Electrode assembly, battery and battery module

Abstract

The utility model provides an electrode assembly, a battery and a battery module, the electrode assembly comprises an electrode main body and a tab, the electrode main body is provided with a first main body edge, a first main body side edge and a second main body side edge; the tabs comprise a first tab and a second tab, and the first tab is positioned between the side edge of the first main body and the second tab along the first direction; the first tab is provided with a first tab side edge and a second tab side edge, and the second tab side edge is close to the first main body side edge; the first tab side edge comprises a first linear sub-section, and the included angle between the first linear sub-section and the first main body edge is a; the second tab side edge comprises a second linear sub-section, and the included angle between the second linear sub-section and the first main body edge is b; 130 degrees < = a < = 150 degrees, and 90 degrees < b < = 100 degrees. According to the electrode assembly, the battery and the battery module provided by the invention, the root part with the relatively large width of the first tab can provide relatively large supporting force for the first tab, so that the risk that the first tab is turned over is reduced.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an electrode assembly, a battery, and a battery module. Background Technology

[0002] Lithium batteries have advantages such as high energy density, long lifespan, and fast charging, and are widely used in new energy vehicle fields such as electric vehicles and hybrid vehicles.

[0003] A battery may comprise one or more bare cells, each bare cell comprising multiple positive electrode plates, a separator, and multiple negative electrode plates. The positive electrode plates are connected to positive tabs, and the negative electrode plates are connected to negative tabs. To improve the battery's overcurrent capacity, the number of positive and negative tabs in the bare cells can be increased.

[0004] Taking the negative electrode tab as an example, based on the connection requirements between the negative electrode tab and the negative electrode post, as the number of negative electrode tabs increases, the extension height of each negative electrode tab needs to be increased accordingly. However, when the extension height of the negative electrode tab is large, it will increase the risk of tabs being inserted in reverse. If there is a case of tabs being inserted in reverse in the battery, it may cause micro-short circuits, short circuits, or thermal runaway in the battery during use and testing, posing a significant safety hazard. Utility Model Content

[0005] In view of this, the purpose of this application is to provide an electrode assembly, battery and battery module to at least partially solve the problem of reverse insertion of the electrode tabs due to the large extension height of the positive or negative electrode tabs.

[0006] Based on the above objectives, a first aspect of this application provides an electrode assembly, comprising: an electrode body and tabs, wherein the electrode body has a first body edge extending along a first direction, and a first body side edge and a second body side edge disposed opposite to each other along the first direction; the tabs include a first tab and a second tab spaced apart and connected to the same side of the first body edge along the first direction, the first tab being located between the first body side edge and the second tab along the first direction; the first tab has a first tab side edge and a second tab side edge disposed opposite to each other along the first direction and intersecting the first body edge respectively, the second tab side edge being close to the first body side edge; the first tab side edge includes a first straight line segment, the angle between the first straight line segment and the first body edge being α; the second tab side edge includes a second straight line segment, the angle between the second straight line segment and the first body edge being β; 130°≤α≤150°, 90°<b≤100°.

[0007] Optionally, the electrode body is a wound structure, comprising a positive electrode sheet, a negative electrode sheet, and a separator separating the positive and negative electrode sheets. The separator, the positive and negative electrode sheets are wound together to form the wound structure. The first body edge is located at the end of the wound structure along the winding axis. The second tab is connected to the positive electrode sheet, and the first tab is connected to the negative electrode sheet. Two first tabs are connected to each turn of the negative electrode sheet along the winding direction. Alternatively, the electrode body is a stacked structure, comprising multiple positive electrode sheets, multiple negative electrode sheets, and a separator. The multiple positive and multiple negative electrode sheets are alternately stacked along a second direction. The separator separates the positive and negative electrode sheets. The first body edge is located at the top of the stacked structure. The second tab is connected to the positive electrode sheet, and each negative electrode sheet is connected to a first tab. The second direction is perpendicular to the first direction.

[0008] Optionally, the electrode body is a wound structure, and multiple first electrode tabs are stacked along the second direction. Along the second direction, the multiple first electrode tabs are divided into two first electrode tab groups by the winding shaft. The negative electrode sheet is also connected to a first end electrode tab, which is located between the two first electrode tab groups. Along the second direction, the orthogonal projection of the first end electrode tab onto the first electrode tab is located inside the first electrode tab.

[0009] Optionally, a coating layer is provided at the root of the tab near the electrode body, the coating layer extending along the first direction from the side edge of the first tab to the side edge of the second tab.

[0010] Optionally, a rounded corner is provided between the first electrode tab side edge and the first body edge, and the coating layer has a first layer edge away from the electrode body; along a third direction, the rounded corner is located on the side of the first layer edge closer to the electrode body; the first direction, the second direction, and the third direction are perpendicular to each other; and / or, a rounded corner is provided between the second electrode tab side edge and the first body edge, and along the third direction, the rounded corner is located on the side of the first layer edge closer to the electrode body.

[0011] Optionally, the electrode body includes a positive electrode and a negative electrode, the second tab is connected to the positive electrode, and the first tab is connected to the negative electrode; the coating material of the second tab includes a ceramic material; the negative electrode includes a current collector and a negative electrode active material layer coated on the surface of the current collector, and the coating material of the first tab is the same as the material of the negative electrode active material layer.

[0012] Optionally, the first electrode tab has a top edge and a bottom edge disposed opposite each other along a third direction, the top edge being away from the electrode body; the dimension of the top edge along the first direction is 20 mm to 30 mm; and / or, the dimension of the bottom edge along the first direction is 35 mm to 85 mm.

[0013] Optionally, the first electrode tab and the second electrode tab have the same shape, and the first electrode tab and the second electrode tab are symmetrically arranged along the central axis of the electrode body.

[0014] Based on the same inventive concept, a second aspect of this application also provides a battery, including a cover plate assembly and an electrode assembly as described in the first aspect; the cover plate assembly includes a cover plate body, and an explosion-proof valve, a positive terminal, and a negative terminal respectively penetrating and connected to the cover plate body, the positive terminal being electrically connected to a second electrode tab, the negative terminal being electrically connected to a first electrode tab, and the explosion-proof valve, at least a portion of the positive terminal, and at least a portion of the negative terminal are all located between the first electrode tab and the second electrode tab.

[0015] Based on the same inventive concept, a third aspect of this application also provides a battery module, including the battery as described in the second aspect.

[0016] As can be seen from the above, the electrode assembly, battery, and battery module provided in this application, for the first electrode tab, have a first straight segment in the side edge of the first electrode tab and a second straight segment in the side edge of the second electrode tab that are inclined relative to the edge of the first main body. This allows the first electrode tab to be constructed as a trapezoidal electrode tab, with its wider root connected to the electrode main body, thereby providing greater support for the first electrode tab and reducing the risk of the first electrode tab flipping over.

[0017] Meanwhile, designing the included angle α between the first straight segment and the edge of the first main body to be 130°≤a≤150° can prevent the first electrode tab from interfering with the structural component near the middle of the edge of the first main body, thereby helping to improve the safety performance of the electrode assembly.

[0018] Furthermore, designing the included angle b between the second straight segment and the edge of the first main body to be 90°<b≤100° makes the second straight segment and the edge of the first main body more perpendicular to each other. The distance between the second straight segment and the side edge of the second main body can be accurately detected by a visual inspection system, which helps to reduce the quality inspection difficulty of the electrode assembly, improve the product yield, and facilitate mass production. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a front view schematic diagram of the electrode assembly according to an embodiment of this application;

[0021] Figure 2 This is a partial front view schematic diagram of the electrode assembly according to an embodiment of this application;

[0022] Figure 3 This is a schematic diagram showing the electrode assembly and cover plate assembly connected according to an embodiment of this application;

[0023] Figure 4 This is a top view schematic diagram of the electrode assembly of the first structure according to an embodiment of this application;

[0024] Figure 5 This is a top view schematic diagram of the electrode assembly with a second structure according to an embodiment of this application;

[0025] Figure 6 This is a partial schematic diagram of the flattened negative electrode sheet in the electrode assembly of an embodiment of this application.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100. Electrode body; 110. First body edge; 120. First body side edge; 130. Diaphragm; 140. Negative electrode plate; 150. Positive electrode plate; 160. First terminal tab; 170. Second body side edge; 180. Insertion space; 181. First space; 182. Second space; 190. Second terminal tab;

[0028] 200, tab; 200a, first tab; 200b, second tab; 210, side edge of first tab; 211, first straight segment; 220, side edge of second tab; 221, second straight segment; 230, coating layer; 231, edge of first layer; 240, rounded corner; 250, top edge; 260, bottom edge; 270, embossed area;

[0029] 300, First tab assembly; 400, Cover plate body; 500, Explosion-proof valve; 600, Positive terminal; 700, Negative terminal; 800, Second tab assembly. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0031] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components described in these embodiments do not limit the scope of this application.

[0032] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0033] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0034] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] Figure 1 A front-view schematic diagram of the electrode assembly is shown. (For example...) Figure 1 This application provides an electrode assembly, including: an electrode body 100 and a tab 200, wherein the electrode body 100 has a tab along a first direction (e.g., ...). Figure 1 The first main body edge 110 extends in the X direction, and the first main body side edge 120 and the second main body side edge 170 are disposed opposite to each other in the first direction; the electrode tab 200 includes a first electrode tab 200a and a second electrode tab 200b that are spaced apart and connected to the first main body edge 110 on the same side in the first direction, the first electrode tab 200a is located between the first main body side edge 120 and the second electrode tab 200b in the first direction; the first electrode tab 200a has a first electrode tab side edge 210 and a second electrode tab side edge 220 that are disposed opposite to each other in the first direction and intersect the first main body edge 110 respectively, the second electrode tab side edge 220 is close to the first main body side edge 120.

[0036] For example, with Figure 1 Taking the structure and orientation shown as an example, both the first tab 200a and the second tab 200b are connected to the upper edge of the first main body 110.

[0037] For example, one of the first electrode 200a and the second electrode 200b can be a positive electrode and the other can be a negative electrode.

[0038] For example, along the first direction, the first tab 200a is close to the first body side edge 120, and the second tab 200b is close to the second body side edge 170.

[0039] Figure 2 A partial front-view schematic diagram of the electrode assembly is shown. (For example...) Figure 2 The first auricle-side edge 210 includes a first straight line segment 211, and the angle between the first straight line segment 211 and the first main body edge 110 is a; the second auricle-side edge 220 includes a second straight line segment 221, and the angle between the second straight line segment 221 and the first main body edge 110 is b; 130°≤a≤150°, 90°<b≤100°.

[0040] For example, with Figure 2 Taking the structure and orientation shown as an example, when the first electrode tab 200a is not bent, it extends vertically. At this time, the first straight segment 211 is located at the middle of the side edge 210 of the first electrode tab. The side edge 210 of the first electrode tab may also include an arc-shaped chamfer located above and / or below the first straight segment 211. Similarly, the second straight segment 221 is located at the middle of the side edge 220 of the second electrode tab.

[0041] For example, 'a' can be 130°, 132°, 135°, 137°, 140°, 142°, 145°, 147° or 150°.

[0042] For example, b can be 91°, 92°, 93°, 94°, 95°, 96°, 97°, 98°, 99° or 100°.

[0043] For example, the first tab 200a and the second tab 200b may have the same or different shapes.

[0044] Still with Figure 2 Taking the structure and orientation shown as an example, both the first straight segment 211 and the second straight segment 221 are inclined relative to the first body edge 110. This makes the first tab 200a trapezoidal in shape, with a root width (i.e., the dimension of the part connected to the first body edge 110 along the first direction) greater than the top width (opposite to the root). Because the root width of the first tab 200a is larger, it can provide greater support for the first tab 200a as a whole, which helps to reduce the risk of the first tab 200a folding and wrinkling, and also helps to reduce the rework rate of the first tab 200a.

[0045] at the same time, Figure 3A schematic diagram showing the electrode assembly and cover plate assembly connected is provided. Figure 3 The positive terminal 600, negative terminal 700 and explosion-proof valve 500 in the cover plate assembly are usually located in the middle position near the edge 110 of the first main body.

[0046] To avoid interference between the first electrode tab 200a, which has a relatively large root width, and the aforementioned structural components, in this embodiment, the angle α between the first straight segment 211 of the first electrode tab 200a, which is closer to the middle of the first main body edge 110, and the first main body edge 110 is designed to be larger. While ensuring a large root width for the first electrode tab 200a, this allows for a larger space above the side edge 210 of the first electrode tab, preventing the first electrode tab 200a from contacting other structural components.

[0047] For the second tab side edge 220 that does not contact other structural components, the angle b between the second straight segment 221 and the first main body edge 110 can be designed to be smaller, that is, the second straight segment 221 and the first main body edge 110 are more perpendicular to each other, so that the first tab 200a and the corresponding pole have a larger connection area, thereby ensuring that the first tab 200a has a better current carrying capacity.

[0048] Furthermore, since the second straight segment 221 is more perpendicular to the first body edge 110, the vision inspection system can more easily capture the position of the second straight segment 221 when the first tab 200a is being detected. This facilitates the accurate measurement of the distance between the second straight segment 221 and the first body side edge 120, which helps to ensure product quality.

[0049] The electrode assembly provided in this application embodiment has a first straight segment 211 in the first tab side edge 210 and a second straight segment 221 in the second tab side edge 220 that are inclined relative to the first body edge 110. This allows the first tab 200a to be constructed as a trapezoidal tab, with its wider root connected to the electrode body 100, thereby providing greater support for the first tab 200a and reducing the risk of the first tab 200a flipping over.

[0050] Meanwhile, by designing a larger angle α between the first straight segment 211 and the first body edge 110, interference between the first electrode tab 200a and the structural component near the middle of the first body edge 110 can be avoided, thereby helping to improve the safety performance of the electrode assembly.

[0051] Furthermore, by designing the included angle b between the second straight segment 221 and the first main body edge 110 to be smaller, the second straight segment 221 and the first main body edge 110 can be made more perpendicular to each other. The distance between the second straight segment 221 and the second main body side edge 170 can be accurately detected by a visual inspection system, which helps to reduce the quality inspection difficulty of the electrode assembly, improve the product yield, and facilitate mass production.

[0052] Figure 4 A top view schematic diagram of the electrode assembly with the first structure is shown. (See attached diagram.) Figure 4 In some embodiments, the electrode body 100 is a wound structure, comprising a positive electrode 150, a negative electrode 140, and a separator 130 separating the positive electrode 150 and the negative electrode 140. The separator 130, the positive electrode 150, and the negative electrode 140 are wound together to form a wound structure, and the first body edge 110 is located along the winding axis of the wound structure. Figure 1 The second tab 200b is connected to the positive electrode 150, and the first tab 200a is connected to the negative electrode 140. The negative electrode 140 is connected to two first tabs 200a for each turn along the winding direction.

[0053] For example, the connection between the first tab 200a and the negative electrode 140 can be welding or integral molding, and the connection between the second tab 200b and the positive electrode 150 can be welding or integral molding.

[0054] For example, in the winding structure, the two first tabs 200a on each turn of the negative electrode 140 are along the second direction (e.g., Figure 4 The Y-direction layering is set up, and the outer contours are roughly aligned.

[0055] Compared to rectangular tabs with equal width at the top and bottom, the trapezoidal first tab 200a has a smaller area extending beyond the electrode body 100 (hereinafter referred to as the extended area). During the winding process to form the electrode body 100, the smaller extended area of ​​the first tab 200a reduces the gravitational force acting on it, thus decreasing the amount of drooping or bending due to gravity and further reducing the risk of the first tab 200a flipping. Therefore, a larger number of first tabs 200a can be provided in the electrode assembly to significantly improve its current-carrying capacity, which helps to increase the volumetric energy density and charge / discharge speed of the battery using the electrode assembly of this embodiment.

[0056] Meanwhile, during the preparation process, the current collector of the negative electrode 140, i.e., the metal foil, will extend and be exposed from at least one edge of the negative electrode 140. The exposed metal foil can be cut to form the first tab 200a. Therefore, when multiple first tabs 200a are connected to the negative electrode 140, the utilization rate of the metal foil can be improved.

[0057] Figure 5 A top-view schematic diagram of the electrode assembly with the second structure is shown. (See attached diagram.) Figure 5 In some embodiments, the electrode body 100 is a stacked structure, which includes a plurality of positive electrode plates 150, a plurality of negative electrode plates 140, and a separator 130; the plurality of positive electrode plates 150 and the plurality of negative electrode plates 140 are alternately stacked along a second direction, and the separator 130 isolates the positive electrode plates 150 and the negative electrode plates 140; the first body edge 110 is located at the top of the stacked structure, the second tab 200b is connected to the positive electrode plate 150, and each negative electrode plate 140 is connected to a first tab 200a; the second direction is perpendicular to the first direction.

[0058] For example, the diaphragm 130 can be folded in a "Z" shape to form a plurality of insertion spaces 180, the plurality of insertion spaces 180 including along a second direction (e.g. Figure 5 A first space 181 and a second space 182 are alternately arranged in the Y direction. A positive electrode 150 is inserted into the first space 181, and a negative electrode 140 is inserted into the second space 182. A first electrode tab 200a is connected to the negative electrode 140 through an opening in the second space 182 located on the side of the first body edge 110, and a second electrode tab 200b is connected to the positive electrode 150 through an opening in the first space 181 located on the side of the first body edge 110.

[0059] In addition to the aforementioned winding structure, the electrode body 100 can also be a stacked structure. In conjunction with the foregoing, during the formation of the electrode body 100, since the trapezoidal first tabs 200a are not easily bent, a larger number of first tabs 200a can be provided to significantly improve the current-carrying capacity of the electrode assembly, thereby helping to improve the volumetric energy density and charge / discharge speed of the battery using the electrode assembly of this embodiment.

[0060] like Figure 4 In some embodiments, the electrode body 100 is a wound structure, and multiple first electrode tabs 200a are stacked along the second direction. Along the second direction, the multiple first electrode tabs 200a are divided into two first electrode tab groups 300 by the winding shaft. The negative electrode sheet 140 is also connected to a first end electrode tab 160, which is located between the two first electrode tab groups 300. Along the second direction, the orthogonal projection of the first end electrode tab 160 is located inside the first electrode tab 200a.

[0061] For example, in the winding structure, the two first tabs 200a connected to each turn of the negative electrode 140 belong to two first tab groups 300.

[0062] For example, Figure 6 A partial schematic diagram of the flattened negative electrode 140 is shown. (Example) Figure 6 For the flattened negative electrode 140, all the first tabs 200a are connected to one side edge of the negative electrode 140 at intervals (this edge is used to form the first body edge 110 after winding). Along the arrangement direction of the first tabs 200a, the first end tab 160 is located at the beginning or end.

[0063] For example, such as Figure 1 and Figure 4 When the second tab 200b has the same shape as the first tab 200a, the positive electrode 150 can be connected to the second end tab 190. Similarly, multiple second tabs 200b are stacked along a second direction, and along this direction, the multiple second tabs 200b are divided into two second tab groups 800 by a winding shaft, with the second end tab 190 located between the two second tab groups 800. Correspondingly, the second end tab 190 can have the same shape as the first end tab 160.

[0064] For example, the first terminal tab 160 can be rectangular in shape.

[0065] For example, the misalignment of the stacked first tabs 200a is less than 10mm to ensure the welding quality between the first tabs 200a and the corresponding pole pieces and reduce the rework rate.

[0066] When preparing the negative electrode 140, it is necessary to process the material along the first direction (e.g., Figure 6 The negative electrode 140 is cut in the X direction to ensure that the length (i.e., the dimension along the X direction) of the flattened negative electrode 140 meets the process requirements. If only a wide first tab 200a is provided on the negative electrode 140, the first tab 200a at the beginning may be too close to the cutting position. During cutting, the first tab 200a at the beginning may be cut.

[0067] Therefore, to avoid the above problems, a smaller first terminal tab 160 can be connected to the negative electrode 140, such as... Figure 1 The width and height of the first end tab 160 are both smaller than those of the first end tab 200a. When the first end tab 160 is located at the beginning, the distance between the side edge of the first end tab 160 and the cutting position can be greater, thereby avoiding the first end tab 160 from being cut and helping to ensure the yield of the electrode assembly.

[0068] like Figure 2In some embodiments, a coating layer 230 is provided at the root of the tab 200 near the electrode body 100, and the coating layer 230 extends along a first direction from the first tab side edge 210 to the second tab side edge 220.

[0069] Understandably, as the thickness of the tab 200 increases, its bending resistance also increases. In this embodiment, the area of ​​the tab 200 covered by the coating layer 230 is relatively thick, thus exhibiting strong bending resistance. During the fabrication of the electrode assembly, because the root of the tab 200 is covered by the coating layer 230, the root region of the tab 200 is less prone to bending, reducing the likelihood of the tab 200 being inserted upside down, thereby preventing internal short circuits in the battery and avoiding potential safety hazards.

[0070] Combination Figure 3 It can be seen that the larger the area covered by the coating layer 230 on the tab 200, the lower the probability of tab inversion. However, during battery manufacturing, multiple tabs 200 with the same polarity need to be welded together to form a whole, but the area covered by the coating layer 230 on the tab 200 cannot be welded. Therefore, in order to ensure reliable connection between multiple tabs 200, the placement of the coating layer 230 needs to be limited, that is, the coating layer 230 needs to be placed at the root of the tab 200.

[0071] Meanwhile, in order to increase the coverage area of ​​the coating layer 230 on the tab 200, the coating layer 230 can be applied to the root of the tab 200 along the first direction, that is, the coating layer 230 extends from the first tab side edge 210 to the second tab side edge 220 along the first direction, so as to further improve the bending resistance of the tab 200.

[0072] like Figure 2 In some embodiments, a rounded corner 240 is provided between the first electrode ear-side edge 210 and the first body edge 110, and the coating layer 230 has a first layer edge 231 away from the electrode body 100; along a third direction (e.g. Figure 2 The Z-direction in the first layer has a rounded corner 240 located on the side of the first layer edge 231 closest to the electrode body 100; the first direction, the second direction, and the third direction are perpendicular to each other.

[0073] by Figure 2 Taking the structure and orientation shown as an example, the first layer edge 231 is the upper edge of the coating layer 230. The rounded corner 240 can avoid stress concentration at the intersection of the first tab side edge 210 and the first body edge 110 (i.e., the connection between the first tab 200a and the electrode body 100), which helps to ensure a reliable connection between the first tab 200a and the electrode body 100 and ensures the yield of the electrode assembly.

[0074] Meanwhile, in this embodiment, along the third direction, the first edge 231 of the coating layer 230 is located above the rounded corner 240. On the one hand, the coating layer 230 can improve the strength of the connection between the first tab 200a and the electrode body 100, thereby improving the connection reliability between the first tab 200a and the electrode body 100. On the other hand, it can ensure that the coating layer 230 has sufficient coverage area on the tab 200, which helps to make the tab 200 have strong bending resistance.

[0075] like Figure 2 In some embodiments, a rounded corner 240 is provided between the second electrode ear-side edge 220 and the first body edge 110. Along the third direction, the rounded corner 240 is located on the side of the first layer edge 231 close to the electrode body 100.

[0076] The beneficial effect of setting a rounded corner 240 between the second pole ear side edge 220 and the first body edge 110 is the same as the beneficial effect of setting a rounded corner 240 between the first pole ear side edge 210 and the first body edge 110 mentioned above, and will not be repeated here.

[0077] like Figure 1 and Figure 4 In some embodiments, the second tab 200b is connected to the positive electrode 150, and the first tab 200a is connected to the negative electrode 140; the coating layer 230 of the second tab 200b is made of ceramic material; the negative electrode 140 includes a current collector and a negative electrode active material layer coated on the surface of the current collector, and the coating layer 230 of the first tab 200a is made of the same material as the negative electrode active material layer.

[0078] For example, the coating layer 230 of the first tab 200a may include graphite and a first binder (e.g., carboxymethyl cellulose CMC, styrene-butadiene rubber SBR, or polyacrylic acid PAA). The graphite accounts for 94 to 98% of the mass of the coating layer 230, for example, 94%, 95%, 96%, 97%, or 98%; the first binder accounts for 2 to 6% of the mass of the coating layer 230, for example, 2%, 3%, 4%, 5%, or 6%.

[0079] For example, the coating layer 230 of the second tab 200b may include boehmite and a second binder (e.g., polyvinylidene fluoride PVDF). The boehmite accounts for 94 to 98% of the mass percentage of the coating layer 230, for example, 94%, 95%, 96%, 97%, or 98%; the second binder accounts for 2 to 6% of the mass percentage of the coating layer 230, for example, 2%, 3%, 4%, 5%, or 6%.

[0080] For example, the current collector of the negative electrode 140 can be a metal foil.

[0081] The coating layer 230 of the second tab 200b is made of ceramic material. Ceramic material not only has strong insulation ability, but also makes the area covered by ceramic material have greater rigidity, which can effectively prevent the tab from being inserted in reverse.

[0082] The coating layer 230 of the first tab 200a can be made of the same material as the negative electrode active material layer of the negative electrode 140. When coating the negative electrode active material layer onto the negative electrode 140, the material coating of the coating layer 230 can also be completed simultaneously. This helps to reduce the manufacturing difficulty and cost of the negative electrode 140 and the first tab 200a, which is beneficial for mass production.

[0083] like Figure 2 In some embodiments, the first electrode tab 200a has a top edge 250 and a bottom edge 260 disposed opposite each other along a third direction, the top edge 250 being away from the electrode body 100; the dimension L1 of the top edge 250 along the first direction is 20 mm to 30 mm.

[0084] For example, L1 can be 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm or 30mm.

[0085] Taking the welding of the first tab 200a to the corresponding terminal as an example, if L1 is too small, on the one hand, the welding area between the first tab 200a and the corresponding terminal may be small, which will adversely affect the welding quality; on the other hand, it will also adversely affect the current carrying capacity of the first tab 200a. If L1 is too large, it may cause the first tab 200a to interfere with other structural components in the battery, and it will also cause the first tab 200a to occupy a large space inside the battery, which will adversely affect the energy density of the battery.

[0086] To avoid the above problems, in this embodiment, L1 is limited to 20mm to 30mm. On the one hand, this can ensure the reliability of the connection between the first tab 200a and the corresponding terminal post, and ensure the overcurrent capacity of the first tab 200a. On the other hand, it can also prevent the first tab 200a from interfering with other structural components in the battery and help improve the energy density of the battery.

[0087] like Figure 2 In some embodiments, the dimension L2 of the bottom edge 260 along the first direction is 35 mm to 85 mm.

[0088] For example, L2 can be 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm or 85mm.

[0089] If L2 is too small, the root of the first tab 200a will not be able to provide sufficient support, and the risk of the first tab 200a flipping over remains relatively high. If L2 is too large, it may cause the first tab 200a to interfere with other structural components in the battery, and it will also cause the first tab 200a to occupy a large amount of space inside the battery, which will have an adverse effect on the energy density of the battery.

[0090] To avoid the above problems, in this embodiment, L2 is limited to 35mm to 85mm. On the one hand, this can ensure that the root of the first tab 200a can provide greater support, thereby reducing the risk of the first tab 200a flipping over; on the other hand, it can also prevent the first tab 200a from interfering with other structural components in the battery and help improve the energy density of the battery.

[0091] like Figure 2 In some embodiments, the first electrode tab 200a and the second electrode tab 200b have the same shape, and the first electrode tab 200a and the second electrode tab 200b are symmetrically arranged along the central axis of the electrode body 100.

[0092] The second electrode 200b is designed to have the same shape as the first electrode 200a. The beneficial effects of the second electrode 200b due to this shape are the same as those of the first electrode 200a due to this shape, and will not be elaborated here.

[0093] like Figure 2 In some embodiments, the tab 200 has an exposed embossed area 270, in which a striped pattern or dotted pattern is formed on a raised surface.

[0094] For example, the embossed area 270 can be the area in the tab 200 other than the area where the coating layer 230 is provided.

[0095] A raised pattern is provided in the embossed area 270 on the tab 200. This pattern helps to improve the structural strength of the tab 200, thereby further reducing the risk of the tab 200 breaking. At the same time, the above pattern also helps to increase the surface area of ​​the tab 200, thereby improving the current carrying capacity of the tab 200, and also helps to improve the connection reliability between the tab 200 and the corresponding pole.

[0096] Based on the same inventive concept and in conjunction with the description of the electrode components in the above embodiments, this embodiment provides a battery that has the corresponding technical effects of the electrode components in the above embodiments, which will not be repeated here.

[0097] like Figure 3The battery provided in this embodiment includes a cover plate assembly and electrode assemblies as described in the various embodiments above. The cover plate assembly includes a cover plate body 400 and an explosion-proof valve 500, a positive electrode post 600, and a negative electrode post 700 that are respectively connected through the cover plate body 400. The positive electrode post 600 is electrically connected to the second electrode tab 200b, and the negative electrode post 700 is electrically connected to the first electrode tab 200a. The explosion-proof valve 500, at least a portion of the positive electrode post 600, and at least a portion of the negative electrode post 700 are all located between the first electrode tab 200a and the second electrode tab 200b.

[0098] For example, the positive terminal 600 and the second tab 200b can be directly connected, or they can be indirectly connected through a connecting piece. Similarly, the negative terminal 700 and the first tab 200a can be directly connected, or they can be indirectly connected through a connecting piece.

[0099] For example, the positive terminal 600 and the negative terminal 700 can be spaced apart along a first direction, and the explosion-proof valve 500 can be disposed between the positive terminal 600 and the negative terminal 700.

[0100] In combination with the foregoing, Figure 3 The structure and orientation are illustrated below. The first tab 200a and the second tab 200b have the same shape and are symmetrically arranged along the central axis of the electrode body 100. This ensures that the relatively inclined edges of the first tab 200a and the second tab 200b are close to the central axis of the electrode body 100, providing ample space for the positive terminal 600, the negative terminal 700, and the explosion-proof valve 500. This effectively prevents interference between the first tab 200a and the second tab 200b and the cover assembly (e.g., the positive terminal 600, the negative terminal 700, and the explosion-proof valve 500) in the battery during assembly, thus improving battery safety.

[0101] Based on the same inventive concept and in conjunction with the description of the battery in the above embodiments, this embodiment provides a battery module that has the corresponding technical effects of the battery in the above embodiments, which will not be repeated here.

[0102] A battery module includes the battery as described in the above embodiments.

[0103] It should be noted that some embodiments of this application have been described above. Other embodiments are within the scope of the appended claims.

[0104] The various embodiments in this application are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0105] The description in this application is given for illustrative purposes and is not intended to be exhaustive or to limit the application to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of this application and to enable those skilled in the art to understand this application and design various embodiments with various modifications suitable for a particular purpose.

[0106] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0107] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0108] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. An electrode assembly, characterized in that, include: The electrode body and the electrode tab, the electrode body having a first body edge extending along a first direction, and a first body side edge and a second body side edge disposed opposite to each other along the first direction; the electrode tab includes a first electrode tab and a second electrode tab spaced apart and connected to the same side of the first body edge along the first direction, the first electrode tab being located between the first body side edge and the second electrode tab along the first direction; The first electrode has a first electrode side edge and a second electrode side edge that are disposed opposite to each other along a first direction and intersect the edge of the first body respectively, and the second electrode side edge is close to the edge of the first body. The first electrode ear-side edge includes a first straight line segment, and the angle between the first straight line segment and the first body edge is a; the second electrode ear-side edge includes a second straight line segment, and the angle between the second straight line segment and the first body edge is b; 130°≤a≤150°, 90°<b≤100°.

2. The electrode assembly according to claim 1, characterized in that, The electrode body is a wound structure, comprising a positive electrode plate, a negative electrode plate, and a separator separating the positive and negative electrode plates. The separator, the positive electrode plate, and the negative electrode plate are wound together to form the wound structure. The edge of the first body is located at the end of the wound structure along the winding axis. The second tab is connected to the positive electrode plate, and the first tab is connected to the negative electrode plate. Two first tabs are connected to each turn of the negative electrode plate along the winding direction; and / or, The electrode body is a stacked structure, comprising multiple positive electrode plates, multiple negative electrode plates, and a separator; the multiple positive electrode plates and multiple negative electrode plates are alternately stacked along a second direction, and the separator isolates the positive electrode plates and the negative electrode plates; the edge of the first body is located at the top of the stacked structure, the second electrode tab is connected to the positive electrode plate, and each negative electrode plate is connected to the first electrode tab; the second direction is perpendicular to the first direction.

3. The electrode assembly according to claim 2, characterized in that, The electrode body is a wound structure, and multiple first electrode tabs are stacked along the second direction. Along the second direction, the multiple first electrode tabs are divided into two first electrode tab groups by the winding shaft. The negative electrode plate is also connected to a first terminal tab, which is located between two sets of first terminal tabs. Along the second direction, the orthographic projection of the first end tab onto the first tab is located inside the first tab.

4. The electrode assembly according to claim 1, characterized in that, A coating layer is provided at the root of the electrode near the electrode body, and the coating layer extends from the side edge of the first electrode to the side edge of the second electrode along the first direction.

5. The electrode assembly according to claim 4, characterized in that, A rounded corner is provided between the edge of the first electrode tab and the edge of the first body; the coating layer has a first layer edge away from the electrode body; along a third direction, the rounded corner is located on the side of the first layer edge closer to the electrode body; the first direction, the second direction, and the third direction are mutually perpendicular; and / or, A rounded corner is provided between the edge of the second electrode ear and the edge of the first body. Along the third direction, the rounded corner is located on the side of the first layer edge closer to the electrode body.

6. The electrode assembly according to claim 4, characterized in that, The electrode body includes a positive electrode plate and a negative electrode plate, the second electrode tab is connected to the positive electrode plate, and the first electrode tab is connected to the negative electrode plate; The coating material of the second electrode includes a ceramic material; The negative electrode sheet includes a current collector and a negative electrode active material layer coated on the surface of the current collector, wherein the material of the coating layer of the first electrode tab is the same as the material of the negative electrode active material layer.

7. The electrode assembly according to claim 1, characterized in that, The first electrode tab has a top edge and a bottom edge disposed opposite each other along a third direction, the top edge being away from the electrode body; The top edge has a dimension of 20 mm to 30 mm along the first direction; and / or, The dimension of the bottom edge along the first direction is 35mm to 85mm.

8. The electrode assembly according to claim 1, characterized in that, The first electrode tab and the second electrode tab have the same shape and are symmetrically arranged along the central axis of the electrode body.

9. A battery, characterized in that, Includes a cover plate assembly and an electrode assembly as described in any one of claims 1 to 8; The cover plate assembly includes a cover plate body, and an explosion-proof valve, a positive terminal, and a negative terminal respectively penetrating and connected to the cover plate body. The positive terminal is electrically connected to the second terminal, and the negative terminal is electrically connected to the first terminal. The explosion-proof valve, at least a portion of the positive terminal, and at least a portion of the negative terminal are all located between the first terminal and the second terminal.

10. A battery module, characterized in that, Includes the battery as described in claim 9.

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