Battery cell

Abstract

The utility model discloses a battery monomer, and belongs to the technical field of batteries, and the battery monomer comprises a shell which is provided with an accommodating cavity and a first opening communicated with the accommodating cavity; the first cover body covers the first opening; the electrode assembly is arranged in the accommodating cavity and comprises a battery cell body, a first tab and a second tab, the battery cell body comprises a main body part and an expansion part, the expansion part is convexly arranged on the part, facing one end of the first cover body, of the main body part, the first tab and the second tab are distributed along the length direction of the first cover body, the first tab is electrically connected with the expansion part and the first cover body, and the second tab is electrically connected with the second cover body. The second tab is arranged at one end, facing the first cover body, of the main body part and is electrically connected with the main body part; and the pole penetrates through the first cover body, the pole and the first cover body are insulated and spaced, and the pole is electrically connected with the second tab. According to the invention, the capacity and energy density of the battery monomer are increased, the cost of the battery monomer is reduced, and the overcurrent capability of the battery monomer is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a battery monomer. BACKGROUND

[0002] At present, a battery usually integrates components such as positive and negative pole columns on a cover plate. Necessary insulation structures and sealing structures need to be arranged between the positive and negative pole columns and the cover plate, and structures such as riveting pieces also need to be arranged according to the fixing type of the pole columns. Not only is the structure complex, but also the pole columns themselves need to occupy part of the internal space of the battery, affecting the energy density of the battery. CONTENT OF THE UTILITY MODEL

[0003] The application aims to overcome the above technical problems.

[0004] TECHNICAL SCHEME: The battery monomer provided by the application comprises:

[0005] A shell having a containing cavity and a first opening communicating with the containing cavity;

[0006] A first cover body covering the first opening;

[0007] An electrode assembly arranged in the containing cavity, the electrode assembly comprising an electric core body, a first tab and a second tab, the electric core body comprising a main body part and an expansion part, the expansion part being protruded from a part of one end of the main body part towards the first cover body, the first tab and the second tab being distributed along the length direction of the first cover body, the first tab being electrically connected with the expansion part and the first cover body, the second tab being arranged at one end of the main body part towards the first cover body, and the second tab being electrically connected with the main body part;

[0008] A pole column penetrating the first cover body, the pole column being insulated and spaced apart from the first cover body, and the pole column being electrically connected with the second tab.

[0009] In some embodiments, the first cover body comprises a first cover part and a second cover part distributed along the length direction of the first cover body, the first cover part and the second cover part have a height difference in the thickness direction of the first cover body, the first cover part and the first tab are arranged oppositely, the second cover part and the second tab are arranged oppositely, and the pole column penetrates the second cover part.

[0010] The shell comprises a main shell part and a protruding part, the protruding part is protruded from a part of one end of the main shell part, and the main shell part and the protruding part enclose the containing cavity and the first opening, the first cover part covers the protruding part, and the second cover part covers the main shell part to seal the first opening.

[0011] In some embodiments, in the thickness direction of the first cover, the end of the pole opposite to the second tab does not protrude from the side of the first cover opposite to the first tab.

[0012] In some embodiments, the first cover is provided with a liquid injection hole, and the liquid injection hole is located between the first tab and the second tab in the length direction of the first cover.

[0013] In some embodiments, the injection hole is located on the second cap portion.

[0014] In some embodiments, the battery cell further includes:

[0015] A first insulating element is arranged in a ring around the pole post, and the first insulating element is insulatingly spaced between the pole post and the first cover.

[0016] A second insulating element is disposed on the side of the first cover facing the battery cell body, and the second insulating element provides insulation between the first cover and the battery cell body.

[0017] In some embodiments, the second insulating member includes a first insulating portion and a second insulating portion connected in the length direction, the first insulating portion and the second insulating portion having a height difference in the thickness direction, and the first insulating portion being connected to the first cover portion and the second insulating portion being connected to the second cover portion.

[0018] In some embodiments, the electrode assembly is provided in multiple forms, and the multiple electrode assemblies are arranged along the width direction of the first cover.

[0019] In some embodiments, the housing further has a second opening communicating with the receiving cavity;

[0020] The battery cell also includes a second cover and an explosion-proof valve disposed on the second cover, the second cover covering the second opening.

[0021] In some embodiments, the battery cell further includes a third insulating member, which is disposed on the side of the second cover facing the cell body. The third insulating member insulatingly separates the second cover and the cell body, and has an exhaust hole through the third insulating member facing the explosion-proof valve.

[0022] In some embodiments, the third insulating member has a groove on the side facing the explosion-proof valve, at least a portion of the explosion-proof valve is opposite the groove, and the vent is located on the groove wall.

[0023] Beneficial Effects: The battery cell of this application embodiment includes a casing, a first cover, an electrode assembly, and a terminal post. The casing has a receiving cavity and a first opening communicating with the receiving cavity, and the first cover is disposed on the first opening. The electrode assembly is disposed in the receiving cavity and includes a cell body, a first tab, and a second tab. The cell body includes a main body portion and an expansion portion. The expansion portion protrudes from the end of the main body portion facing the first cover. The first tab and the second tab are distributed along the length direction of the first cover. The first tab is electrically connected to the expansion portion and the first cover. The second tab is disposed at the end of the main body portion facing the first cover and is electrically connected to the main body portion. The terminal post passes through the first cover, and the terminal post and the first cover are insulated from each other. The terminal post is electrically connected to the second tab. By eliminating the terminal post on the first electrode tab side of the battery cell, and using the first cover as one electrode of the battery cell and the terminal post as the other electrode, the electrical connection structure on the first electrode tab side is simplified, and multiple components are eliminated. This provides space for the capacity expansion section, which increases the capacity of the battery cell body, improves the energy density of the battery cell, and simultaneously reduces the cost of the battery cell and improves its overcurrent capacity. Attached Figure Description

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

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

[0026] Figure 2 This is a schematic diagram of the exploded structure of a single battery cell provided in an embodiment of this application;

[0027] Figure 3 An exploded view of the first cover and the second insulating member provided in the embodiments of this application;

[0028] Figure 4 This is a schematic diagram of the structure of the electrode assembly provided in the embodiments of this application;

[0029] Figure 5 This is a schematic diagram of the structure of the shell provided in an embodiment of this application;

[0030] Figure 6 This is a schematic diagram of the structure of the first cover provided in an embodiment of this application;

[0031] Figure 7 for Figure 6 Sectional view along line AA;

[0032] Figure 8An exploded view of the second cover and the third insulating member provided in the embodiments of this application;

[0033] Reference numerals: 1. Shell; 10. Receiving cavity; 11. First opening; 12. Second opening; 13. Main shell portion; 14. Protrusion; 2. First cover; 20. Electrode post hole; 21. Injection hole; 22. First cover portion; 23. Second cover portion; 3. Electrode assembly; 30. Cell body; 300. Main body portion; 301. Expansion portion; 31. First electrode tab; 32. Second electrode tab; 4. Electrode post; 5. First insulating component; 6. Second insulating component; 60. Through hole; 61. First insulating portion; 62. Second insulating portion; 7. Second cover; 70. Explosion-proof hole; 71. Support component; 8. Explosion-proof valve; 9. Third insulating component; 90. Vent hole; 91. Groove; X, Length direction; Y, Thickness direction; Z, Width direction. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0035] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, and "at least one" can mean one, two, or more, unless otherwise explicitly specified.

[0036] Batteries typically integrate components such as the positive and negative terminals onto a cover plate. The positive and negative terminals require necessary insulation and sealing structures between themselves and the cover plate. Depending on the type of terminal fixing, structures such as riveting fittings are also needed. This not only complicates the structure but also occupies some of the battery's internal space, affecting the battery's energy density.

[0037] In view of this, refer to Figures 1 to 8 This application provides a battery cell to overcome at least one of the above-mentioned technical problems.

[0038] Reference Figures 1 to 7 A single battery cell includes a housing 1, a first cover 2, an electrode assembly 3, and a terminal post 4.

[0039] It should be noted that in the following embodiments of this application, there are intersecting length directions X, thickness directions Y, and width directions Z. Specifically, length direction X refers to the length direction X of the first cover 2, thickness direction Y refers to the thickness direction Y of the first cover 2, and width direction Z refers to the width direction Z of the first cover 2.

[0040] The housing 1 has a receiving cavity 10 and a first opening 11 communicating with the receiving cavity 10. A first cover 2 is disposed on the first opening 11. An electrode assembly 3 is disposed in the receiving cavity 10. The electrode assembly 3 includes a cell body 30, a first tab 31, and a second tab 32. The cell body 30 includes a main body portion 300 and an expansion portion 301. The expansion portion 301 protrudes from the portion of the main body portion 300 facing the first cover 2. The first tab 31 and the second tab 32 are distributed along the length direction X of the first cover 2. The first tab 31 is electrically connected to the expansion portion 301 and the first cover 2. The second tab 32 is disposed at the end of the main body portion 300 facing the first cover 2 and is electrically connected to the main body portion 300. A terminal post 4 passes through the first cover 2, and the terminal post 4 and the first cover 2 are insulated from each other. The terminal post 4 is electrically connected to the second tab 32.

[0041] By eliminating the terminal post 4 on the first tab 31 side of the battery cell, and using the first cover 2 as one pole of the battery cell and the terminal post 4 as the other pole of the battery cell, the electrical connection structure on the first tab 31 side is simplified, and multiple components are eliminated, thereby providing expansion space for the capacity expansion section 301. By increasing the capacity of the cell body 30 through the capacity expansion section 301, it is beneficial to improve the energy density of the battery cell, while reducing the cost of the battery cell and improving the overcurrent capacity of the battery cell.

[0042] In some embodiments, refer to Figures 1 to 5 The first cover 2 includes a first cover portion 22 and a second cover portion 23 distributed along the length direction X. The first cover portion 22 and the second cover portion 23 have a height difference along their thickness direction Y. The first cover portion 22 and the first electrode tab 31 are disposed opposite each other, and the second cover portion 23 and the second electrode tab 32 are disposed opposite each other. The electrode post 4 passes through the second cover portion 23. The housing 1 includes a main housing portion 13 and a protrusion 14. The protrusion 14 protrudes from one end of the main housing portion 13, and the main housing portion 13 and the protrusion 14 enclose a receiving cavity 10 and a first opening 11. The first cover portion 22 covers the protrusion 14, and the second cover portion 23 covers the main housing portion 13 to seal the first opening 11.

[0043] After removing the pole post 4 on the side of the first tab 31, a stepped structure with a height difference is formed by the first cover 22 and the second cover 23. At the same time, a protrusion 14 is provided on the main shell 13 corresponding to the first cover 22. The first cover 22 and the protrusion 14 cooperate to form a space for accommodating the expansion part 301, which is conducive to further increasing the size of the expansion part 301, thereby increasing the capacity of the cell body 30 and the energy density of the battery cell.

[0044] In some embodiments, refer to Figure 3 and Figure 7 In the thickness direction Y, the end of the electrode post 4 facing away from the second tab 32 does not protrude beyond the side of the first cover 22 facing away from the first tab 31. This embodiment shows that the end of the electrode post 4 facing away from the second tab 32 and the side of the first cover 22 facing away from the first tab 31 are flush, facilitating electrical connection of the two poles of the battery cell at the same height. It is understood that in other embodiments, the end of the electrode post 4 facing away from the second tab 32 may also be lower than the side of the first cover 22 facing away from the first tab 31, which is beneficial for the first cover 22 and the protrusion 14 to form a space to accommodate a larger capacity expansion portion 301, thereby increasing the capacity of the cell body 30. Furthermore, in other embodiments, the end of the electrode post 4 facing away from the second tab 32 may also be higher than the side of the first cover 22 facing away from the first tab 31, which will not be elaborated further here.

[0045] In some embodiments, refer to Figure 2 and Figure 7 The first cover 2 is provided with an injection hole 21, and in the length direction X of the first cover 2, the injection hole 21 is located between the first tab 31 and the second tab 32. By setting the injection hole 21 in a position that avoids the first tab 31 and the second tab 32, it is beneficial to prevent the electrolyte from directly washing over the first tab 31 and the second tab 32 during the electrolyte injection process into the receiving cavity 10. This reduces the risk of lint on the first tab 31 and the second tab 32 being washed away by the electrolyte and introduced into the receiving cavity 10, thus reducing the risk of lint causing puncture or short circuit of the cell body 30 in the receiving cavity 10. Specifically, refer to... Figure 2 and Figure 7 In this embodiment, the injection hole 21 is located on the second cover 23, which helps to avoid the injection hole 21 occupying the electrical connection space of the first cover 22 used as a pole.

[0046] In some embodiments, to ensure the insulation effect between the pole post 4 and the second cover 23, and between the first cover 2 and the cell body 30, refer to Figure 3 and Figure 7 The battery cell also includes a first insulating member 5 and a second insulating member 6. The first insulating member 5 is arranged in a ring around the terminal post 4, and the first insulating member 5 is insulatingly spaced between the terminal post 4 and the second cover 23. The second insulating member 6 is located on the side of the first cover 2 facing the cell body 30, and the second insulating member 6 insulatingly separates the first cover 2 and the cell body 30. At the same time, the second insulating member 6 has a through hole 60 to avoid the first tab 31, so that the first tab 31 can be electrically connected to the first cover 22. The terminal post 4 can be connected to the first cover 2 by riveting or other methods. The first insulating member 5 and the second insulating member 6 ensure that the terminal post 4 and the first cover 2 are independently overcurrent, thereby improving the overcurrent stability of the battery cell.

[0047] In some embodiments, in order to reduce the occupancy of the second insulating member 6 on the receiving cavity 10, refer to Figure 3 The second insulating member 6 includes a first insulating portion 61 and a second insulating portion 62 connected in the length direction X. The first insulating portion 61 and the second insulating portion 62 have a height difference in the thickness direction Y. The first insulating portion 61 is connected to the first cover portion 22, and the second insulating portion 62 is connected to the second cover portion 23. A through hole 60 is provided in the first insulating portion 61. By fitting the first insulating portion 61 and the second insulating portion 62 with the height difference between the first cover portion 22 and the second cover portion 23, the space occupied in the area where the capacity expansion portion 301 is located is reduced, which is conducive to accommodating a larger-sized capacity expansion portion 301, thereby increasing the capacity of the cell body 30 and the energy density of the battery cell.

[0048] In some embodiments, in order to further increase the capacity of a single battery cell, refer to Figure 1 and Figure 4 Multiple electrode assemblies 3 are provided, and the multiple electrode assemblies 3 are arranged along the width direction Z of the first cover 2. Correspondingly, the first cover 22 is connected to multiple first electrode tabs 31, and the electrode post 4 is connected to multiple second electrode tabs 32.

[0049] In some embodiments, refer to Figure 2 , Figure 7 and Figure 8 The housing 1 also has a second opening 12 that connects to the receiving cavity 10 in the thickness direction YZ. The battery cell also includes a second cover 7 and an explosion-proof valve 8 disposed on the second cover 7. The second cover 7 covers the second opening 12 and has an explosion-proof hole 70, within which the explosion-proof valve 8 is disposed. By placing the explosion-proof valve 8 on the side of the battery cell away from its own terminal post 4, thermoelectric separation is achieved, reducing the risk of damage to the battery cell's electrical connection structure in the event of thermal runaway.

[0050] In some embodiments, to improve the insulation effect between the second cover 7 and the cell body 30, refer to Figure 7 and Figure 8 The battery cell also includes a third insulating component 9, which is located on the side of the second cover 7 facing the cell body 30. The third insulating component 9 provides insulation between the second cover 7 and the cell body 30, and has a vent hole 90 extending through it towards the explosion-proof valve 8. The vent hole 90 helps prevent the third insulating component 9 from blocking the venting passage of the explosion-proof valve 8, thereby improving the explosion-proof effect of the battery cell.

[0051] In some embodiments, in order to further enhance the reference Figure 7 and Figure 8The third insulating element 9 has a groove 91 on the side facing the explosion-proof valve 8, at least a portion of the explosion-proof valve 8 is directly opposite the groove 91, and the vent 90 is located on the groove wall of the groove 91. By placing the vent 90 on the groove wall of the groove 91, the risk of the explosion-proof valve 8 blocking the vent 90 when the battery cell experiences thermal runaway is further reduced, thus improving the pressure relief stability of the battery cell.

[0052] In some embodiments, refer to Figure 7 and Figure 8 The battery cell also includes a support member 71, which connects to the side of the second cover 7 facing the cell body 30. The support member 71 is embedded in a groove 91, and its melting point is higher than that of the third insulating member 9. By embedding the support member 71 in the groove 91, the stability of the third insulating member 9 is improved, ensuring that the vent 90 is directly opposite the explosion-proof valve 8. By using the support member 71, whose melting point is higher than that of the third insulating member 9, in the event of thermal runaway in the battery cell, the third insulating member 9 melts before the support member 71. The support member 71 helps maintain the support interval between the cell body 30 and the explosion-proof valve 8, preventing the cell body 30 from blocking the explosion-proof valve 8 and improving the pressure relief stability and safety of the battery cell.

[0053] The battery cell provided in the embodiments of this application has been described in detail above, and specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized in that, include: The housing (1) has a receiving cavity (10) and a first opening (11) communicating with the receiving cavity (10); The first cover (2) is provided on the first opening (11); An electrode assembly (3) is disposed in the receiving cavity (10). The electrode assembly (3) includes a battery cell body (30), a first electrode tab (31), and a second electrode tab (32). The battery cell body (30) includes a main body (300) and an expansion portion (301). The expansion portion (301) protrudes from the part of the main body (300) facing the first cover (2). The first electrode tab (31) and the second electrode tab (32) are distributed along the length direction (X) of the first cover (2). The first electrode tab (31) is electrically connected to the expansion portion (301) and the first cover (2). The second electrode tab (32) is disposed at the end of the main body (300) facing the first cover (2) and is electrically connected to the main body (300). A pole post (4) is inserted through the first cover (2), the pole post (4) and the first cover (2) are insulated from each other, and the pole post (4) is electrically connected to the second tab (32).

2. The battery cell according to claim 1, characterized in that, The first cover (2) includes a first cover portion (22) and a second cover portion (23) distributed in its own length direction (X). The first cover portion (22) and the second cover portion (23) have a height difference in their own thickness direction (Y). The first cover portion (22) and the first electrode tab (31) are arranged opposite to each other, the second cover portion (23) and the second electrode tab (32) are arranged opposite to each other, and the pole post (4) passes through the second cover portion (23). The housing (1) includes a main housing portion (13) and a protrusion portion (14). The protrusion portion (14) protrudes from one end of the main housing portion (13), and the main housing portion (13) and the protrusion portion (14) enclose the receiving cavity (10) and the first opening (11). The first cover portion (22) covers the protrusion portion (14), and the second cover portion (23) covers the main housing portion (13) to seal the first opening (11).

3. The battery cell according to claim 2, characterized in that, In the thickness direction (Y) of the first cover (2), the end of the pole post (4) away from the second pole tab (32) does not protrude from the side of the first cover (22) away from the first pole tab (31).

4. The battery cell according to claim 2, characterized in that, The first cover (2) is provided with a liquid injection hole (21), and in the length direction (X) of the first cover (2), the liquid injection hole (21) is located between the first tab (31) and the second tab (32).

5. The battery cell according to claim 4, characterized in that, The injection hole (21) is located on the second cover (23).

6. The battery cell according to claim 2, characterized in that, The battery cell also includes: A first insulating element (5) is arranged around the pole post (4), and the first insulating element (5) is insulatingly spaced between the pole post (4) and the first cover (2); A second insulating member (6) is disposed on the side of the first cover (2) facing the battery cell body (30), and the second insulating member (6) provides insulation between the first cover (2) and the battery cell body (30).

7. The battery cell according to claim 6, characterized in that, The second insulating member (6) includes a first insulating part (61) and a second insulating part (62) connected in the length direction (X), the first insulating part (61) and the second insulating part (62) having a height difference in the thickness direction (Y), and the first insulating part (61) is connected to the first cover part (22), and the second insulating part (62) is connected to the second cover part (23).

8. The battery cell according to claim 1, characterized in that, The electrode assembly (3) is provided in multiple ways, and the multiple electrode assemblies (3) are arranged along the width direction (Z) of the first cover (2).

9. The battery cell according to any one of claims 1 to 8, characterized in that, The housing (1) also has a second opening (12) communicating with the receiving cavity (10); The battery cell also includes a second cover (7) and an explosion-proof valve (8) disposed on the second cover (7), the second cover (7) covering the second opening (12).

10. The battery cell according to claim 9, characterized in that, The battery cell also includes a third insulating member (9), which is disposed on the side of the second cover (7) facing the cell body (30). The third insulating member (9) insulates the second cover (7) and the cell body (30) and has an exhaust hole (90) through it facing the explosion-proof valve (8).

11. The battery cell according to claim 10, characterized in that, The third insulating member (9) has a groove (91) on the side facing the explosion-proof valve (8), at least a portion of the explosion-proof valve (8) is directly opposite the groove (91), and the exhaust hole (90) is located on the groove wall of the groove (91).

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