Battery monomer and battery pack

Abstract

The utility model relates to the technical field of new energy batteries, and discloses a single battery and a battery pack, the single battery has a first direction, the single battery comprises: a housing, the housing comprises a bottom plate and a side plate connected with the bottom plate, the bottom plate and the side plate enclose to form an accommodating cavity, and the bottom plate is also provided with a pressure relief hole; the electrode assembly is arranged in the accommodating cavity; the explosion-proof valve is fixedly connected with the bottom plate and blocks the pressure relief hole insulating film, the bottom film and the side film connected with the bottom film; the bottom film comprises a film body and convex parts connected with the film body, the convex parts are located on the side, close to the bottom plate, of the film body in the first direction, the multiple convex parts are arranged at intervals, concave parts are formed between every two adjacent convex parts of the film body, the concave parts and the convex parts define exhaust channels, and the exhaust channels extend to the anti-explosion valve. And gas can be quickly discharged to the explosion-proof valve through the exhaust channel, so that the risk of explosion caused by overlarge internal pressure of the single battery is reduced, and the safety of the single battery is improved.

Description

Technical Field

[0001] This utility model relates to the field of new energy battery technology, and in particular to a battery cell and battery pack. Background Technology

[0002] Lithium-ion batteries can experience thermal runaway if they are damaged by impact or have an internal open circuit. Thermal runaway can cause an increase in internal pressure. To improve the safety of lithium-ion batteries, an explosion-proof valve is installed. This valve can be ruptured to quickly reduce the internal pressure of the lithium-ion battery.

[0003] A typical lithium-ion battery includes a casing, a top cover, an insulating film, electrode assemblies, and an explosion-proof valve. The electrode assemblies are housed within the casing, the top cover seals the casing, and the insulating film encases the electrode assemblies to insulate them from the casing. The explosion-proof valve is located on either the top cover or the casing. The design of placing the explosion-proof valve on the top cover, which has terminals, is prone to dual failures of electrical insulation and thermal runaway in the event of cell misuse or extreme conditions. With increasingly stringent safety requirements for power batteries, thermal-electric separation designs are becoming more common to mitigate the risk of these dual failures.

[0004] Typical thermoelectric separation designs eliminate the explosion-proof valve on the top cover, placing it instead at the bottom of the casing. This prevents electrical connection and thermal runaway from interfering with each other in the event of cell misuse. However, with the explosion-proof valve on the casing, when thermal runaway occurs, the gas cannot be quickly discharged to the valve area. This causes the internal pressure of the casing to rise, potentially leading to an explosion of the lithium-ion battery and a safety accident. Utility Model Content

[0005] The purpose of this invention is to provide a battery cell that solves the problem of poor gas emission after the explosion-proof valve is installed on the casing of a lithium-ion battery in the prior art; this invention also provides a battery pack using this battery cell.

[0006] To achieve the above objectives, this utility model provides a battery cell having a first orientation, the battery cell comprising:

[0007] The outer casing includes a base plate and a side plate connected to the base plate, the base plate and the side plate forming a receiving cavity, and the base plate is also provided with a pressure relief hole;

[0008] An explosion-proof valve is used to seal the pressure relief hole and is fixedly connected to the base plate.

[0009] An insulating film is disposed in the receiving cavity. The insulating film includes a bottom film and a side film connected to the bottom film. The bottom film and the bottom plate are disposed opposite to each other along the first direction.

[0010] The bottom membrane includes a membrane body and protrusions connected to the membrane body. The protrusions are located on the side of the membrane body close to the bottom plate along the first direction. Multiple protrusions are spaced apart. The membrane body forms a recess between two adjacent protrusions. The recess and the adjacent protrusion enclose an exhaust channel. The exhaust channel is connected to the pressure relief hole.

[0011] In some embodiments, the membrane body is provided with a first weak portion or a through hole, the through hole penetrating the membrane body along the first direction.

[0012] In some embodiments, the membrane body is provided with either a groove or a toothed line, the groove or toothed line forming the first weak portion.

[0013] In some embodiments, the protrusion is elongated and extends along a second direction, which is perpendicular to the first direction.

[0014] In some embodiments, the protrusion has a first wall and a second wall, the first wall being disposed opposite to the base plate along the first direction and in contact with the base plate, the second wall being connected between the first wall and the recess, and the second wall having a second weak portion.

[0015] In some embodiments, the second wall is further provided with an air passage that extends along the second direction and penetrates the protrusion along a third direction. The second weak portion is alternately arranged with the air passage along the second direction, and the third direction and the second direction are perpendicular to the first direction.

[0016] In some embodiments, the protrusions are hemispherical, and the protrusions are arranged in an array at intervals.

[0017] In some embodiments, the protrusion includes a support member, the support member including a plurality of spaced protrusions, the gap between two adjacent protrusions forming the exhaust channel.

[0018] In some embodiments, the support member includes a plurality of support blocks fixedly connected to the membrane body. The support blocks are rectangular and extend along a second direction. Each support block is spaced apart along a third direction. The support blocks form the protrusions. The second direction and the third direction are perpendicular to the first direction.

[0019] In some embodiments, the membrane body has a third weak portion, which is located between two adjacent support blocks.

[0020] In some embodiments, the support member includes a support plate and a protrusion. The protrusion is disposed on the side of the support plate facing the membrane body along the first direction. The protrusion is an elongated strip extending along the second direction. Multiple protrusions are spaced apart along a third direction. The protrusions form the boss. The second direction and the third direction are perpendicular to the first direction.

[0021] In some embodiments, the support member further includes a flat plate disposed between the support plate and the bottom film, the flat plate connecting the boss and the bottom film, and the flat plate having a fourth weak portion.

[0022] In some embodiments, the protrusion further has a clearance portion, which is disposed opposite to the explosion-proof valve along the first direction.

[0023] This utility model also provides a battery pack, including the battery cells described in any of the above technical solutions.

[0024] Compared with the prior art, the battery cell and battery pack of this utility model embodiment have the following advantages: The protrusions and concave portions are formed on the membrane body of the bottom film, so that the protrusions and concave portions form an exhaust channel. In the event of thermal runaway of the battery cell, the gas can be quickly discharged to the explosion-proof valve position through the exhaust channel, reducing the risk of explosion due to excessive internal pressure of the battery cell and improving the safety of the battery cell. In addition, the exhaust channel is formed by the protrusions and concave portions, which simplifies the structure of the exhaust channel and can reduce manufacturing costs. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a single battery cell of this utility model;

[0026] Figure 2 yes Figure 1 A schematic diagram of the insulating film structure of a single battery cell;

[0027] Figure 3 yes Figure 2 A partial side view of the insulating film;

[0028] Figure 4 yes Figure 1 A schematic diagram of the structure after through holes are set on the insulating film of a battery cell;

[0029] Figure 5 yes Figure 1 A schematic diagram of the structure after an air-proof part is set on the insulating film of the battery cell;

[0030] Figure 6 yes Figure 1 A schematic diagram of the structure when the protrusion of the insulating film of a single battery cell is elongated;

[0031] Figure 7 yes Figure 6 A magnified schematic diagram of the insulating film at point A;

[0032] Figure 8 yes Figure 6 A partially enlarged side view of the insulating film;

[0033] Figure 9 This is a schematic diagram of the structure of the battery cell of this utility model when a support block is set on the insulating film to form a support member;

[0034] Figure 10 yes Figure 9 An exploded structural diagram of the insulating film and supporting components;

[0035] Figure 11 yes Figure 9 A structural diagram when the supporting component is a support plate;

[0036] Figure 12 yes Figure 11 A partially enlarged side view of the support components and insulating film after assembly;

[0037] Figure 13 yes Figure 9 A structural diagram showing the support components as a support plate and a flat plate.

[0038] Figure 14 yes Figure 13 A partially enlarged side view of the support components and insulating film after assembly.

[0039] In the diagram, 1. Outer shell, 11. Bottom plate, 12. Side plate, 13. Receiving cavity, 14. Pressure relief hole, 2. Electrode assembly, 3. Insulating membrane, 31. Bottom membrane, 311. Membrane body, 312. Protrusion, 3121. First wall, 3122. Second wall, 3123. Second weak part, 3124. Air passage, 313. Recess, 32. Side membrane, 33. First weak part, 34. Through hole, 35. Third weak part, 4. Support member, 41. Boss, 42. Support block, 43. Support plate, 44. Protruding ridge, 46. Flat plate, 461. Fourth weak part, 5. Exhaust passage, 6. Explosion-proof valve, 7. Air vent, Z. First direction, Y. Second direction, X. Third direction. Detailed Implementation

[0040] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0041] A preferred embodiment of the battery cell and battery pack of this utility model is as follows: Figures 1 to 14As shown, the battery cell includes a casing 1, an electrode assembly 2, an insulating film 3, and an explosion-proof valve 6. The electrode assembly 2 and the insulating film 3 are both disposed inside the casing 1, which protects the internal structures. The battery cell has a first direction Z. In this embodiment, the battery cell is a square lithium battery, the casing 1 is rectangular, and the first direction Z is the height direction of the battery cell.

[0042] The outer casing 1 includes a base plate 11 and a side plate 12, which are connected to the base plate 11. The base plate 11 and the side plate 12 together form a receiving cavity 13, which is a cuboid. The electrode assembly 2, the insulating film 3, and the support member 4 are all disposed within the receiving cavity 13. The insulating film 3 is used to cover the electrode assembly 2, which can insulate and isolate the electrode assembly 2 from the outer casing 1, thereby improving the insulation safety of the battery cell. The base plate 11 is also provided with a pressure relief hole 14. An explosion-proof valve 6 is fixedly connected to the base plate 11 and seals the pressure relief hole 14. In the event of thermal runaway of the battery cell, the gas can open the explosion-proof valve 6 and be discharged from the pressure relief hole 14.

[0043] The insulating film 3 includes a bottom film 31 and a side film 32. The bottom film 31 and the side film 32 are connected. The bottom film 31 is disposed opposite to the bottom plate 11 of the outer shell 1 along the first direction Z, and the side film 32 is disposed opposite to the side plate 12 of the outer shell 1. The insulating film 3 is generally in the shape of a cuboid with an opening at the top, which can enclose the electrode assembly 2 in the cavity formed by the bottom film 31 and the side film 32.

[0044] In some embodiments, such as Figures 2 to 8 As shown, the bottom membrane 31 includes a membrane body 311 and protrusions 312. The protrusions 312 are connected to the membrane body 311 and are located on the side of the membrane body 311 along the first direction Z close to the bottom plate 11. There are multiple protrusions 312, which are spaced apart. The membrane body 311 forms a recess 313 between two adjacent protrusions 312. The recess 313 and the adjacent protrusion 312 enclose an exhaust channel 5, which communicates with a pressure relief hole 14. In this embodiment, the protrusions 312 and recesses 313 are integrally formed with the membrane body 311, and the recesses 313 are the positions of the membrane body 311 where the protrusions 312 are not formed.

[0045] After the battery cell is assembled, the top of the protrusion 312 will abut against the bottom plate 11 of the outer casing 1 under the action of gravity. There is a gap between the recess 313 and the bottom plate 11 in the first direction Z. The gap is the exhaust channel 5 in case of thermal runaway of the battery cell. When the battery cell experiences thermal runaway, the gas can be discharged from the insulating film 3 through the exhaust channel 5 to the explosion-proof valve 6 area and discharged through the explosion-proof valve 6, which can quickly reduce the pressure inside the battery cell.

[0046] The battery cell has protrusions 312 and recesses 313 formed on the membrane body 311 of the bottom film 31. The protrusions 312 and recesses 313 form an exhaust channel 5. In the event of thermal runaway of the battery cell, the gas can be quickly discharged to the explosion-proof valve 6 through the exhaust channel 5, reducing the risk of explosion due to excessive internal pressure of the battery cell and improving the safety of the battery cell. In addition, the exhaust channel 5 is formed by the protrusions 312 and recesses 313, which simplifies the structure of the exhaust channel 5 and can reduce manufacturing costs.

[0047] In some embodiments, the membrane body 311 is provided with a first weak portion 33 or a through hole 34, the through hole 34 penetrating the membrane body 311 along the first direction Z.

[0048] like Figure 2 and Figure 4 As shown, the first weak portion 33 results in low strength of the membrane body 311 at the first weak portion 33. When a battery cell experiences thermal runaway, gas can tear through the bottom membrane 31 from the first weak portion 33, allowing the gas to quickly enter the exhaust channel 5 and be discharged. In this embodiment, the through hole 34 penetrates the recess 313 on the membrane body 311 along the first direction Z. The through hole 34 connects the inner and outer sides of the bottom membrane 31. When a battery cell experiences thermal runaway, gas can quickly enter the exhaust channel 5 through the through hole 34.

[0049] In some embodiments, the membrane body 311 is provided with grooves or serrated lines, which form a first weak portion 33.

[0050] like Figure 2 , Figure 3 , Figure 5 and Figure 8 As shown, the indentation does not penetrate the membrane body 311. The indentation and serrated lines reduce the local strength of the membrane body 311, making it easier for the gas to tear the bottom membrane 31 at this point. The first weak part 33 is formed by indentation or serrated lines. The processing methods for indentation and serrated lines are mature, simplifying the manufacturing and shaping of the first weak part 33 and reducing costs.

[0051] In some embodiments, the protrusion 312 is elongated and extends along a second direction Y, which is perpendicular to the first direction Z.

[0052] like Figures 6 to 8 As shown, the protrusion 312 on the bottom membrane 31 is elongated, which increases the contact area with the bottom plate 11 and defines the direction of the exhaust channel 5, allowing gas to be discharged quickly. In this embodiment, one side of the elongated protrusion 312 is recessed from the membrane body 311 toward the side plate 12 to form a groove, so as to better reduce weight and cost; in other embodiments, the elongated protrusion 312 can also be a solid structure to provide better support for the air passage 3124.

[0053] In some embodiments, the protrusion 312 has a first wall 3121 and a second wall 3122. The first wall 3121 is disposed opposite to the base plate 11 along a first direction Z and contacts the base plate 11. The second wall 3122 is connected between the first wall 3121 and the recess 313 and is provided with a second weak portion 3123.

[0054] like Figure 7 and Figure 8 As shown, the first wall 3121 of the protrusion 312 can contact the base plate 11 to provide support. A second weak portion 3123 is provided on the second wall 3122. When the battery cell experiences thermal runaway, gas can tear the protrusion 312 through the second weak portion 3123, further rapidly releasing pressure. In this embodiment, the second weak portion 3123 can also be a notch or a serrated line.

[0055] In some embodiments, the second wall 3122 is further provided with an air passage 3124, which extends along the second direction Y and passes through the protrusion 312 along the third direction X. The second weak portion 3123 is alternately arranged with the air passage 3124 along the second direction Y, and the third direction X, the second direction Y and the first direction Z are perpendicular to each other.

[0056] The second wall 3122 is provided with an air passage 3124 extending along the second direction Y, and the air passage 3124 penetrates the protrusion 312 along the third direction X. The air passage 3124 can quickly discharge gas and reduce the pressure inside the insulating membrane 3. The second weak part 3123 and the air passage 3124 are alternately arranged along the second direction Y. When the air passage 3124 is insufficient to quickly relieve pressure, gas can further tear the bottom membrane 31 through the air passage 3124. In this embodiment, there are multiple air passages 3124, and each air passage 3124 is spaced apart along the second direction Y.

[0057] In some embodiments, the protrusions 312 are hemispherical, and the protrusions 312 are arranged in an array at intervals.

[0058] like Figures 2 to 5 As shown, the protrusions 312 of the base film 31 are hemispherical, and the protrusions 312 are arranged in an array at intervals. In other embodiments, the protrusions 312 of the base film 31 can also be other shapes, such as elliptical, wavy, etc., and the protrusions 312 can also be irregularly distributed.

[0059] In some embodiments, the protrusion 312 includes a support member 4, which includes a plurality of spaced protrusions 41, and the gap between two adjacent protrusions 41 forms an exhaust channel 5.

[0060] like Figures 9 to 14As shown, in this embodiment, the support member 4 and the membrane body 311 are separately disposed. The support member 4 is located on the side of the bottom membrane 31 facing away from the electrode assembly 2 along the first direction Z, that is, the support member 4 is located between the bottom membrane 31 and the bottom plate 11. The support member 4 is used to support the bottom membrane 31 so that the side of the membrane body 311 near the bottom plate 11 forms an exhaust channel 5. In this embodiment, the support member 4 and the bottom membrane 31 are made of different materials.

[0061] After the multiple protrusions 41 of the support member 4 are connected to the bottom membrane 31, the bottom membrane 31 and the bottom plate 11 are separated by the protrusions 41 of the support member 4, so that the gap between the protrusions 41 forms an exhaust channel 5 to quickly discharge the gas of the battery cell and reduce the pressure of the battery cell.

[0062] In this embodiment, the dimension of the boss 41 or the protrusion 312 along the first direction Z is H, which satisfies 0.1mm≤H≤5mm, and the interval between two adjacent protrusions 312 or bosses 41 is D, which satisfies 0.2mm≤D≤40mm, which can ensure the venting and pressure relief effect of the battery cell under thermal runaway state.

[0063] In some embodiments, the support member 4 includes a plurality of support blocks 42 fixedly connected to the membrane body 311. The support blocks 42 are rectangles extending along the second direction Y. Each support block 42 is spaced apart along the third direction X. The support blocks 42 form protrusions 41. The second direction Y, the third direction X and the first direction Z are perpendicular to each other.

[0064] like Figure 9 and Figure 10 As shown, the support member 4 is formed by multiple support blocks 42 extending along the second direction Y. The support blocks 42 have higher strength to ensure the stability of the exhaust channel 5. In this embodiment, the support blocks 42 are made of different materials from the bottom membrane 31, and the support blocks 42 are fixedly connected to the bottom by hot melting or ultrasonic welding.

[0065] In some embodiments, the membrane body 311 has a third weak portion 35, which is disposed between two adjacent support blocks 42.

[0066] The membrane body 311 has a third weak point 35 between two adjacent support blocks 42. The third weak point 35 results in low strength of the bottom membrane 31 at the third weak point 35. When the battery cell experiences thermal runaway, gas can tear the bottom membrane 31 through the third weak point 35, and the gas can quickly enter the exhaust channel 5 and be discharged. In this embodiment, the third weak point 35 can be either a notch or a toothed line.

[0067] In some embodiments, the support member 4 includes a support plate 43 and a protrusion 44. The protrusion 44 is disposed on the side of the support plate 43 facing the membrane body 311 along the first direction Z. The protrusion 44 is an elongated strip extending along the second direction Y. Multiple protrusions 44 are spaced apart along the third direction X. The protrusion 44 forms a boss 41. The second direction Y and the third direction X are perpendicular to the first direction Z.

[0068] like Figure 11 and Figure 12 As shown, the support member 4 is formed by a support plate 43 and a protruding rib 44 on the support plate 43. The protruding rib 44 is located on the side facing the bottom membrane 31, which can directly form an exhaust channel 5 between the bottom membrane 31 and the support plate 43, accelerating the gas discharge to the explosion-proof valve 6. The boss 41 on the support member 4 is formed by the protruding rib 44, which simplifies the formation of the boss 41. The protruding rib 44 is an elongated strip extending along the second direction Y, which has a good supporting effect. The side of the support member 4 facing away from the protruding rib 44 abuts against the bottom plate 11, increasing the contact area with the bottom plate 11 and avoiding direct contact and wear between the protruding rib 44 and the bottom plate 11.

[0069] In some embodiments, the support member 4 further includes a flat plate 46, which is disposed between the support plate 43 and the bottom film 31. The flat plate 46 connects the boss 41 and the bottom film 31, and the flat plate 46 is provided with a fourth weak part 461.

[0070] like Figure 13 and Figure 14 As shown, a flat plate 46 is provided between the support plate 43 and the bottom membrane 31 to connect the boss 41 and the bottom membrane 31. An exhaust channel 5 is formed between the support plate 43 and the flat plate 46. The flat plate 46 increases the support effect of the support member 4 while ensuring the stability of the exhaust channel 5. The flat plate 46 is first connected to the boss 41 and then to the bottom membrane 31. In this embodiment, the flat plate 46 is connected to the boss 41 and the bottom membrane 31 by hot-melt or ultrasonic welding. A fourth weak portion 461 is provided on the flat plate 46. The strength of the support member 4 is reduced at the fourth weak portion 461, allowing gas to tear the support member 4 at the fourth weak portion 461, facilitating rapid gas discharge.

[0071] In some embodiments, the protrusion 312 further has a clearance portion 7, which is disposed opposite to the explosion-proof valve 6 along the first direction Z.

[0072] like Figure 5 , Figure 10 , Figure 11 and Figure 13 As shown, a vent 7 is provided on the protrusion 312 at a position opposite to the explosion-proof valve 6. When depressurization occurs, gas can be quickly released to the explosion-proof valve 6 through the vent 7.

[0073] This utility model also provides a preferred embodiment of a battery pack, including a battery cell. The specific structure of the battery cell is the same as that of the battery cell described in any of the above embodiments, and will not be repeated here.

[0074] In summary, this utility model provides a battery cell and a battery pack, in which protrusions and recesses are formed on the membrane body of the bottom film, such that the protrusions and recesses form an exhaust channel, or a support member is provided on the side of the bottom film away from the electrode assembly, and multiple protrusions are spaced apart on the support member to form an exhaust channel. In the event of thermal runaway of the battery cell, the gas can be quickly discharged to the explosion-proof valve through the exhaust channel, reducing the risk of explosion due to excessive internal pressure of the battery cell and improving the safety of the battery cell. In addition, the exhaust channel is formed by the enclosed protrusions and recesses, which simplifies the structure of the exhaust channel and can reduce manufacturing costs.

[0075] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A battery cell, characterized in that, The battery cell has a first orientation, and the battery cell includes: The outer casing includes a base plate and a side plate connected to the base plate, the base plate and the side plate forming a receiving cavity, and the base plate is also provided with a pressure relief hole; An explosion-proof valve is used to seal the pressure relief hole and is fixedly connected to the base plate. An insulating film is disposed in the receiving cavity. The insulating film includes a bottom film and a side film connected to the bottom film. The bottom film and the bottom plate are disposed opposite to each other along the first direction. The bottom membrane includes a membrane body and protrusions connected to the membrane body. The protrusions are located on the side of the membrane body close to the bottom plate along the first direction. Multiple protrusions are spaced apart. The membrane body forms a recess between two adjacent protrusions. The recess and the adjacent protrusion enclose an exhaust channel. The exhaust channel is connected to the pressure relief hole.

2. The battery cell according to claim 1, characterized in that, The membrane body is provided with a first weak part or a through hole, and the through hole penetrates the membrane body along the first direction.

3. The battery cell according to claim 2, characterized in that, The membrane body is provided with either a groove or a toothed line, and the groove or toothed line forms the first weak part.

4. The battery cell according to any one of claims 1-3, characterized in that, The protrusion is elongated and extends along a second direction, which is perpendicular to the first direction.

5. The battery cell according to claim 4, characterized in that, The protrusion has a first wall and a second wall. The first wall is disposed opposite to the base plate along the first direction and contacts the base plate. The second wall is connected between the first wall and the recess, and the second wall has a second weak part.

6. The battery cell according to claim 5, characterized in that, The second wall is also provided with an air passage that extends along the second direction and penetrates the protrusion along the third direction. The second weak part is alternately arranged with the air passage along the second direction, and the third direction and the second direction are perpendicular to the first direction.

7. The battery cell according to any one of claims 1-3, characterized in that, The protrusions are hemispherical, and the protrusions are arranged in an array at intervals.

8. The battery cell according to any one of claims 1-3, characterized in that, The protrusion includes a support member, which includes a plurality of spaced protrusions, and the gap between two adjacent protrusions forms the exhaust channel.

9. The battery cell according to claim 8, characterized in that, The support member includes a plurality of support blocks fixedly connected to the membrane body. The support blocks are rectangular and extend along the second direction. Each support block is spaced apart along the third direction. The support blocks form the protrusions. The second direction and the third direction are perpendicular to the first direction.

10. The battery cell according to claim 9, characterized in that, The membrane body has a third weak portion, which is located between two adjacent support blocks.

11. The battery cell according to claim 8, characterized in that, The support member includes a support plate and a protruding ridge. The protruding ridge is disposed on the side of the support plate facing the membrane body along the first direction. The protruding ridge is an elongated strip extending along the second direction. Multiple protruding ridges are spaced apart along the third direction. The protruding ridges form the boss. The second direction and the third direction are perpendicular to the first direction.

12. The battery cell according to claim 11, characterized in that, The support member also includes a flat plate, which is disposed between the support plate and the bottom film. The flat plate connects the boss and the bottom film, and the flat plate has a fourth weak part.

13. The battery cell according to any one of claims 1-3, characterized in that, The protrusion also has a clearance portion, which is arranged opposite to the explosion-proof valve along the first direction.

14. A battery pack, characterized in that, Includes the battery cell described in any one of claims 1-13.

Images