Battery

Abstract

This application provides a battery, comprising: an adapter piece including a first connecting portion and a second connecting portion; two cell stacks disposed within a receiving space, each cell stack including a first clamping member and at least two cells, wherein the tabs of each cell in each cell stack are stacked to form a tab group, and the tab groups of the two cell stacks are respectively welded to the first connecting portion and the second connecting portion; the first clamping member is used to constrain each cell in the cell stack; a second clamping member is used to constrain the two cell stacks; wherein the first clamping member is disposed near the cover plate to ensure that the tabs are neatly stacked to form a tab group during the stacking process, which facilitates welding and avoids tearing of the welding points due to cell misalignment; the second clamping member is disposed near the base plate to facilitate the assembly of the cell stacks into the casing; the synergistic effect of the first clamping member and the second clamping member effectively improves the reliability of the battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery. Background Technology

[0002] Currently, most high-capacity wound batteries use a structure of ≥4 cells. Multiple cells require numerous clamping components to fix them in place, in order to restrain vibrations and displacements generated during processing and under various operating conditions, and to prevent safety risks or performance failures. However, how to rationally arrange these clamping components on the cells remains to be solved. Utility Model Content

[0003] In view of the above, this application aims to provide a battery that solves some or all of the aforementioned technical problems.

[0004] For the purposes described above, this application provides a battery, comprising:

[0005] The housing and the cover plate are provided. At least one end of the housing is provided with an opening. The cover plate is used to close the opening to form an accommodating space. The housing includes a bottom plate, which is disposed opposite to the cover plate. The cover plate is provided with a connecting piece on the side near the bottom plate. The connecting piece includes a first connecting part and a second connecting part arranged along a first direction.

[0006] Two battery cell stacks are arranged along a first direction within the receiving space. Each battery cell stack includes a first clamping member and at least two battery cells stacked along the first direction. The tabs of each battery cell in each battery cell stack are stacked to form a tab group. The tab groups of the two battery cell stacks are respectively welded to a first connecting portion and a second connecting portion. The first clamping member is disposed around at least a portion of the at least two battery cells to constrain each battery cell in the battery cell stack.

[0007] A second clamping member is disposed around at least a portion of the two cell stacks to constrain the two cell stacks.

[0008] The first fastening member is disposed near the cover plate, and the second fastening member is disposed near the bottom plate.

[0009] Furthermore, each of the cell stacks includes a first surface and a second surface disposed opposite to each other along a first direction; one end of the first clamping member is bonded to the first surface of one of the cell stacks, and the other end is bonded to the second surface of the cell stack; one end of the second clamping member is bonded to the first surface of one of the cell stacks, and the other end is bonded to the second surface of another cell stack.

[0010] Furthermore, the cell stack also includes a constraint side connecting the first surface and the second surface in a first direction. The second fastening member includes a non-adhesive portion and an adhesive portion located at both ends of the non-adhesive portion. The non-adhesive portion is opposite to the constraint side of the two cell stacks. One adhesive portion is bonded to the first surface of one cell stack, and the other adhesive portion is bonded to the second surface of the other cell stack.

[0011] Furthermore, the cell stack also includes a constraint side connecting the first surface and the second surface in a first direction. The second fastening member includes a first adhesive portion and second adhesive portions located at both ends of the first adhesive portion. The first adhesive portion is bonded to the constraint side of the two cell stacks, one second adhesive portion is bonded to the first surface of one cell stack, and the other second adhesive portion is bonded to the second surface of another cell stack.

[0012] Wherein, the bonding strength of the first adhesive part is less than the bonding strength of the second adhesive part.

[0013] Furthermore, each of the battery cells is formed by winding a first electrode, a second electrode, and an insulating film disposed between the first electrode and the second electrode with opposite polarities, and forming multiple winding layers. The first electrode and the second electrode of the multiple winding layers disposed near the second center surface are provided with tabs extending in the direction toward the cover plate. The tabs in the same battery cell stack group move closer to the second center surface to form the tab group.

[0014] Wherein, the second center surface is the center surface of the cell stack in the first direction; the number of winding layers with tabs accounts for at least two-thirds of the total number of winding layers.

[0015] Furthermore, in the two cell stacks, the tabs of each cell are arranged facing the cover plate. The cover plate includes a first terminal post and a second terminal post. The adapter includes a first adapter and a second adapter. The tabs include a first tab and a second tab with opposite polarities. The tab group includes a first tab group and a second tab group with opposite polarities.

[0016] The first electrode extends toward the cover plate and is provided with a plurality of first electrode tabs, and the second electrode extends toward the cover plate and is provided with a plurality of second electrode tabs. The plurality of first electrode tabs in the same cell stack group are stacked to form a first electrode tab group, and the plurality of second electrode tabs in the same cell stack group are stacked to form a second electrode tab group. The first electrode tab groups of two cell stack groups are connected via the first adapter piece, and the second electrode tab groups of two cell stack groups are connected via the second adapter piece.

[0017] The first adapter piece is integrally connected to the first pole post or is connected separately; the second adapter piece is integrally connected to the second pole post or is connected separately.

[0018] Furthermore, the adapter plate also includes a protrusion located between the first connecting portion and the second connecting portion, the protrusion extending toward the cover plate.

[0019] Furthermore, the first and second fastening members do not overlap with the first center surface;

[0020] Wherein, the first center plane is the center plane of the cell stack in its height direction.

[0021] Furthermore, the distance between the first clamping member and the first center surface, and the distance between the second clamping member and the first center surface, are both greater than or equal to one-fifth of the height of the cell stack.

[0022] Furthermore, the distance between the first clamping member and the top of the cell stack is L1, and the distance between the second clamping member and the bottom of the cell stack is L2, with the ratio between L1 and L2 being (3-7):1.

[0023] As described above, the battery provided in this application includes two cell stacks. Each cell within a cell stack is constrained by a first clamping member, which is located near the cover plate and constrains the upper part of the cell stack, close to the tabs. This ensures that the tabs are neatly stacked during the stacking process, forming a tab assembly. This provides a stable foundation for welding the tab assembly to the adapter plate and prevents tearing of the welding points due to cell misalignment, protecting the long-term reliability of the welding points. The two cell stacks are then constrained by a second clamping member, located near the base plate. The second clamping member's main function is to constrain the relative positions of the two cell stacks, and its proximity to the base plate facilitates the assembly of the cell stacks into the casing. In other words, through the synergistic effect of the first and second clamping members, the battery structure in this application not only achieves stable constraint within and overall the cell stacks but also optimizes the assembly process, effectively improving the battery's reliability and lifespan. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the external structure of the battery in an embodiment of this application;

[0026] Figure 2 This is a three-dimensional structural diagram of the shell according to an embodiment of this application;

[0027] Figure 3 This is a schematic diagram of the cell stacking group structure in an embodiment of this application;

[0028] Figure 4 for Figure 3 A schematic diagram of the side view direction;

[0029] Figure 5 This is a schematic diagram of the winding configuration of two adjacent cells in a cell stacking group in an embodiment of this application;

[0030] Figure 6 This is a schematic diagram of the structure of a winding layer in an embodiment of this application;

[0031] Figure 7 This is a schematic diagram of the connection structure of two battery cell stacks in the unfolded state in an embodiment of this application;

[0032] Figure 8 for Figure 7 A top-down view diagram;

[0033] Figure 9 This is a schematic diagram of the adapter plate in the embodiments of this application;

[0034] Figure 10 for Figure 9 A diagram illustrating the upward viewing direction;

[0035] Figure 11 for Figure 8 A schematic diagram of the connection structure of two battery cell stacks in their assembled state;

[0036] Figure 12 for Figure 11 A magnified view of a portion of the image;

[0037] Figure 13 This is a schematic diagram of the structure of the battery cell stack and the cover plate after they are assembled in an embodiment of this application;

[0038] Figure 14 for Figure 13 Side view direction illustration Figure 1 ;

[0039] Figure 15 for Figure 13 Side view direction illustration Figure 2 ;

[0040] Figure 16 This is a schematic diagram of the structure of the first fastening member in an embodiment of this application;

[0041] Figure 17This is a schematic diagram of the structure of the second fastening member in the embodiments of this application. Figure 1 ;

[0042] Figure 18 This is a schematic diagram of the structure of the second fastening member in the embodiments of this application. Figure 2 .

[0043] Explanation of reference numerals in the attached drawings: 100, housing; 110, base plate; 120, receiving space; 130, opening; 200, cover plate; 210, pole post; 211, first pole post; 212, second pole post; 220, adapter piece; 221, first adapter piece; 221a, first connecting part; 221b, second connecting part; 221c, protrusion; 222, second adapter piece; 300, cell stack; 310, cell; 310a, first surface; 310b, second surface; 310c, restraining side; 311, first electrode plate; 31 2. Second electrode sheet; 313. Separating membrane; 313a. Adhesive component; 314. Winding layer; 315. Electrode tab; 315a. First electrode tab; 315b. Second electrode tab; 315c. Welding point; 316. Electrode tab assembly; 316a. First electrode tab assembly; 316b. Second electrode tab assembly; 320. First fastening component; 400. Second fastening component; 410. Non-adhesive portion; 420. Adhesive portion; 430. First adhesive portion; 440. Second adhesive portion; X. First direction; Y. Height direction; M1. First center plane; M2. Second center plane. Detailed Implementation

[0044] 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.

[0045] 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 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 covers the element or object listed following the word and its 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.

[0046] As described in the background section, most high-capacity (500+ Ah) wound batteries in related technologies adopt a structure of ≥4 cells. Multiple cells are divided into two groups to form two cell stacks. Each cell in each cell stack and the two cell stacks require a large number of fastening components (such as binding tape) for fixation. Specifically, each cell in a cell stack needs to be paired and bonded by binding tape, and the two cell stacks also need to be bonded together by binding tape. For the convenience of subsequent description, in the following embodiments of this application, the binding tape used for pairing and bonding within the cell stack is referred to as pairing tape, and the tape used for bonding together is referred to as bonding tape. The pairing tape used to bond a single cell stack and the bonding tape used to bond two cell stacks can restrain the vibration and displacement generated by the cells during processing and under various operating conditions, preventing the cells from causing safety risks or performance failures.

[0047] Currently, there are no universally accepted standards in the industry regarding the binding methods and positions of mating tapes used to bond individual cell stacks and bonding tapes used to bond two cell stacks in wound batteries. The applicant has found that arbitrary adhesive placement and methods can lead to manufacturing problems, hindering stable and efficient cell assembly. For example, during battery charging and discharging, electrochemical reactions occur inside the cell, causing it to expand. This expansion primarily occurs in the central region of the cell's height. If adhesive is applied in this central region, excessive tape constraint can impede normal cell expansion. This impediment may result in uneven pressure distribution within the cell, leading to abnormal lithium plating in lithium-ion batteries and thus reducing the cell's electrochemical performance. For example, since a single cell stack consists of at least two cells and is quite heavy, when the two cell stacks are assembled into the casing, there will inevitably be some misalignment in the height direction between the two cell stacks. If the adhesive tape used is applied too tightly to the two cell stacks, it will affect the elasticity of the adhesive tape itself. Once misalignment occurs in the height direction, the weight of one cell stack can easily be transferred to the tab welding point of the other cell stack, which may cause the welding point to be pulled or even broken, thereby affecting the electrochemical performance of the cell.

[0048] Therefore, optimizing the adhesive application location and tape type for wound batteries is an urgent problem to be solved.

[0049] Based on this, this application provides a battery in which the adhesive placement and tape form inside the battery are optimized to improve the electrochemical stability of the cell 310 in the battery.

[0050] The following describes specific embodiments in conjunction with... Figures 1-18 The technical solution of this application will be described in detail below.

[0051] In view of this, such as Figure 1 , Figure 2 , Figures 7-14 As shown, in some embodiments, a battery includes: a housing 100 and a cover plate 200. At least one end of the housing 100 has an opening 130, and the cover plate 100 is used to close the opening 130 to form a receiving space 120. The housing 100 includes a bottom plate 110, which is disposed opposite to the cover plate 200. The cover plate 200 has an adapter piece 220 on its side near the bottom plate 110. The adapter piece 220 includes components along a first direction (i.e.,...). Figure 4 , Figure 14 The first connecting portion 221a and the second connecting portion 221b are arranged in the direction shown in the middle X; two battery cell stack groups 300 are arranged in the receiving space 120 along the first direction X. Each battery cell stack group 300 includes a first clamping member 320 and at least two battery cells 310 stacked along the first direction X. The tabs 315 of each battery cell 310 in each battery cell stack group 300 are stacked to form a tab group 316. The tab groups 316 of the two battery cell stack groups 300 are respectively welded to the first connecting portion 221a and the second connecting portion 221b; the first clamping member 320 is arranged around at least a portion of the at least two battery cells 310 to constrain each battery cell 310 in the battery cell stack group 300; and a second clamping member 400 is arranged around at least a portion of the two battery cell stack groups 300 to constrain the two battery cell stack groups 300.

[0052] The first tensioning member 320 is used to constrain the relative positions of the individual cells 310 within the cell stack 300; that is, the first tensioning member 320 can be the aforementioned mating tape. The second tensioning member 400 is used to constrain the relative positions of the cell stack 300; that is, the second tensioning member 400 can be the aforementioned core-joining tape. It is understood that, in addition to tape, the first tensioning member 320 and the second tensioning member 400 can also be annular elastic elements such as rubber bands or rubber sleeves.

[0053] The first fastening member 320 is disposed near the cover plate 200. Specifically, the first fastening member 320 is disposed around at least a portion of a cell stack 300, for example, around all sides of the cell stack 300 or only constraining a portion of the sides of the cell stack 300. Its main function is to constrain the relative position of each cell 310 within the cell stack 300, preventing displacement of the cells 310 during stacking. In addition, by disposing of the first fastening member 320 near the cover plate 200, the upper part of the cell stack 300 can be effectively fixed. Near the tab 315, the initial position of the tab 315 can be effectively fixed, making it easier for the tabs 315 of each wound cell 310 to maintain a neat stacked state during stacking and forming a neat tab group 316. This provides a prerequisite for the stability of the tab groups 316 of the subsequent two cell stacks 300 during the welding process with the first connection portion 221a and the second connection portion 221b of the adapter piece 220, respectively.

[0054] Furthermore, it should be noted that within the cell stack 300, the tabs 315 of each cell 310 are stacked and welded to form a neat tab assembly 316, with the solder marks highly overlapping during the welding process. This structure makes the tab assembly 316 highly integral after stacking, but it also means that it is more sensitive to stress. Once the cell stack 300 is subjected to external forces, such as vibration or impact, if a slight misalignment occurs between the cells 310, the welding points 315c between the tabs 315 of each cell 310 and the overlapping solder marks will bear the brunt of the enormous tensile force. This tensile force may not only cause the welding points 315c to tear, but also disrupt the overlap of the solder marks, thereby affecting the electrical connection stability of the entire cell stack 300, and may even cause serious faults such as internal short circuits in the battery. Therefore, the setting of the first clamping member 320 is crucial. It is positioned around at least a portion of the cell stack 300, particularly near the cover plate 200, effectively securing the upper part of the cell stack 300, close to the initial position of the tabs 315. This not only makes it easier for the tabs 315 of each wound cell 310 to maintain a neat stacked state during the stacking process, but also, during subsequent use, when the battery is subjected to external forces, the first fastener 320 can effectively prevent misalignment between the cells 310 by constraining the upper part of the cell stack 300, thereby protecting the welding points 315c between the tabs 315 and the overlapping areas of the solder marks from being pulled, ensuring the long-term reliability of the welding points 315c, and providing strong protection for the safe and stable operation of the battery.

[0055] The second clamping member 400 is disposed near the base plate 110. Specifically, the second clamping member 400 is disposed around at least a portion of the two cell stacks 300, for example, around all sides of the two cell stacks 300 or only constraining a portion of the sides of the two cell stacks 300. Its main function is to constrain the relative position of the two cell stacks 300, ensuring the overall structural stability of the battery. For example, during battery assembly and use, the two cell stacks 300 may experience relative displacement due to factors such as vibration, impact, or thermal expansion. This displacement can disrupt the internal structural balance of the battery, thereby affecting its performance and lifespan. The second clamping member 400, by constraining the relative position of the two cell stacks 300, can effectively prevent such displacement, thereby ensuring the stability of the internal structure of the battery. In addition, the second fastening member 400 is located near the base plate 110 and can effectively fix the lower part of the cell stack 300. The constraint effect of the second fastening member 400 on the lower part of the two cell stack 300 facilitates the assembly of the two cell stack 300 into the shell, and can also prevent the cell stack 300 from colliding or interfering due to vibration or impact during the transportation and use of the battery.

[0056] Based on the above description, the first clamping member 320 is used to constrain the upper part of a single cell stack 300, and the second clamping member 400 is used to constrain the lower part of two cell stacks 300. Compared with the related technology where clamping members are provided in the upper, middle, and lower regions of a single cell stack 300, and where clamping members are provided in the upper, middle, and lower regions of two cell stacks 300, this not only reduces the number of clamping members but also simplifies the battery structure. Furthermore, the reduced-weight clamping members of this embodiment can meet the requirement of neatly stacked tabs 315 within a single cell stack 300, the requirement of stable welding of tabs 316 between two cell stacks 300, and the requirement of easy assembly of two cell stacks 300 into the casing. In other words, the reduced-weight clamping member layout of this embodiment can meet the manufacturing requirements of the entire battery, and the reduced-weight clamping members can also meet the requirements of subsequent transportation and use of the battery.

[0057] Further optional, such as Figure 15 As shown, the first clamping member 320 and the second clamping member 400 do not overlap with the first center surface M1; wherein, the first center surface M1 is the center surface of the cell stack 300 in its height direction Y. That is, based on the first clamping member 320 being positioned near the cover plate 200 and the second clamping member 400 being positioned near the bottom plate 110, the first clamping member 320 and the second clamping member 400 also avoid the central region where the cell 310 expands the most, allowing the cell 310 to expand freely during charging and discharging, further reducing the resistance to the expansion of the cell 310 and optimizing the electrochemical performance of the battery.

[0058] Optionally, the distance between the first clamping member 320 and the first center surface M1, and the distance between the second clamping member 400 and the first center surface M1, are both greater than or equal to one-fifth of the height of the cell stack 300. This design ensures that the clamping members do not get too close to the central region of the cell stack 300, thereby avoiding excessive constraint on the expansion of the cell 310. Furthermore, this design results in a relatively large distance between the first clamping member 320 and the second clamping member 400. This layout ensures the stability of the battery structure while also providing sufficient space for the normal expansion of the cells, further optimizing the overall performance and reliability of the battery.

[0059] In this embodiment, the battery includes two cell stacks 300. Each cell 310 within a cell stack 300 is constrained by a first clamping member 320. This first clamping member 320 is located near the cover plate 200, constraining the upper part of the cell stack 300, near the tab 315. This ensures that the tabs 315 are neatly stacked during the stacking process to form a tab assembly 316, providing a stable condition for welding the tab assembly 316 to the adapter piece 220. It also prevents the welding point 315c from tearing due to misalignment of the cells 310, protecting the long-term reliability of the welding point 315c. The two cell stacks 300 are constrained by a second clamping member 400. The second clamping member 400 is located near the base plate 110, primarily constraining the relative position of the two cell stacks 300. Its proximity to the base plate 110 facilitates the assembly of the cell stacks 300 into the casing. Through the synergistic effect of the first clamping member 320 and the second clamping member 400, the battery structure in this embodiment not only achieves stable constraint within and as a whole of the cell stack 300, but also optimizes the assembly process, effectively improving the reliability and service life of the battery.

[0060] In some embodiments, such as Figure 4 , Figure 14 As shown, each of the cell stacks 300 includes a first surface 310a and a second surface 310b disposed opposite to each other along a first direction X; one end of the first clamping member 320 is bonded to the first surface 310a of one of the cell stacks 300, and the other end is bonded to the second surface 310b of the same cell stack; one end of the second clamping member 400 is bonded to the first surface 310a of one of the cell stacks 300, and the other end is bonded to the second surface 310b of another cell stack 300.

[0061] Specifically, the cell stack group 300 includes a first surface 310a and a second surface 310b disposed opposite to each other along the first direction X. In the two cell stack groups 300, the second surface 310b of one cell stack group 300 is superimposed on the first surface 310a of the other cell stack group 300. That is, in the first direction X, the opposite sides of the two cell stack groups 300 are the first surface 310a of one cell stack group 300 and the second surface 310b of the other cell stack group 300.

[0062] For each of the two cell stack groups 300, the first fastening member 320 acts as a pairing tape, with one end bonded to the first surface 310a of the cell stack group 300 and the other end bonded to the second surface 310b of the cell stack group 300. In this way, the first fastening member 320 can bond the first surface 310a and the second surface 310b of each cell stack group 300 together to achieve binding and restraint of each cell stack group 300, ensuring that the cells 310 in the cell stack group 300 will not be misaligned.

[0063] The second fastening member 400 acts as a core-binding tape, with one end bonded to the first surface 310a of one of the cell stacks 300 and the other end bonded to the second surface 310b of another cell stack 300. In this way, the second fastening member 400 can bond the first surface 310a and the second surface 310b of the two cell stacks 300 together to achieve binding and restraint of the two cell stacks 300 and ensure that the two cell stacks 300 do not misalign.

[0064] Based on the above description, the cross-sections of the first clamping member 320 and the second clamping member 400 in the first direction X are both U-shaped, such as Figure 13 , Figure 14 As shown, each cell stack 300 has two U-shaped first clamping members 320 on its upper periphery, which are symmetrically arranged; the two cell stacks 300 have two U-shaped second clamping members 400 on their lower periphery, which are also symmetrically arranged. Compared with the technical solutions of setting a full circle of first clamping members 320 on the periphery of the cell stack 300 and setting a full circle of second clamping members 400 on the periphery of the two cell stacks 300, the U-shaped first clamping members 320 and second clamping members 400 in this embodiment save the amount of clamping members used, reduce the constraint area of ​​the cell stack 300, and further reduce the increase of internal stress and lithium plating phenomenon in the cell 310 caused by excessive constraint force.

[0065] In some embodiments, such as Figure 4 , Figure 14 , Figure 17As shown, the cell stack 300 further includes a constraint side 310c that connects the first surface 310a and the second surface 310b in the first direction X. The second fastening member 400 includes a non-adhesive portion 410 and adhesive portions 420 located at both ends of the non-adhesive portion 410. The non-adhesive portion 410 is opposite to the constraint side 310c of the two cell stacks 300. One adhesive portion 420 is bonded to the first surface 310a of one cell stack 300, and the other adhesive portion 420 is bonded to the second surface 310b of another cell stack 300.

[0066] The second clamping member 400 is bonded to the first surface 310a and the second surface 310b of the two cell stacks 300 via two adhesive portions 420, respectively. The non-adhesive portion 410 located between the two adhesive portions 420 only faces the constraint side 310c of the two cell stacks 300; this portion is not adhesive-backed and is not bonded to the constraint side 310c of the cell stacks 300. This design ensures that the relative position of the two cell stacks 300 in the first direction X is effectively constrained, preventing relative displacement in the first direction X during assembly and use. The non-adhesive portion 410 enhances the elasticity of the second clamping member 400, thereby improving the battery's adaptability under dynamic conditions.

[0067] It should be noted that, in order to ensure the stability of battery use, theoretically, it is desirable that there is no relative displacement between the two cell stacks 300, either in the first direction (X) or in the height direction (Y). However, in actual assembly and use, since each cell stack 300 consists of at least two cells 310, its weight is relatively large. These heavier cell stacks 300 inevitably experience relative displacement in the height direction (Y) due to external forces (such as vibration, impact, or thermal expansion) during casing or use. If this displacement is not controlled, it may lead to damage to the internal structure of the battery, thereby affecting the battery's performance and safety.

[0068] In traditional designs, the second clamping member 400 typically uses a fully adhesive backing, meaning the entire back of the clamping member is sticky. While this design provides strong fixing force, it also has some significant limitations. First, the fully adhesive backing design affects the elasticity of the second clamping member 400. When the cell stack 300 experiences relative displacement, the clamping member, lacking elasticity, cannot effectively buffer the force from this displacement. Second, once misalignment occurs, the fully adhesive clamping member is difficult to return to its original position, which may lead to breakage. More seriously, the weight of the cell stack 300 may be transferred to the electrode tab 315 welding point 315c of the other cell stack 300, causing tension on the electrode tab 315. This tension not only affects the stability of the welding point 315c but may also damage the electrode tab 315, potentially leading to safety issues such as internal battery short circuits.

[0069] To address the problems inherent in conventional designs, this embodiment introduces a non-adhesive portion 410. Specifically, the second clamping member 400 includes a non-adhesive portion 410 and adhesive portions 420 located at both ends of the non-adhesive portion 410. The non-adhesive portion 410 faces the constraint side 310c of the two cell stacks 300 but is not bonded to the constraint side 310c, while the adhesive portions 420 are bonded to the first surface 310a and the second surface 310b of the two cell stacks 300, respectively. The key advantage of this design is that the presence of the non-adhesive portion 410 provides the second clamping member 400 with greater elasticity in this region. When the cell stack 300 undergoes relative displacement in the height direction Y, the non-adhesive portion 410 can effectively buffer the force caused by this displacement, thereby reducing the pulling on the welding point 315c of the tab 315. In addition, the presence of the non-adhesive portion 410 allows the two cell stacks 300 to recover from vibration, impact or thermal expansion when relative displacement occurs, so that the relative position of the two cell stacks 300 can reach a dynamic balance, thereby improving the battery's adaptability under dynamic conditions.

[0070] It should be noted that, as Figure 16 As shown, in this embodiment, the first fastening member 320 is a fully adhesive-backed mating tape. Since the tabs 315 of the cells 310 in the same cell stack 300 are stacked and then welded to the first connecting part 221a or the second connecting part 221b of the adapter piece 220, any relative displacement in the height direction Y will cause the welding point 315c of the tabs 315 to tear. In addition, each cell 310 in the same cell stack 300 needs to move at the same frequency. Therefore, the first fastening member 320 is fully adhesive-backed to strictly limit the position of each cell 310 in the same cell stack 300.

[0071] In this embodiment, by introducing a non-adhesive portion 410 into the second clamping member 400, and having the non-adhesive portion 410 opposite to the constraint side 310c of the two cell stacks 300, the overall elasticity of the second clamping member 400 is enhanced. When the two cell stacks 300 experience relative displacement in the height direction Y, the non-adhesive portion 410 will share most of the weight of the cell stacks 300, preventing one cell stack 300 from pulling on the tab 315 of the other cell stack 300, thus improving the stability and reliability of the welding point 315c, thereby improving the battery's adaptability under dynamic conditions.

[0072] In some embodiments, such as Figure 4 , Figure 14 , Figure 18 As shown, the cell stack 300 further includes a constraint side 310c that connects the first surface 310a and the second surface 310b in the first direction X. The second fastening member 400 includes a first adhesive portion 430 and second adhesive portions 420 located at both ends of the first adhesive portion 430. The first adhesive portion 430 is bonded to the constraint side 310c of the two cell stack 300s, one second adhesive portion 420 is bonded to the first surface 310a of one cell stack 300, and the other second adhesive portion 420 is bonded to the second surface 310b of another cell stack 300.

[0073] In this design, the second clamping member 400 is bonded to the first surface 310a and the second surface 310b of the two cell stacks 300 via two second adhesive portions 420, respectively. A first adhesive portion 430 located between the two second adhesive portions 420 is bonded to and opposite the constraint side 310c of the two cell stacks 300. This design ensures that the relative positions of the two cell stacks 300 are effectively constrained. However, the adhesive strength of the first adhesive portion 430 is less than that of the second adhesive portion 420. Compared to cases where both the backing adhesives of the second clamping member 400 have a second strength, the presence of the first adhesive portion 430 enhances the elasticity of the second clamping member 400, thereby improving the battery's adaptability under dynamic conditions.

[0074] Specifically, the presence of the first adhesive portion 430 gives the second clamping member 400 greater elasticity in this area. When the cell stack 300 undergoes relative displacement in the height direction Y, the first adhesive portion 430 can effectively buffer the force caused by this displacement, thereby reducing the pulling on the welding point 315c of the tab 315. In addition, the first adhesive portion 430 does not firmly bond the constraint sides 310c of the two cell stack 300s, so that the two cell stack 300s will recover with changes in vibration, impact or thermal expansion when relative displacement occurs, so that the relative positions of the two cell stack 300s can reach a dynamic balance, thereby improving the battery's adaptability under dynamic conditions.

[0075] In this embodiment, by introducing a first adhesive portion 430 and a second adhesive portion 420 with different adhesive strengths into the second fastening member 400, the adhesive strength of the first adhesive portion 430 is less than that of the second adhesive portion 420, making the second fastening member 400 more elastic at the first adhesive portion 430. The first adhesive portion 430 is opposite to and bonded to the constraint side 310c of the two cell stack groups 300, but its bonding effect is not very strong. When the two cell stack groups 300 have a relative displacement in the height direction Y, the first adhesive portion 430 will share most of the weight of the cell stack group 300, avoiding the pulling of the tab 315 of the other cell stack group 300 by one cell stack group 300, improving the stability and reliability of the welding point 315c, thereby improving the adaptability of the battery under dynamic conditions.

[0076] In some embodiments, such as Figure 5 , Figure 6 , Figure 15 As shown, each of the battery cells 310 is formed by winding a first electrode 311, a second electrode 312 with opposite polarities and a separator 313 disposed between the first electrode 311 and the second electrode 312, forming a plurality of winding layers 314. The first electrode 311 and the second electrode 312 of the plurality of winding layers 314 disposed near the second center surface M2 extend with tabs 315 in the direction toward the cover plate 200. The tabs 315 in the same battery cell stack group 300 move closer to the second center surface M2 to form the tab group 316.

[0077] Wherein, the second center surface M2 is the center surface of the cell stack 300 in the first direction X; the number of winding layers 314 with tabs 315 accounts for at least two-thirds of the total number of winding layers 314.

[0078] Specifically, the separator 313 is longer than both the first electrode 311 and the second electrode 312, so that after the first electrode 311 and the second electrode 312 are wound, the excess separator 313 can be used to wrap the outermost winding layer 314. Therefore, the cell 310 also includes an adhesive member 313a to constrain the tail of the separator 313. Figure 3 , Figure 13 As shown, this is to maintain the constraint of the separator 313 on each winding layer 314 and to prevent the tail of the separator 313 from lifting up.

[0079] Specifically, the first electrode 311 can be a positive electrode, serving as the positive electrode material of the battery and responsible for providing lithium ions in the electrochemical reaction. The second electrode 312 can be a negative electrode, serving as the negative electrode material of the battery and responsible for inserting and extracting lithium ions in the electrochemical reaction. A separator 313 is disposed between the first electrode 311 and the second electrode 312 to prevent direct contact between the positive and negative electrodes, avoiding short circuits, while allowing lithium ions to pass through. The battery cell 310 forms multiple wound layers 314 by winding the first electrode 311, the second electrode 312, and the separator 313 together. This winding structure gives the battery cell 310 high energy density and good electrochemical performance.

[0080] In this embodiment, the winding structure of the battery cell 310 is designed such that the first electrode 311 and the second electrode 312 of multiple winding layers 314 near the second center surface M2 extend toward the cover plate 200 to form a tab group 316. Specifically, each battery cell 310 is formed by winding a first electrode 311, a second electrode 312, and an insulating film 313 disposed between them, forming multiple winding layers 314. To optimize the current transmission path, the first electrode 311 and the second electrode 312 of the multiple winding layers 314 near the second center surface M2 extend toward the cover plate 200 to form tabs 315. These tabs 315 move closer to the second center surface M2 in the battery cell stack 300, ultimately forming a neat tab group 316. The tabs 316 of the two cell stacks 300 are welded to the first connecting portion 221a and the second connecting portion 221b of the adapter piece 220, respectively, and the adapter piece 220 is connected to the terminal post 210 on the cover plate 200. Thus, a current transmission path consisting of the electrode, the tab 315, the adapter piece 220 and the terminal post 210 is formed.

[0081] In this embodiment, the number of winding layers 314 with tabs 315 accounts for at least two-thirds of the total number of winding layers 314. For example, if the number of winding layers of two cells 310 in a cell stack 300 is 30 layers each, then at least two-thirds of the winding layers 314 will have tabs 315, that is, each cell 310 will have 20 winding layers 314 with tabs 315. These 20 winding layers 314 are all located close to the second center surface M2, and the tabs 315 of each of the 20 winding layers 314 of the two cells 310 will move towards the second center surface M2 to form a tab group 316. The reason for this design is that the closer the tabs 315 are to the second center surface M2, the shorter the current transmission path and the smaller the internal resistance, thereby improving electrical efficiency. In addition, the fact that the number of winding layers 314 with tabs 315 accounts for at least two-thirds of the total number of winding layers 314 can increase the number of current collection points. More current collection points mean that current can be transmitted to the tab 315 through more paths, thereby improving the efficiency of current collection.

[0082] Furthermore, the tabs 315 of both cells 310 are brought closer together towards the second center surface M2, forming a tab assembly 316 which is then welded to the adapter piece 220. It is worth noting that the cells 310 generate heat during operation, and the tabs 315 are not only key components for current transmission but also important pathways for heat dissipation. This arrangement results in more uniform heat dissipation for the two cells 310. Because the tab assembly 316 is close to the second center surface M2 and neatly arranged, heat can be dissipated more evenly to the outside of the cell stack 300 through the tabs 315, preventing localized overheating and improving the overall thermal stability of the battery. This optimized tab 315 layout not only improves current transmission efficiency but also enhances the heat dissipation performance of the cells 310, enabling the battery to maintain good operating conditions even under high loads and extending its lifespan.

[0083] In some embodiments, such as Figure 1 , Figure 3 , Figure 7As shown, in the two cell stacks 300, the tabs 315 of each cell 310 are all positioned facing the cover plate 200 (i.e., tabs 315 on the same side). The terminal post 210 includes a first terminal post 211 and a second terminal post 212. The adapter piece 220 includes a first adapter piece 221 and a second adapter piece 222. The tabs 315 include a first tab 315a and a second tab 315b with opposite polarities. The tab group 316 includes a first tab group 316a and a second tab group 316b with opposite polarities. The first electrode 311 extends towards the cover plate 200 with multiple first tabs 315a, and the second electrode 312 extends towards the cover plate 200 with multiple first tabs 315a. Multiple second tabs 315b are stacked within the same cell stack 300 to form a first tab group 316a, and multiple second tabs 315b are stacked within the same cell stack 300 to form a second tab group 316b. The first tab groups 316a of two cell stacks 300 are connected via the first adapter piece 221, and the second tab groups 316b of two cell stacks 300 are connected via the second adapter piece 222. The first adapter piece 221 and the first terminal 211 are integrally connected or separately connected. The second adapter piece 222 and the second terminal 212 are integrally connected or separately connected.

[0084] The first tab group 316a is formed by stacking multiple first tabs 315a (positive tabs) within the same cell stack group 300. The second tab group 316b is formed by stacking multiple second tabs 315b (negative tabs) within the same cell stack group 300. A first adapter piece 221 connects the first tab groups 316a of the two cell stack groups 300 to ensure efficient transmission of positive current. A second adapter piece 222 connects the second tab groups 316b of the two cell stack groups 300 to ensure efficient transmission of negative current. A first terminal post 211 is connected to the first adapter piece 221 to transmit positive current to the outside of the battery. A second terminal post 212 is connected to the second adapter piece 222 to transmit negative current to the outside of the battery. The first adapter piece 221 and the first terminal post 211, and the second adapter piece 222 and the second terminal post 212, can be integrally connected or separately connected. Integrated connections reduce resistance at connection points and improve current transmission efficiency; separate connections facilitate assembly and maintenance.

[0085] Further optional, such as Figure 9 As shown, the adapter piece 220 also includes a protrusion 221c located between the first connecting portion 221a and the second connecting portion 221b, the protrusion 221c extending toward the cover plate 200.

[0086] Specifically, the first connecting portion 221a of the first adapter piece 221 is used to weld to the first tab group 316a of a cell stack 300, and the second connecting portion 221b is used to weld to the first tab group 316a of another cell stack 300. The first connecting portion 221a of the second adapter piece 222 is used to weld to the second tab group 316b of a cell stack 300, and the second connecting portion 221b is used to weld to the second tab group 316b of another cell stack 300.

[0087] The protrusion 221c is located between the first connecting portion 221a and the second connecting portion 221b, extending towards the cover plate 200. During the welding process between the adapter piece 220 and the pole post 210, the protrusion 221c ensures more accurate alignment between the adapter piece 220 and the pole post 210. As the center point for welding, the protrusion 221c provides precise positioning for the welding of the adapter piece 220 and the pole post 210, thereby reducing welding deviation and improving welding quality.

[0088] In this embodiment, the tabs 315 of the two cell stacks 300 are both positioned facing the cover plate 200, forming a first tab group 316a and a second tab group 316b. A first adapter piece 221 connects the first tab groups 316a of the two cell stacks 300, and a second adapter piece 222 connects the second tab groups 316b of the two cell stacks 300, and is connected to the first terminal post 211 and the second terminal post 212 on the cover plate 200 respectively, achieving efficient current transmission. The adapter piece 220 is designed to include a protrusion 221c, located between the first connecting portion 221a and the second connecting portion 221b, extending towards the cover plate 200. The protrusion 221c serves as a center point during the welding process between the adapter piece 220 and the terminal post 210, ensuring accurate alignment between the adapter piece 220 and the terminal post 210, reducing welding deviation, and improving welding quality. This design not only optimizes the current transmission path and reduces internal resistance, but also enhances the stability and reliability of welding, thereby improving the overall performance and safety of the battery.

[0089] In some embodiments, such as Figure 15 As shown, the distance between the first clamping member 320 and the top of the cell stack 300 is L1, and the distance between the second clamping member 400 and the bottom of the cell stack 300 is L2. The ratio between L1 and L2 is (3~7):1.

[0090] It should be noted that after the two cell stacks 300 are wrapped with insulating film, they are assembled into the housing 100 and sealed by the cover plate 200. Electrolyte is then injected into the housing 100 through the injection hole on the cover plate 200. If the first clamping member 320 is too close to the top of the cell stack 300, it will exert an excessively tight constraint on the upper part of the cell stack 300. During the assembly of the cover plate 200, this may generate additional compressive force on the cell stack 300. The excessively tight constraint makes it impossible to buffer this compressive force, which may cause deformation or damage to the cell 310. A larger L1 distance can effectively avoid this situation and ensure the smooth progress of the assembly process. In addition, this excessively tight constraint will also hinder the process of electrolyte being siphoned through the separator 313 to the upper part of the cell 310. The uniform distribution of electrolyte is crucial for the electrochemical reaction of the cell 310, especially in the upper part of the cell 310. Insufficient electrolyte will lead to incomplete reaction between the electrode and the electrolyte, thereby reducing the battery's electrical efficiency. A larger L1 distance ensures sufficient space at the top of the cell 310 for electrolyte distribution, resulting in more uniform contact between the electrodes and the electrolyte. This helps improve the overall reaction efficiency of the cell 310, reduces local overcharging or over-discharging caused by uneven electrolyte distribution, and thus extends the battery's lifespan.

[0091] Furthermore, the distance between the second clamping member 400 and the bottom of the cell stack 300 is relatively small (i.e., L2 is small). This smaller L2 distance allows the second clamping member 400 to be closer to the bottom of the cell stack 300, which facilitates smoother installation of the cell stack 300 into the housing 100 during assembly. Because the second clamping member 400 provides strong restraint, the close proximity to the bottom effectively prevents displacement or shaking of the cell stack 300 during installation, reducing assembly errors caused by improper clamping member positioning and improving the overall assembly quality of the battery. Additionally, the smaller L2 distance allows the second clamping member 400 to be closer to the bottom of the cell stack 300, providing stronger bottom support. This support effectively prevents displacement of the cell stack 300 due to vibration or impact during use, improving the overall structural stability of the battery.

[0092] In this embodiment, by rationally designing the distance L1 between the first clamping member 320 and the top of the cell stack 300, and the distance L2 between the second clamping member 400 and the bottom of the cell stack 300, and setting the ratio between L1 and L2 to (3-7):1, the distribution of electrolyte is optimized, reducing local overcharging or over-discharging caused by uneven electrolyte distribution, and reducing mechanical stress during the assembly of the cover plate 200, thereby improving assembly efficiency and reducing the defect rate caused by improper assembly. Furthermore, the rational distribution of constraint forces improves the structural stability of the battery during use, reducing performance degradation and safety risks caused by dynamic stress.

[0093] 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 (including the claims) is limited to these examples; within the framework 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 the different aspects of this application as described above, which are not provided in the details for the sake of brevity.

[0094] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery, characterized in that, include: The housing and the cover plate are provided. At least one end of the housing is provided with an opening. The cover plate is used to close the opening to form an accommodating space. The housing includes a bottom plate, which is disposed opposite to the cover plate. The cover plate is provided with a connecting piece on the side near the bottom plate. The connecting piece includes a first connecting part and a second connecting part arranged along a first direction. Two battery cell stacks are arranged in the receiving space along a first direction. Each battery cell stack includes a first clamping member and at least two battery cells stacked along the first direction. The tabs of each battery cell in each battery cell stack are stacked to form a tab group. The tab groups of the two battery cell stacks are respectively welded to the first connecting part and the second connecting part. The first clamping member is arranged around at least a portion of the at least two battery cells to constrain each battery cell in the battery cell stack. as well as A second clamping member is disposed around at least a portion of the two cell stacks to constrain the two cell stacks. The first fastening member is disposed near the cover plate, and the second fastening member is disposed near the bottom plate.

2. The battery according to claim 1, characterized in that, Each of the cell stacks includes a first surface and a second surface disposed opposite to each other along a first direction; one end of the first clamping member is bonded to the first surface of a cell stack, and the other end is bonded to the second surface of the cell stack. One end of the second clamping member is bonded to the first surface of one of the cell stacks, and the other end is bonded to the second surface of another cell stack.

3. The battery according to claim 2, characterized in that, The cell stack also includes a constraint side connecting the first surface and the second surface in a first direction. The second fastening member includes a non-adhesive portion and an adhesive portion located at both ends of the non-adhesive portion. The non-adhesive portion is opposite to the constraint side of the two cell stacks. One adhesive portion is bonded to the first surface of one cell stack, and the other adhesive portion is bonded to the second surface of the other cell stack.

4. The battery according to claim 2, characterized in that, The cell stack also includes a constraint side connecting the first surface and the second surface in a first direction. The second fastening member includes a first adhesive portion and a second adhesive portion located at both ends of the first adhesive portion. The first adhesive portion is bonded to the constraint side of the two cell stacks. One second adhesive portion is bonded to the first surface of one cell stack and the other second adhesive portion is bonded to the second surface of another cell stack. Wherein, the bonding strength of the first adhesive part is less than the bonding strength of the second adhesive part.

5. The battery according to claim 1, characterized in that, Each of the aforementioned cells is formed by winding a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode with opposite polarities, and forming multiple winding layers. The first electrode and the second electrode of the multiple winding layers disposed near the second center surface are provided with tabs extending in the direction toward the cover plate. The tabs in the same cell stack group move closer to the second center surface to form the tab group. Wherein, the second center surface is the center surface of the cell stack in the first direction; the number of winding layers with tabs accounts for at least two-thirds of the total number of winding layers.

6. The battery according to claim 5, characterized in that, It also includes pole posts, in which the tabs of each cell in the two cell stacks are all arranged facing the cover plate. The pole posts include a first pole post and a second pole post. The adapter includes a first adapter and a second adapter. The tabs include a first tab and a second tab with opposite polarities. The tab group includes a first tab group and a second tab group with opposite polarities. The first electrode extends toward the cover plate and is provided with a plurality of first electrode tabs, and the second electrode extends toward the cover plate and is provided with a plurality of second electrode tabs. The plurality of first electrode tabs in the same cell stack group are stacked to form a first electrode tab group, and the plurality of second electrode tabs in the same cell stack group are stacked to form a second electrode tab group. The first electrode tab groups of two cell stack groups are connected via the first adapter piece, and the second electrode tab groups of two cell stack groups are connected via the second adapter piece. The first adapter piece is integrally connected to the first pole post or is connected separately; the second adapter piece is integrally connected to the second pole post or is connected separately.

7. The battery according to claim 1, characterized in that, The adapter plate also includes a protrusion located between the first connecting portion and the second connecting portion, the protrusion extending toward the cover plate.

8. The battery according to claim 1, characterized in that, The first and second fastening members do not overlap with the first center surface; Wherein, the first center plane is the center plane of the cell stack in its height direction.

9. The battery according to claim 8, characterized in that, The distance between the first clamping member and the first center surface, and the distance between the second clamping member and the first center surface, are both greater than or equal to one-fifth of the height of the cell stack.

10. The battery according to claim 1, characterized in that, The distance between the first clamping member and the top of the cell stack is L1, and the distance between the second clamping member and the bottom of the cell stack is L2. The ratio between L1 and L2 is (3~7):1.

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