2≤2H1.

[0079] The thickness H1 of the main body 221 of the second electrode 22 is the dimension in the lamination direction F1.

[0080] If the thickness of the protective element 25 is too small, on the one hand, it will be difficult to manufacture and form an excessively thin protective element 25, and on the other hand, it will be difficult for an excessively thin protective element 25 to effectively protect the second electrode 22. If the thickness of the protective element 25 is too large, the excessively thick protective element 25 will protrude too much from the second electrode 22, which will affect the assembly of the electrode assembly 20 and occupy additional space within the battery cell 100, resulting in a reduction in energy density. Therefore, the thickness H2 of the protective element 25 can be limited to between 0.5H1 and 2H1. H2 can be any 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 between any two points.

[0081] Therefore, the protective component 25 can effectively protect the main body 221 of the second electrode 22 without taking up too much space, thus avoiding a certain degree of reduction in the energy density of the battery cell 100.

[0082] As shown in Figure 8, in some embodiments, the protective element 25 includes at least one protective layer 251 and a heat-absorbing layer 252 with heat-absorbing properties. The protective layer 251 and the heat-absorbing layer 252 are arranged along the stacking direction F1 of the electrode assembly 20. A protective layer 251 is provided on the side of the heat-absorbing layer 252 that is away from the second electrode 22.

[0083] It is understandable that the protective layer 251 can be used to protect the heat-absorbing layer 252 and can also separate the heat-absorbing layer 252 from the pressure claw 30. When the pressure claw 30 is pulled out, even if the pressure claw 30 generates a certain amount of heat due to friction with the protective component 25, the protective layer 251 can transfer the heat to the heat-absorbing layer 252, and the heat-absorbing layer 252 absorbs the heat, thereby reducing the temperature at that point and further avoiding the probability of the separator 24 being burned, thus improving the reliability and qualification of the battery cell 100.

[0084] As shown in Figure 8, in some embodiments, the protective layer 251 includes two layers, with the heat-absorbing layer 252 sandwiched between the two protective layers 251.

[0085] The protective element 25 forms a three-layer sandwich structure, thereby protecting the heat-absorbing layer 252 between the two protective layers 251. This can improve the stability of the overall structure and, to a certain extent, prevent the heat-absorbing layer 252 from undergoing phase change or deformation due to heat absorption, which would affect the reliability of the protection provided by the protective element 25. At the same time, it also prevents the heat-absorbing layer 252 from directly contacting the second electrode 22 and causing other adverse effects.

[0086] In some embodiments, the heat-absorbing layer 252 is a paraffin layer. By using paraffin material, when the protective member 25 rubs against the pressure claw 30, the heat-absorbing layer 252 can absorb the heat generated by friction through phase change, reducing the probability of heat being transferred to the second electrode 22, reducing the probability of the second electrode 22 being burned, and improving the reliability and qualification of the electrode assembly 20.

[0087] In some embodiments, the protective layer 251 is a polyolefin layer. By using polyolefin materials, the protective layer 251 can effectively protect the heat-absorbing layer 252. Polyolefin materials have good chemical stability, insulation properties, and are easy to process and manufacture, which facilitates the large-scale manufacturing and use of the protective component 25.

[0088] In some embodiments, the protective element 25 is bonded to the second electrode 22, thereby achieving a fixed connection between the protective element 25 and the second electrode 22. The assembly process is simple, easy to assemble and form, reduces manufacturing difficulty, and reduces manufacturing costs.

[0089] As shown in Figure 8, in some embodiments, the protective member 25 has an adhesive layer 253 on the side facing the second electrode 22.

[0090] During the manufacturing process, an adhesive layer 253 can be pre-applied on the protective component 25. When the protective component 25 is placed on the second electrode 22, the adhesive layer 253 contacts the second electrode 22, thus achieving the bonding between the protective component 25 and the second electrode 22, which is convenient.

[0091] Of course, the protective element 25 can also be bonded to the second electrode 22 with adhesive.

[0092] In some embodiments, the material of the protective element 25 includes one of polypropylene, polyethylene, and polyethylene terephthalate.

[0093] The protective component 25 here can be a single-layer structural component, which is a polypropylene layer, a polyethylene layer, or a polyethylene terephthalate layer. Of course, the protective component 25 can also be a multi-layer material component, in which case one layer of the protective component 25 is a polypropylene layer, a polyethylene layer, or a polyethylene terephthalate layer.

[0094] By using the above materials, the protective component 25 has good chemical stability, insulation properties, and is easy to process and manufacture, with low cost, making it convenient for large-scale manufacturing and use.

[0095] As shown in Figures 5 and 6, in some embodiments, the side of the protective member 25 facing away from the second pole piece 22 is a smooth plane, which can reduce the friction between the pressure claw 30 and the protective member 25 when the pressure claw 30 is pulled out, reduce the probability of wear of the protective member 25, and at the same time facilitate the extraction of the pressure claw 30 and reduce the obstruction of movement.

[0096] In some embodiments, the Shore hardness of the protective element 25 is 30A-90A.

[0097] Understandably, when the hardness of the protective element 25 is too low, it is difficult for it to provide effective protection. When the claw 30 is pulled out, the protective element 25 may deform, which could cause the second electrode 22 to still wear. However, when the hardness of the protective element 25 is too high, after the electrode assembly 20 with the protective element 25 is installed in the casing, the protective element 25 may collide with the outer casing 10 of the battery cell 100, thereby damaging the outer casing 10 or the electrode assembly 20. Therefore, the Shore hardness of the protective element 25 is limited to between 30A and 90A. The Shore hardness of the protective element 25 can be any value among 30A, 40A, 50A, 60A, 70A, 80A, and 90A, or a range between any two values.

[0098] This allows the protective component 25 to effectively protect the second electrode 22 and improve the pass rate of the battery cell 100 after assembly.

[0099] The battery 1000 according to the second aspect of this application includes the battery cell 100 according to the first aspect of this application. By using the battery cell 100, the manufacturing efficiency of the battery 1000 can be improved and the probability of defective products can be reduced.

[0100] The electrical device 2000 according to a third aspect embodiment of this application includes a battery 1000 according to the second aspect embodiment of this application described above. The battery 1000 is used to provide electrical energy to the electrical device 2000. Therefore, by using the battery 1000 described above, it is beneficial to improve the safety and reliability of the electrical device 2000.

[0101] Optionally, as shown in Figure 1, when the battery 1000 is used in a vehicle, the battery 1000 can be located at the bottom, front, or rear of the vehicle. The battery 1000 can be used to power the vehicle; for example, the battery 1000 can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor, the controller being used to control the battery 1000 to power the motor, for example, to meet the vehicle's power needs during starting, navigation, and driving.

[0102] The following describes a specific embodiment of a battery 1000 and a vehicle having the same, in conjunction with the accompanying drawings.

[0103] As shown in Figure 1, the battery 1000 is located at the bottom of the vehicle. As shown in Figures 2 and 3, the battery 1000 includes a housing 200 and a battery cell 100. The battery cell 100 includes a housing 10 and an electrode assembly 20, where the electrode assembly 20 is a stacked type.

[0104] As shown in Figures 5, 7 and 8, the electrode assembly 20 includes multiple electrode sheets and a separator 24 arranged in layers. Along the stacking direction, the multiple electrode sheets include a first electrode sheet 21, multiple intermediate electrode sheets 23 and a second electrode sheet 22 in sequence. The multiple 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 tab 222. The main body 221 is square and has four corners. Each corner has a protective member 25 on the side away from the intermediate electrode sheet 23.

[0105] Along the length direction F2 of the main body 221, the minimum dimension of each protective member 25 is L2, and the length dimension of the main body 221 is L1, where 0.1L1≤L2≤0.5L1.

[0106] In the width direction F3 of the main body 221, the minimum dimension of each protective member 25 is B2, the width dimension of the main body 221 is B1, and 0.1B1≤B2≤0.5B1.

[0107] In the stacking direction F1, the thickness of the main body 221 is H1, the maximum thickness of the protective member 25 is H2, and 0.5H1≤H2≤2H1.

[0108] The protective element 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.

[0109] The protective component 25 also has an adhesive layer 253. The size of the adhesive layer 253 can be slightly smaller than the size of other layers, or it can be the same as the size of other layers. The protective component 25 is bonded to the second electrode 22 through the adhesive layer 253.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The electrode assembly includes a plurality of electrode sheets and a separating membrane arranged in a stacked manner. Along the stacking direction, the plurality of electrode sheets include at least a first electrode sheet and a second electrode sheet located at opposite ends in the stacking direction. The second electrode sheet includes a main body portion and an electrode tab. The second electrode has a protective member on the side opposite to the first electrode, and the protective member covers at least a portion of the main body of the second electrode 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 electrode is square and has four corners, and each corner is provided with a protective member on the side opposite to the first electrode.

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

4. The battery cell according to claim 2, characterized in that, The main body of the second electrode 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 electrode 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 electrode is H1, and the maximum thickness of the protective component is H2, where 0.5H1≤H2≤2H1.

6. The battery cell according to claim 1, characterized in that, The protective element includes at least one protective layer and a heat-absorbing layer with heat-absorbing properties. The protective layer and the heat-absorbing layer are arranged along the stacking direction of the electrode assembly. The protective layer is provided on the side of the heat-absorbing layer opposite to the second electrode.

7. The battery cell according to claim 6, characterized in that The protective layer comprises two layers, with the heat-absorbing layer sandwiched between the two protective layers.

8. The battery cell according to claim 6, characterized in that, The heat-absorbing 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 component is bonded to the second electrode.

10. The battery cell according to claim 9, characterized in that, The protective component has an adhesive layer on the side facing the second electrode.

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

12. The battery cell according to claim 1, characterized in that, The side of the protective element facing away from the second electrode is a smooth plane.

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

14. A battery, characterized in that, Includes the battery cell according to any one of claims 1-13.

15. An electrical appliance, characterized in that, Includes the battery according to claim 14, the battery being used to provide electrical energy.

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