Casing structure and battery

Abstract

This utility model relates to a housing structure and a battery, belonging to the field of battery technology. The housing structure of this utility model includes a housing cover, a support assembly, and a terminal cover plate. The housing cover has a receiving cavity and a terminal hole communicating with the receiving cavity, the receiving cavity being used to receive a battery cell. The support assembly is respectively disposed within the terminal hole and cooperates with the housing cover, the support assembly including a support hole and a limiting step surface. The terminal cover plate is connected to the limiting step surface and its lower end is inserted into the support hole. The terminal cover plate can connect with the tabs of the battery cell within the receiving cavity to form a current channel. The technical solution disclosed in this utility model not only simplifies the top cover manufacturing process and reduces battery manufacturing costs, but also expands the internal space of the battery and increases the energy density of the battery.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a casing structure and a battery. Background Technology

[0002] A battery consists of a casing, battery cells, and a top cover. The battery cells are located inside the casing and encapsulated by the top cover. The top cover is a crucial component of the battery cells; its structure and manufacturing process determine its cost and also affect the cell's capacity. Currently, adapter plates are commonly used as a carrier to connect the battery cells and the top cover. However, adapter plates not only increase the production process and manufacturing cost of the top cover but also occupy internal battery space, reducing the space available for storing electrolyte and electrolytic plates, thus lowering the battery's energy density. Utility Model Content

[0003] This utility model provides a housing structure and battery that not only simplifies the top cover manufacturing process and reduces battery manufacturing costs, but also expands the internal space of the battery and increases its energy density.

[0004] In a first aspect, embodiments of the present invention provide a shell structure, comprising:

[0005] The casing has a receiving cavity and an electrode post hole communicating with the receiving cavity, the receiving cavity being used to receive the battery cell;

[0006] Support components are respectively disposed within the pole post holes and cooperate with the shell cover; each support component includes a support hole and a limiting step surface; and

[0007] The electrode cover plate is connected to the limiting step surface and its lower end is inserted into the support hole; wherein, the electrode cover plate can be connected to the electrode tab of the battery cell in the receiving cavity to form a current channel.

[0008] In one embodiment, the support component includes:

[0009] The upper plastic part includes a first stepped portion and a second stepped portion, wherein the first stepped portion abuts against the shell cover;

[0010] The pressure ring plate abuts against the second stepped portion; and

[0011] The support ring includes a third step portion, which abuts against the upper plastic part, and the top of the support block is connected to the pressure ring plate;

[0012] The limiting step surface is disposed on the pressure ring plate, and the pressure ring plate is connected to the support ring to form the support hole.

[0013] In one embodiment, the pressure ring plate includes:

[0014] The outer pressure ring abuts against the second stepped portion; and

[0015] An inner pressure ring is disposed on the inner wall of the outer pressure ring, and the inner pressure ring and the outer pressure ring form the limiting step surface and the supporting step surface;

[0016] The supporting step surface is connected to the supporting ring.

[0017] In one embodiment, the pole cap plate includes:

[0018] The cover plate body mates with the support hole, and the cover plate body is used for welding to the electrode tab of the battery cell; and

[0019] A cover flange is provided on the outer wall of the cover plate body, and the cover flange abuts against the limiting step surface.

[0020] In one embodiment, the housing structure further includes a seal disposed between the support ring and the upper plastic component.

[0021] In one embodiment, the housing structure further includes a lower plastic component disposed within the housing cover and abutting against the top of the housing cover.

[0022] In one embodiment, the lower plastic part is provided with a guide hole corresponding to the pole hole, and a positioning post is provided on the top of the lower plastic part, the positioning posts being spaced apart along the width direction; wherein, the top of the shell cover is provided with a positioning groove that mates with the positioning post.

[0023] The bottom of the lower plastic part is provided with a first limiting boss and a second limiting boss. The first limiting boss is arranged at intervals along the length direction, and the second limiting boss is arranged at intervals along the width direction, so as to limit the battery cell in the length direction and the width direction.

[0024] In one embodiment, the housing structure further includes a base plate connected to the bottom of the housing cover.

[0025] Secondly, this utility model provides a battery, including the casing structure as described above.

[0026] In one implementation, it includes:

[0027] A battery cell is disposed within the receiving cavity, and the electrode tabs of the battery cell pass through guide holes and support holes and are connected to the electrode cap plate; and

[0028] An insulating film is wrapped around the outer wall of the battery cell.

[0029] Compared with the prior art, the advantages of this utility model embodiment are that by integrating the outer shell and the top cover into a single shell cover, the shell cover can be used as both the outer shell and the top cover, thus eliminating the need for a separate top cover and reducing production costs; by directly inserting the electrode cover plate into the support hole and welding it to the electrode post, the use of an adapter plate is eliminated, which effectively prevents the electrode tabs from being inserted backwards and the core from being wound up; on the other hand, it not only simplifies the battery production process and reduces battery manufacturing costs, but also further expands the internal space of the battery and improves the energy density of the battery. Attached Figure Description

[0030] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings.

[0031] Figure 1 This is an exploded view of the shell structure provided in one embodiment of the present invention;

[0032] Figure 2 yes Figure 1 An exploded view of the shell cover and support assembly provided in the Chinese embodiment;

[0033] Figure 3 yes Figure 1 A schematic diagram of the installation of the lower plastic part and the shell cover provided in the embodiment;

[0034] Figure 4 yes Figure 1 A cross-sectional view of the shell cover and support assembly provided in the Chinese embodiment in the front view direction;

[0035] Figure 5 yes Figure 4 Enlarged view of section A;

[0036] Figure 6 yes Figure 1 A cross-sectional view of the upper plastic part provided in the embodiment;

[0037] Figure 7 yes Figure 1 A cross-sectional view of the pressure ring plate provided in the Chinese embodiment;

[0038] Figure 8 yes Figure 1 A cross-sectional view of the support ring provided in the Chinese embodiment;

[0039] Figure 9 yes Figure 1 A schematic diagram of the positive electrode post cover plate provided in the embodiment;

[0040] Figure 10 This is an exploded view of a battery provided in another embodiment of the present invention;

[0041] Figure 11 yes Figure 10A schematic diagram of the connection between the electrode tab and the electrode post cover plate provided in the embodiment;

[0042] Figure 12 yes Figure 10 A cross-sectional view of the battery provided in the Chinese embodiment in the side view direction.

[0043] Figure label:

[0044] 1. Battery cell; 2. Insulating film; 3. Positive electrode tab; 4. Negative electrode tab;

[0045] 10. Shell cover; 110. Receiving cavity; 1201. Positive electrode post hole; 1202. Negative electrode post hole; 130. Explosion-proof valve mounting hole; 140. Explosion-proof valve; 150. Protective film;

[0046] 20. Support assembly; 210. Support hole; 220. Limiting step surface; 230. Upper plastic part; 2301. First step; 2302. Second step; 2303. Horizontal plastic ring; 2304. Vertical plastic ring; 240. Pressure ring plate; 2401. Outer pressure ring; 2402. Inner pressure ring; 250. Support ring; 2501. Third step;

[0047] 310. Positive electrode post cover plate; 320. Negative electrode post cover plate; 330. Cover plate body; 340. Cover plate flange;

[0048] 40. Sealing components;

[0049] 50. Lower plastic part; 510. Guide hole; 520. First limiting boss; 530. Second limiting boss; 550. Covering part; 560. Positioning post;

[0050] 60. Base plate. Detailed Implementation

[0051] The present invention will be further described below with reference to the accompanying drawings.

[0052] A battery consists of a casing, battery cells, and a top cover. The battery cells are located inside the casing and encapsulated by the top cover. The top cover is a crucial component of the battery cells; its structure and manufacturing process determine its cost and also affect the cell's capacity. Currently, adapter plates are commonly used as a carrier to connect the battery cells and the top cover. However, adapter plates not only increase the production process and manufacturing cost of the top cover but also occupy internal battery space, reducing the space available for storing electrolyte and electrolytic plates, thus lowering the battery's energy density.

[0053] Example 1

[0054] like Figures 1-5As shown, in order to solve the above-mentioned technical problems, this utility model embodiment provides a housing structure, including a housing cover 10, a support assembly 20, and an electrode post cover plate; the housing cover 10 is provided with a receiving cavity 110 and an electrode post hole communicating with the receiving cavity 110, the receiving cavity 110 is used to receive the battery cell 1; the support assembly 20 is respectively disposed in the electrode post hole and cooperates with the housing cover 10, the support assembly 20 includes a support hole 210 and a limiting step surface 220; the electrode post cover plate is connected to the limiting step surface 220 and its lower end is inserted into the support hole 210; wherein, the electrode post cover plate can be connected to the electrode tab of the battery cell 1 in the receiving cavity 110 to form a current channel.

[0055] As can be seen from the above, by integrating the outer shell and top cover into a single design called shell cover 10, the shell cover 10 can be used as both the outer shell and the top cover, thus eliminating the need for a separate top cover and reducing production costs. By directly inserting the electrode cover plate into the support hole 210 and welding it to the electrode post, the use of an adapter plate is eliminated. This effectively prevents the electrode tabs from being inserted backwards into the core. Furthermore, it not only simplifies the battery production process and reduces battery manufacturing costs, but also further expands the internal space of the battery and improves its energy density.

[0056] It should be noted that the terminal hole is located on the top of the shell cover 10, and there are two terminal holes, namely the positive terminal hole 1201 and the negative terminal hole 1202. Therefore, the two terminal holes are respectively provided with support components 20; the positive electrode tab 3 of the cell 1 passes through the positive terminal hole 1201 and the negative electrode tab 4 passes through the negative terminal hole 1202.

[0057] It should also be noted that the thickness of the pole cap is 1-10mm, and the shape includes, but is not limited to, one of the following: oval, round, and square; Figure 2 As shown, there are two electrode cover plates, namely a positive electrode cover plate and a negative electrode cover plate. The positive electrode cover plate corresponds to the positive electrode hole 1201, and the negative electrode cover plate corresponds to the negative electrode hole 1202. Specifically, the positive electrode cover plate is an aluminum plate, and the negative electrode cover plate is a copper-aluminum composite plate.

[0058] It should also be noted that the top of the cover 10 is provided with a liquid injection hole and an explosion-proof valve mounting hole 130. An explosion-proof valve 140 is provided in the explosion-proof valve mounting hole 130, and a protective film 150 is provided on the explosion-proof valve 140. Specifically, the explosion-proof valve 140 is an aluminum sheet with engravings on its surface, which is used to depressurize the battery cell 1, and the protective film 150 is used to prevent the explosion-proof valve 140 from being contaminated by the external environment.

[0059] It should also be noted that the electrode cover plate is welded to the electrode tab of cell 1, and the welding method includes, but is not limited to, laser welding and ultrasonic welding.

[0060] Example 2

[0061] like Figures 1-5As shown, the housing structure includes a housing cover 10, a support assembly 20, and an electrode post cover plate. The housing cover 10 is provided with a receiving cavity 110 and an electrode post hole communicating with the receiving cavity 110. The receiving cavity 110 is used to receive the battery cell 1. The support assembly 20 is respectively disposed in the electrode post hole and cooperates with the housing cover 10. The support assembly 20 includes a support hole 210 and a limiting step surface 220. The electrode post cover plate is connected to the limiting step surface 220 and its lower end is inserted into the support hole 210. The electrode post cover plate can be connected to the electrode tab of the battery cell 1 in the receiving cavity 110 to form a current channel.

[0062] As can be seen from the above, by integrating the outer shell and top cover into a single design called shell cover 10, the shell cover 10 can be used as both the outer shell and the top cover, thus eliminating the need for a separate top cover and reducing production costs. By directly inserting the electrode cover plate into the support hole 210 and welding it to the electrode post, the use of an adapter plate is eliminated. This effectively prevents the electrode tabs from being inserted backwards into the core. Furthermore, it not only simplifies the battery production process and reduces battery manufacturing costs, but also further expands the internal space of the battery and improves the battery's energy density.

[0063] It should be noted that the terminal hole is located on the top of the shell cover 10, and there are two terminal holes, namely the positive terminal hole 1201 and the negative terminal hole 1202. Therefore, the two terminal holes are respectively provided with support components 20; the positive electrode tab 3 of the cell 1 passes through the positive terminal hole 1201 and the negative electrode tab 4 passes through the negative terminal hole 1202.

[0064] It should also be noted that the thickness of the pole cap is 1-10mm, and the shape includes, but is not limited to, one of the following: oval, round, and square; Figure 2 As shown, there are two electrode cover plates, namely a positive electrode cover plate and a negative electrode cover plate. The positive electrode cover plate corresponds to the positive electrode hole 1201, and the negative electrode cover plate corresponds to the negative electrode hole 1202. Specifically, the positive electrode cover plate is an aluminum plate, and the negative electrode cover plate is a copper-aluminum composite plate.

[0065] It should also be noted that the top of the cover 10 is provided with a liquid injection hole and an explosion-proof valve mounting hole 130. An explosion-proof valve 140 is provided in the explosion-proof valve mounting hole 130, and a protective film 150 is provided on the explosion-proof valve 140. Specifically, the explosion-proof valve 140 is an aluminum sheet with engravings on its surface, which is used to depressurize the battery cell 1, and the protective film 150 is used to prevent the explosion-proof valve 140 from being contaminated by the external environment.

[0066] It should also be noted that the electrode cover plate is welded to the electrode tab of cell 1, and the welding method includes, but is not limited to, laser welding and ultrasonic welding.

[0067] like Figures 2-8In some embodiments shown, the support assembly 20 includes an upper plastic part 230, a pressure ring plate 240, and a support ring 250; the upper plastic part 230 includes a first step portion 2301 and a second step portion 2302, the first step portion 2301 abutting against the cover 10; the pressure ring plate 240 abutting against the second step portion 2302; and the support ring 250 includes a third step portion 2501, the third step portion 2501 abutting against the upper plastic part 230, and the top of the support block is connected to the pressure ring plate 240; wherein, a limiting step surface 220 is disposed on the pressure ring plate 240, and the pressure ring plate 240 is connected to the support ring 250 to form a support hole 210.

[0068] The upper plastic part 230 protects the internal structure of the battery, effectively isolating the positive and negative electrode materials inside the battery and preventing short circuits caused by direct contact. The upper plastic part 230 is limited and fixed by the connection between the pressure ring plate 240 and the support ring 250, while forming the support hole 210 and the limiting step surface 220 for the installation of the electrode cover plate, providing a structural basis for the installation of the electrode cover plate.

[0069] It should be noted that the upper plastic part 230 is made of plastic, such as PPS or LCP. The plastic material can play a role in buffering and shock absorption, reducing the impact and vibration that the battery may be subjected to during use, thereby avoiding damage to the internal structure of the battery.

[0070] It should also be noted that, such as Figure 6 As shown, the upper plastic part 230 includes a horizontal plastic ring 2303 plate and vertical plastic ring 2304 plates connected to both ends of the horizontal plastic ring 2303 plate, thereby forming a first step portion 2301 and a second step portion 2302 respectively; an annular limiting groove is provided at the bottom of the horizontal plastic ring 2303 plate; wherein, an annular protrusion is provided at the top of the cover 10, the annular protrusions correspond one-to-one with the pole post holes, the annular protrusions surround the corresponding pole post holes, and the annular protrusions cooperate with the annular limiting groove; thereby playing a positioning role for the upper plastic part 230.

[0071] It should also be noted that, such as Figure 8 As shown, the support ring 250 includes an upper support ring and a lower support ring connected to the outer wall of the upper support ring, so that the cross section of the support ring 250 is L-shaped, and the upper support ring and the lower support ring form a third step portion 2501.

[0072] It should also be noted that the support ring 250 is welded to the pressure ring plate 240.

[0073] In some embodiments, such as Figure 7As shown, the pressure ring plate 240 includes an outer pressure ring 2401 and an inner pressure ring 2402; the outer pressure ring 2401 abuts against the second step portion 2302; the inner pressure ring 2402 is disposed on the inner wall of the outer pressure ring 2401, and the inner pressure ring 2402 and the outer pressure ring 2401 form a limiting step surface 220 and a supporting step surface; wherein, the supporting step surface is connected to the supporting ring 250.

[0074] By setting the outer pressure ring 2401 and the inner pressure ring 2402 to form the limiting step surface 220 and the supporting step surface, it is convenient to cooperate and install the pole post cover plate and the supporting ring 250, improve the assembly efficiency, and at the same time play a limiting role.

[0075] It should also be noted that the top of the inner pressure ring 2402 is provided with a guide groove to facilitate welding with the pole cap plate.

[0076] like Figure 9 As shown, in some embodiments, the electrode cover plate includes a cover plate body 330 and a cover plate flange 340; the cover plate body 330 cooperates with the support hole 210 and is used to weld to the electrode tab of the battery cell 1; the cover plate flange 340 is disposed on the outer wall of the cover plate body 330 and is connected to the limiting step surface 220.

[0077] The cover plate flange 340 is welded to the limiting step surface 220, and the cover plate body 330 is welded to the electrode tab of the battery cell 1, thereby realizing the installation of the electrode cover plate and the connection between the electrode cover plate and various components.

[0078] like Figure 2 , Figure 5 As shown, in some embodiments, the housing structure further includes a seal 40 disposed between the support ring 250 and the upper plastic part 230.

[0079] By placing the sealing element 40 between the support ring 250 and the upper plastic part 230, the support ring 250 and the pressure ring plate 240 compress the sealing element 40, causing the sealing element 40 to deform and achieve the initial sealing requirements. Then, the pressure ring plate 240 is welded to the pole post cover plate to form the final sealing effect.

[0080] It should be noted that the seal 40 is a rubber seal ring, including but not limited to fluororubber seal rings.

[0081] like Figures 2-5 , Figure 12 As shown, in some embodiments, the housing structure further includes a lower plastic member 50, which is disposed inside the housing cover 10 and abuts against the top of the housing cover 10.

[0082] like Figure 2As shown, in some embodiments, the lower plastic part 50 is provided with a guide hole 510 corresponding to the pole hole, and a positioning post 560 is provided on the top of the lower plastic part 50. The positioning posts 560 are arranged at intervals along the width direction; wherein, the top of the cover 10 is provided with a positioning groove that cooperates with the positioning post 560.

[0083] The bottom of the lower plastic part 50 is provided with a first limiting boss 520 and a second limiting boss 530. The first limiting boss 520 is arranged at intervals along the length direction, and the second limiting boss 530 is arranged at intervals along the width direction, so as to limit the battery cell 1 in the length and width directions.

[0084] By setting the lower plastic part 50, the battery cell 1 inside the receiving cavity 110 can be in contact with the top of the shell. At the same time, the lower plastic part 50 can protect the internal structure of the battery, effectively isolate the positive and negative electrode materials inside the battery, and prevent short circuits caused by direct contact. The positioning post 560 and the positioning groove cooperate to position the lower plastic part 50, ensuring the accuracy of the installation position of the lower plastic part 50. The first limiting boss 520 limits the two sides of the length direction of the battery cell 1, and the second limiting boss 530 limits the two sides of the width direction of the battery cell 1, thereby restricting the position of the battery cell 1.

[0085] It should be noted that the guide holes 510 correspond one-to-one with the pole hole; the lower plastic part 50 is also provided with a shielding part 550 for shielding the explosion-proof valve 140; the positioning post 560 is provided on the shielding part 550.

[0086] It should also be noted that the length direction is parallel to the X direction, and the width direction is parallel to the Y direction.

[0087] like Figure 1 As shown, in some embodiments, the housing structure further includes a base plate 60, which is connected to the bottom of the cover 10.

[0088] The base plate 60 is connected to the bottom of the cover 10, sealing the receiving cavity 110 and providing a completely sealed space for the battery cell 1.

[0089] It should be noted that the base plate 60 can be an aluminum plate.

[0090] Example 3

[0091] like Figure 10 As shown, this utility model embodiment also provides a battery, including the casing structure of any embodiment of this utility model, and thus has all the technical effects brought about by the technical solutions of the above embodiments.

[0092] like Figures 10-12As shown, in some embodiments, the battery cell 1 and the insulating film 2 are included; the battery cell 1 is disposed in the receiving cavity 110, and the electrode tab of the battery cell 1 passes through the guide hole 510 and the support hole 210 and is connected to the electrode cover plate; the insulating film 2 covers the outer wall of the battery cell 1.

[0093] It should be noted that cell 1 is one of single-wound, double-wound, or multi-wound cells, and cell 1 includes a multi-layer tab structure.

[0094] It should also be noted that the lower plastic part 50 is fixed by the positioning post 560 and the positioning groove, and the sealing part 40 is sleeved on the support ring 250. It passes through the guide hole 510 and the pole hole from the bottom of the cover 10, and installs the upper plastic part 230 and the pressure ring plate 240. The pressure ring plate 240 and the support ring 250 are connected by through welding or splicing to form an initial sealing state.

[0095] The battery cell 1 is covered with an insulating film 2. The tabs of the battery cell 1 are inserted into the receiving cavity 110 from the bottom of the shell cover 10. The positive tab 3 of the battery cell 1 is inserted from the corresponding positive terminal hole 1201, and the negative tab 4 is inserted from the corresponding negative terminal hole 1202. Then, the positive tab 3 is stacked on the positive terminal cover plate 310 and welded to the positive terminal cover plate 310. The negative tab 4 is stacked on the negative terminal cover plate 320 and welded to the negative terminal cover plate 320. Then, the positive terminal cover plate 310 and the negative terminal cover plate 320 are welded to the pressure ring plate 240 to form the final sealed state of the terminal cover plate. Finally, the bottom plate 60 is welded to the shell cover 10 to ensure that the battery cell 1 is completely sealed.

[0096] It should also be noted that the insulating film 2 includes, but is not limited to, PP film.

[0097] Although the present invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A shell structure, characterized in that, include: The casing has a receiving cavity and an electrode post hole communicating with the receiving cavity, the receiving cavity being used to receive the battery cell; Support components are respectively disposed within the pole post holes and cooperate with the shell cover; each support component includes a support hole and a limiting step surface; and The electrode cover plate is connected to the limiting step surface and its lower end is inserted into the support hole; wherein the electrode cover plate can be connected to the electrode tab of the battery cell in the receiving cavity to form a current channel.

2. The shell structure according to claim 1, characterized in that, The support components include: The upper plastic part includes a first stepped portion and a second stepped portion, wherein the first stepped portion abuts against the shell cover; The pressure ring plate abuts against the second stepped portion; and The support ring includes a third step portion, which abuts against the upper plastic part, and the top of the support block is connected to the pressure ring plate; The limiting step surface is disposed on the pressure ring plate, and the pressure ring plate is connected to the support ring to form the support hole.

3. The shell structure according to claim 2, characterized in that, The pressure ring plate includes: The outer pressure ring abuts against the second stepped portion; and An inner pressure ring is disposed on the inner wall of the outer pressure ring, and the inner pressure ring and the outer pressure ring form the limiting step surface and the supporting step surface; The supporting step surface is connected to the supporting ring.

4. The shell structure according to any one of claims 1-3, characterized in that, The pole cap plate includes: The cover plate body mates with the support hole, and the cover plate body is used for welding to the electrode tab of the battery cell; and A cover flange is provided on the outer wall of the cover plate body, and the cover flange is connected to the limiting step surface.

5. The shell structure according to claim 2, characterized in that, The housing structure also includes a seal, which is disposed between the support ring and the upper plastic component.

6. The shell structure according to any one of claims 1-3, characterized in that, The housing structure also includes a lower plastic component, which is disposed inside the housing cover and abuts against the top of the housing cover.

7. The shell structure according to claim 6, characterized in that, The lower plastic part is provided with a guide hole corresponding to the pole hole, and a positioning post is provided on the top of the lower plastic part. The positioning posts are spaced apart along the width direction. The top of the shell cover is provided with a positioning groove that cooperates with the positioning post. The bottom of the lower plastic part is provided with a first limiting boss and a second limiting boss. The first limiting boss is arranged at intervals along the length direction, and the second limiting boss is arranged at intervals along the width direction, so as to limit the battery cell in the length direction and the width direction.

8. The shell structure according to any one of claims 1-3, characterized in that, The shell structure also includes a base plate, which is connected to the bottom of the shell cover.

9. A battery, characterized in that, Includes the shell structure as described in any one of claims 1-8.

10. The battery according to claim 9, characterized in that, include: A battery cell is disposed within the receiving cavity, and the electrode tabs of the battery cell pass through guide holes and support holes and are connected to the electrode cap plate; and An insulating film is wrapped around the outer wall of the battery cell.

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