Battery cell

Abstract

The utility model relates to the technical field of battery cells, and provides a battery cell which comprises a shell, a pole core and a top cover structure, the top cover structure comprises a shell sealing cover, a sealing insulating layer and a conducting strip, and a first through hole and a second through hole are formed in the shell sealing cover; the sealing insulation layer is arranged on the side, facing the pole core, of the shell sealing cover and provided with a third through hole communicated with the first through hole, the conducting strip is provided with a boss, and the boss penetrates through the third through hole and is connected with the pole core. The sealing shell cover plays a role in sealing the battery cell, the boss in the conducting strip plays a role in forming a pole, the sealing insulating layer is used for sealing and insulating the sealing shell cover and the conducting strip, the three-layer structure is mutually matched, execution of each function does not interfere with each other, the structural design is simple, the performance is stable, and the comprehensive performance of the battery cell is improved.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to an electrode core. Background Art

[0002] A cylindrical battery generally consists of a housing, a top cover structure, and an electrode core. The top cover structure is installed on the top of the housing, and the electrode core is disposed inside the housing. In a cylindrical battery, the top cover structure generally serves as the positive electrode of the battery. On the one hand, the top cover structure needs to be electrically connected to the electrode core, and on the other hand, it needs to seal the battery. The structural design of the top cover structure has a direct impact on the connection reliability between the top cover structure and the electrode core and the sealing performance of the top cover structure for the battery, thereby affecting the comprehensive performance of the battery. The top cover structure in the related art is unreasonable in structural design, resulting in poor comprehensive performance of the battery. Summary of the Utility Model

[0003] This application provides an electrode core, which can improve the comprehensive performance of the electrode core.

[0004] One aspect of this application provides an electrode core, including:

[0005] A housing having a receiving cavity and an opening communicating with the receiving cavity;

[0006] An electrode core disposed in the receiving cavity;

[0007] A top cover structure that seals the opening, and the top cover structure includes:

[0008] A sealing cover on which a first through hole and a second through hole are formed, and a second through hole cover is disposed on the second through hole;

[0009] A sealing insulating layer disposed on a side of the sealing cover facing the electrode core and having a third through hole communicating with the first through hole;

[0010] And a conductive sheet disposed on a side of the sealing insulating layer facing the electrode core, the conductive sheet having a boss that passes through the third through hole and the first through hole and is connected to the electrode core.

[0011] The top cover structure in the embodiments of the present application includes a sealing cover, a sealing insulating layer, and a conductive sheet. The sealing cover can be connected to the outer shell to seal the battery cell. The boss on the conductive sheet can pass through the first through-hole and the third through-hole and be connected to the electrode core. The boss in the conductive sheet serves to form a terminal post. The second through-hole can be used as the liquid injection hole of the battery cell, and the sealing insulating layer is used to seal and insulate the sealing cover and the conductive sheet. The three-layer structure cooperates with each other, and the execution of each function does not interfere with each other. The structural design is simple and the performance is stable, which is beneficial to improving the comprehensive performance of the battery cell. In addition, by using the boss to form the terminal post, the sealing insulating layer can be well wrapped around the boss, which can simplify the setting method of the sealing insulating layer on the basis of forming a good seal. The boss can also form a better connection with the electrode core, which can also improve the comprehensive performance of the battery cell.

[0012] Based on the layered structure design of the top cover structure in the embodiments of the present application, the structural design of the battery cell is simple and the performance is stable, which is beneficial to improving the comprehensive performance of the battery cell.

[0013] In a possible implementation manner, the second through-hole is located at the center position of the sealing cover, the first through-hole is located on one side of the second through-hole, or the first through-hole is located at the center position of the sealing cover, and the second through-hole is located on one side of the first through-hole.

[0014] In a possible implementation manner, the periphery of the third through-hole extends into the first through-hole, and the inner diameter of the third through-hole is smaller than the inner diameter of the first through-hole.

[0015] In a possible implementation manner, the length L1 of the periphery of the third through-hole extending into the first through-hole satisfies the relationship:

[0016] L1≥0.1mm.

[0017] In a possible implementation manner, the boss extends out of the first through-hole.

[0018] In a possible implementation manner, the length L2 of the boss extending out of the first through-hole satisfies the relationship:

[0019] L2 = 0.05mm to 0.2mm.

[0020] In a possible implementation manner, the sealing insulating layer, the sealing cover, and the conductive sheet form a overlapping section around the vicinity of the first through-hole, and the length L3 of the overlapping section satisfies the relationship:

[0021] L3>0.5mm.

[0022] In a possible implementation manner, the sealing and insulating layer includes a sealant film. The sealing and insulating layer forms overflow glue portions at both ends of the overlapping section, a uniform insulating layer is formed between the overflow glue portions, and the thickness of the overflow glue portions is greater than the thickness of the uniform insulating layer.

[0023] In a possible implementation manner, when the first through hole is located at the center position of the sealing cover and the second through hole is located on one side of the first through hole, the distance L4 between the center of the second through hole and the edge of the sealing cover adjacent to the second through hole satisfies the relationship:

[0024] L4 > 0.6 mm.

[0025] In a possible implementation manner, the second through hole is provided in a protruding manner.

[0026] In a possible implementation manner, the sealing and insulating layer and the conductive sheet extend from one side of the first through hole to the other side of the first through hole and extend to a predetermined length.

[0027] In a possible implementation manner, the sealing and insulating layer has a fourth through hole communicating with the second through hole, the conductive sheet has a fifth through hole communicating with the second through hole, and the second through hole, the fourth through hole, and the fifth through hole are in communication.

[0028] In a possible implementation manner, the diameter of the second through hole is D1, the diameter of the cover of the second through hole is D2, and D1 and D2 satisfy the relationship:

[0029] D2 - D1 > 0.5 mm.

[0030] In a possible implementation manner, the thickness of the cover of the second through hole is H1, the thickness of the sealing cover is H2, and H1 and H2 satisfy the relationship:

[0031] H1 < 0.75H2.

[0032] In a possible implementation manner, the electrode core includes a positive electrode sheet, a negative electrode sheet, and a separator located between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet has a positive electrode tab, and the negative electrode sheet has a negative electrode tab;

[0033] The positive electrode tab is connected to the conductive sheet, and the negative electrode tab is connected to the outer shell.

[0034] In a possible implementation manner, the projection of the positive electrode tab in the thickness direction of the battery cell does not overlap with the projection of the cover of the second through hole in the thickness direction of the battery cell.

[0035] In a possible implementation manner, the conductive sheet includes a first notch, the sealing insulating layer is provided with a second notch corresponding to the first notch, and the projection of the second through hole in the thickness direction of the battery cell does not overlap with the projection of the conductive sheet or the sealing insulating layer in the thickness direction of the battery cell.

[0036] In a possible implementation manner, the cover of the casing includes a convex portion extending in a direction away from the electrode core, and the second through hole is formed on the convex portion.

[0037] In a possible implementation manner, the plane of the second through hole cover on the second through hole does not exceed the top surface of the conductive sheet.

[0038] In a possible implementation manner, the end of the sealing insulating layer close to the outer casing extends beyond the end of the conductive sheet close to the outer casing.

[0039] In a possible implementation manner, the cover of the casing is made of a first material, the first material at least includes stainless steel, and / or, the second through hole cover is made of a second material, the second material at least includes stainless steel.

[0040] In a possible implementation manner, the boss is a hollow structure or the boss is a solid structure.

[0041] In a possible implementation manner, a first step is provided on the side of the cover of the casing facing the outer casing, and a second step is provided on the side of the outer casing facing the cover of the casing.

[0042] In a possible implementation manner, the electrode core has a central through hole, an electrode core insulating layer is provided on the upper side of the electrode core, the electrode core insulating layer is provided with an insulating through hole, and the diameter of the insulating through hole is smaller than the diameter of the central through hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0044] Figure 1 Shows a schematic structural diagram of a battery cell provided according to an embodiment of the present application;

[0045] Figure 2 Shows an exploded schematic diagram of a battery cell provided according to an embodiment of the present application;

[0046] Figure 3Shows a cross-sectional view of a battery cell provided according to an embodiment of the present application;

[0047] Figure 4 Shows a cross-sectional view of another battery cell provided according to an embodiment of the present application;

[0048] Figure 5 Shows a cross-sectional view of yet another battery cell provided according to an embodiment of the present application;

[0049] Figure 6 Shows an exploded view of another battery cell provided according to an embodiment of the present application;

[0050] Figure 7 Shows a cross-sectional view of another battery cell provided according to an embodiment of the present application;

[0051] Figure 8 Shows an exploded view of yet another battery cell provided according to an embodiment of the present application;

[0052] Figure 9 Shows a cross-sectional view of yet another battery cell provided according to an embodiment of the present application.

[0053] Reference numerals:

[0054] 100 - Outer shell; 101 - Receiving cavity;

[0055] 200 - Electrode core; 201 - Central through hole; 210 - Positive electrode tab;

[0056] 300 - Top cover structure; 310 - Sealing cover; 320 - Sealing insulation layer; 330 - Conductive sheet; 340 - Second through hole cover; 311 - First through hole; 312 - Second through hole; 313 - Protrusion; 321 - Third through hole; 322 - Fourth through hole; 323 - Glue overflow part; 324 - Uniform insulation layer; 325 - Second notch; 331 - Boss; 332 - Fifth through hole; 333 - First notch;

[0057] 400 - Insulating part;

[0058] 500 - Liquid injection structure;

[0059] 600 - Electrode core insulation layer; 601 - Insulating through hole. Detailed implementation manners

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0061] The outer shell of a cylindrical battery cell is generally designed in a structure with an open upper end. After the electrode core is inserted into the outer shell, the negative electrode tab of the electrode core is connected to the bottom of the outer shell to form the negative electrode of the battery cell at the bottom. The positive electrode tab of the electrode core needs to be connected to the top cover structure, and the top cover structure is used as the positive electrode of the battery cell. When designing a cylindrical battery cell, on the one hand, the top cover structure needs to play a role in sealing the battery cell, and on the other hand, it also needs to be connected to the electrode core. Therefore, for the top cover structure, in addition to designing necessary openings (such as liquid injection holes), the top cover structure adopts an integral structure. To ensure the performance and safety of the battery cell during the specific design of the top cover structure, the entire top cover structure is not designed as the positive electrode, but a part of the top cover structure forms the positive electrode post. Therefore, certain parts in the top cover structure need to be isolated by parts with insulating properties, and then the isolated part is used as the positive electrode post and connected to the electrode core, so that this isolated part of the top cover structure forms the positive electrode.

[0062] For the top cover structure with the above structure, the selection of the insulating part and the connection design between the insulating part and the top cover structure play a decisive role in the sealing performance. Using the above method is likely to cause poor sealing, resulting in liquid leakage, and at the same time, the quality requirements for the insulating part are relatively high. In addition, since the electrode core needs to be connected to the isolated part of the top cover structure, the connection method is limited and the connection reliability is low.

[0063] Therefore, for the existing top cover structure, there are unreasonable structural designs, resulting in poor comprehensive performance of the battery cell.

[0064] Based on the above status quo and problems, the embodiments of the present application provide a battery cell. The top cover structure in this battery cell adopts a layered structure, and different layers perform different functions. For example, the first layer can be designed to seal the battery cell, and the second layer can be designed to form an electrode post (which can be a positive electrode post). This electrode post needs to pass from the inside to the outside or from the inside to the outside through the first layer for sealing the battery cell, and then a third layer with sealing and insulating properties is arranged between the first layer and the second layer to achieve the sealing and insulation between the first layer and the second layer.

[0065] In the above design concept, the top cover structure adopts a layered structure design, where the execution of each function does not interfere with each other, the structure design is simple, and the performance is stable, which is beneficial to improving the comprehensive performance of the battery cell.

[0066] It should be noted that in the embodiments of the present application, the stacking order of different functional layers in the layered structure is not limited. For example, the aforementioned second layer can be arranged on the upper side of the first layer, or the second layer can be arranged on the lower side of the first layer. In the following embodiments, the above two situations will be introduced separately. For ease of understanding, the embodiments in which the second layer is arranged on the upper side of the first layer are collectively referred to as the first type of embodiments, and the embodiments in which the second layer is arranged on the lower side of the first layer are collectively referred to as the second type of embodiments. It can be understood that in the above two types of embodiments, in order to achieve the sealing and insulation between the first layer and the second layer, the third layer needs to be designed between the first layer and the second layer, or at least part of the third layer is arranged between the first layer and the second layer.

[0067] It can be recognized that in the following descriptions of the first type of embodiments and the second type of embodiments, there will be differences in the structures caused by the different stacking orders of different functional layers. These differences are mainly reflected in the formation method of the pole column and the connection method between the pole column and the pole core. It should be understood that in the two types of embodiments described below, many structure designs can be borrowed from each other, such as the design of the boss in the following embodiments.

[0068] It should be recognized that the battery cell in the embodiments of the present application mainly realizes performance optimization based on the design of the top cover structure. The top cover structure includes multiple different functional layers, such as the aforementioned first layer, second layer, and third layer. Structural bodies such as the pole column are formed by a certain functional layer among them. For example, the pole column is formed by the second layer, and the sealing and insulation performance needs to be realized by the third layer arranged between the first layer and the second layer. To ensure the stability of the layered structure of the top cover structure, on the one hand, the shapes and sizes of each structural body including the pole column need to be designed according to the size of the battery cell and the sizes of different functional layers, so that each structural body including the pole column can occupy a reasonable ratio in terms of size. For example, the size of the pole column has a reasonable ratio to the size of the second layer; on the other hand, the third layer arranged between the first layer and the second layer also needs to have a reasonable structure, or the third layer has a suitable overlapping length with the first layer and the second layer. These detailed designs are described in detail in the following embodiments.

[0069] Figure 1 shows a schematic structural diagram of a battery cell provided according to an embodiment of the present application; Figure 2 shows an exploded view of a battery cell provided according to an embodiment of the present application; Figure 3 shows a cross-sectional view of a battery cell provided according to an embodiment of the present application. In the embodiments of the present application, the battery cell includes a housing 100 and a pole core 200 (which can be combined with reference to Figure 7) and a top cover structure 300.

[0070] The outer shell 100 serves as a protective housing for the battery cell. To ensure its strength and structural stability, the outer shell 100 can be made of materials such as aluminum or aluminum alloy. The outer shell 100 can be manufactured by stamping or integrally injection molding. The outer shell 100 has a receiving cavity 101 and an opening communicating with the receiving cavity 101. The outer shell 100 can be configured as a cylindrical shape. Specifically, it can be a cylindrical structure with one end open. In other embodiments, the outer shell 100 can also be configured as other structures.

[0071] The electrode core 200 is disposed in the receiving cavity 101. The electrode core 200 can adopt different structural forms. For example, when adapting to the above-mentioned cylindrical outer shell 100, the electrode core 200 can adopt a wound core structure, and the wound core structure can be formed by winding a positive electrode sheet, a separator, and a negative electrode sheet and is in a cylindrical shape. Of course, the electrode core 200 can also adopt other structures.

[0072] To achieve electrical connection between the electrode core 200 and the top cover structure 300, the electrode core 200 is further provided with a positive electrode tab 210 and a negative electrode tab. The positive electrode tab 210 and the negative electrode tab can be disposed at both ends of the electrode core 200. The positive electrode tab 210 is connected to the positive electrode sheet, and the negative electrode tab is connected to the negative electrode sheet. Combining the foregoing, the positive electrode tab 210 can also be connected to the top cover structure 300, and the negative electrode tab can be connected to the bottom of the outer shell 100. Of course, in some cases, the positive electrode tab 210 can be connected to the bottom of the outer shell 100, and the negative electrode tab can be connected to the top cover structure 300.

[0073] The top cover structure 300 adopts the above-mentioned layered structure. The top cover structure 300 can seal the opening of the outer shell 100. A boss 331 is formed by the protrusion of a certain functional layer in the top cover structure 300. The boss 331 can be used as the aforementioned pole column. The boss 331 can be connected to the electrode core 200. Specifically, it can be connected to the positive electrode tab 210 of the electrode core 200 or the negative electrode tab of the electrode core 200. For the convenience of description, in the following embodiments, the case where the boss 331 is connected to the positive electrode tab 210 will be taken as an example for illustration.

[0074] In the above battery cell, due to the layered structure design of the top cover structure 300, the structural design of the battery cell is simple and the performance is stable, which is beneficial to improving the comprehensive performance of the battery cell. In addition, the pole column is designed as the boss 331, and the third layer can be designed in a structure form that wraps the boss 331, so the sealing performance is better, and the boss 331 can also form a better connection with the positive electrode tab 210.

[0075] In some embodiments, please refer to Figure 3 , the boss 331 is formed with a flat connection surface, and the electrode core 200 has a planar-shaped tab. A surface contact is formed between the boss 331 and the tab.

[0076] The convex platform 331 is in surface contact with the tab, which can improve the connection reliability between the convex platform 331 and the tab, and is beneficial to improving the comprehensive performance of the battery cell.

[0077] In the above embodiments, the connection surface can be continuous or discontinuous. For the former, the convex platform 331 can be formed by a single bending process. For the latter, the convex platform 331 can be designed into a continuously bent zigzag structure through multiple bending processes.

[0078] It can be understood that in actual design, the size of the convex platform 331 can be determined according to specific requirements. For example, when a larger current-carrying area is required to avoid excessive heat generation at the convex platform 331, the convex platform 331 can be designed larger so that it can be connected to the tab with a larger contact area. Another example is that when the overall size of the battery cell is small, the convex platform 331 can be designed smaller according to the ratio with the overall size of the battery cell.

[0079] In some embodiments, please refer to Figure 3 , when the second layer for forming the convex platform 331 in the top cover structure 300 is located above the first layer, that is, corresponding to the foregoing first type of embodiments, in order to achieve sealing and insulation between the first layer and the second layer, an insulating member 400 also needs to be designed between the tab and the first layer. The insulating member 400 can be an insulating film, insulating adhesive tape, etc.

[0080] In some embodiments, please refer to Figure 3 , the battery cell is further provided with a liquid injection structure 500, which can be formed in the top cover structure 300, and the liquid injection structure 500 is used for injecting liquid into the battery cell.

[0081] The formation method of the liquid injection structure 500 and its surrounding structure can refer to the relevant embodiments of the following top cover structure 300. In this battery cell structure, the liquid injection structure 500 can be located at the center of the battery cell (as shown in Figure 3 ), or can be located at the edge of the battery cell (as shown in Figure 6 ). The size of the liquid injection structure 500 can be considered according to factors such as the overall size of the battery cell, and the distance between the liquid injection structure 500 and the convex platform 331 can also be designed according to actual requirements.

[0082] In the first type of embodiments of the present application, please refer to Figure 1 and Figure 3 , the top cover structure 300 includes a sealing cover 310, a sealing and insulating layer 320, and a conductive sheet 330.

[0083] Combined with the foregoing description, the sealing cover 310 is the foregoing first layer, the conductive sheet 330 can be the foregoing second layer, and the sealing and insulating layer 320 can be the foregoing third layer.

[0084] The sealing cover 310 can be hermetically connected to the outer shell 100 of the battery cell, and the connection method is not limited. For example, the connection between the sealing cover 310 and the outer shell 100 can be achieved by laser welding. To improve the connection reliability, structures that can fit together can be provided on the edge of the sealing cover 310 and the inner side of the top of the outer shell 100. For example, a first step is designed on the edge of the sealing cover 310, and a second step is designed on the outer shell 100. During assembly, a fit can be formed between the first step and the second step to achieve pre-positioning between the sealing cover 310 and the outer shell 100, and then the two are fixedly connected by laser welding.

[0085] A first through-hole 311 is formed in the sealing cover 310, and a second through-hole 312 can also be provided. The first through-hole 311 is used to receive the convex platform 331 in the top cover structure 300, and the second through-hole 312 can serve as a liquid injection hole for the battery cell, capable of forming a liquid injection channel, thereby forming the aforementioned liquid injection structure 500.

[0086] The sealing and insulating layer 320 is provided on the side of the sealing cover 310 facing away from the electrode core 200 and is formed with a third through-hole 321 communicating with the first through-hole 311. After the third through-hole 321 communicates with the first through-hole 311, a channel for the convex platform 331 to extend into or pass through can be formed.

[0087] The conductive sheet 330 is provided on the side of the sealing and insulating layer 320 facing away from the electrode core 200. The conductive sheet 330 is formed with the aforementioned convex platform 331, and the convex platform 331 can pass through the third through-hole 321 and the first through-hole 311 and be connected to the electrode core 200.

[0088] In the above-mentioned top cover structure 300, the sealing cover 310 can be connected to the outer shell 100 to seal the battery cell. The convex platform 331 on the conductive sheet 330 can pass through the first through-hole 311 and the third through-hole 321 and be connected to the electrode core 200. The convex platform 331 in the conductive sheet 330 serves to form a terminal post. The second through-hole 312 can serve as a liquid injection hole for the battery cell, and the sealing and insulating layer 320 is used to seal and insulate the sealing cover 310 and the conductive sheet 330. The three-layer structure cooperates with each other, and the execution of each function does not interfere with each other. The structural design is simple and the performance is stable, which is beneficial to improving the comprehensive performance of the battery cell. In addition, by using the convex platform 331 to form the terminal post, the sealing and insulating layer 320 can be well wrapped around the convex platform 331, which can simplify the setting method of the sealing and insulating layer 320 on the basis of forming a good seal. The convex platform 331 can also form a better connection with the electrode core 200, which can also improve the comprehensive performance of the battery cell.

[0089] In the embodiment of the present application, the battery cell is designed based on the layered structure of the top cover structure 300, which makes the structural design of the battery cell simple and the performance stable, and is beneficial to improving the comprehensive performance of the battery cell.

[0090] In the above-mentioned top cover structure 300, the aperture of the first through hole 311 on the sealing cover 310 and the aperture of the third through hole 321 on the sealing insulating layer 320 are both larger than the outer diameter of the boss 331, so that the boss 331 can protrude from the third through hole 321 and the first through hole 311. For the first through hole 311, the size of the first through hole 311 can be designed according to the outer diameter of the boss 331 and the overall size of the sealing cover 310, and the size of the third through hole 321 can be designed according to the outer diameter of the boss 331 and the overall size of the sealing insulating layer 320.

[0091] In some embodiments, the aperture of the first through hole 311 is the same as the aperture of the third through hole 321, so that the first through hole 311 and the third through hole 321 are flush. This setting method with the same aperture can be used as a positioning reference to enable the sealing cover 310 and the sealing insulating layer 320 to achieve more precise assembly based on this positioning reference.

[0092] In some embodiments, please refer to Figure 3 , the periphery of the third through hole 321 extends into the first through hole 311, and the inner diameter of the third through hole 321 is smaller than the inner diameter of the first through hole 311.

[0093] In the above-mentioned embodiment, the sealing insulating layer 320 is closer to the boss 331 than the sealing cover 310, and can play a better sealing and insulating role.

[0094] In some specific embodiments, the length L1 of the periphery of the third through hole 321 extending into the first through hole 311 satisfies the relationship:

[0095] L1 ≥ 0.1 mm.

[0096] With this design, the diameter of the first through hole 311 is the largest, the outer diameter of the boss 331 is the second largest, and the aperture of the third through hole 321 is the smallest. Taking the above value of L1 can improve the sealing and insulating properties while ensuring the structural stability.

[0097] It can be understood that the value of L1 should not be too large, and its specific value can be set according to specific requirements.

[0098] In the above specific embodiment, please refer to Figure 3, a gap S is formed between the boss 331 and the enclosure cover 310. To improve the sealing and insulation performance, a material with insulation and sealing properties can also be filled in the gap S. This part of the material can be the same as or different from the material used for the sealing and insulating layer 320. It can be understood that, as the side closer to the electrode core 200, the material filled in the gap S can have better heat resistance. Thus, for the boss 331, the sealing and insulating layer 320 and the gap S can form a two-layer structure between the enclosure cover 310 and the conductive sheet 330, improving the sealing and insulation performance.

[0099] In some embodiments, please refer to Figure 3 , the boss 331 extends out of the first through hole 311. It can be understood that the conductive sheet 330 is located on the upper side of the sealing and insulating layer 320, and a boss 331 is formed at a certain part of the conductive sheet 330. The boss 331 can pass through the third through hole 321 and the first through hole 311, so that the connection surface of the boss 331 can extend beyond the enclosure cover 310.

[0100] It can be understood that designing the boss 331 to extend beyond the enclosure cover 310 can effectively reduce the structure of the tab. Specifically, the tab in the electrode core 200 needs to be led out from one side or one end of the battery cell. To achieve the connection between the tab and the boss 331 while ensuring insulation between the tab and the enclosure cover 310, a better way is that the tab cannot touch the enclosure cover 310 after being connected to the boss 331. It can be understood that using the design of the boss 331 extending beyond the enclosure cover 310 can avoid contact between the tab and the enclosure cover 310. For the tab, there is no need to design a related avoidance structure, making the structure of the tab simple. For example, as described above, in Figure 3 the illustrated example, the connection surface of the boss 331 is a continuous plane, and the side of the enclosure cover 310 facing the electrode core 200 is also designed as a plane. When the boss 331 extends beyond the enclosure cover 310, it means that the two planes will never intersect in the horizontal direction. When the tab, which is also planar, is connected to the boss 331 in a surface-contact manner, the tab naturally avoids the enclosure cover 310.

[0101] In the above embodiments, the length of the boss 331 extending out of the first through hole 311 can be designed so that the tab can fully avoid the enclosure cover 310 without affecting the overall size of the battery cell.

[0102] In some specific embodiments, the length L2 of the boss 331 extending out of the first through hole 311 satisfies the relationship:

[0103] L2 = 0.05 mm to 0.2 mm.

[0104] It can be understood that by adopting the above-mentioned values for L2, the tab can be fully avoided from the sealing cover 310 while the size of the battery cell is compressed as much as possible, and it can be avoided that the boss 331 occupies a large amount of internal space of the battery cell due to exceeding the sealing cover 310, which affects the energy density of the battery cell.

[0105] Combined with the foregoing content, it can be seen that in the embodiment of the present application, the sealing cover 310 can be directly connected to the outer shell 100 of the battery cell and seal the opening of the outer shell 100. It is mainly used to form the packaging structure of the battery cell together with the outer shell 100. Therefore, the sealing cover 310 can be made of a metal material. The sealing cover 310 can be designed to be non-conductive to current, while the conductive sheet 330 can be set to be conductive to current. Each performs its own functions, and then the insulation and sealing between the sealing cover 310 and the conductive sheet 330 are achieved through the setting of the sealing insulating layer 320. For the conductive sheet 330, its main purpose is to form the boss 331. In order to enable the boss 331 to be connected to the electrode core 200 located inside the outer shell 100, the boss 331 needs to pass through the sealing cover 310 and the sealing insulating layer 320. At this time, for the peripheral structure of the boss 331, a tight assembly relationship needs to be set among the sealing cover 310, the sealing insulating layer 320, and the boss 331, and at the same time, it is necessary to ensure that the top cover structure 300 has sufficient structural strength around the boss 331.

[0106] Based on the above considerations, the embodiment of the present application designs the overlapping manner of the sealing cover 310, the sealing insulating layer 320, and the conductive sheet 330. For example, please refer to Figure 3 , in some embodiments, a coincidence section W is formed around the sealing insulating layer 320, the sealing cover 310, and the conductive sheet 330 adjacent to the first through hole 311, and the length L3 of the coincidence section W satisfies the relational expression:

[0107] L3 > 0.5 mm.

[0108] It can be understood that in the Figure 3 shown example, from the diameter direction of the battery cell, two coincidence sections W are formed around the boss 331. To ensure the balanced connection strength, sealing performance, and insulation performance, the lengths of the two coincidence sections W both need to meet the above numerical range.

[0109] In the embodiments of the present application, it can be understood that since both the sealed insulating tube layer 320 and the conductive sheet 330 are provided on the upper side of the housing cover 310, for the internal space of the battery cell, it mainly depends on the sizes of the outer shell 100 and the housing cover 310, and is also affected by the size of the boss 331. This influence mainly comes from the design method where the boss 331 exceeds the housing cover 310. In addition, the size design of the boss 331 is related to the overall size design of the battery cell, the size design of the conductive sheet 330, and the size design of the housing cover 310. Therefore, when designing the top cover structure 300, various size indicators need to be comprehensively considered.

[0110] In the above embodiments, some important dimensions were sorted out and described mainly from the common aspects of the top cover structure 300, such as L1, L2, and L3 in the foregoing embodiments. In other words, the size designs of L1, L2, and L3 can be applied to most top cover structures 300. In addition to these size designs, it should be recognized that other size designs in the top cover structure 300 also affect the performance of the battery cell.

[0111] In some embodiments, the diameter of the boss 331 is 1 mm to 5 mm, and the height of the boss 331 is 0.1 mm to 0.5 mm.

[0112] When the boss 331 is designed with the above dimensions, it is easy to form, and at the same time, it can ensure its conductive function. For example, when the diameter of the boss 331 is designed to be 1 mm and its height is designed to be 0.1 mm, the boss 331 with this proportional relationship is more stable in structure; when the diameter of the boss 331 is designed to be 2.5 mm and its height is designed to be 0.25 mm, this proportional relationship is more balanced in performance; when the diameter of the boss 331 is designed to be 5 mm and its height is designed to be 0.5 mm, the boss 331 with this proportional relationship can provide a larger current-carrying area, making it applicable to large-capacity battery cells.

[0113] In some embodiments, the thickness of the housing cover 310 is 0.1 mm to 0.5 mm. The housing cover 310 includes a stainless steel layer and a nickel-plated layer, and the thickness of the nickel-plated layer is 0.5 μm to 3 μm.

[0114] When the housing cover 310 is designed with the above dimensions, it has a high structural strength, and at the same time, based on the design of the nickel-plated layer, the housing cover 310 can have a high hardness. It can be understood that the thickness of the nickel-plated layer should be designed according to the overall thickness of the housing cover 310, and the overall thickness of the housing cover 310 can be designed according to the capacity required by the battery cell.

[0115] In some embodiments, the thickness of the conductive sheet 330 is 0.1 mm to 0.5 mm. The thickness of the conductive sheet 330 can be designed with reference to the housing cover 310. On the basis of ensuring that the conductive sheet 330 has sufficient structural strength, the thickness of the conductive sheet 330 can be the same as that of the housing cover 310, thereby improving the overall strength of the top cover structure 300.

[0116] In some embodiments, the sealing and insulating layer 320 includes a sealing adhesive film, and the sealing adhesive film is connected between the housing cover 310 and the conductive sheet 330 by hot pressing. The thickness of the sealing adhesive film before hot pressing is H and H = 0.08 mm to 0.2 mm, and the thickness of the sealing adhesive film after hot pressing is h and h = (20% to 80%) * H.

[0117] The thickness of the above-mentioned sealing adhesive film can be comprehensively considered in combination with the thickness of the conductive sheet 330 and the housing cover 310. After hot pressing the sealing adhesive film, it can be tightly connected between the housing cover 310 and the conductive sheet 330.

[0118] When performing hot pressing, it can be concentrated on the central area of the overlapping section w, so that the sealing adhesive film can evenly diffuse from the central area to both sides on the overlapping section w, thereby improving the connection reliability between the housing cover 310 and the conductive sheet 330. It can be understood that by adopting the above hot pressing method, the overflow part of the sealing adhesive film will be concentrated at both ends of the overlapping section, for example, concentrated at the connection between the sealing adhesive film and the boss 331. This overflow method will form a thicker overflow layer at the connection, which is beneficial to improving the sealing performance and insulation performance.

[0119] For example, please refer to Figure 3 , the sealing and insulating layer 320 forms overflow parts 323 at both ends of the overlapping section W, and a uniform insulating layer 324 is formed between the overflow parts 323. The thickness of the overflow part 323 is greater than the thickness of the uniform insulating layer 324. The overflow part 323 can form a thicker overflow layer, thereby improving the sealing performance and insulation performance.

[0120] Figure 4 Shows a cross-sectional view of another battery cell provided according to an embodiment of the present application; Figure 5 Shows a cross-sectional view of yet another battery cell provided according to an embodiment of the present application.

[0121] In some embodiments, please refer to Figure 4 , the conductive sheet 330 can form a boss 331 through a stamping process, and the boss 331 is a hollow structure.

[0122] The stamping process has simple molding and low process cost. The hollow-structured boss 331 can save the material of the conductive sheet 330 and reduce the material cost.

[0123] In some embodiments, please refer to Figure 5, the conductive sheet 330 can form a boss 331 through an extrusion process, and the boss 331 is a solid structure.

[0124] The boss 331 with a solid structure specifically has higher strength, which can improve the connection reliability between the boss 331 and the tab.

[0125] The above content fully describes the main structural components of the top cover structure 300. In addition to the above content, for the battery cell, it also needs to be configured with a second through hole 312, and the second through hole 312 can also be integrally designed into the top cover structure 300. It can be understood that the size and position of the second through hole 312 can be set according to requirements.

[0126] For example, in some embodiments, please refer to Figure 1 and Figure 3 , the top cover structure 300 adopts a central liquid injection method. A second through hole 312 is also provided on the sealing cover 310. The second through hole 312 is located at the center of the sealing cover 310, and the first through hole 311 is located on one side of the second through hole 312. The sealing insulating layer 320 has a fourth through hole 322 communicating with the second through hole 312, and the conductive sheet 330 has a fifth through hole 332 communicating with the second through hole 312.

[0127] The second through hole 312, the fourth through hole 322, and the fifth through hole 332 communicate to form a liquid injection structure 500 with a liquid injection channel, and the electrolyte can enter the battery cell through a liquid injection device and through the liquid injection channel.

[0128] It can be understood that the apertures of the second through hole 312, the fourth through hole 322, and the fifth through hole 332 are not limited, and the three can have the same aperture or different apertures.

[0129] In some specific embodiments, the second through hole 312 can be designed as a stepped hole, which is convenient for correspondingly designing the second through hole cover 340 in the following embodiments. The plane of the second through hole cover 340 does not exceed the top surface of the conductive sheet 330, so that the second through hole cover 340 can be hidden and installed into the second through hole 312.

[0130] In some specific embodiments, please refer to Figure 3 , the second through hole 312 is provided in a protruding manner. For example, a protruding portion 313 can be formed on the sealing cover 310, and then the second through hole 312 is provided on the protruding portion 313. The protruding portion 313 forms a liquid injection platform, which is convenient for the liquid injection device to be connected to the liquid injection platform. The height of the liquid injection platform is not limited, and it can be designed to be slightly higher than the conductive sheet 330 or slightly lower than the conductive sheet 330.

[0131] In some specific embodiments, please refer to Figure 4 andFigure 5 The second through - hole 312 is directly formed on the encapsulation cover 310. The second through - hole 312 can be hidden by the sealing insulation layer 320 and the conductive sheet 330, which can protect the second through - hole 312.

[0132] In some specific embodiments, the encapsulation cover 310 is made of a first material, and the first material at least includes stainless steel. The top - cover structure 300 further includes a second through - hole cover 340 for closing the second through - hole 312.

[0133] Here, the material of the encapsulation cover 310 is designed to be made of the first material, and the first material at least includes stainless steel. The second through - hole cover 340 can be connected to the encapsulation cover 310 by laser welding, thereby improving the connection strength.

[0134] In addition, the second through - hole cover 340 on the second through - hole 312 can also be made of a second material, and the second material at least includes stainless steel. Thus, when using laser welding, based on the characteristics of the stainless - steel material, the phenomenon of welding explosion points can be avoided during the welding process, and the connection strength between the second through - hole cover 340 and the encapsulation cover 310 can be further improved.

[0135] For another example, in some other embodiments, reference can be made to Figure 6 and Figure 7 The top - cover structure 300 adopts an eccentric liquid - injection method. The encapsulation cover 310 is further provided with a second through - hole 312. The first through - hole 311 is located at the center of the encapsulation cover 310, and the second through - hole 312 is located on one side of the first through - hole 311.

[0136] In these other embodiments, the aperture setting, height setting, etc. of the second through - hole 312 can refer to the foregoing content and will not be elaborated here.

[0137] It can be understood that based on the layered design of the top - cover structure 300, the purpose of conveniently adjusting the liquid - injection method can be achieved. When designing the top - cover structure 300, only the position where the second through - hole 312 is located needs to be reasonably arranged. The position selection of the second through - hole 312 is diverse and the structure is simple.

[0138] In some embodiments, the sealing insulation layer 320 and the conductive sheet 330 extend from one side of the second through - hole 312 to the other side of the second through - hole 312 and extend to a predetermined length.

[0139] Combined with the foregoing dimension design of the overlapping section, it can be known that for the top cover structure 300 in the embodiments of the present application, the parts that need to be sealed are mainly concentrated in the second through hole 312 and the first through hole 311. For the second through hole 312, based on the foregoing material selection of the enclosure cover 310, the second through hole cover 340 can be directly connected to the enclosure cover 310. Therefore, excellent sealing of the second through hole 312 can be achieved, and the sealing can be achieved without involving the sealing insulating layer 320 and the conductive sheet 330, and the sealing can be achieved by connecting the second through hole cover 340 to the enclosure cover 310; for the first through hole 311, the sealing needs to be achieved by means of the stacking relationship of the enclosure cover 310, the sealing insulating layer 320 and the conductive sheet 330. To achieve this sealing, the conductive sheet 330 and the sealing insulating layer 320 need to be reasonably arranged around the first through hole 311.

[0140] Based on the above considerations, reference can be made to Figures 3 to 5 , the sealing insulating layer 320 and the conductive sheet 330 located on the left side of the second through hole 312 can be completely removed without affecting the overall performance of the battery cell. Here, reference can be made to Figure 8 , it can be understood that the part with a notch (such as the first notch 333 and the second notch 325 in the following embodiments) can correspond to the position of the second through hole 312, and the materials of the sealing insulating layer 320 and the conductive sheet 330 can be saved.

[0141] Figure 6 FIG. shows an exploded schematic view of another battery cell provided according to an embodiment of the present application; Figure 7 FIG. shows a cross-sectional view of another battery cell provided according to an embodiment of the present application.

[0142] In the second type of embodiments of the present application, please refer to Figure 6 and Figure 7 , the top cover structure 300 includes an enclosure cover 310, a sealing insulating layer 320 and a conductive sheet 330.

[0143] The enclosure cover 310 serves as the aforementioned first layer, the conductive sheet 330 serves as the aforementioned second layer, and the sealing insulating layer 320 serves as the aforementioned third layer.

[0144] The enclosure cover 310 can be sealingly connected to the outer shell 100 of the battery cell, and the connection method is not limited. For example, the connection between the enclosure cover 310 and the outer shell 100 can be achieved by laser welding. To improve the connection reliability, a mutually fitting structure form can be adopted, and this mutually fitting structure can refer to the aforementioned first type of embodiments.

[0145] A first through hole 311 and a second through hole 312 are formed in the casing cover 310. A second through hole cover 340 may be provided on the second through hole 312. The first through hole 311 is used to receive the boss 331 in the top cover structure 300, and the second through hole 312 may serve as a liquid injection hole.

[0146] The sealing and insulating layer 320 is disposed on the side of the casing cover 310 facing the electrode core 200 and is formed with a third through hole 321 communicating with the first through hole 311. After the third through hole 321 communicates with the first through hole 311, a channel for the boss 331 to extend into or pass through can be formed.

[0147] The conductive sheet 330 is disposed under the sealing and insulating layer 320. The conductive sheet 330 is formed with the boss 331, and the boss 331 can pass through the third through hole 321 and be connected to the electrode core 200.

[0148] In the above-mentioned top cover structure 300, the casing cover 310 functions to seal the battery cell, the boss 331 in the conductive sheet 330 functions to form a pole column, and the sealing and insulating layer 320 is used to seal and insulate the casing cover 310 and the conductive sheet 330. The three-layer structure cooperates with each other, and the execution of each function does not interfere with each other. The structure design is simple and the performance is stable, which is beneficial to improving the comprehensive performance of the battery cell. In addition, by using the boss 331 to form the pole column, the sealing and insulating layer 320 can be well wrapped around the boss 331, which can simplify the setting method of the sealing and insulating layer 320 on the basis of forming a good seal. The boss 331 can also form a better connection with the electrode core 200, which can also improve the comprehensive performance of the battery cell.

[0149] Different from the foregoing first type of embodiments, in this second type of embodiments, both the sealing and insulating layer 320 and the conductive sheet 330 are located under the casing cover 310. For the boss 331 formed on the conductive sheet 330, the boss 331 can be connected to the tab in the electrode core 200. The protruding direction of the boss 331 is different from that of the foregoing first type of embodiments. In this second type of embodiments, the protruding direction of the boss 331 is from bottom to top, and its purpose is to form the positive electrode of the battery cell so as to form an electrical connection with an external electronic device.

[0150] In addition, please refer to Figure 7 Since the conductive sheet 330 is disposed under the casing cover 310, and the sealing and insulating layer 320 is between the conductive sheet 330 and the casing cover 310, insulation and sealing have already been formed between the two. When the tab is connected to the boss 331, the tab is naturally isolated from the casing cover 310, and a current path can be naturally avoided from being formed between the casing cover 310 and the tab.

[0151] In addition to the above, in this second type of embodiment, regarding the size design of each structure and the design of the positional relationship of each structure, for example, the size design of the boss 331, the aperture settings of the first through hole 311 and the third through hole 321, and the design of their positional relationship, reference may be made to the aforementioned first type of embodiment, and details will not be elaborated here.

[0152] It should be noted that in this second type of embodiment, for the peripheral structure of the boss 331, a tight fitting relationship needs to be set among the enclosure cover 310, the sealing insulation layer 320, and the boss 331. At the same time, it is also necessary to ensure that the top cover structure 300 has sufficient structural strength around the boss 331. In this regard, the length of the overlapping section W can be reasonably configured with reference to the first type of embodiment.

[0153] In this second type of embodiment, the liquid injection form can also be appropriately changed. For example, a second through hole 312 is further provided on the enclosure cover 310. The second through hole 312 can be located at the center of the enclosure cover 310, and the first through hole 311 is located on one side of the second through hole 312, or the first through hole 311 is located at the center of the enclosure cover 310, and the second through hole 312 is located on one side of the first through hole 311. The sealing insulation layer 320 has a fourth through hole 322 communicating with the second through hole 312, and the conductive sheet 330 has a fifth through hole 332 communicating with the second through hole 312. The detailed design method can refer to the aforementioned first type of embodiment.

[0154] In some embodiments, please refer to Figure 7 When the first through hole 311 is located at the center of the enclosure cover 310 and the second through hole 312 is located on one side of the first through hole 311, the distance L4 between the center of the second through hole 312 and the edge of the enclosure cover 310 adjacent to the second through hole 312 satisfies the relationship:

[0155] L4 > 0.6 mm.

[0156] Setting L4 according to the above dimensions can ensure that the edge of the second through hole 312 has sufficient structural strength, enabling the enclosure cover 310 to be stably connected to the outer shell 100. At the same time, it can avoid interference of the side wall on liquid injection, that is, prevent the electrolyte from easily remaining between the enclosure cover and the outer shell during the liquid injection process, resulting in electrolyte loss and affecting the wetting effect of the winding core. This size design can be applied to the aforementioned first type of embodiment.

[0157] In some embodiments, the diameter of the second through hole 312 is D1, and the diameter of the second through hole cover 340 is D2. D1 and D2 satisfy the relationship:

[0158] D2 - D1 > 0.5 mm.

[0159] The size of the second through-hole cover 340 is designed to be larger than that of the second through-hole 312, which can enable the second through-hole cover 340 to completely seal the second through-hole 312, and can improve the sealing effect of the second through-hole cover 340 on the second through-hole 312. In addition, the second through-hole cover 340 has a greater buffer margin when covering the second through-hole 312, which helps to maintain a stable sealing state even when the battery cell vibrates or the temperature changes greatly, and extends the service life of the battery cell. This size design can be applied to the aforementioned first type of embodiments.

[0160] In some embodiments, the thickness of the second through-hole cover 340 is H1, and the thickness of the case cover 310 is H2, and H1 and H2 satisfy the relational expression:

[0161] H1 < 0.75H2.

[0162] The thickness of the second through-hole cover 340 and the thickness of the case cover 310 are designed here, so that the thickness of the second through-hole cover 340 is less than that of the case cover 310, which can avoid local extrusion of the case cover 310 due to the large weight at the position of the second through-hole cover 340, can balance the strength relationship between the case cover 310 and the second through-hole cover 340, and improve the overall strength of the top cover structure 300. On the other hand, designing the thickness of the second through-hole cover 340 to be smaller means that the welding parameters, welding power and welding time are smaller, so that faster heat transfer can be provided, which helps to form weld marks faster and ensure the weld quality. At the same time, it can prevent excessive thermal deformation of the second through-hole cover 340 and reduce unnecessary distortion or deformation. This size design can be applied to the aforementioned first type of embodiments.

[0163] It should be noted that in this second type of embodiment, the notch design method can also be adopted, that is, the sealing insulating layer 320 and the conductive sheet 330 are designed to have a notched shape.

[0164] In some embodiments, please refer to Figure 7 , the projection of the positive electrode tab 210 in the thickness direction of the battery cell does not overlap with the projection of the second through-hole cover 340 in the thickness direction of the battery cell, which can prevent the positive electrode tab 210 from interfering with the liquid injection during the liquid injection process and affecting the infiltration of the electrolyte into the battery cell.

[0165] Figure 8 shows an exploded view of another battery cell provided according to an embodiment of the present application; Figure 9 shows a cross-sectional view of another battery cell provided according to an embodiment of the present application.

[0166] Please refer to Figure 8 and Figure 9, the sizes of the conductive sheet 330 and the sealing insulating layer 320 are smaller than the size of the housing cover 310. The conductive sheet 330 and the sealing insulating layer 320 are each formed with a notch. For this second type of embodiment, the existence of this notch can reduce the space occupied by the conductive sheet 330 and the sealing insulating layer 320 within the battery cell, which is beneficial to improving the energy density of the battery cell.

[0167] Specifically, the conductive sheet 330 includes a first notch 333, the sealing insulating layer 320 is provided with a second notch 325 corresponding to the first notch 333, and the projection of the second through-hole cover 340 in the thickness direction of the battery cell does not overlap with the projection of the conductive sheet 330 or the sealing insulating layer 320 in the thickness direction of the battery cell.

[0168] Through the design of the above-mentioned first notch 333 and second notch 325, the material usage of the sealing insulating layer 320 and the conductive sheet 330 can be reduced, the space occupied by the conductive sheet 330 and the sealing insulating layer 320 within the battery cell can be reduced, which is beneficial to improving the energy density of the battery cell.

[0169] In this second type of embodiment, the housing cover 310 may also include a convex portion extending in a direction away from the electrode core 200, and the second through-hole 312 may be formed on this convex portion.

[0170] In some embodiments, the end of the sealing insulating layer 320 close to the outer shell 100 extends beyond the end of the conductive sheet 320 close to the outer shell 100. With this design, it is possible to prevent the short-circuit phenomenon caused by the conductive sheet 330 shaking up and down and contacting the housing cover 310 during the transportation of the battery cell.

[0171] In some embodiments, please refer to Figure 9 , the electrode core 200 has a central through-hole 201, an electrode core insulating layer 600 is provided on the upper side of the electrode core 200, the electrode core insulating layer 600 is provided with an insulating through-hole 601, and the diameter of the insulating through-hole 601 is smaller than the diameter of the central through-hole 201.

[0172] The setting of this electrode core insulating layer 600 can further improve the insulation performance and prevent the short-circuit phenomenon caused by the positive electrode tab 210 partially falling off and connecting to the electrode core 200.

[0173] In the embodiments of the present application, various detailed designs of the top cover structure 300 (such as the above-mentioned size design and positional relationship design, the hollow design or solid design of the boss 331, the notch design or non-notch design, etc.) are not shown in the same drawing. It can be understood that these detailed designs can be combined as needed to form a variety of top cover structures 300 and battery cells that meet different requirements.

[0174] In an embodiment of the present application, an explosion-proof structure may also be provided on the top cover structure 300. For example, a pressure relief port may be opened at an appropriate position of the enclosure cover 310, and an explosion-proof valve is provided on one side of the pressure relief port. Under normal use conditions, the explosion-proof valve seals the pressure relief port. When the temperature inside the battery cell rises sharply and exceeds a predetermined value, the high-temperature gas can push open the explosion-proof valve to achieve the purpose of pressure relief and prevent the battery cell from exploding.

[0175] The explosion-proof valve can be selected according to actual requirements. In some cases, the explosion-proof valve can also be replaced with an explosion-proof diaphragm.

[0176] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0177] In the description of the present utility model, it should be understood that the terms "comprising" and "having" used in the present application and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0178] Unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be directly connected, or indirectly connected through an intermediate medium, which may be the connection inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0179] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery cell, characterized in that, Comprising: A housing having a receiving cavity and an opening communicating with the receiving cavity; An electrode core disposed in the receiving cavity; A top cover structure for sealing the opening, the top cover structure comprising: A sealing cover, on which a first through hole and a second through hole are formed, and a second through hole cover is disposed on the second through hole; A sealing insulating layer disposed on a side of the sealing cover facing the electrode core and having a third through hole communicating with the first through hole; And a conductive sheet disposed on a side of the sealing insulating layer facing the electrode core, the conductive sheet having a boss that passes through the third through hole and the first through hole and is connected to the electrode core.

2. The battery cell according to claim 1, characterized in that, The second through hole is located at the center of the sealing cover, the first through hole is located on one side of the second through hole, or the first through hole is located at the center of the sealing cover, and the second through hole is located on one side of the first through hole.

3. The cell according to claim 1, wherein A periphery of the third through hole extends into the first through hole, and an inner diameter of the third through hole is smaller than an inner diameter of the first through hole.

4. The battery cell according to claim 1, wherein, The boss extends out of the first through hole.

5. The cell according to claim 1, characterized in that, The sealing insulating layer has a fourth through hole communicating with the second through hole, the conductive sheet has a fifth through hole communicating with the second through hole, and the second through hole, the fourth through hole and the fifth through hole communicate with each other.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The electrode core includes a positive electrode sheet, a negative electrode sheet and a separator disposed between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet having a positive electrode tab, and the negative electrode sheet having a negative electrode tab; The positive electrode tab is connected to the conductive sheet, and the negative electrode tab is connected to the housing.

7. The battery cell according to claim 6, wherein, A projection of the positive electrode tab in the thickness direction of the battery cell does not overlap with a projection of the second through hole cover in the thickness direction of the battery cell.

8. The battery cell according to any one of claims 1 to 5, characterized in that, The conductive sheet includes a first notch, the sealing insulating layer is provided with a second notch corresponding to the first notch, and a projection of the second through hole cover in the thickness direction of the battery cell does not overlap with a projection of the conductive sheet or the sealing insulating layer in the thickness direction of the battery cell.

9. The battery cell according to any one of claims 1 to 5, characterized in that The sealing cover includes a convex portion extending in a direction away from the electrode core, and the second through hole is formed on the convex portion.

10. The battery cell according to any one of claims 1 to 5, characterized in that, A plane of the second through hole cover on the second through hole does not exceed a top surface of the conductive sheet.

11. The battery cell according to any one of claims 1 to 5, characterized in that, An end of the sealing insulating layer close to the housing extends beyond an end of the conductive sheet close to the housing.

12. The battery cell according to any one of claims 1 to 5, characterized in that, The boss is a hollow structure or a solid structure.

13. The cell according to any one of claims 1 to 5, characterized in that, A first step is provided on a side of the sealing cover facing the housing, and a second step is provided on a side of the housing facing the sealing cover.

14. The battery cell according to any one of claims 1 to 5, characterized in that, The electrode core has a central through hole, an electrode core insulating layer is provided on an upper side of the electrode core, and the electrode core insulating layer is provided with an insulating through hole, and a diameter of the insulating through hole is smaller than a diameter of the central through hole.

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