Square-shell battery cell
By forming a group of the roll core of the square shell battery cell and using an insulating tape and heat dissipation medium, the problem of loose contact in the corner area of the roll core is solved, the lithium-ion phenomenon is improved, the energy density and heat dissipation performance of the battery cell are improved, and the energy density and heat dissipation performance of the battery cell are improved, making it easier to manufacture.
Patent Information
- Application Number
- CN202422442557.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2034-10-10
AI Technical Summary
The positive and negative electrode sheets in the corner area of the rolling core in the square shell battery cell are loosely in contact with the diaphragm, resulting in serious lithium extraction and affecting the performance of the battery cell. The multi-coil stacking design exacerbates this problem.
The core is formed into a group and contained in the casing, and the corner area of the core group is covered with a first insulating tape, and its end is extended to the corner area of the adjacent core to avoid increasing thickness in the plane area, while a heat dissipation medium is provided between the core groups to improve heat conduction ability.
The lithium-ion phenomenon is improved, the energy density and heat dissipation ability of the battery cell are improved, and it is convenient for processing and manufacturing.
Smart Images
Figure CN223296876U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lithium batteries, in particular to a square shell battery cell. Background Art
[0002] The core in the square shell battery cell is formed by stacking the positive and negative electrodes and the separator and then winding them. The outer peripheral surface of the core along the winding direction includes corner areas and flat areas. Among them, since the outer peripheral surface of the core has a curvature in the corner area, it cannot be hot-pressed. Therefore, the contact between the positive and negative electrodes and the separator in the corner area is loose and the gap is large. As a result, during the long-term cycle of the battery cell, the surface of the negative electrode in the corner area is prone to lithium deposition, affecting the performance of the battery cell. In addition, in the current common mass-produced products, due to process and other reasons, a multi-core stacking design is often adopted for square shell batteries of a certain thickness. The number of corner areas in the battery cell increases, and the bending angles of the positive and negative electrodes and the separator in the corner area become larger, resulting in an increasingly serious impact of abnormal lithium deposition on the performance of the battery cell. Utility Model Content
[0003] The technical problem to be solved by the utility model is to provide a square shell battery cell in order to overcome the defect of the prior art that the winding core is prone to abnormal lithium deposition, which affects the performance of the battery cell.
[0004] The utility model solves the above technical problems through the following technical solutions:
[0005] A square-shell battery cell, comprising a shell and two core groups housed within the shell, each core group comprising at least two cores stacked along a first direction, wherein the outer circumference of each core along the winding direction comprises two planar regions and a first corner region and a second corner region respectively connected to opposite ends of the two planar regions, and both planar regions are perpendicular to the first direction; the core in the core group adjacent to the shell along the first direction is a first core, the two planar regions of the first core include the first planar region adjacent to the shell, and the core in the core group adjacent to another core group is a second core;
[0006] Each of the core groups further includes a first insulating tape covering at least a portion of the first corner region of the second core, and one end of the first insulating tape extends through the first corner region of the second core to the first corner region of the first core.
[0007] This prismatic battery cell is constructed by combining two or more cores into a core pack, which is then housed within a housing, facilitating the overall processing and manufacturing of the prismatic battery cell. The core pack is provided with a first insulating tape covering the first corner region of each core in the pack. This first insulating tape tightens the corner region of each core, ensuring a tight fit between the electrode and the separator at the first corner region of the core, thereby reducing lithium deposition.
[0008] In addition, one end of the first insulating tape is extended through the first corner area of the second core to the surface of the first corner area of the first core, instead of extending to the first plane area of the first core, so as to increase the coverage area of the first insulating tape on the surface of the corner area of the core group while avoiding the first insulating tape being set in the plane area of the core to increase the overall thickness of the core, so that the square shell battery cell can accommodate more cores along the first direction, and the energy density is relatively higher.
[0009] Preferably, one end of the first insulating tape extends through the first corner area of the second winding core to the junction of the first corner area and the first plane area of the first winding core.
[0010] When the first insulating tape does not extend to the first plane area of the first winding core, the coverage area of the first insulating tape on the corner area of the first winding core is increased by extending the end of the first insulating tape to the junction of the first corner area and the first plane area of the first winding core.
[0011] Preferably, the other end of the first insulating tape is disposed at the junction of the first corner area of the second winding core and the plane area of the second winding core.
[0012] The other end of the first insulating tape is arranged at the junction of the first corner area of the second winding core and the plane area of the second winding core, so as to increase the coverage area of the first insulating tape on the corner area of the second winding core.
[0013] Among them, the end of the first insulating tape is arranged at the junction of the first corner area and the plane area of the second winding core instead of extending to the surface of the plane area. This can avoid the first insulating tape being arranged in the plane area of the winding core and increasing the overall thickness of the winding core, so that the square shell battery cell can accommodate more winding cores in the first direction, and the energy density is relatively higher.
[0014] Preferably, the square shell battery cell further includes a heat dissipation medium, and the heat dissipation medium is arranged between the two core groups.
[0015] By placing a heat-conducting heat dissipation medium between two adjacent core groups, the heat conduction capacity between the core groups is improved, thereby enhancing the overall heat dissipation capacity of the square shell battery cell.
[0016] Preferably, the two planar areas of the second core include a second planar area adjacent to another core group, the heat dissipation medium is arranged between the second planar areas of the two core groups, and the heat dissipation medium is connected to the end of the first insulating tape.
[0017] By arranging a heat dissipation medium with heat conductivity between the second plane areas of the two core groups, the heat conduction capacity between the core groups can be improved.
[0018] Connecting the heat dissipation medium to the end of the first insulating tape can strengthen the connection between the first insulating tape and each winding core, thereby improving the tightening ability of each corner area of the winding core.
[0019] At the same time, the heat dissipation medium is connected to the end of the first insulating tape, and the heat conduction path between the heat dissipation medium and the first insulating tape is continuous, so that the heat of the heat dissipation medium can be transferred outward through the first insulating tape, and the heat dissipation capacity is better.
[0020] Preferably, the winding core is formed by winding a positive electrode sheet, a negative electrode sheet and a separator, the separator is sandwiched between the positive electrode sheet and the negative electrode sheet, and the tail end of the separator extends beyond the tail ends of the positive electrode sheet and the negative electrode sheet;
[0021] The square shell battery cell also includes a tail tape, which is attached to the tail end of the diaphragm and fixes the tail end of the diaphragm to the outer peripheral surface of the winding core. The tail tape and the heat dissipation medium are staggered on the outer peripheral surface of the winding core.
[0022] Preferably, the square shell battery cell further comprises a second insulating tape, wherein the second insulating tape covers at least a portion of the first corner region of the second winding core of the two winding core groups;
[0023] Alternatively, the second insulating tape covers at least a portion of the second corner region of the second winding cores of the two winding core groups.
[0024] The square shell battery cell is provided with a second insulating tape to cover at least the corner part (first corner area or second corner area) of the second core of the two core groups, so as to fix the position between the two core groups and avoid displacement between the core groups during the processing and manufacturing process, so as to facilitate the storage of the core in the shell and the implementation of subsequent manufacturing processes (such as connecting the tabs of the two core groups).
[0025] Preferably, the square shell battery cell further includes a second insulating tape, and at least one end of the second insulating tape extends to a second corner area of the first winding core of at least one of the winding core groups.
[0026] The second insulating tape is extended to the second corner area of the first core of the core group, so that the part of the first core of the core group not covered by the first insulating tape is tightened by the second insulating tape, so that the electrode and the diaphragm at the side corner area are more closely fitted.
[0027] Preferably, the square shell battery cell further includes a second insulating tape, and at least one end of the second insulating tape extends to the surface of the first insulating tape of at least one of the winding core groups.
[0028] The second insulating tape is covered on the surface of the first insulating tape of the winding core group to strengthen the structure of the first insulating tape and improve the tightening effect of the first insulating tape on the corner area of the covered winding core.
[0029] Among them, the solution of covering one end of the second insulating tape on the surface of the first insulating tape of one core group and extending the other end to the corner area of the first core of another core group can adapt to different core closing schemes and avoid interference with the already pasted first insulating tape.
[0030] Preferably, the winding core is formed by winding a positive electrode sheet, a negative electrode sheet and a separator, and the separator is sandwiched between the positive electrode sheet and the negative electrode sheet. Along the width direction of the separator, the width D1 of the first insulating band ranges from 60% to 90% of the width D of the separator.
[0031] By making the first insulating tape adhere to and cover the surface of the corner area of the winding core over a large area, the effective area of the first insulating tape and the corner area of the winding core is increased, so that the first insulating tape can better tighten the pole piece and the diaphragm of the winding core.
[0032] Preferably, the first insulating tape includes at least two first sub-insulating tapes, each of which covers at least a portion of the first corner area of the second winding core, and one end of each of the first sub-insulating tapes extends to the first plane area through the first corner area of the first winding core, and each of the first sub-insulating tapes is arranged at intervals along the diaphragm width direction of the winding core.
[0033] By providing a plurality of first sub-insulating tapes to collectively form a first insulating tape, the difficulty of providing the first insulating tape on each core of the core group is reduced while ensuring the coverage area of the first insulating tape on the outer circumference of the core.
[0034] The positive progress effect of this utility model is:
[0035] The square shell battery cell is constructed by forming a core group with two or more cores, and then accommodating the two core groups in a shell, which facilitates the overall processing and manufacturing of the square shell battery cell.
[0036] By setting a first insulating tape to cover the first corner area of each core in the core group, a tightening effect is generated on the corner area of each core, so that the electrode and the diaphragm at the first corner area of the core are tightly fitted, thereby improving the lithium plating phenomenon.
[0037] By extending one end of the first insulating tape through the first corner area of the second core to the surface of the first corner area of the first core instead of extending to the first plane area of the first core, the coverage area of the first insulating tape on the surface of the corner area of the core group is increased while avoiding the first insulating tape being set in the plane area of the core to increase the overall thickness of the core, so that the square shell battery cell can accommodate more cores along the first direction and the energy density is relatively higher. BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Figure 1 This is a schematic structural diagram of the square shell battery cell of Example 1 of the present utility model.
[0039] Figure 2 This is a schematic structural diagram of the winding core of Example 1 of the present utility model.
[0040] Figure 3 This is a surface area distribution diagram of the winding core of Example 1 of the present utility model.
[0041] Figure 4 This is a three-dimensional schematic diagram of the winding core of Example 1 of the present utility model.
[0042] Figure 5 This is a schematic plan view of a specific implementation scheme of the first insulating tape of Example 1 of the present utility model.
[0043] Figure 6 for Figure 5 A three-dimensional schematic diagram of the core group in FIG.
[0044] Figure 7 This is a schematic plan view of another specific implementation scheme of the first insulating tape of Example 1 of the present utility model.
[0045] Figure 8 for Figure 7 A three-dimensional schematic diagram of the core group in FIG.
[0046] Figure 9 This is a schematic diagram of the arrangement position of the first insulating tape on the surface of the winding core in Example 1 of the present utility model.
[0047] Figure 10 This is a schematic diagram of the arrangement position of the first sub-insulating tape on the surface of the winding core in Example 1 of the utility model.
[0048] Figure 11 This is a schematic diagram (1) of the processing state of the winding core group of Example 1 of the present invention.
[0049] Figure 12 This is a schematic diagram (2) of the processing state of the winding core group of Example 1 of the present invention.
[0050] Figure 13 Schematic diagram (3) of the processing state of the winding core group of Example 1 of the present invention.
[0051] Figure 14 This is a structural schematic diagram (1) of the core assembly of the square shell battery cell of Example 2 of the present utility model.
[0052] Figure 15 This is a structural schematic diagram (2) of the core assembly of the square shell battery cell of Example 2 of the present utility model.
[0053] Figure 16 This is a structural schematic diagram of the core assembly of the square shell battery cell of Example 3 of the present utility model.
[0054] Figure 17 This is a structural schematic diagram (1) of the core winding assembly of the square shell battery cell of Example 4 of the present utility model.
[0055] Figure 18 for Figure 17 A three-dimensional schematic diagram of the core group in FIG.
[0056] Figure 19 This is a structural schematic diagram (2) of the core assembly of the square shell battery cell of Example 4 of the present utility model.
[0057] Figure 20 Schematic diagram (1) of the processing state of the square shell battery cell of Example 4 of the present utility model.
[0058] Figure 21 This is a schematic diagram (2) of the processing state of the square shell battery cell of Example 4 of the present utility model.
[0059] Description of reference numerals:
[0060] Square shell battery cell 100, first direction A
[0061] Housing 10
[0062] Core set 20
[0063] Core 30, winding direction B
[0064] Positive electrode sheet 301, positive electrode ear 3011
[0065] Negative electrode sheet 302, negative electrode ear 3021
[0066] Diaphragm 303
[0067] Plane area 304
[0068] The first plane area 304a and the second plane area 304b
[0069] Corner Area 305
[0070] The first corner area 305a and the second corner area 305b
[0071] First winding core 31, second winding core 32, third winding core 33
[0072] First insulating tape 40, first sub-insulating tape 41
[0073] Heat dissipation medium 50
[0074] Second insulating tape 70
[0075] Finishing tape 80 DETAILED DESCRIPTION
[0076] A preferred embodiment is given below, and the present invention is described more clearly and completely in conjunction with the accompanying drawings.
[0077] Example 1
[0078] like Figure 1 As shown, the square shell battery cell 100 includes a shell 10 and a plurality of winding cores 30 disposed in the shell 10, and each winding core 30 is stacked along a first direction A. For a single winding core 30, as shown in FIG. Figure 2 As shown, the core 30 is actually wound with a positive electrode sheet 301, a negative electrode sheet 302, and a separator 303. The positive electrode sheet 301 and the negative electrode sheet 302 are led out at one end of the core 30 through their respective positive electrode tabs 3011 and negative electrode tabs 3021. To prevent short circuits between the electrode sheet and the negative electrode sheet 302, two relatively large separators 303 are used to cover the front and back sides of the electrode sheets, separating the positive electrode sheet 301 from the negative electrode sheet 302 to prevent short circuits. In addition, a tail tape 80 is provided on the core 30. The tail tape 80 is adhered to the tail end of the separator 303 and fixed to the outer peripheral surface of the core 30 to close the separator 303 of the core 30.
[0079] like Figure 3 and Figure 4 As shown, along the winding direction B of the core 30, the outer peripheral surface of the core 30 includes two plane areas 304 and two corner areas 305 respectively connected at the opposite ends of the two plane areas 304, and the two corner areas 305 are respectively a first corner area 305a and a second corner area 305b.
[0080] For the square shell battery cell 100 provided by the present invention, in order to facilitate the processing and shell placement of each core 30, the core 30 disposed in the shell 10 is divided into two core groups 20, each core group 20 includes at least two stacked cores 30. Figure 5 and Figure 6 As shown, the prismatic battery cell 100 in this embodiment has four cores 30 and is therefore divided into two core groups 20. Each core group 20 includes two cores 30 stacked along a first direction A, with two planar regions 304 of each core 30 perpendicular to the first direction A. The core 30 in the core group 20 that is adjacent to the housing 10 along the first direction A is a first core 31. The two planar regions 304 of the first core 31 include a first planar region 304a adjacent to the housing 10. The core 30 in the core group 20 that is adjacent to the other core group 20 is a second core 32.
[0081] like Figure 5 and Figure 6 As shown, taking the core group 20 located on the upper side of the figure as an example, the core group 20 includes a first insulating tape 40, the first insulating tape 40 covers the first corner area 305a of the second core 32, and one end of the first insulating tape 40 extends through the first corner area 305a of the second core 32 to the first corner area 305a of the first core 31, but does not further extend to the first plane area 304a of the first core 31.
[0082] The prismatic battery cell 100 is constructed by forming a core assembly 20 with two cores 30 and then housing the two core assemblies 20 within the housing 10, facilitating the overall processing and manufacturing of the prismatic battery cell 100. The core assembly 20 is provided with a first insulating tape 40 covering the first corner region 305a of each core 30 in the core assembly 20. The first insulating tape 40 tightens the corner region 305 of each core 30, ensuring a tight fit between the electrode and the separator 303 at the first corner region 305a of the core 30, thereby reducing lithium deposition.
[0083] In addition, the first insulating tape 40 is extended to the surface of the first corner area 305a of the first winding core 31 adjacent to the shell 10 along the first direction A, and is spaced apart from the first plane area 304a to increase the coverage area of the first insulating tape 40 on the surface of the core group 20, while avoiding the first insulating tape 40 being set in the plane area 304 of the winding core 30 to increase the overall thickness of the winding core 30, so that the square shell battery cell 100 can accommodate more winding cores 30 along the first direction A, and the energy density is relatively higher.
[0084] In other embodiments, when a single core group 20 includes three or more cores 30, the first insulating tape 40 should also extend from the first corner area 305a of the second core 32 adjacent to another core group 20 to the first corner area 305a of the first core 31 adjacent to the shell 10, so as to contact the first corner areas 305a of all the cores 30 in the core group 20 at the same time.
[0085] Specifically, Figure 5 and Figure 6The square shell battery cell 100 is a specific implementation scheme provided by this embodiment: the first insulating tape 40 of the two core groups 20 covers the right side of the core 30 of the core group 20. Therefore, Figure 5 In the provided square-shell battery cell 100 , the first corner regions 305 a of the winding cores 30 of the two winding core groups 20 are both on the right side.
[0086] In other specific embodiments, Figure 7 and Figure 8 As shown in the figure, the right side of the winding core 30 of the winding core group 20 located on the upper side is covered with the first insulating tape 40, and the left side of the winding core 30 of the winding core group 20 located on the lower side is covered with the first insulating tape 40. Therefore, Figure 7 In the provided prismatic battery cell 100, the first corner regions 305a of the cores 30 of the core assembly 20 located on the upper side of the figure are all on the right side, while the first corner regions 305a of the cores 30 of the core assembly 20 located on the lower side of the figure are all on the left side. Of course, the above two specific embodiments are for illustrative purposes only; the first insulating tape 40 can be provided on either side of the core assembly 20 as desired.
[0087] Specifically in this embodiment, the first insulating tape 40 is arranged at one end of the second winding core 32 at the junction of the first corner area 305a of the second winding core 32 and the plane area 304, so that the coverage area of the first insulating tape 40 on the corner area 305 of the winding core 30 can be increased.
[0088] The end of the first insulating tape 40 is disposed at the junction of the first corner region 305a and the flat region 304 of the second winding core 32, rather than extending to the surface of the flat region 304. This prevents the first insulating tape 40 from being disposed in the flat region 304 of the winding core 30, thereby preventing the overall thickness of the winding core 30 from being increased. This allows the square-shell battery cell 100 to accommodate more winding cores 30 along the first direction A, resulting in a relatively higher energy density. Of course, in other embodiments, the first insulating tape 40 disposed at one end of the second winding core 32 may not extend to the junction of the first corner region 305a and the flat region 304 of the second winding core 32, or may extend directly to the flat region 304 of the second winding core 32 via the first corner region 305a of the second winding core 32.
[0089] At the same time, the first insulating tape 40 is arranged at one end of the first winding core 31 and also at the junction of the first corner area 305a and the first plane area 304a of the first winding core 31, which can avoid the first insulating tape 40 being arranged in the first plane area 304a of the first winding core 31 and increasing the overall thickness of the winding core 30, while ensuring the coverage area of the first winding core 31 on the first corner area 305a of the first winding core 31, so that the diaphragm and the electrode at this location are more tightly fitted.
[0090] Specifically, such as Figure 9 As shown, it is Figure 5 and Figure 7 The top view of the first winding core 31 of the winding core assembly 20, located on the upper side, shows that the first insulating tape 40 extends to the first corner area 305a on the right side, but does not extend to the first flat area 304a at the top of the winding core 30. To increase the effective area between the first insulating tape 40 and the corner area 305 of the winding core 30, and to enable the first insulating tape 40 to better tighten the electrode and diaphragm 303 of the winding core 30, the width D1 of the first insulating tape 40 should be greater than or equal to 60% of the width D of the diaphragm 303 to ensure that the first insulating tape 40 adheres to and covers a large area of the surface of the winding core 30. At the same time, the width D1 of the first insulating tape 40 should be less than or equal to 100% of the width D of the diaphragm 303 to prevent the two sides of the first insulating tape 40 from extending beyond the diaphragm 303 and affecting insertion into the shell. More preferably, the width D1 of the first insulating tape 40 should be less than or equal to 90% of the width D of the diaphragm 303.
[0091] In addition, the first insulating tape 40 is not necessarily formed by a single wide insulating tape, but can also be formed by a plurality of narrow insulating tapes. For example, in another specific embodiment of the present invention, the first insulating tape 40 includes two first sub-insulating tapes 41, and the two first sub-insulating tapes 41 cover the first corner area 305a of the second winding core 32. Figure 10 As shown, one end of the two first sub-insulating strips 41 extends to the first corner region 305 a of the first winding core 31 , and the two first sub-insulating strips 41 are spaced apart along the membrane width direction C of the winding core 30 .
[0092] When the first insulating tape 40 is formed by multiple first sub-insulating tapes 41, the sum of the widths of the first sub-insulating tapes 41 (D2+D3 in this embodiment) along the separator width direction C should be greater than or equal to 60% of the width D of the separator 303. Of course, in other embodiments, three or more first sub-insulating tapes 41 may be used to cover the surface of the winding core assembly 20, thereby replacing a single wide insulating tape with multiple narrower insulating tapes to achieve the purpose of tightening the corner area 305 of the winding core 30. The use of multiple narrower insulating tapes can also reduce processing difficulty.
[0093] In addition, to improve the heat dissipation effect, the first insulating tape 40 may also be made of an adhesive tape with heat dissipation capability, so that the first insulating tape 40 covering the surface of the winding core assembly can improve the heat dissipation effect.
[0094] Preferably, the thickness of the first insulating tape 40 is in the range of 10 to 60 μm, and the thickness of the adhesive layer is in the range of 5 to 30 μm. The thickness of the tape can generally be twice the thickness of the adhesive layer. Furthermore, the first insulating tape 40 should be positioned away from the tail tape 80 and the thermal conductive tape (not shown) on the surface of the winding core 30 to prevent overlap and increase in thickness of the tape, thereby occupying more space within the housing along the first direction A.
[0095] The square shell battery cell 100 provides a first insulating tape 40 at the first corner area 305a of all the cores 30 in the core group 20. The first insulating tape 40 can also be used to fix the relative positions of the cores 30 in the core group 20, thereby facilitating the connection between the tabs of each core 30.
[0096] Specifically, when processing each core group 20, first Figure 11 As shown in FIG. 1 , the cores 30 in the core group 20 are stacked together along the first direction A so that the cores 30 are aligned. Figure 12 As shown, the first insulating tape 40 is pasted on the first corner area 305a of each winding core 30 to fix the position between the winding cores 30. Figure 13 As shown, the positive electrode tabs 3011 of each winding core 30 are gathered together and welded, while the negative electrode tabs 3021 of each winding core 30 are gathered together and welded. When two winding cores 30 are assembled into the winding core assembly 20 as in this embodiment, the tabs of one winding core 30 can be positioned closer to the other winding core 30 to reduce the difficulty of gathering and welding the tabs and facilitate processing.
[0097] Example 2
[0098] This embodiment also provides a square shell battery cell 100, whose structure is substantially the same as the square shell battery cell 100 in Example 1, except that: in this embodiment, the square shell battery cell 100 further includes a heat dissipation medium 50, which is arranged between two adjacent core groups 20 to improve the heat dissipation capacity between the core groups 20.
[0099] The thermal conductivity of the heat dissipation medium 50 preferably ranges from 0.1 to 1.0. The thermally conductive layer of the heat dissipation medium 50 can be a polymer material (e.g., PTFE, PET, GPO, RF, etc.), an inorganic thermally conductive material (e.g., aluminum foil, silicone, etc.), or a metal material (e.g., a metal sheet). Specifically, in this embodiment, the heat dissipation medium 50 is formed by attaching a heat-dissipating insulating tape to the surface of the winding core assembly 20. When the heat dissipation medium 50 is an insulating tape, the thermally conductive layer of the tape is composed of a heat dissipation material known in the art, such as a polymer material or an inorganic thermally conductive material.
[0100] By disposing the heat dissipation medium 50 with heat conductivity between the core groups 20 , the heat conduction capability between the core groups 20 can be improved, thereby enhancing the overall heat dissipation capability of the prismatic battery cell 100 .
[0101] Specifically, Figure 14 As shown, in this embodiment, the two planar areas 304 of the second core 32 include a second planar area 304 b adjacent to another core group 20 , and the heat dissipation medium 50 in the form of an insulating tape is arranged between the two second planar areas 304 b of the two core groups 20 .
[0102] The heat dissipation medium 50 should be arranged away from the closing tape 80 and the thermal conductive tape on the surface of the winding core 30 to avoid excessively occupying the space of the winding core assembly 20 along the first direction A.
[0103] In addition, when the heat dissipation medium 50 is disposed between the two second planar regions 304b, the end of the heat dissipation medium 50 can be connected to the end of the first insulating tape 40 to strengthen the connection between the first insulating tape 40 and each winding core 30 and improve the tightening capability of each corner region 305 of the winding core 30. Specifically, the heat dissipation medium 50 and the first insulating tape 40 can be connected in various ways:
[0104] For example, the heat dissipation medium 50 and the first insulating tape 40 can be connected by covering each other, and the heat conduction path of the heat dissipation medium 50 and the first insulating tape 40 is continuous, so that the heat of the heat dissipation medium 50 can be transferred outward through the first insulating tape 40, and the heat dissipation capacity is better.
[0105] For another example, when the heat dissipation medium 50 is in the form of an insulating tape, if the heat dissipation medium 50 is in the same form as the first insulating tape 40, the heat dissipation medium 50 and the first insulating tape 40 of one of the winding core groups 20 can be formed together by a single insulating tape. Figure 15 As shown, the heat dissipation medium 50 in this embodiment is formed together with the first insulating tape 40 of the upper core assembly 20 in the figure, using a single strip of insulating tape. Specifically, the lower end of the first insulating tape 40 of the upper core assembly 20 is directly adhered to the second flat surface area 304b of the second core 32 to form the heat dissipation medium 50. This improves the heat dissipation between the cores 30 and further strengthens the connection between the first insulating tape 40 and the core 30.
[0106] Example 3
[0107] This embodiment also provides a square shell battery cell 100, which has a structure substantially the same as that of the square shell battery cell 100 in embodiment 1, except that: in this embodiment, when the first insulating tape 40 is provided on the core group 20 to tighten the first corner area 305a of each core 30 of the core group 20, the second corner area 305b of each core 30 of the core group 20 is further tightened. Figure 16 As shown, the first insulating tape 40 also covers all second corner regions 305b of the core assembly 20. Specifically, the portion of the first insulating tape 40 disposed on the first planar region 304a of the first core 31 is discontinuous, and the first insulating tape 40 does not extend to the first planar region 304a of the first core 31. By interrupting the first insulating tape 40 at the first planar region 304a, the first insulating tape 40 is able to release stress while wrapping a large area of the core surface, thus preventing stress transfer. Furthermore, while wrapping the first and second corner regions 305a, 305b of each core 30, the first insulating tape 40 does not extend to the first planar region 304a, thus avoiding occupying space along the first direction A of the core assembly 20 and achieving a compact layout.
[0108] Specifically in this embodiment, two adhesive tapes are used to wrap the first corner area 305 a and the second corner area 305 b of the winding core assembly 20 respectively to form a first insulating tape 40 that is discontinuous at the first plane area 304 a .
[0109] Example 4
[0110] This embodiment also provides a square shell battery cell 100, whose structure is roughly the same as the square shell battery cell 100 in Example 1, except that: the square shell battery cell 100 further includes a second insulating tape 70 on the basis of the square shell battery cell 100, and the two ends of the second insulating tape 70 respectively cover the two core groups 20 to achieve the position fixation between the two core groups 20, avoid displacement between the core groups 20 during the processing and manufacturing process, facilitate the accommodation of the core 30 in the shell 10, and also facilitate the implementation of subsequent manufacturing processes (such as connecting the tabs of the two core groups 20).
[0111] Specific as Figure 17As shown, based on the square shell battery cell 100 provided in Example 1, a second insulating tape 70 is provided on both sides of the core group 20. Among them, the upper end of the second insulating tape 70 located on the left side in the figure covers the surface of the core 30 of the core group 20 on the upper side (for example, in this embodiment, it extends to the second corner area 305b of the first core 31), and the lower end of the second insulating tape 70 on the left side covers the surface of the first insulating tape 40 of the core group 20 on the lower side. The upper end of the second insulating tape 70 located on the right side in the figure covers the surface of the first insulating tape 40 of the core group 20 on the upper side in the figure, and the lower end of the second insulating tape 70 on the right side covers the surface of the core 30 of the core group 20 on the lower side (for example, in this embodiment, it extends to the second corner area 305b of the first core 31). From Figure 18 As can be seen in FIG. 4 , the width of the second insulating tape 70 may be different from that of the first insulating tape 40 , for example, may be slightly narrower than the first insulating tape 40 .
[0112] The second insulating tape 70 is extended to the corner area 305 of the first core 31 of the core assembly 20. This second insulating tape 70 tightens the corner area 305 of the core assembly 20, ensuring a tighter fit between the electrode and the diaphragm 303 at the corner area 305. Simultaneously, the second insulating tape 70 covers the surface of the first insulating tape 40 of the core assembly 20 to structurally reinforce the first insulating tape 40 and enhance the tightening effect of the first insulating tape 40 on the corner area 305 of the covered core 30. This scheme, in which one end of the second insulating tape 70 extends to the surface of the first insulating tape 40 of one core assembly 20 and the other end extends to the corner area 305 of the first core 31 of another core assembly 20, can adapt to different core assembly schemes and avoid interference with the already attached first insulating tape 40.
[0113] In addition, if Figure 19 As shown, based on the prismatic battery cell 100 provided in Example 3, a second insulating tape 70 is provided on both sides of the core assembly 20. The upper end of the second insulating tape 70 on the left side of the figure covers the surface of the first insulating tape 40 of the upper core assembly 20, and the lower end of the second insulating tape 70 on the left side covers the surface of the first insulating tape 40 of the lower core assembly 20. The upper end of the second insulating tape 70 on the right side of the figure covers the surface of the first insulating tape 40 of the upper core assembly 20, and the lower end of the second insulating tape 70 on the right side covers the surface of the first insulating tape 40 of the lower core assembly 20.
[0114] Specifically, in other embodiments, the second insulating tape 70 may be applied to both sides of the two winding core assemblies 20, or only to one side of the two winding core assemblies 20. The specific arrangement can be determined based on actual conditions. The location, thickness, and adhesive layer of the second insulating tape 70 may refer to the specific arrangement of the first insulating tape 40 in the aforementioned embodiment.
[0115] By setting the second insulating tape 70 to cover the two core groups 20 respectively, the position of the two core groups 20 can be fixed to facilitate the implementation of subsequent processing. Figure 20 As shown, two core groups 20 are stacked together along the first direction A. Figure 21 As shown, a second insulating tape 70 is applied between the two core assemblies 20. The second insulating tape 70 can cover the surface of the core 30 of the core assembly 20 or the surface of the first insulating tape 40 of the core assembly 20. The specific covering method can be set according to actual conditions. Finally, the two core assemblies 20 secured together by the second insulating tape 70 are installed in the housing 10, and the subsequent processing of the prismatic battery cell 100 is carried out.
[0116] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of protection of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of protection of the present invention.
Claims
1. A square shell battery cell, characterized in that: It includes a shell and two core groups accommodated in the shell, each of the core groups includes at least two cores stacked along a first direction, wherein the outer circumference of each core along the winding direction includes two plane areas and a first corner area and a second corner area respectively connected to opposite ends of the two plane areas, and the two plane areas are perpendicular to the first direction. The core in the core group that is adjacent to the shell along the first direction is a first core, and the two plane areas of the first core include the first plane area adjacent to the shell. The core in the core group that is adjacent to the other core group is a second core; Each of the core groups further includes a first insulating tape covering at least a portion of the first corner region of the second core, and one end of the first insulating tape extends through the first corner region of the second core to the first corner region of the first core.
2. The square shell battery cell according to claim 1, characterized in that: One end of the first insulating tape extends through the first corner area of the second winding core to the junction of the first corner area and the first plane area of the first winding core.
3. The square shell battery cell according to claim 1, characterized in that: The other end of the first insulating tape is disposed at a junction of a first corner region of the second winding core and a plane region of the second winding core.
4. The square shell battery cell according to claim 1, characterized in that: The square shell battery cell further includes a heat dissipation medium, which is arranged between the two core groups.
5. The square shell battery cell according to claim 4, characterized in that: The two planar areas of the second core include a second planar area adjacent to another core group. The heat dissipation medium is disposed between the second planar areas of the two core groups. The heat dissipation medium is connected to an end of the first insulating tape.
6. The square shell battery cell according to claim 4, characterized in that: The winding core is formed by winding a positive electrode sheet, a negative electrode sheet and a separator, wherein the separator is sandwiched between the positive electrode sheet and the negative electrode sheet, and the tail end of the separator extends beyond the tail ends of the positive electrode sheet and the negative electrode sheet; The square shell battery cell also includes a tail tape, which is attached to the tail end of the diaphragm and fixes the tail end of the diaphragm to the outer peripheral surface of the winding core. The tail tape and the heat dissipation medium are staggered on the outer peripheral surface of the winding core.
7. The square shell battery cell according to any one of claims 1 to 6, characterized in that: The square shell battery cell further includes a second insulating tape, wherein the second insulating tape covers at least a portion of the first corner region of the second winding core of the two winding core groups; Alternatively, the second insulating tape covers at least a portion of the second corner region of the second winding cores of the two winding core groups.
8. The square shell battery cell according to any one of claims 1 to 6, characterized in that: The square shell battery cell further includes a second insulating tape, at least one end of which extends to a second corner area of the first winding core of at least one of the winding core groups; And / or, at least one end of the second insulating tape extends to the surface of the first insulating tape of at least one of the winding core groups.
9. The square shell battery cell according to any one of claims 1 to 6, characterized in that: The winding core is formed by winding a positive electrode sheet, a negative electrode sheet and a separator. The separator is sandwiched between the positive electrode sheet and the negative electrode sheet. Along the width direction of the separator, the width D1 of the first insulating band ranges from 60% to 90% of the width D of the separator.
10. The square shell battery cell according to claim 9, characterized in that: The first insulating tape includes at least two first sub-insulating tapes, each of which covers at least a portion of the first corner area of the second winding core, and one end of each of the first sub-insulating tapes extends to the first plane area through the first corner area of the first winding core, and each of the first sub-insulating tapes is arranged at intervals along the diaphragm width direction of the winding core.