Secondary batteries

Abstract

This application relates to a secondary battery, comprising: a battery cell and an adapter plate. The battery cell includes a cell body and a tab cluster. The tab cluster includes a positive tab cluster and a negative tab cluster. Each positive and negative tab cluster includes at least two tab groups. Each tab group includes at least one tab unit. The cell body has a tab lead-out end. Each tab unit extends from the tab lead-out end. The adapter plate has multiple tab slots. Each tab slot penetrates the adapter plate along its thickness direction. Each tab group corresponds one-to-one with a tab slot, and each tab group is disposed within its corresponding tab slot and is electrically connected to the adapter plate. This secondary battery allows current to flow more evenly from each tab group through the adapter plate, achieving uniform current distribution across all tab units.

Description

Technical Field

[0001] This application relates to the field of batteries, specifically to a secondary battery. Background Technology

[0002] In the structure of a secondary battery, the tabs are typically connected to the top cover via an adapter plate. However, regardless of whether the tabs are welded to the top or bottom of the adapter plate, the following problems exist:

[0003] (1) The contact position between the tab and the adapter is limited to the welding part of the two. The current concentration phenomenon is very easy to occur at the welding part. The size of the welding part determines the size of the current flow area. A smaller welding part will increase the overcurrent temperature rise, while a larger welding part requires the area and volume of the adapter and the tab to be increased.

[0004] (2) When welding the electrode tab to the adapter piece, due to the limitations of process conditions (welding error), a large area must be reserved for welding to prevent poor welding or welding misalignment. This results in a great waste of the adapter piece volume and increases the weight of the structural components.

[0005] (3) In order to weld the tabs to the surface of the adapter plate, the tabs need to be bent. For example, multiple tabs are gathered together and wrapped around the outside of the adapter plate, then bent and welded to the surface of the adapter plate. Due to the difference in length between the tabs located inside the cell and the tabs located outside the cell, the resistance changes and the current does not flow evenly through the tabs. Utility Model Content

[0006] This application proposes a secondary battery that can distribute current evenly without increasing or even decreasing the volume of the adapter plate and the weight of the structural components, in order to address the above-mentioned technical problems.

[0007] The technical solution adopted in this application to solve the above-mentioned technical problems is a secondary battery, comprising: a battery cell and an adapter plate. The battery cell includes a battery cell body and a tab cluster. The tab cluster includes a positive tab cluster and a negative tab cluster. The positive tab cluster and the negative tab cluster each include at least two tab groups. Each tab group includes at least one tab unit. The battery cell body has a tab lead-out end. Each tab unit extends from the tab lead-out end. The adapter plate has multiple tab grooves. Each tab groove penetrates the adapter plate along the thickness direction. The tab groups correspond one-to-one with the tab grooves, and each tab group is inserted into the corresponding tab groove and is electrically connected to the adapter plate.

[0008] In one embodiment of this application, all the electrode units in the electrode assembly are located inside the electrode groove, and the electrode assembly is welded to the inner wall of the electrode groove.

[0009] In one embodiment of this application, the electrode unit in the electrode assembly includes a bent portion extending out of the electrode groove, the bent portion being welded to the upper surface of the adapter piece and forming at least one solder mark.

[0010] In one embodiment of this application, all the tab units in the tab group are gathered together by welding, and a gathering weld portion is provided at the welding point, the gathering weld portion being located inside the tab groove.

[0011] In one embodiment of this application, the tab group has a tab width along a first direction, the at least one solder mark extends along a second direction, the first direction is perpendicular to the second direction, and the solder mark simultaneously passes through the bending portions of all the tab groups in the positive tab cluster or the negative tab cluster.

[0012] In one embodiment of this application, the adapter piece has a terminal post, and in the width direction of the secondary battery, the plurality of tab grooves are all located on the same side of the terminal post.

[0013] In one embodiment of this application, the adapter piece has a first opening on the side away from the electrode post. In the thickness direction of the secondary battery, the first opening is located in the middle of the adapter piece and divides the plurality of electrode slots into two groups of equal number.

[0014] In one embodiment of this application, the adapter piece has a terminal post, and in the thickness direction of the secondary battery, the plurality of tab grooves are respectively located on both sides of the terminal post.

[0015] In one embodiment of this application, the adapter piece has a first side edge that is close to the interior of the secondary battery in the width direction of the secondary battery, and the tab groove has a second opening on the first side edge.

[0016] In one embodiment of this application, the adapter piece has a comb-like portion formed at the second opening, and the outer end of the comb-like portion has a chamfer or a sharp corner.

[0017] The secondary battery of this application includes a cell and an adapter plate. Each cell has multiple tab groups with corresponding tab grooves on the adapter plate. Each tab group can be electrically connected to the adapter plate through its corresponding tab groove, preventing inconsistent tab group lengths due to varying distances between the welding points of different tab groups and the adapter plate. This allows for more even current flow from each tab group through the adapter plate, achieving uniform current distribution across all tab units. Furthermore, since each tab group has a corresponding tab groove, the welding position between each tab group and the adapter plate is fixed, eliminating the need for misalignment areas. This allows for a reduction in the area and volume of the adapter plate, thus reducing the weight of the structural components. If the size of the adapter plate remains unchanged, the larger free area allows for widening and / or thickening of the tab units, thereby enhancing the current-carrying capacity of the tab cluster. Attached Figure Description

[0018] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings, wherein:

[0019] Figure 1 This is a partial three-dimensional structural schematic diagram of the secondary battery according to Embodiment 1 of this application;

[0020] Figure 2 It is along Figure 1 A sectional view of line AA in the diagram;

[0021] Figure 3 This is a three-dimensional schematic diagram of the adapter piece in the secondary battery of Embodiment 1 of this application;

[0022] Figure 4 This is a cross-sectional view of a secondary battery according to an embodiment of this application, including an enlarged schematic diagram of region A1;

[0023] Figure 5 This is a cross-sectional view of a secondary battery according to an embodiment of this application;

[0024] Figure 6 yes Figure 1 A top view of the secondary battery of the embodiment shown, including an enlarged view of region A2;

[0025] Figure 7 This is a schematic diagram of a variation of the adapter piece in Embodiment 1;

[0026] Figure 8 This is a partial three-dimensional structural schematic diagram of the secondary battery according to Embodiment 2 of this application;

[0027] Figure 9 It is along Figure 8 A sectional view of the BB line in the middle;

[0028] Figure 10This is a three-dimensional schematic diagram of the adapter piece in the secondary battery of Embodiment 2 of this application;

[0029] Figure 11 This is a schematic diagram of a variation of the adapter plate in Embodiment 2;

[0030] Figure 12 This is a partial three-dimensional structural schematic diagram of the secondary battery according to Embodiment 3 of this application;

[0031] Figure 13 It is along Figure 12 A cross-sectional view of the CC line in the diagram;

[0032] Figure 14 This is a three-dimensional schematic diagram of the adapter piece in the secondary battery of Embodiment 3 of this application;

[0033] Figure 15 This is a schematic diagram of a variation of the adapter plate in Embodiment 3;

[0034] Figure 16 This is a partial three-dimensional structural schematic diagram of the secondary battery according to Embodiment 4 of this application;

[0035] Figure 17 It is along Figure 16 A sectional view of the DD line in the middle;

[0036] Figure 18 This is a three-dimensional schematic diagram of the adapter piece in the secondary battery of Embodiment 4 of this application;

[0037] Figure 19 This is a schematic diagram of a variation of the adapter plate in Embodiment 4;

[0038] Figure 20 This is a schematic diagram of the solder marks formed after the tabs of the secondary battery corresponding to Example 3 are bent.

[0039] Figure 21 yes Figure 20 Enlarged schematic diagram of area A3 in the middle. Detailed Implementation

[0040] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0041] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein, and therefore this application is not limited to the specific embodiments disclosed below.

[0042] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0043] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0044] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0045] The embodiments of this application will now be described based on the accompanying drawings. However, the embodiments shown below are examples of secondary batteries used to embody the technical concept of this application, and the secondary battery of this application is not specifically defined as described below. Furthermore, in order to facilitate understanding of the scope of the claims, the components corresponding to those shown in the embodiments are assigned numbers to the components shown in the "Claims" and "Utility Model Content" columns. However, this is by no means to specify the components shown in the claims as components of the embodiments. In particular, the dimensions, materials, shapes, and relative arrangements of the constituent components described in the embodiments, unless specifically stated, are not intended to limit the scope of this application, but are merely illustrative examples.

[0046] However, the dimensions or positional relationships of the components shown in the accompanying drawings are sometimes exaggerated for clarity. Therefore, in the following description, detailed descriptions of the same names and symbols representing the same or homogeneous components are appropriately omitted. Furthermore, the elements constituting this application may be multiple elements composed of the same components, thus allowing one component to function as multiple elements; conversely, multiple components may share the function of one component. Additionally, the content described in some embodiments and implementations can be applied to other embodiments and implementations. Furthermore, in this specification, "upper" is not limited to the case of being formed in contact with an upper surface, but also includes the case of being formed separately on top, and also includes the meaning of an intermediate layer between layers.

[0047] The secondary batteries described in this application include, but are not limited to, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid (or lead-acid) batteries, lithium-ion batteries, and polymer lithium-ion batteries. The shapes of the secondary batteries include square and round. This application specification uses a square battery as an example for illustration.

[0048] Figure 1 This is a partial three-dimensional schematic diagram of the secondary battery structure according to Embodiment 1 of this application. Figure 2 It is along Figure 1 A cross-sectional view along line AA in the diagram. Figure 3 This is a three-dimensional schematic diagram of the adapter piece in the secondary battery according to Embodiment 1 of this application. (Reference) Figures 1-3 As shown, the secondary battery includes a cell 110 and an adapter plate 120. The cell 110 includes a cell body 111 and a tab cluster. The tab cluster includes a positive tab cluster 112a and a negative tab cluster 112b. The positive tab cluster 112a and the negative tab cluster 112b each include at least two tab groups 113, and each tab group 113 includes at least one tab unit. The cell body 111 has a tab lead-out end 111a, from which multiple tab units extend. The adapter plate 120 is provided with multiple tab grooves 121, each tab groove 121 penetrating the adapter plate 120 along its thickness direction. The tab groups 113 correspond one-to-one with the tab grooves 121, and each tab group 113 is disposed in the corresponding tab groove 121. Each tab group 113 is electrically connected to the adapter plate 120 through the corresponding tab groove 121.

[0049] like Figure 1 As shown, the secondary battery in Embodiment 1 includes four cells 110 arranged side by side. Figure 1 For illustrative purposes only and not intended to limit the number of cells. In some embodiments, the secondary battery includes at least one cell 110.

[0050] In some embodiments, the battery cell 110 is a wound core, i.e., it is formed by winding a stacked separator, a negative electrode sheet, a separator, and a positive electrode sheet. The positive electrode sheet includes a positive metal substrate, a positive tab, and a positive electrode coating coated on the positive metal substrate; the negative electrode sheet includes a negative metal substrate, a negative tab, and a negative electrode coating coated on the negative metal substrate. Tab units can be formed on the stacked structure by die-cutting before winding. After winding, multiple tab units are arranged side-by-side at one end of the top surface of the secondary battery, for example, to form a positive tab cluster 112a; multiple tab units are arranged side-by-side at the other end of the top surface of the secondary battery, correspondingly forming a negative tab cluster 112b. Figure 1 As shown, for a single cell 110, viewed along the width direction X of the secondary battery, the positive electrode tab cluster 112a is located at one end, for example... Figure 1 At the left end, the negative electrode ear cluster 112b is located at the other end, for example... Figure 1 The right end of the structure. In this embodiment, all the tab units in the positive tab cluster 112a are divided into two tab groups 113, and all the tab units in the negative tab cluster 112b are also divided into two tab groups 113.

[0051] In some embodiments, the cell 110 may also be a cell formed using a lamination process. According to these embodiments, a full-tab configuration is typically used. The positive tab cluster may include multiple stacked positive full tabs, and the negative tab cluster may include multiple stacked negative full tabs. For a secondary battery with a full-tab configuration, the increased tab thickness restricts the internal height space of the secondary battery. The secondary battery of this application effectively solves this space constraint problem.

[0052] exist Figure 1 In the secondary battery, along the height direction Z, the tab lead-out end 111a is located at one end, i.e., the top, of the cell body 111. Combined with... Figure 1 and Figure 2 As shown, a tab group 113 may include at least one tab unit. When a tab group 113 includes multiple tab units, the multiple tab units are first brought together and then pass through the corresponding tab groove 121 together. In some embodiments, the multiple tab units can be brought together by welding. This application does not limit the size of the tab units. After the multiple tab units are brought together, it can be understood that the width and height of the tab group 113 are substantially the same as the width and height of a single tab unit, and the thickness of the tab group 113 is at least equal to the stacked thickness of the multiple tab units within the group. Considering solder joints, the thickness of the tab group 113 may be greater than the stacked thickness of the multiple tab units within the group.

[0053] In some embodiments, the secondary battery may have tab leads at both ends along the height direction Z, that is, the secondary battery is a battery with tabs at both ends. Specifically, the tab cluster leading out from one end of the secondary battery is a positive tab cluster, and the tab cluster leading out from the other end is a negative tab cluster.

[0054] exist Figure 1 In this application, a connector 120 is provided for each of the positive electrode tab clusters 112a and 112b, namely a positive connector and a negative connector. In this application, the tab slot configuration is the same for both the positive and negative connectors; therefore, the following description focuses on the connector 120, and the relevant content applies to both the positive and negative connectors. The number of tab slots 121 on the connector 120 is the same as the number of tab groups 113, and their positions correspond one-to-one. For example... Figure 1 In the illustrated embodiment, the secondary battery having four cells 110 has 16 tab groups 113, of which 8 tab groups 113 belong to the positive tab cluster 112a and the other 8 tab groups 113 belong to the negative tab cluster 112b. Correspondingly, there are also 16 tab slots 121, of which 8 tab slots 121 are located on the positive electrode adapter and the other 8 tab slots 121 are located on the negative electrode adapter.

[0055] like Figure 1 and Figure 2 As shown, each tab assembly 113 is electrically connected to the adapter piece 120 via a corresponding tab groove 121. By designing the dimensions of the tab assembly 113 and the tab groove 121 to match, the tab assembly 113 can make contact with the tab groove 121. Since both the tab assembly 113 and the adapter piece 120 are made of conductive materials, they can be electrically connected when they are in full contact.

[0056] The matching of the dimensions of the tab assembly 113 and the tab groove 121 can be explained as follows: the tab assembly 113 has a first width X1 along the width direction X of the secondary battery and a first thickness Y1 along the thickness direction Y of the secondary battery; the tab groove 121 has a second width X2 along the width direction X and a second thickness Y2 along the thickness direction Y, wherein the second width X2 is greater than or equal to the first width X1, and the second thickness Y2 is greater than or equal to the first thickness Y1. In some embodiments, the first width X1 is close to the second width X2, and the first thickness Y1 is close to the second thickness Y2, so that the tab assembly 113 is precisely inserted into the tab groove 121 and makes full contact with the inner wall of the tab groove 121. This allows for a simple insertion to securely connect the two, resulting in a tight structure and forming a conductive connection with the adapter piece 120. No additional soldering steps are required.

[0057] It should be noted that in the accompanying drawings of this application, the width direction X, thickness direction Y, and height direction Z are indicated by line segments with arrows. These arrows are not used to limit the orientation of each direction, and each direction can be directed to both sides in a direction parallel to the line segment.

[0058] The secondary battery of this application, by placing each tab group 113 within a corresponding tab groove 121 and electrically connecting it to the adapter piece 120, avoids inconsistent tab group lengths caused by varying distances between different tab groups and the welding portion of the adapter piece. This allows current to flow more evenly from each tab group through the adapter piece, achieving uniform current distribution across all tab units. Furthermore, since each tab group 113 has a corresponding tab groove 121, the connection position between each tab group 113 and the adapter piece 120 is essentially fixed, preventing misalignment. Therefore, there is no need to reserve a misalignment area, allowing for a reduction in the area and volume of the adapter piece and a lighter structural component. If the size of the adapter piece remains unchanged, the larger free area allows for widening and / or thickening of the tab groups, thereby enhancing their current-carrying capacity.

[0059] Figure 4 This is a cross-sectional view of a secondary battery according to an embodiment of this application, including an enlarged schematic diagram of region A1. (See reference) Figure 4 As shown, in this embodiment, all the tab units in the tab assembly 113 are located inside the tab groove 121. That is, the overall length of the tab assembly 113 is relatively short, and when the tab assembly 113 is inserted into the tab groove 121, none of the tab units protrude from the tab groove 121. According to this embodiment, the tab assembly 113 is welded to the inner wall 1212 of the tab groove 121. In some embodiments, this welding connection includes seam welding, that is, welding is performed through the opening of the tab groove 121, so that the tab assembly 113 is securely and electrically connected to the inner wall 1212 of the tab groove 121. The length of the weld can be equal to the width of the tab groove 121.

[0060] By welding the tab assembly 113 to the tab groove 121, each tab assembly 113 can make full contact with the adapter piece 120, increasing the contact area between the tab assembly 113 and the adapter piece 120 and ensuring the performance of the battery.

[0061] In some embodiments, the weld penetration depth is less than 2 / 3 of the thickness of the adapter piece 120. According to these embodiments, it can be ensured that the weld will not melt the tab. In some embodiments, the thickness of the adapter piece 120 ranges from 0.5 mm to 1.5 mm, for example, 0.5 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.5 mm, etc.

[0062] Figure 5 This is a cross-sectional view of a secondary battery according to an embodiment of this application. (Reference) Figure 5As shown, the tab unit in the tab assembly 113 includes a bent portion 113b extending from the tab groove 121. That is, the overall length of the tab assembly 113 is relatively long, and it is bent after passing through the tab groove 121 to form the bent portion 113b. According to this embodiment, the tab assembly 113 is flattened after bending, contacts the upper surface of the adapter piece 120, and the bent portion 113b is welded to the adapter piece 120 by through soldering to form a solder mark 510. This application does not limit the number of solder marks 510, and there can be at least one.

[0063] like Figure 5 As shown, the portion of the tab assembly 113 located in the tab groove 121 is referred to as the groove interior 113a. In some embodiments, all tab units in the tab assembly 113 are gathered together by welding, and a gathering weld portion is provided at the welding point, the gathering weld portion being located inside the tab groove 121. Figure 5 As shown, the retractable weld portion is located at any position inside the groove 113a. To ensure the retractable weld portion is located inside the tab groove 121, a welding position closer to the cell body can be selected along the length of the tab assembly 113 during the retractable welding process. The retractable weld portion is relatively rigid and difficult to bend once formed. In these embodiments, by setting the retractable weld portion inside the tab groove 121, the retractable weld portion can be avoided when bending the portion of the tab assembly 113 extending out of the tab groove 113, thereby facilitating the bending of the tab assembly 113 and forming the bent portion 113b. In some embodiments, the retractable welding is performed by through welding.

[0064] Figure 6 yes Figure 1 The illustrated embodiment of the secondary battery is shown in a top view, including an enlarged view of region A2. This specification adopts... Figure 6 Supplementary Explanation Figure 5 Features of the solder mark 510. Assume that the tab assembly 113 has a tab width X1 along the first direction D1 (i.e., the first width X1 mentioned above, so the same reference numeral is used), at least one solder mark 510 extends along the second direction D2, the first direction D1 is perpendicular to the second direction D2, and the solder mark 510 simultaneously passes through the bend 113b of each tab unit in all tab assemblies 113 of either the positive tab cluster 112a or the negative tab cluster 112b. Figure 6 In the illustrated embodiment, the first direction D1 and the second direction D2 are respectively Figure 1 The width direction X and thickness direction Y are defined in the figure. In other embodiments, the first direction D1 and the second direction D2 may also be different from X and Y. By making the extension direction of the solder mark 510 perpendicular to the width direction of the tab assembly 113, the solder mark 510 can be minimized while being welded to all the tab assemblies 113.

[0065] In some embodiments, the length of the solder mark 510 along the second direction D2 is related to the width of the adapter piece 120 along the thickness direction Y. For Figure 6 The adapter piece 120 shown has a first opening 1202 in its center. Therefore, the length of the solder mark 510 is only related to the width of the portion of the adapter piece located on the side of the first opening 1202. Assuming the width of this portion of the adapter piece is 20mm, the length of the solder mark 510 can also be 20mm. The width of the solder mark 510 can be approximately 1.5mm, for example, 1.0mm-2.0mm.

[0066] It should be noted that, for Figure 5 In the embodiment shown, the bent portion 113b is welded by through-welding, so there is no need to use seam welding to weld the tab assembly 113 through the groove of the tab groove 121, so as to avoid the mutual influence of the weld marks and the resulting explosion.

[0067] In some embodiments, such as Figures 1-3 As shown, the adapter piece 120 is provided with a pole post 130. (As indicated...) Figure 1 As shown, each adapter piece 120 has a terminal 130. The terminal 130 on the positive adapter piece is the positive terminal, and the terminal 130 on the negative adapter piece is the negative terminal. Figure 3 As shown, the pole post 130 has a third width X3 along the width direction X, and the first width X1 and the second width X2 are both greater than the third width X3. With this arrangement, sufficient space is reserved on the adapter piece 120 for the tab assembly 113, making the tab assembly 113 wider, thereby enhancing the current carrying capacity of the tab.

[0068] like Figures 1-3 As shown, in this embodiment, in the width direction X of the secondary battery, multiple tab grooves 121 are located on the same side of the electrode post 130. Figure 1 As shown, the terminal post 130 is located at one end near the outer side of the cell 110, thereby providing sufficient distance between the positive and negative terminals of the secondary battery.

[0069] like Figure 3 As shown, in some embodiments, the adapter piece 120 has a first opening 1202. Along the thickness direction Y, this first opening 1202 is located at the center of the adapter piece 120. The length of the first opening 1202 along the thickness direction Y is significantly greater than the second thickness Y2 of a tab groove 121. According to these embodiments, this effectively reduces the area and volume of the adapter piece 120 at the first opening 1202, thereby reducing the area of ​​the adapter piece 120 and simultaneously reducing the weight of the structural component.

[0070] Accordingly, when assembling multiple battery cells 110, the position of the protruding tab assembly 113 can be adapted to the position of the tab slot 121. For example, refer to... Figure 2As shown, the lead-out position of the tab group 113 of cell 110a is close to the inner side of the cell, the lead-out position of the tab group 113 of cell 110b is close to the outer side of the cell, the lead-out position of the tab group 113 of cell 110c is close to the outer side of the cell, and the lead-out position of the tab group 113 of cell 110d is close to the inner side of the cell.

[0071] refer to Figure 1 As shown, in some embodiments, the secondary battery has a central axis OO extending along the width direction X, and the structure of the secondary battery is symmetrical about this central axis OO. Specifically, for the plurality of tab groups 113, the number of tab groups 113 located on both sides of the central axis OO is equal, and their positions are symmetrical. For a single adapter piece 120, the first opening 1202 is symmetrical about the central axis OO, and the tab groove 121 is also symmetrical about the central axis OO. According to this symmetrical structure, the current can be symmetrically distributed on the tabs, further improving the uniformity of the current distribution.

[0072] Figure 7 This is a variation of the adapter plate in Embodiment 1. For example... Figure 7 As shown, the adapter 120 has a first side 140, which is close to the interior of the secondary battery in the width direction X. The tab groove 121 has a second opening 1214 on the first side 140. With this configuration, when assembling the secondary battery, the adapter 120 can be pushed from a distance towards the multiple tab groups 113 from the direction with the second opening 1214, so that the adapter 120 can be inserted into the multiple tab groups 113 like combing hair, making the assembly process simpler.

[0073] In some embodiments, the adapter piece 120 has a comb-like portion 1215 formed at the second opening 1214, similar to the teeth of a comb. Figure 7 In the illustrated embodiment, the outer end of the comb tooth portion 1215 is a right angle. In other embodiments, the outer end of the comb tooth portion 1215 is rounded or chamfered, which serves to enlarge the opening during installation and guide the tab assembly 113 into the second opening 1214, further improving the ease of assembly.

[0074] Figure 8 This is a partial three-dimensional schematic diagram of the secondary battery structure according to Embodiment 2 of this application. Figure 9 It is along Figure 8 A cross-sectional view of the BB line. Figure 10 This is a three-dimensional schematic diagram of the adapter piece in the secondary battery according to Embodiment 2 of this application. (Reference) Figures 8-10As shown, the secondary battery includes a cell 210 and an adapter plate 220. The cell 210 includes a cell body 211 and multiple tab groups 213. The cell body 211 has a tab lead-out end 211a, and the multiple tab groups 213 extend from the tab lead-out end 211a. The adapter plate 220 is provided with multiple tab grooves 221. Each tab groove 221 penetrates the adapter plate 220 along the thickness direction. The multiple tab groups 213 correspond one-to-one with the multiple tab grooves 221, and each tab group 213 is inserted into the corresponding tab groove 221. Each tab group 213 is electrically connected to the adapter plate 220 through the corresponding tab groove 221.

[0075] refer to Figure 8 and Figure 9 As shown, the secondary battery of this embodiment includes two cells 210 arranged side by side.

[0076] The main difference between Embodiment 2 and Embodiment 1 lies in the adapter piece 210. For a description of the battery cell 210 and the electrode assembly 213, please refer to the description of Embodiment 1, which will not be repeated here.

[0077] refer to Figure 10 As shown, the adapter piece 220 has a terminal post 230, and multiple tab grooves 221 are located on both sides of the terminal post 230 along the thickness direction Y of the secondary battery. In Embodiment 2, the terminal post 230 is racetrack-shaped, unlike the circular terminal post 130 in Embodiment 1. According to Embodiment 2, the first width X1 of the tab assembly 213 and the second width X2 of the tab groove 221 can both be relatively long, and can be as long as possible along the width direction X of the adapter piece 220, thereby giving the tab assembly 213 a wider width and enhancing the current carrying capacity of the tabs.

[0078] In Embodiment 2, the number of tab grooves 221 located on both sides of the pole post 230 is equal.

[0079] Similar to Example 1, the secondary battery in Example 2 can also be symmetrical about the central axis (not shown).

[0080] refer to Figure 9 As shown, the two cells 210 are cell 210a and cell 210b. The lead-out positions of the tab group 213 of cells 210a and 210b are both close to the outer side of the cell.

[0081] Figure 11 This is a variation of the adapter plate in Embodiment 2. For example... Figure 11As shown, the adapter piece 220 has a first side 240, which is close to the interior of the secondary battery in the width direction X. The tab groove 221 has a second opening 2214 on the first side 240. With this configuration, when assembling the secondary battery, the adapter piece 220 can be pushed from a distance towards the multiple tab groups 213 from the direction with the second opening 2214, so that the adapter piece 220 can be inserted into the multiple tab groups 213 like combing hair, making the assembly process simpler.

[0082] In some embodiments, the adapter piece 220 has a comb-like portion 2215 formed at the second opening 2214, similar to the teeth of a comb. Figure 11 In the illustrated embodiment, the outer end of the comb teeth 2215 is chamfered. The chamfer serves to enlarge the opening during installation and guide the tab assembly 213 into the opening 2214, further improving the ease of assembly.

[0083] Figure 12 This is a partial three-dimensional structural schematic diagram of the secondary battery according to Embodiment 3 of this application. Figure 13 It is along Figure 12 A cross-sectional view of the CC line. Figure 14 This is a three-dimensional schematic diagram of the adapter piece in the secondary battery according to Embodiment 3 of this application. (Reference) Figures 12-14 As shown, the secondary battery includes a cell 310 and an adapter plate 320. The cell 310 includes a cell body 311 and multiple tab groups 313. The cell body 311 has a tab lead-out end 311a, and the multiple tab groups 313 extend from the tab lead-out end 311a. The adapter plate 320 is provided with multiple tab grooves 321, each tab groove 321 penetrating the adapter plate 320 along the thickness direction. The multiple tab groups 313 correspond one-to-one with the multiple tab grooves 321, and each tab group 313 is inserted into the corresponding tab groove 321. Each tab group 313 is electrically connected to the adapter plate 320 through the corresponding tab groove 321.

[0084] The main difference between Embodiment 3 and Embodiment 1 lies in the number of tab groups 313 and tab slots 321. The cell 310 in Embodiment 3 has a significantly larger number of tab groups 313, and correspondingly, the adapter piece 320 also has a larger number of tab slots 321, making it a more densely packed adapter piece. Due to the larger number of tab groups 313 and tab slots 321, Embodiment 3 provides a secondary battery with greater overcurrent capacity.

[0085] In some embodiments, each tab group 313 in Embodiment 3 includes only one tab unit.

[0086] The remaining technical features of Embodiment 3 are the same as or similar to those of Embodiment 1, and can be explained using the relevant descriptions in Embodiment 1, without further repetition.

[0087] It should be noted that for the encrypted design, due to the large number of tab slots 321, seam welding is relatively complex. Therefore, through welding is preferred. This involves designing the tab length to exceed the thickness of the adapter piece 320 or the depth of the tab slot 321, so that the tab assembly 313 extends out of the tab slot 321 and then bends to form a bend. At least one weld mark is formed at the bend using through welding, thus simplifying the welding process. Compared to the encrypted design, the tab slots 321 in Embodiments 1 and 2 are fewer in number and sparsely distributed, and can be referred to as a standard design. Users can choose between encrypted or standard designs of tab assemblies and tab slots based on the specific characteristics and support capabilities of the secondary battery; this application does not impose any restrictions on this.

[0088] Figure 15 This is a variation of the adapter plate in Embodiment 3. For example... Figure 15 As shown, the adapter piece 320 has a first side 340, which is close to the interior of the secondary battery in the width direction X. The tab groove 321 has a second opening 3214 on the first side 340. With this arrangement, when assembling the secondary battery, the adapter piece 320 can be pushed from a distance towards the multiple tab groups 313 from the direction with the second opening 3214, so that the adapter piece 320 can be inserted into the multiple tab groups 313 like combing hair, making the assembly process simpler.

[0089] In some embodiments, the adapter piece 320 has a comb-like portion 3215 formed at the second opening 3214, similar to the teeth of a comb. Figure 15 In the illustrated embodiment, the outer end of the comb teeth 3215 is a sharp corner. The sharp corner serves to enlarge the opening during installation and guide the tab assembly 313 into the second opening 3214, further improving assembly convenience. This application does not limit the angle of the sharp corner.

[0090] In some embodiments, after inserting the adapter 320 into the plurality of tab assemblies 313 like combing hair, the process may further include: using a tool to compress the second opening 3214 in the width direction perpendicular to the tab groove 321 (i.e., along the thickness Y direction), so that the second opening 3214 is in complete contact with the plurality of tab assemblies 313 without gaps. This eliminates the need for welding the tabs. Furthermore, after compressing the second opening 3214, the second opening 3214 may be welded in the second direction D2 to further prevent the tab assemblies 313 from leaving the tab groove 321.

[0091] Figure 16 This is a partial three-dimensional schematic diagram of the secondary battery structure of Embodiment 4 of this application. Figure 17 It is along Figure 16 A cross-sectional view of the DD line. Figure 18 This is a three-dimensional schematic diagram of the adapter piece in the secondary battery according to Embodiment 4 of this application. (Reference) Figures 16-18As shown, the secondary battery includes a cell 410 and an adapter plate 420. The cell 410 includes a cell body 411 and multiple tab groups 413. The cell body 411 has a tab lead-out end 411a, and the multiple tab groups 413 extend from the tab lead-out end 411a. The adapter plate 420 is provided with multiple tab grooves 421, each tab groove 421 penetrating the adapter plate 420 along the thickness direction. The multiple tab groups 413 correspond one-to-one with the multiple tab grooves 421, and each tab group 413 is inserted into the corresponding tab groove 421. Each tab group 413 is electrically connected to the adapter plate 420 through the corresponding tab groove 421.

[0092] The main difference between Embodiment 4 and Embodiment 2 lies in the number of tab groups 413 and tab slots 421. The cell 410 in Embodiment 4 has a significantly larger number of tab groups 413, and correspondingly, the adapter piece 420 also has a larger number of tab slots 421, making it a more densely packed adapter piece. Because Embodiment 4 has a larger number of tab groups 413 and tab slots 421, the secondary battery has a greater overcurrent capacity.

[0093] In some embodiments, each tab group 413 in Embodiment 4 includes only one tab unit.

[0094] The remaining technical features of Embodiment 4 are the same as or similar to those of Embodiment 2, and can be explained using the relevant descriptions in Embodiment 2, without further repetition.

[0095] Figure 19 This is a variation of the adapter plate in Embodiment 4. For example... Figure 19 As shown, the adapter piece 420 has a first side 440, which is close to the interior of the secondary battery in the width direction X. The tab groove 421 has a second opening 4214 on the first side 440. With this arrangement, when assembling the secondary battery, the adapter piece 420 can be pushed from a distance towards the multiple tab groups 413 from the direction with the second opening 4214, so that the adapter piece 420 can be inserted into the multiple tab groups 413 like combing hair, making the assembly process simpler.

[0096] In some embodiments, the adapter piece 420 has a comb-like portion 4215 formed at the second opening 4214, similar to the teeth of a comb. Figure 19 In the illustrated embodiment, the outer end of the comb teeth 4215 is a pointed corner. The pointed corner serves to enlarge the opening during installation and guide the tab assembly 413 into the second opening 4214, further improving assembly convenience. This application does not limit the angle of the pointed corner.

[0097] Figure 20 This is a schematic diagram of the solder mark formed after the tab of the secondary battery corresponding to Example 3 is bent. Figure 21 yes Figure 20 A magnified view of area A3 in the middle. (Combined with...) Figure 20 and Figure 21 As shown, each tab assembly 313 has a bent portion, and this application does not limit the bending direction of the bent portion. For example... Figure 21 As shown, the bending portion 531 of a portion of the tab assembly 313 bends to one side along the thickness direction Y, while the bending portion 532 of another portion of the tab assembly 313 bends to the other side along the thickness direction Y. That is, all tab assemblies 313 are bent towards the interior of the battery cell. Three solder marks 520 are formed on these multiple tab assemblies 313, perpendicularly passing through all tab assemblies 313, thereby establishing a reliable solder connection between the tabs and the adapter piece 320. The inventors of this application have discovered through experimental research that three solder marks 520 provide a reliable connection and conductivity. In other embodiments, the number of solder marks 520 can be greater than three.

[0098] It should be noted that for a single battery cell, both the positive electrode tab 112a and the negative electrode tab 112b have three solder marks formed on each. For example... Figure 20 For the secondary battery shown, which consists of four cells, since the adapter 320 has a first opening in the middle, the adapter 320 is divided into two parts. One part is used to connect with the tabs of two individual cells, and the other part is used to connect with the tabs of another two individual cells. Therefore, for this secondary battery, the total number of solder marks is 3*4=12.

[0099] While the foregoing disclosure has discussed some application embodiments that are currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. Rather, the claims are intended to cover all modifications and equivalent combinations that conform to the substance and scope of the embodiments of this application.

[0100] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the present application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0101] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0102] Although this application has been described with reference to specific embodiments, those skilled in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, any changes or modifications to the above embodiments within the essential spirit of this application will fall within the scope of the claims of this application.

Claims

1. A secondary battery, characterized in that, include: The battery cell includes a cell body and a tab cluster. The tab cluster includes a positive tab cluster and a negative tab cluster. The positive tab cluster and the negative tab cluster each include at least two tab groups. Each tab group includes at least one tab unit. The cell body has a tab lead-out end. Each tab unit extends from the tab lead-out end. The adapter has multiple tab slots. Each tab slot penetrates the adapter along the thickness direction of the adapter. The tab groups correspond one-to-one with the tab slots. Each tab group is inserted into the corresponding tab slot and is electrically connected to the adapter.

2. The secondary battery as described in claim 1, characterized in that, All the electrode units in the electrode assembly are located inside the electrode groove, and the electrode assembly is welded to the inner wall of the electrode groove.

3. The secondary battery as described in claim 1, characterized in that, The electrode unit in the electrode assembly includes a bent portion extending out of the electrode groove, the bent portion being welded to the upper surface of the adapter piece and forming at least one weld mark.

4. The secondary battery as described in claim 3, characterized in that, All the tab units in the tab assembly are gathered together by welding, and have a gathering weld at the welding point, the gathering weld being located inside the tab groove.

5. The secondary battery as described in claim 3, characterized in that, The tab assembly has a tab width along a first direction, and the at least one solder mark extends along a second direction, the first direction being perpendicular to the second direction, and the solder mark simultaneously passes through the bending portions of all the tab assemblies in the positive tab cluster or the negative tab cluster.

6. The secondary battery according to any one of claims 1 to 5, characterized in that, The adapter plate has a terminal post, and in the width direction of the secondary battery, the plurality of tab grooves are all located on the same side of the terminal post.

7. The secondary battery as described in claim 6, characterized in that, The adapter plate has a first opening on the side away from the electrode post. In the thickness direction of the secondary battery, the first opening is located in the middle of the adapter plate and divides the plurality of electrode slots into two groups of equal number.

8. The secondary battery according to any one of claims 1 to 5, characterized in that, The adapter plate has a terminal post, and in the thickness direction of the secondary battery, the plurality of tab grooves are respectively located on both sides of the terminal post.

9. The secondary battery as described in claim 1, characterized in that, The adapter piece has a first side edge that is close to the interior of the secondary battery in the width direction of the secondary battery, and the tab groove has a second opening on the first side edge.

10. The secondary battery as described in claim 9, characterized in that, The adapter plate has a comb-like portion formed at the second opening, and the outer end of the comb-like portion has a chamfer or a sharp corner.

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