Top cover assembly, battery cell and battery pack

Abstract

This invention relates to the field of battery technology, providing a top cover assembly, a battery cell, and a battery pack. The top cover assembly includes: a top cover body, terminals, an explosion-proof valve, and an insulating component. The top cover body has a first through hole and a second through hole penetrating the top cover body, and the first and second through holes are spaced apart along the length of the top cover body. The terminals pass through the first through hole and are electrically connected to the tabs of the battery cell. The explosion-proof valve is installed in the second through hole and is located beside the terminal. The insulating component is located on the side of the top cover body facing the tabs. Along the length of the top cover body, side guards are arranged at both ends of the insulating component. The side guards include a first plate and a second plate, which are connected. The first plate is connected to the insulating component and located on the side of the electrode assembly. The second plate is bent from the first plate toward the bottom surface of the electrode assembly to cover the bottom surface of the electrode assembly. The top cover assembly provided by this invention omits the process of hot-melting the side plates, improving the assembly efficiency of the battery cell.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a top cover assembly, a battery cell, and a battery pack. Background Technology

[0002] The battery pack includes a housing and battery modules assembled inside the housing. Each battery module consists of multiple cells, and the terminals of the multiple cells are electrically connected through busbars. The housing provides physical support and protection for the battery modules. Each battery cell includes a housing, a top cover assembly, and terminal groups, which are disposed within a cavity formed by the housing and top cover assembly.

[0003] The top cover assembly includes a top cover body, pole posts, and an insulating component. The pole posts are disposed on the top cover body, and the top cover body is welded and sealed to the housing. The insulating component is located between the cover body and the pole group and defines a space for accommodating the pole group's tabs.

[0004] In traditional battery cell structures, an insulating film covers the outside of the electrode assembly, and a side plate is installed on the outside of the insulating film. During battery cell assembly, the side plate is first heat-fused to the insulating film and then wrapped around the outside of the electrode assembly. However, in some battery cell structures, the heat-fusion process between the side plate and the insulating film takes a long time, thus extending the battery cell manufacturing process. Summary of the Invention

[0005] This invention provides a top cover assembly, a battery cell, and a battery pack to solve the problem that the heat fusion of the side plate and the insulating film in the battery cell structure in the prior art prolongs the battery cell production process.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows:

[0007] In a first aspect, the present invention provides a top cover assembly for use in a battery cell, comprising:

[0008] The top cover body has a first through hole and a second through hole that penetrate the top cover body, and the first through hole and the second through hole are spaced apart along the length direction of the top cover body;

[0009] The electrode post is inserted through the first through hole and electrically connected to the electrode tab of the battery cell;

[0010] An explosion-proof valve is installed in the second through hole and located beside the pole post;

[0011] An insulating element is disposed on the side of the top cover body facing the electrode tab. Along the length direction of the top cover body, side guard plates are disposed at both ends of the insulating element. The side guard plate includes a first plate and a second plate. The first plate and the second plate are connected. The first plate is connected to the insulating element and is located on the side of the electrode assembly. The second plate is bent from the first plate toward the bottom surface of the electrode assembly to cover the bottom surface of the electrode assembly.

[0012] According to a top cover assembly provided by the present invention, a notch structure is provided at the connection between the first plate and the second plate;

[0013] The notch structure includes a first notch and a second notch. The first notch and the second notch are arranged opposite to each other and both extend along the width direction of the top cover body. The first notch is located on the side of the first plate away from the pole group, and the second notch is located on the side of the first plate facing the pole group.

[0014] According to a top cover assembly provided by the present invention, both the first notch and the second notch are strip-shaped grooves, and the groove opening end of the second notch is chamfered.

[0015] According to a top cover assembly provided by the present invention, the thickness of the first plate is T, the wall thickness at the notch structure is T1, and the width of the notch structure along the height direction of the top cover body is W1, satisfying:

[0016] 0.7mm≤T≤1.0mm, 0.4≤T1 / T≤0.6, W1≥0.5mm.

[0017] According to a top cover assembly provided by the present invention, the notch structure is also provided at the connection between the first plate and the insulating member.

[0018] According to a top cover assembly provided by the present invention, the second plate includes a pressing portion and an overlapping portion;

[0019] The pressing part is connected to the first plate body, the overlapping part is connected to the pressing part, and the two overlapping parts overlap at the bottom of the electrode assembly.

[0020] According to a top cover assembly provided by the present invention, the thickness of the first plate is T, and the wall thickness of the overlapping part is T2, satisfying: 0.35≤T2 / T≤0.5;

[0021] And / or, along the length direction of the top cover body, the length of the overlapping portion along the length direction of the top cover body is A, and the length of the pole group is L3, satisfying: 0.15≤A / L3≤0.2, A≥35mm;

[0022] And / or, the overlapping portion is provided with an adhesive layer, and the two overlapping portions are fixedly bonded by the adhesive layer; the thickness of the adhesive layer is t4, which satisfies: 0.1mm≤t4≤0.15mm;

[0023] And / or, the overlapping portion is provided with an adhesive layer, and the two overlapping portions are fixedly bonded by the adhesive layer; the area of ​​the adhesive layer is S1, and the surface area of ​​the side of the overlapping portion having the adhesive layer is S, satisfying:

[0024] 0.4≤S1 / S≤0.7;

[0025] And / or, the first plate is provided with a plurality of ventilation holes;

[0026] The total area of ​​the vent holes is S2, and the surface area of ​​the first plate on the side facing the pole group is S3, satisfying: 0.3≤S2 / S3≤0.5.

[0027] In a second aspect, the present invention provides a battery cell comprising: an electrode assembly, a housing, an insulating film, and a top cover assembly as described above;

[0028] The housing has an opening, the top cover assembly is disposed in the opening and surrounds the housing to form a receiving cavity, the electrode group is disposed in the receiving cavity, the insulating film is located between the electrode group and the housing, and the electrode group is electrically connected to the top cover assembly through electrode tabs.

[0029] According to a battery cell provided by the present invention, the width of the electrode group is W2 and the width of the first plate is W3 along the width direction of the battery cell, satisfying: 23.5mm≤W2≤72.5mm, 20mm≤W3≤67mm, and 1.5mm≤(W2-W3) / 2≤3mm.

[0030] Thirdly, the present invention provides a battery pack, comprising: a busbar, a housing, and battery cells as described above;

[0031] The housing forms a receiving cavity, and multiple battery cells are provided, with the multiple battery cells stacked in the receiving cavity; the busbar is connected to the terminals of the multiple battery cells.

[0032] The top cover assembly, battery cell, and battery pack provided by this invention utilize side guards configured at both ends of the insulating component. Each side guard includes a first plate and a second plate. The second plate can be bent relative to the first plate toward the bottom surface of the electrode assembly. When assembling the top cover assembly with the electrode assembly, the second plate can be bent after the top cover body is installed in place, so that the side guard covers the sides and bottom surfaces of the electrode assembly. The side guard forms a surrounding structure for the electrode assembly, providing a better fixing effect. Furthermore, compared to the prior art where the side plate is first heat-fused to the insulating film before assembly, the heat-fusion process of the side plate is omitted, improving the assembly efficiency of the battery cell. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in this invention 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is one of the three-dimensional structural schematic diagrams of the top cover assembly provided by the present invention.

[0035] Figure 2 This is the second three-dimensional structural schematic diagram of the top cover assembly provided by the present invention.

[0036] Figure 3 This is the third three-dimensional structural schematic diagram of the top cover assembly provided by the present invention.

[0037] Figure 4 This is a front view of the top cover assembly provided by the present invention.

[0038] Figure 5 This invention provides Figure 4 A magnified view of the U-shaped part.

[0039] Figure 6 This invention provides Figure 4 A magnified view of the V-shaped section.

[0040] Figure 7 This invention provides Figure 4 A magnified view of the Z-section.

[0041] Figure 8 This is a front view of the pole group provided by the present invention.

[0042] Figure 9 This is a top view of the pole group provided by the present invention.

[0043] Figure 10 This is one of the three-dimensional structural schematic diagrams of the top cover assembly provided by the present invention.

[0044] Figure 11 This is a front view of the top cover assembly provided by the present invention.

[0045] Figure 12 This is a three-dimensional structural diagram of the top cover body provided by the present invention.

[0046] Figure 13 This is an unfolded view of the insulating film provided by the present invention.

[0047] Figure 14 This is a schematic diagram of the three-dimensional structure of the insulating film after folding, provided by the present invention.

[0048] Figure 15 This is a front view of the insulating film provided by the present invention after folding.

[0049] Figure 16 This is one of the three-dimensional structural diagrams of the top cover assembly and pole assembly provided by the present invention.

[0050] Figure 17This is the second schematic diagram of the three-dimensional structure of the top cover assembly and the pole assembly provided by the present invention.

[0051] Figure 18 This is the third schematic diagram of the three-dimensional structure of the top cover assembly and the pole assembly provided by the present invention.

[0052] Figure 19 This is the fourth schematic diagram of the three-dimensional structure of the top cover assembly and the pole assembly provided by the present invention.

[0053] Figure 20 This is a three-dimensional structural diagram of the battery cell provided by the present invention.

[0054] Figure label:

[0055] 1. Insulating film; 11. First film assembly; 12. Second film assembly; 13. First adhesive layer; 14. Second adhesive layer; 15. Third adhesive layer; 16. Crease; 111. First film body; 112. Second film body; 113. Third film body; 121. First fold body; 122. Second fold body; 123. Third fold body; 1111. First wrapping part; 1112. Second wrapping part; 1121. Clearance hole; 1122. Receiving platform; 1131. Third wrapping part; 1132. Fourth wrapping part;

[0056] 2. Top cover assembly; 21. Top cover body; 22. Pole post; 23. Explosion-proof valve; 24. Insulating component; 25. Connecting piece; 26. Side guard plate; 211. First protrusion; 212. Second protrusion; 213. Rib; 214. Vent hole; 241. Slot; 251. Base part; 252. Extension part; 261. First plate; 262. Second plate; 263. Notch structure; 2131. First rib; 2132. Second rib; 2611. Vent hole; 2621. Overlapping part; 2622. Overlapping part; 2623. Adhesive layer; 2631. First notch; 2632. Second notch;

[0057] 3. Pole assembly; 31. First side surface; 32. Second side surface; 33. First end face; 34. Second end face; 35. Pole tab; 331. Support platform; 3311. Exhaust groove;

[0058] 4. Casing; 100. Battery cell. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0060] The following is combined with Figures 1 to 20 The top cover assembly, battery cell, and battery pack provided in this invention will be described in detail through specific embodiments and application scenarios.

[0061] Firstly, such as Figure 1 , Figure 2 and Figure 3 As shown, this embodiment provides a top cover assembly 2, which is applied to the battery cell 100, including: a top cover body 21, a terminal post 22, an explosion-proof valve 23, and an insulating component 24.

[0062] The top cover body 21 has a first through hole and a second through hole that penetrate the top cover body 21. The first through hole and the second through hole are arranged at intervals along the length direction of the top cover body 21.

[0063] The electrode post 22 passes through the first through hole and is electrically connected to the electrode tab 35 of the battery cell 100.

[0064] The explosion-proof valve 23 is installed in the second through hole and is located next to the pole 22.

[0065] The insulating member 24 is located on the side of the top cover body 21 facing the electrode tab 35. Along the length of the top cover body 21, the two ends of the insulating member 24 are provided with side guard plates 26. The side guard plate 26 includes a first plate 261 and a second plate 262. The first plate 261 and the second plate 262 are connected. The first plate 261 is connected to the insulating member 24 and is located on the side of the electrode group 3. The second plate 262 is bent from the first plate 261 toward the bottom surface of the electrode group 3 to cover the bottom surface of the electrode group 3.

[0066] Understandably, in order to isolate the top cover body 21 from the pole post 22 and to provide insulation protection for the pole post 22 and the explosion-proof valve 23, this embodiment provides an insulating member 24 on the side of the top cover body 21 facing the pole lug 35. The insulating member 24 is provided along its entire length and has a through hole for the pole post 22 to pass through, as well as an exhaust hole 214 to facilitate the exhaust of the explosion-proof valve 23.

[0067] In this embodiment, there are multiple exhaust holes 214, which are evenly spaced and form an exhaust channel with the explosion-proof valve 23. When the battery cell 100 fails due to high temperature, the high temperature gas can be quickly discharged to the outside of the battery cell 100 to ensure the safety of the battery cell 100.

[0068] Meanwhile, side guard plates 26 are provided at both ends of the insulating component 24. The side guard plates 26 are connected to the insulating component 24 and are integrated as a whole when the top cover assembly 2 leaves the factory. The first plate 261 is connected to the second plate 262. The second plate 262 can be bent relative to the first plate 261, so that the first plate 261 and the second plate 262 form a surrounding structure on the underside of the top cover body 21, covering the three sides of the pole group 3.

[0069] Specifically, the side guard plate 26 and the top cover body 21 can be installed vertically or at an angle. The side guard plate 26 can be a strip plate, an arc plate, or a zigzag plate.

[0070] The top cover assembly 2 provided by the present invention is applied to the battery cell 100. By configuring side guard plates 26 at both ends of the insulating member 24, the side guard plate 26 includes a first plate 261 and a second plate 262. The second plate 262 can be bent relative to the first plate 261 toward the bottom surface of the electrode group 3. When the top cover assembly 2 is assembled with the electrode group 3, the second plate 262 can be bent after the top cover body 21 is installed in place, so that the side guard plate 26 covers the side and bottom surfaces of the electrode group 3. The side guard plate 26 forms a surrounding structure for the electrode group 3, which has a better fixing effect on the electrode group 3. Moreover, compared with the prior art, which first heat-melts the side plate to the insulating film 1 and then assembles it, the heat-melting process of the side plate is omitted, which improves the assembly efficiency of the battery cell 100.

[0071] like Figure 1 As shown, a notch structure 263 is provided at the connection between the first plate 261 and the second plate 262 in this embodiment.

[0072] The notch structure 263 includes a first notch 2631 and a second notch 2632. The first notch 2631 and the second notch 2632 are arranged opposite to each other and both extend along the width direction of the top cover body 21. The first notch 2631 is located on the side of the first plate 261 away from the pole group 3, and the second notch 2632 is located on the side of the first plate 261 facing the pole group 3.

[0073] Understandably, to ensure ease of bending the second plate 262 relative to the first plate 261, this embodiment provides a notch structure 263 at the connection between the first plate 261 and the second plate 262. The notch structure 263 includes a first notch 2631 and a second notch 2632, located on both sides of the connection between the first plate 261 and the second plate 262. This ensures that when the second plate 262 is bent relative to the first plate 261, the first notch 2631 is in an enlarged state, and the second notch 2632 is in a contracted state, with both notches 2631 and 2632 working together to complete the bending at the connection. For the operator, the first notch 2631 and the second notch 2632 reduce the resistance force encountered during bending from both sides of the connection, making it easier for the operator and improving the efficiency of bending the second plate 262 relative to the first plate 261.

[0074] like Figure 1 As shown, in this embodiment, both the first notch 2631 and the second notch 2632 are strip-shaped grooves, and the groove opening of the second notch 2632 is chamfered.

[0075] Understandably, the strip groove forms a pre-set bending position at the connection between the first plate 261 and the second plate 262, ensuring the straightness and precision of the bending line. Furthermore, the strip groove smoothly guides stress distribution during bending, dispersing concentrated stress to the end of the groove, greatly reducing the risk of cracking. Further, the groove opening of the second notch 2632 has a chamfer, increasing its volume and preventing interference when the two opposing openings of the second notch 2632 move towards each other, ensuring smooth bending.

[0076] like Figure 4 , Figure 6 and Figure 7 As shown, in this embodiment, the thickness of the first plate 261 is T, the wall thickness at the notch structure 263 is T1, and the width of the notch structure 263 along the height direction of the top cover body 21 is W1, satisfying:

[0077] 0.7mm≤T≤1.0mm, 0.4≤T1 / T≤0.6, W1≥0.5mm.

[0078] Understandably, in order to ensure the structural strength of the connection between the first plate 261 and the second plate 262, the thickness of the first plate 261 and the ratio of the wall thickness at the notch structure 263 to the thickness of the first plate 261 need to meet a certain range.

[0079] Specifically, the thickness T of the first plate 261 can be 0.7mm, 0.85mm, or 1.0mm; T1 / T can be 0.4, 0.5, or 0.6.

[0080] Furthermore, in order to ensure that the two opposing sidewalls at the notch structure 263 do not interfere when the second plate 262 is bent relative to the first plate 261, the width of the notch structure 263 needs to meet a certain range.

[0081] Specifically, the width W1 of the notch structure 263 can be 0.5mm, 0.6mm, or 0.7mm.

[0082] like Figure 4 As shown, the connection between the first plate 261 and the insulating member 24 in this embodiment is also provided with a notch structure 263.

[0083] Since the two first plates 261 at both ends of the insulating member 24 are ultimately assembled on both sides of the pole group 3, the two first plates 261 and the top cover body 21 are arranged in a "U" shape. In order to facilitate the transportation and storage of the top cover assembly 2, a notch structure 263 is also provided at the connection between the first plate 261 and the insulating member 24 in this embodiment. After the top cover assembly 2 is manufactured, the first plate 261 is folded relative to the insulating member 24 through the notch structure 263, so that the two side guards 26 are attached to the lower side of the top cover body 21, the top cover assembly 2 is folded up, the volume is reduced and it is easier to store. When the top cover assembly 2 is assembled with the pole group 3, the first plate 261 is folded in the opposite direction, so that the first plate 261 is perpendicular to the top cover body 21.

[0084] like Figure 2 and Figure 3 As shown, the second plate 262 in this embodiment includes a pressing part 2621 and an overlapping part 2622.

[0085] The pressing part 2621 is connected to the first plate 261, and the overlapping part 2622 is connected to the pressing part 2621. The two overlapping parts 2622 overlap at the bottom of the pole group 3.

[0086] Understandably, the pressing portion 2621 is bent relative to the first plate 261 and pressed onto the bottom surface of the electrode group 3. The two pressing portions 2621 are folded and pressed onto the bottom of the electrode group 3 from both sides along the length of the cell 100. Since the sum of the lengths of the two second plates 262 is greater than the length of the bottom of the electrode group 3, the excess length is the overlap length of the two overlapping portions 2622. To facilitate the fixing of the second plates 262 to the bottom of the electrode group 3 and ensure the stability of the side guard plate 26 fixing to the electrode group 3, this embodiment sets the two overlapping portions 2622 overlapping at the bottom of the electrode group 3. The reliability of the fixing of the second plates 262 to the bottom of the electrode group 3 is enhanced by fixing the overlapping portion to the bottom of the electrode group 3.

[0087] like Figure 4 , Figure 5 and Figure 7 As shown, the thickness of the first plate 261 in this embodiment is T, and the wall thickness of the overlapping part 2622 is T2, satisfying: 0.35≤T2 / T≤0.5.

[0088] Understandably, in order to ensure that the overlap of the 2622 does not affect the uniformity of the appearance of the first plate 261, the ratio of the wall thickness of the 2622 to the thickness of the first plate 261 in this embodiment needs to meet a certain range.

[0089] Specifically, T2 / T can be 0.35, 0.425, or 0.5.

[0090] like Figure 19 As shown, along the length of the top cover body 21, the length of the overlapping part 2622 in this embodiment along the length of the top cover body 21 is A, and the length of the pole group 3 is L, satisfying: 0.15≤A / L3≤0.2, A≥35mm.

[0091] Understandably, in order to ensure the overlapping and fixing effect of the overlapping portion 2622, the length A of the overlapping portion 2622 in this embodiment needs to meet a certain range. Furthermore, the length of the overlapping portion 2622 cannot be too long, so as not to make the overlapping range too large and affect the fixing of the first plate 261. Therefore, the ratio of the length of the overlapping portion 2622 to the length of the pole group 3 needs to meet a certain range.

[0092] Specifically, A / L3 can be 0.15, 0.175, or 0.2; A can be 35mm, 40mm, or 45mm.

[0093] like Figure 4 and Figure 5As shown, the overlapping portion 2622 in this embodiment is provided with an adhesive layer 2623, and the two overlapping portions 2622 are fixedly bonded by the adhesive layer 2623; the thickness of the adhesive layer 2623 is t4, which satisfies: 0.1mm≤t4≤0.15mm.

[0094] Understandably, in this embodiment, an adhesive layer 2623 is provided on the overlapping portion 2622. When fixing the two overlapping portions 2622 to the electrode assembly 3, the two overlapping portions 2622 are glued and fixed by the adhesive layer 2623. In this embodiment, the adhesive layer 2623 is provided on the overlapping portion 2622 in advance. When fixing the second plate 262, it is only necessary to peel off the self-adhesive sticker on the surface of the adhesive layer 2623 to expose the adhesive surface, and the two second plates 262 can be glued together. Since there is no need for an additional tape wrapping and pasting step, the assembly process of the side guard plate 26 and the electrode assembly 3 is simplified, and the process efficiency is improved.

[0095] To ensure the bonding strength of the side guard plate 26, the thickness of the adhesive layer 2623 needs to meet a certain range.

[0096] Specifically, the thickness t4 of the adhesive layer 2623 can be 0.1mm, 0.125mm, or 0.15mm.

[0097] like Figure 2 As shown, the overlapping portion 2622 of this embodiment is provided with an adhesive layer 2623, and the two overlapping portions 2622 are fixedly bonded by the adhesive layer 2623; the area of ​​the adhesive layer 2623 is S1, and the surface area of ​​the side of the overlapping portion 2622 with the adhesive layer 2623 is S, satisfying: 0.4≤S1 / S≤0.7.

[0098] Understandably, to avoid adhesive overflow, the area of ​​the adhesive layer 2623 cannot be too large, and to ensure bonding strength, the area of ​​the adhesive layer 2623 cannot be too small. Therefore, the ratio of the area of ​​the adhesive layer 2623 to the surface area of ​​the overlap 2622 needs to meet certain conditions.

[0099] Specifically, S1 / S can be 0.4, 0.55, or 0.7.

[0100] like Figure 2 and Figure 3 As shown, the first plate 261 of this embodiment is provided with a plurality of ventilation holes 2611.

[0101] The total area of ​​the vent 2611 is S2, and the surface area of ​​the first plate 261 facing the pole group 3 is S3, satisfying: 0.3≤S2 / S3≤0.5.

[0102] Understandably, in order to facilitate the timely discharge of high-temperature gases generated by the electrode group 3 in the event of thermal runaway in the battery cell 100, the first plate 261 is provided with multiple vent holes 2611. Furthermore, in this embodiment, the multiple vent holes 2611 are evenly spaced to ensure the uniformity of exhaust from the electrode group 3.

[0103] To ensure the supporting strength of the first plate 261 and the smoothness of venting, the ratio of the total area of ​​the plurality of vent holes 2611 to the surface area of ​​the first plate 261 in this embodiment needs to meet a certain range.

[0104] Specifically, S2 / S3 can be 0.3, 0.4, or 0.5.

[0105] like Figure 10 and Figure 11 As shown, the top cover assembly 2 provided in this embodiment of the invention includes a top cover body 21, a terminal post 22, and an explosion-proof valve 23. The top cover body 21 is bent to form a boss, which includes a plurality of protrusions stacked along the height direction of the top cover body 21. The topmost protrusion has a vent hole 214 penetrating the top cover body 21, and at least one of the other protrusions is adapted to be connected to the battery pack housing for support. The terminal post 22 is inserted into the top cover body 21 along the height direction and is spaced apart from the boss along the length direction of the top cover body 21. The explosion-proof valve 23 is installed on the topmost protrusion and is opposite to the vent hole 214.

[0106] See the length, width, and height directions of the top cover body 21. Figure 10 Specifically, the top cover body 21 has a first side 31 and a second side 32 facing away from each other in its height direction. The first side 31 faces the outside of the battery cell 100, and the second side 32 faces the electrode group 3 inside the accommodating cavity. A boss is formed by bending the top cover body 21 along its length direction, thus forming a boss on the first side 31. This boss can be manufactured by a stamping process, and the bent shape of the boss helps to improve its processing stability. Correspondingly, the second side 32 of the top cover body 21 forms a recess corresponding to the position of the boss, and this recess extends through the opposite sides of the top cover body 21 along its width direction.

[0107] Specifically, the top cover body 21 includes a base plate portion and a bent portion. The bent portion is connected to the base plate portion at both ends along the length of the top cover body 21. The bent portion is bent relative to the base plate portion to form a boss, and two pole posts 22 are correspondingly inserted into the two base plate portions. The boss can be manufactured by a stamping process, and the bent shape of the boss helps to improve its processing stability.

[0108] The boss comprises multiple protrusions stacked along the height direction of the top cover body 21. It can be understood that the cross-sectional area of ​​the multiple protrusions decreases sequentially along the protruding direction of the boss, forming a stepped boss. The topmost protrusion has an exhaust port for installing the explosion-proof valve 23. When the boss is formed by a stamping process, it can be formed through multiple stampings, reducing the height of a single stamping, preventing sheet metal breakage, and ensuring the structural strength of the boss.

[0109] like Figure 10 As shown, taking a boss with two protrusions as an example, the two protrusions are a first protrusion 211 and a second protrusion 212. The second protrusion 212 protrudes from the upper surface of the first protrusion 211, and the upper surface of the first protrusion 211 is connected to the battery pack housing support. A vent 214 is provided on the second protrusion 212. The second protrusion 212 is located at the middle of the first protrusion 211 along the length of the top cover body 21, which facilitates stamping. Furthermore, the first protrusion 211 can be connected to the battery pack housing support through its portions located on both sides of the second protrusion 212 to provide more stable support.

[0110] In some embodiments of the present invention, the boss is provided with ribs 213, which extend from one protrusion to another. It is understood that a portion of the rib 213 is connected to one protrusion and another portion is connected to another protrusion. The rib 213 connects at least two adjacent protrusions to locally reinforce multiple protrusions and improve the overall impact resistance of the boss.

[0111] Optionally, the rib 213 extends along the length of the top cover body 21. The principal stress direction of the protrusion is consistent with the stacking direction of the multiple protrusions. The rib 213 extends from one protrusion to another and along the length of the top cover body 21, so that the extension direction of the rib 213 is consistent with the principal stress direction of the protrusion, which can significantly increase the structural strength of the protrusion and disperse the stress of the protrusion.

[0112] like Figure 10 As shown, in one example, the rib 213 connecting the first protrusion 211 and the second protrusion 212 extends from the upper surface of the second protrusion 212 along the length direction to the upper surface of the first protrusion 211.

[0113] It is understood that the protruding direction of the rib 213 is consistent with the protruding direction of the boss, and the rib 213 extends along the length of the top cover body 21. The second protrusion 212 protrudes from the upper surface of the first protrusion 211, and a part of the rib 213 is connected to the upper surface of the first protrusion 211, and another part is connected to the upper surface of the second protrusion 212.

[0114] In some embodiments of the present invention, the second protrusion 212 has a first side and a second side opposite to each other in the length direction of the top cover body 21. For example... Figure 10As shown, the boss has multiple first ribs 2131 connecting the first side and the first protrusion 211, and multiple second ribs 2132 connecting the second side and the first protrusion 211. The multiple first ribs 2131 are spaced apart in the width direction of the top cover body 21, and the multiple second ribs 2132 are spaced apart in the width direction of the top cover body 21. The multiple first ribs 2131 and the multiple second ribs 2132 are arranged opposite each other in the length direction of the top cover body 21.

[0115] It is understandable that multiple first ribs 2131 and multiple second ribs 2132 are spaced apart along the length, and the vent 214 is located between the multiple first ribs 2131 and multiple second ribs 2132. The first and second sides of the second protrusion 212 are its main stress areas. The first side is structurally reinforced by multiple first ribs 2131, and the second side is structurally reinforced by multiple second ribs 2132. This prevents the second protrusion 212 from deforming and increasing structural stress when the protrusion is impacted, thus avoiding abnormal cracking of the explosion-proof valve 23.

[0116] The multiple first ribs 2131 and multiple second ribs 2132 are arranged opposite each other in the length direction of the top cover body 21, which can form an exhaust channel extending along the length direction of the top cover body 21 on the upper surface of the second protrusion 212. The gas discharged by the explosion-proof valve 23 can flow along the exhaust channel, which is beneficial to improving the exhaust efficiency.

[0117] Optionally, in the height direction of the top cover body 21, the height of the busbar relative to the reference surface of the top cover body 21 is less than the height of the second protrusion 212 relative to the reference surface. When the side of the housing facing the terminal 22 is flat, a gap exists between the busbar and the housing while ensuring the support connection between the protrusion and the housing. This ensures that the protrusion serves as the main load-bearing part of the cell 100, protecting the busbar and the terminal 22, and improving the safety of the battery pack.

[0118] In some embodiments of the present invention, the housing includes a first plate and a second plate disposed opposite to each other. A clearance structure is provided on the first plate, and the protrusion of the boss is supported and connected to the first plate; the two can be directly contacted or bonded together with insulating and thermally conductive adhesive. The end of the battery cell 100 furthest from the top cover assembly 2 is supported and connected to the second plate.

[0119] In some embodiments, the first plate and the second plate can be the shell structure 4 of the housing. For example, the first plate is the top cover of the housing, and the second plate is the bottom shell of the housing. The shell 4 of the housing is usually made of thermally conductive steel or aluminum. The heat of the battery cell 100 is transferred to the housing through the outer shell (protrusion and housing 4) of the battery cell 100, and heat is exchanged between the housing and the outside air through convection.

[0120] In other embodiments, the first plate portion includes a first housing 4 and a first cold plate, the first cold plate being located between the first housing 4 and the battery cell 100, the protrusion of the boss fitting against the first cold plate, and the clearance structure penetrating at least through the first cold plate. The second plate portion includes a second housing 4 and a second cold plate, the second cold plate being located between the second housing 4 and the battery cell 100, with one end of the battery cell 100 away from the top cover assembly 2 fitting against the second cold plate. The first cold plate and the second cold plate can be any of a liquid cooling plate, a direct cooling plate, or a phase change material cold plate. The heat from the battery cell 100 can be transferred to the first and second cold plates through the boss and the housing 4, improving the cooling effect on the battery pack.

[0121] like Figure 10 and Figure 12 As shown, the top cover assembly 2 in this embodiment also includes an insulating member 24. The insulating member 24 is disposed on the side of the top cover body 21 away from the boss, and the insulating member 24 has an exhaust structure opposite to the exhaust port 214, and the pole post 22 passes through the insulating member 24.

[0122] When the top cover assembly 2 is installed on the housing 4, the insulating member 24 is located between the top cover body 21 and the electrode group 3, serving as insulation between them. The electrode post 22 passes through both the top cover body 21 and the insulating member 24, with one end of the electrode post 22 located on the side of the insulating member 24 away from the top cover body 21, for connection to the electrode tab 35 of the electrode group 3. The vent 214 communicates with the venting structure, allowing gas inside the battery cell 100 to be discharged through the explosion-proof valve 23.

[0123] like Figure 11 As shown, in some embodiments of the present invention, the pole post 22 passes through the top cover body 21. The connecting piece 25 includes a base portion 251 and an extension portion 252. The base portion 251 is connected to the pole post 22, and the extension portion 252 is used for welding to the tab 35.

[0124] Specifically, a recess is formed on the side of the top cover body 21 near the insulating member 24 corresponding to the position of the boss, and a protrusion is formed on the side of the insulating member 24 near the top cover body 21, with the protrusion located within the recess of the top cover body 21. A groove 241 is formed on the side of the insulating member 24 away from the top cover body 21 corresponding to the position of the protrusion. The groove 241 is a stepped groove adapted to the shape of the stepped boss. The tabs 35 of the electrode assembly 3 can be retracted into the groove 241, thereby reducing the gap between the insulating member 24 and the electrode assembly 3, making full use of the space inside the boss, allowing for more space inside the cell 100 to accommodate the body of the electrode assembly 3, improving the space utilization rate inside the cell 100, and increasing the capacity of the cell 100. Optionally, the shape of the protrusion of the insulating member 24 is adapted to the shape of the recess of the top cover body 21 to maximize the use of the internal space of the boss.

[0125] Secondly, such as Figure 20As shown, this embodiment provides a battery cell 100, including: an electrode group 3, a housing 4, an insulating film 1, and a top cover assembly 2 as described above.

[0126] The housing 4 has an opening, the top cover assembly 2 is disposed in the opening and surrounds the housing 4 to form a receiving cavity, the electrode group 3 is disposed in the receiving cavity, the insulating film 1 is located between the electrode group 3 and the housing 4, and the electrode group 3 is electrically connected to the top cover assembly 2 through the electrode tab 35.

[0127] Specifically, since the battery cell 100 includes a top cover assembly 2, and the specific structure of the top cover assembly 2 is as described in the above embodiments, the battery cell 100 shown in this embodiment includes all the technical solutions of the above embodiments. Therefore, it has at least all the beneficial effects obtained by all the technical solutions of the above embodiments, which will not be described in detail here.

[0128] Understandably, the insulating film 1 wraps around the outside of the electrode assembly 3, the top cover assembly 2 covers the opening of the housing 4, and the electrode assembly 3 is electrically connected to the pole post 22 of the top cover assembly 2 through the pole tab 35 to realize the transmission of current. The side guard plate 26 covers the electrode assembly 3 from both sides and the bottom, and is installed in the housing 4 together with the electrode assembly 3.

[0129] In this embodiment, side guard plates 26 are configured at both ends of the insulating member 24. The side guard plate 26 includes a first plate 261 and a second plate 262. The second plate 262 can be bent relative to the first plate 261 toward the bottom surface of the electrode group 3, so that the side guard plate 26 covers the side and bottom surfaces of the electrode group 3, which has a better fixing effect on the electrode group 3. In addition, the process of hot-melting the side plate is omitted, which improves the assembly efficiency of the cell 100.

[0130] like Figure 18 As shown, along the width direction of the cell 100, the width of the electrode group 3 in this embodiment is W2, and the width of the first plate 261 is W3, satisfying: 23.5mm≤W2≤72.5mm, 20mm≤W3≤67mm, and 1.5mm≤(W2-W3) / 2≤3mm.

[0131] Understandably, in order to ensure the ease of assembly of the side guard plate 26 with the pole group 3, the top cover body 21 and the insulating component 24, this embodiment limits the width of the pole group 3 and the width of the first plate 261 respectively. The width of the first plate 261 needs to be slightly smaller than the width of the pole group 3 to ensure that when the side guard plate 26 is installed on the outside of the pole group 3, it will not be larger than the outer wall of the pole group 3, thus ensuring that the pole group 3 and the side guard plate 26 can be smoothly installed into the housing 4.

[0132] Specifically, W2 can be 23.5mm, 48mm, or 72.5mm. W3 can be 20mm, 43.5mm, or 67mm. (W2-W3) / 2 can be 1.5mm, 2.25mm, or 3mm.

[0133] like Figure 13 and Figure 14 As shown, this embodiment provides an insulating film 1, which is applied to a battery cell 100, including: a first film assembly 11 and a second film assembly 12.

[0134] The first membrane assembly 11 includes a first membrane body 111, a second membrane body 112 and a third membrane body 113 connected sequentially along a first direction. The second membrane body 112 is provided with a clearance hole 1121 through which the electrode tab 35 passes. On the side of the clearance hole 1121, the second membrane body 112 forms a receiving platform 1122 protruding to one side, which is used to receive the support platform 331 of the electrode assembly 3.

[0135] The first membrane group 11 is connected to a second membrane group 12 on each side of the second direction. The second membrane group 12 includes a first folding body 121, a second folding body 122 and a third folding body 123 distributed along the first direction. The first folding body 121 is connected to the first membrane group 111, the second folding body 122 is connected to the second membrane group 112, and the third folding body 123 is connected to the third membrane group 113.

[0136] The first membrane 111 or the third membrane 113 is provided with a first adhesive layer 13 at the end opposite to the second membrane 112, the second folding body 122 is provided with a second adhesive layer 14, and the first folding body 121 or the third folding body 123 is provided with a third adhesive layer 15. The first membrane 111 and the third membrane 113 can be folded relative to the second membrane 112 and connected by the first adhesive layer 13. The first folding body 121, the second folding body 122 and the third folding body 123 of each second membrane group 12 can be folded relative to the first membrane group 11 and connected by the second adhesive layer 14 and the third adhesive layer 15, so that the first membrane group 11 and the two second membrane groups 12 form a box structure.

[0137] Understandably, the insulating film 1 is wrapped around the outside of the electrode group 3 and installed together in the housing 4. The top cover assembly 2 is placed on the open end of the housing 4. The electrode group 3 is electrically connected to the pole post 22 of the top cover assembly 2 through the pole tab 35 to realize the transmission of current.

[0138] In this embodiment, the insulating film 1 is applied to the cubic structure of the battery cell 100 to wrap around the outside of the cubic electrode assembly 3. During the assembly of the battery cell 100, the insulating film 1 is a pre-cut sheet of insulating film.

[0139] Two second membrane units 12 are respectively connected to the two sides of the first membrane unit 11. A first folding body 121 is connected to each side of the first membrane 111, a second folding body 122 is connected to each side of the second membrane 112, and a third folding body 123 is connected to each side of the third membrane 113.

[0140] like Figure 8 and Figure 9 As shown, the electrode assembly 3 has a first end face 33 and a second end face 34 facing away from each other. An electrode tab 35 is connected to the first end face 33, and two first side faces 31 and two second side faces 32 are connected between the first end face 33 and the second end face 34. The two first side faces 31 are arranged facing away from each other, and the two second side faces 32 are arranged facing away from each other.

[0141] Furthermore, a receiving platform 1122 is formed beside the clearance hole 1121. The receiving space of the receiving platform 1122 faces the electrode group 3, and the receiving space is used to receive the support platform 331 of the electrode group 3. The length of the support platform 331 is less than the length of the receiving platform 1122. Since the support platform 331 is assembled into the receiving platform 1122, the receiving platform 1122 can limit the displacement of the electrode group 3 within the insulating film 1. The peripheral wall of the receiving platform 1122 stops the electrode group 3 from the length and width directions of the cell 100, thus fixing the electrode group 3. When the cell 100 is subjected to impact force, it prevents the electrode group 3 from moving along the length and width directions of the cell 100, which would lead to poor insulation of the electrode group 3. Since both the insulating film 1 and the electrode group 3 protrude towards the top cover assembly 2, the capacity of the cell 100 is increased.

[0142] When the insulating film 1 is wrapped around the electrode assembly 3, the second film 112 can be wrapped around the first end face 33, and the electrode tab 35 can be passed through the clearance hole 1121, so that the support platform 331 of the electrode assembly 3 extends into the receiving platform 1122. The first film 111 and the third film 113 are both folded relative to the second film 112, so that the first film 111 wraps around at least a part of a first side face 31 and a second end face 34, and the other second film 112 wraps around at least a part of another first side face 31 and a second end face 34. Then, the first folding body 121 of one of the second membrane groups 12 is folded relative to the first membrane body 111, the second folding body 122 is folded relative to the second membrane body 112, and the third folding body 123 is folded relative to the third membrane body 113. The first folding body 121, the second folding body 122, and the third folding body 123 are stacked on a second side surface 32. Similarly, the first folding body 121, the second folding body 122, and the third folding body 123 of the other second membrane group 12 are stacked on another second side surface 32.

[0143] The insulating film 1 wraps around the six sides of the electrode assembly 3, namely the first end face 33, the second end face 34, the two first side faces 31, and the two second side faces 32, forming a cubic box structure. The first membrane 111 and the third membrane 113 can be fixedly connected by adhesive, as can the first folded body 121, the second folded body 122, and the third folded body 123. In this embodiment, a first adhesive layer 13 is provided at the end of the first membrane 111 or the third membrane 113 facing away from the second membrane 112, a second adhesive layer 14 is provided on the second folded body 122, and a third adhesive layer 15 is provided on the first folded body 121 or the third folded body 123. When the insulating film 1 forms the box structure, it is adhered and fixed by the first adhesive layer 13, the second adhesive layer 14, and the third adhesive layer 15. Compared to existing technologies that fold the insulating film 1 to form a box and then wrap and secure it with tape on the outer surface of the box, this embodiment pre-applies three adhesive layers to the insulating film 1. When securing the insulating film 1, simply peel off the adhesive stickers covering the three adhesive layers to expose the adhesive surfaces. This allows for the separate attachment of the first film 111 and the third film 113 at the end opposite to the second film 112, the attachment of the second folded body 122 to the second side 32 of the electrode assembly 3, and the attachment of the first folded body 121 and the third folded body 123. Since no additional tape wrapping or pasting step is required, the assembly process of the insulating film 1 and the electrode assembly 3 is simplified, improving process efficiency.

[0144] like Figure 13 and Figure 14 As shown, the first membrane 111 in this embodiment includes a first wrapping portion 1111 and a second wrapping portion 1112, with the first wrapping portion 1111 connected to the second membrane 112; the third membrane 113 includes a third wrapping portion 1131 and a fourth wrapping portion 1132, with the third wrapping portion 1131 connected to the second membrane 112.

[0145] The second wrapping portion 1112 can be folded relative to the first wrapping portion 1111, and the fourth wrapping portion 1132 can be folded relative to the third wrapping portion 1131, so that the second wrapping portion 1112 and the fourth wrapping portion 1132 at least partially overlap and are pasted through the first adhesive layer 13, and are opposite to the second film body 112.

[0146] Understandably, the first wrapping portion 1111 and the third wrapping portion 1131 respectively cover the two first side surfaces 31 of the pole group 3. The second wrapping portion 1112 is folded over relative to the first wrapping portion 1111 and covers at least a portion of the second end face 34. The fourth wrapping portion 1132 is folded over relative to the third wrapping portion 1131 and covers at least a portion of the second end face 34. The second wrapping portion 1112 and the fourth wrapping portion 1132 overlap and cover the second end face 34, and the two can be fixedly connected by adhesive. In this embodiment, a first adhesive layer 13 is provided on the second wrapping portion 1112 or the fourth wrapping portion 1132, and the overlapping portion of the second wrapping portion 1112 and the fourth wrapping portion 1132 is glued and fixed by the first adhesive layer 13.

[0147] Optionally, a crease 16 is provided at the connection between the first wrapping part 1111 and the second wrapping part 1112, and a crease 16 is provided at the connection between the third wrapping part 1131 and the fourth wrapping part 1132. The crease 16 can be formed by mechanical creasing or hot creasing.

[0148] like Figure 13 and Figure 14 As shown, in this embodiment, a crease 16 is provided at the connection between the first membrane 111 and the second membrane 112, and a crease 16 is provided at the connection between the second membrane 112 and the third membrane 113; a crease 16 is provided at the connection between the first folding body 121 and the first membrane 111, a crease 16 is provided at the connection between the second folding body 122 and the second membrane 112, and a crease 16 is provided at the connection between the third folding body 123 and the third membrane 113.

[0149] Understandably, in order to optimize the covering effect of the insulating film 1, this embodiment provides creases 16 at the connection between the first film 111 and the second film 112, the connection between the second film 112 and the third film 113, the connection between the first folding body 121 and the first film 111, the connection between the second folding body 122 and the second film 112, and the connection between the third folding body 123 and the third film 113.

[0150] In this embodiment, the crease 16 is a continuous indentation used to pre-bend the insulating film 1, so that the insulating film 1 is quickly bent along the crease 16 during the process of covering the electrode assembly 3. The insulating film 1 can be permanently creased by means of mechanical indentation or thermal indentation.

[0151] In some embodiments of the present invention, the distance between the creases 16 at both ends of the second membrane 112 in the first direction and the clearance hole 1121 is D1, where D1 ≥ 1 mm. This ensures that the second membrane 112 covers the edge of the second end face 34. If the value of D1 is too small, when the insulating film 1 wraps the electrode group 3, it is easy to cause a short circuit when the portion of the first side 31 or the second side 32 near the first end face 33 comes into contact with the housing 4.

[0152] like Figure 13 As shown, this embodiment has two clearance holes 1121, which are located on both sides of the receiving platform 1122 along the length of the battery cell 100.

[0153] Understandably, the electrode assembly 3 in this embodiment is provided with two tabs 35, one positive tab and one negative tab. Along the length of the cell 100, the positive tab and the negative tab pass through two clearance holes 1121 on both sides of the receiving platform 1122, respectively. The positive tab is connected to the positive terminal of the top cover assembly 2, and the negative tab is connected to the negative terminal of the top cover assembly 2.

[0154] Furthermore, the receiving platform 1122 is located in the middle of the two clearance holes 1121 and is equidistant from the two clearance holes 1121, making the structure of the second membrane 112 more regular and easier to process and manufacture.

[0155] like Figure 15 As shown, along the height direction of the cell 100, the height of the receiving platform 1122 in this embodiment is H2; the thickness of the second membrane 112 is t2; satisfying: 15≤H2 / t2≤20.

[0156] Understandably, on the second membrane 112, the height of the receiving platform 1122 above the rest of the second membrane 112 is H2, and the thickness of the second membrane 112 is t2. In order to ensure that the receiving platform 1122 cooperates with the support platform 331 to fix the electrode group 3, the ratio of the height of the receiving platform 1122 to the thickness of the second membrane 112 needs to meet a certain range.

[0157] Specifically, H2 / t2 can be 15, 17.5, or 20.

[0158] The outer surface area of ​​the receiving platform 1122 in this embodiment is S01, and the projected area of ​​the receiving platform 1122 in the length and width directions of the battery cell 100 is S0, satisfying: 1.8≤S01 / S0≤2.0.

[0159] Understandably, the receiving platform 1122 can be stamped on the insulating film 1. In order to meet the structural strength and process requirements of the stamped receiving platform 1122, the ratio of the outer surface area of ​​the receiving platform 1122 to the projected area of ​​the receiving platform 1122 in the length and width directions of the cell 100 needs to meet a certain range.

[0160] Specifically, S01 / S0 can be 1.8, 1.9, or 2.0.

[0161] like Figure 14As shown, the first adhesive layer 13, the second adhesive layer 14 and the third adhesive layer 15 in this embodiment have the same thickness, and the thickness is t, which satisfies: 0.05mm≤t1≤0.1mm.

[0162] Understandably, for ease of processing, the first adhesive layer 13, the second adhesive layer 14, and the third adhesive layer 15 in this embodiment have equal thicknesses. Furthermore, this embodiment uses cotton adhesive, which possesses excellent temperature resistance, good insulation properties, flexibility, and adhesion, facilitating the bonding of the first membrane 111 and the third membrane 113 at the end opposite to the second membrane 112, the bonding of the second folded body 122 to the second side surface 32 of the electrode assembly 3, and the bonding of the first folded body 121 and the third folded body 123.

[0163] Specifically, the thickness t can be 0.05mm, 0.075mm, or 0.1mm.

[0164] Figure 14 As shown, in this embodiment, the distance between the first adhesive layer 13, the second adhesive layer 14 and the third adhesive layer 15 and the edge of the insulating film 1 is a, which satisfies: a≥3mm.

[0165] Understandably, to avoid adhesive overflow, the distances between the first adhesive layer 13, the second adhesive layer 14, and the third adhesive layer 15 and the edge of the insulating film 1 cannot be too small. Specifically, the distance between the position of the first adhesive layer 13 at the end of the first film 111 or the third film 113 opposite to the edge of the end of the first film 111 or the third film 113 opposite to the second film 112 is a; the distance between the position of the second adhesive layer 14 on the second folded body 122 and the edge of the second folded body 122 is a; and the distance between the position of the third adhesive layer 15 on the first folded body 121 or the third folded body 123 and the first folded body 121 or the third folded body 123 is a.

[0166] Specifically, 'a' can be 3mm, 3.5mm, or 4mm.

[0167] like Figure 8 As shown, a support platform 331 is provided on the first end face 33 of the electrode assembly 3. The support platform 331 is inserted into the insulating member 24 on the top cover assembly 2. Since the support platform 331 is assembled into the insulating member 24, the support platform 331 limits the displacement of the electrode assembly 3 relative to the top cover assembly 2. The insulating member 24 stops the electrode assembly 3 from the length and width directions of the cell 100, thus fixing the electrode assembly 3. When the cell 100 is subjected to impact force, it prevents the electrode assembly 3 from moving along the length and width directions of the cell 100 and damaging the tab 35, thereby improving the safety performance of the cell 100.

[0168] like Figure 9As shown, in this embodiment, the support platform 331 of the electrode group 3 is provided with an exhaust groove 3311 on the side facing the top cover assembly 2; the exhaust groove 3311 extends along the length or width direction of the cell 100.

[0169] Understandably, in order to ensure the smooth flow of the exhaust channel of the explosion-proof valve 23, the support platform 331 of the electrode group 3 in this embodiment is provided with an exhaust groove 3311. There are multiple exhaust grooves 3311, some of which extend along the length direction of the battery cell 100, and the remaining parts of which extend along the width direction of the battery cell 100. The exhaust grooves 3311 along the length direction and the exhaust grooves 3311 along the width direction intersect.

[0170] The exhaust groove 3311 is connected to the exhaust channel of the explosion-proof valve 23, allowing the high-temperature gas to have sufficient space to flow until it reaches the explosion-proof valve 23. Furthermore, since the exhaust groove 3311 is arranged along the length and width of the cell 100, the high-temperature gas from other parts of the electrode group 3 can also enter the exhaust groove 3311 from the side of the support platform 331, which is beneficial to the flow of high-temperature gas.

[0171] like Figure 16 , Figure 17 , Figure 18 , Figure 19 and Figure 20 As shown, taking a battery cell 100 with two electrode groups 3 as an example, the assembly process of electrode group 3 and top cover assembly 2 is explained. First, a single electrode group 3 is assembled with insulating film 1. Insulating film 1 is wrapped around the outside of electrode group 3, and the two tabs 35 of electrode group 3 pass through the clearance hole 1121 of the second film body 112 respectively, and the support platform 331 of electrode group 3 extends into insulating film 1. Then, with the electrode assembly 3 and the tab 35 flattened, the two electrode assemblies 3 covered with insulating film 1 are placed on both sides of the top cover body 21 along the width direction of the top cover body 21. The two tabs 35 are aligned with the two pole posts 22, and the tabs 35 are welded to the pole posts 22. At this time, the side guard plate 26 is arranged perpendicular to the top cover body 21. Next, the two electrode assemblies 3 are rotated 90° away from the top cover assembly 2, so that the top cover assembly 2 is located on the side of the electrode assemblies 3, and the side guard plate 26 is located on the outside of the side of the two electrode assemblies 3. The second plate 262 is bent toward the bottom of the electrode assemblies 3, and the two overlapping parts 2622 are connected and fixed. Finally, the electrode assemblies 3 covered with insulating film 1 are installed into the housing 4, and the top cover assembly 2 is located at the opening end of the housing 4.

[0172] In this embodiment, the production line tests various indicators of the battery cell 100 to verify the technical effects of different data. The thickness T of the first plate 261, the wall thickness T1 at the notch structure 263, the wall thickness T2 of the overlapping portion 2622, the width W1 of the notch structure 263, the thickness t4 of the adhesive layer 2623, the length A of the overlapping portion 2622, the length L3 of the electrode group 3, the area S1 of the adhesive layer 2623, the surface area S of the overlapping portion 2622, the ratio T1 / T of the wall thickness at the notch structure 263 to the thickness of the first plate 261, the ratio T2 / T of the wall thickness of the overlapping portion 2622 to the thickness of the first plate 261, the ratio A / L3 of the length of the overlapping portion 2622 to the length of the electrode group 3, and the ratio S1 / S of the area of ​​the adhesive layer 2623 to the surface area of ​​the overlapping portion 2622 are used to perform simulation analysis on the battery cell 100.

[0173] As can be seen from Tables 1 and 2, when the structural design of the side guard plate 26 meets the above requirements, the strength of the side guard plate 26 meets the assembly and use requirements, and the assembly efficiency of the battery cell 100 is improved.

[0174] Table 1

[0175]

[0176] Table 2

[0177]

[0178] Thirdly, this embodiment provides a battery pack, including: a busbar, a housing, and the battery cell 100 as described above.

[0179] The housing forms a receiving cavity, and multiple battery cells 100 are provided, with multiple battery cells 100 stacked in the receiving cavity; the busbar is connected to the terminals 22 of the multiple battery cells 100.

[0180] Specifically, since the battery pack includes a cell 100, and the specific structure of the cell 100 is as described in the above embodiments, the battery pack shown in this embodiment includes all the technical solutions of the above embodiments. Therefore, it has at least all the beneficial effects achieved by all the technical solutions of the above embodiments, which will not be described in detail here.

[0181] Understandably, after the cells 100 are assembled into groups, the terminal post 22 of each cell 100 is welded to the tap on the busbar. The busbar connects the stacked cells 100 into groups, and the tap is fixedly connected to the battery pack housing through a heat-conducting layer. In this embodiment, side guard plates 26 are configured at both ends of the insulating component 24. The side guard plate 26 includes a first plate 261 and a second plate 262. The second plate 262 can be bent relative to the first plate 261 towards the bottom surface of the electrode group 3, so that the side guard plate 26 covers the sides and bottom surface of the electrode group 3, providing a better fixing effect on the electrode group 3. Furthermore, the process of heat-melting the side plates is omitted, improving the assembly efficiency of the cells 100.

[0182] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A top cover assembly, applied to a battery cell, characterized in that, include: The top cover body has a first through hole and a second through hole that penetrate the top cover body, and the first through hole and the second through hole are spaced apart along the length direction of the top cover body; The electrode post is inserted through the first through hole and electrically connected to the electrode tab of the battery cell; An explosion-proof valve is installed in the second through hole and located beside the pole post; An insulating element is disposed on the side of the top cover body facing the electrode tab. Along the length direction of the top cover body, side guard plates are disposed at both ends of the insulating element. The side guard plate includes a first plate and a second plate. The first plate and the second plate are connected. The first plate is connected to the insulating element and is located on the side of the electrode assembly. The second plate is bent from the first plate toward the bottom surface of the electrode assembly to cover the bottom surface of the electrode assembly. A notch structure is provided at the connection between the first plate and the second plate; The thickness of the first plate is T, the wall thickness at the notch is T1, and the width of the notch along the height of the top cover body is W1, satisfying: 0.7mm≤T≤1.0mm, 0.4≤T1 / T≤0.6, W1≥0.5mm; The second plate includes a pressing portion and an overlapping portion; The pressing part is connected to the first plate body, the overlapping part is connected to the pressing part, and the two overlapping parts overlap at the bottom of the electrode assembly; Along the length of the top cover body, the length of the overlapping portion along the length of the top cover body is A, and the length of the pole group is L3, satisfying: 0.15≤A / L3≤0.2, A≥35mm; The overlapping portion is provided with an adhesive layer, and the two overlapping portions are fixedly bonded together by the adhesive layer; the area of ​​the adhesive layer is S1, and the surface area of ​​the side of the overlapping portion with the adhesive layer is S, satisfying: 0.4≤S1 / S≤0.

7.

2. The top cover assembly according to claim 1, characterized in that, The notch structure includes a first notch and a second notch. The first notch and the second notch are arranged opposite to each other and both extend along the width direction of the top cover body. The first notch is located on the side of the first plate away from the pole group, and the second notch is located on the side of the first plate facing the pole group.

3. The top cover assembly according to claim 2, characterized in that, Both the first notch and the second notch are strip-shaped grooves, and the groove opening of the second notch has a chamfer.

4. The top cover assembly according to claim 1, characterized in that, The notch structure is also provided at the connection between the first plate and the insulating component.

5. The top cover assembly according to claim 1, characterized in that, The thickness of the first plate is T, and the wall thickness of the overlapping part is T2, satisfying: 0.35≤T2 / T≤0.5; And / or, the overlapping portion is provided with an adhesive layer, and the two overlapping portions are fixedly bonded by the adhesive layer; the thickness of the adhesive layer is t4, which satisfies: 0.1mm≤t4≤0.15mm; And / or, the first plate is provided with a plurality of ventilation holes; The total area of ​​the vent holes is S2, and the surface area of ​​the first plate on the side facing the pole group is S3, satisfying: 0.3≤S2 / S3≤0.

5.

6. A battery cell, characterized in that, include: The electrode assembly, housing, insulating film, and top cover assembly as described in any one of claims 1 to 5; The housing has an opening, the top cover assembly is disposed in the opening and surrounds the housing to form a receiving cavity, the electrode group is disposed in the receiving cavity, the insulating film is located between the electrode group and the housing, and the electrode group is electrically connected to the top cover assembly through electrode tabs.

7. The battery cell according to claim 6, characterized in that, Along the width direction of the battery cell, the width of the electrode group is W2, and the width of the first plate is W3, satisfying: 23.5mm≤W2≤72.5mm, 20mm≤W3≤67mm, and 1.5mm≤(W2-W3) / 2≤3mm.

8. A battery pack, characterized in that, include: Busbar, housing, and battery cell as described in any one of claims 6 to 7; The housing forms a receiving cavity, and multiple battery cells are provided, with the multiple battery cells stacked in the receiving cavity; the busbar is connected to the terminals of the multiple battery cells.

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