Battery cells and battery packs

Abstract

A battery cell according to one embodiment of the present application includes an electrode assembly, a battery case for accommodating the electrode assembly, and a cover assembly disposed on an upper portion of the battery case and including a top cover, wherein the top cover includes an inwardly bent portion bent from an edge of the top cover and extending toward a center of the top cover. The battery cell and battery pack according to the present application have the effect of enhanced impact resistance against external impact (crushing).

Description

Technical Field

[0001] This invention relates to battery cells and battery packs, and more particularly to battery cells and battery packs having enhanced impact resistance to compression in cylindrical battery cells. Background Technology

[0002] Unlike primary batteries, which are non-rechargeable, secondary batteries are rechargeable and dischargeable. They are used not only in portable devices but also in vehicles powered by electric sources, such as electric vehicles (EVs) and hybrid electric vehicles (HEVs).

[0003] Currently widely used rechargeable battery types include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of a single rechargeable battery cell, or individual battery cell, is approximately 2.5V to 4.6V. Therefore, when a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Alternatively, depending on the required charge / discharge capacity of the battery pack, multiple battery cells can be connected in parallel to construct a battery pack. Therefore, the number of battery cells included in a battery pack can be determined differently depending on the required output voltage or charge / discharge capacity.

[0004] When multiple battery cells are connected in series and / or in parallel to form a battery pack, a battery module comprising at least one, preferably multiple, battery cells is typically constructed first, and then the battery pack is constructed using at least one such battery module along with additional components. Here, a battery module is a unit comprising multiple battery cells connected in series or in parallel, while a battery pack comprises multiple battery modules interconnected in series or in parallel to enhance total capacity and output.

[0005] Based on the external shape of the battery box, battery cells can be classified as pouch-type, cylindrical, or prismatic.

[0006] Cylindrical batteries are mainly housed in metal boxes with cylindrical structures, which gives them excellent safety. Their advantage is that cylindrical batteries can achieve high energy density by housing wound electrode assemblies, and they are also easy to construct large-capacity power storage devices by connecting multiple batteries in series or parallel.

[0007] Electrode assemblies housed in cylindrical boxes are rechargeable power generation devices with a stacked structure of positive, spacers, and negative electrodes, and are categorized into wound, stacked, and stack / folded types. In the wound type, spacers are positioned between elongated positive and negative electrodes coated with active material, and the assembly is wound. The stacked type consists of multiple positive and negative electrodes of predetermined dimensions stacked sequentially with spacers between them. The stack / folded type is a hybrid structure of wound and stacked types. Among these, the wound electrode assembly has the advantages of being easy to manufacture and having a high energy density per unit weight.

[0008] The wound electrode assembly is in the form of a wound assembly, wherein a separator is located between the positive electrode and the negative electrode, each coated with an active material; a positive electrode contact protruding upwards from the positive electrode is provided on the positive electrode, and a negative electrode contact protruding downwards from the negative electrode may be provided on the negative electrode.

[0009] The compression test of cylindrical battery cells is an evaluation method that applies a constant force to the battery while it is placed horizontally, and the passing condition is that no fire occurs. However, during the compression process, the can may not withstand the external force and may be crushed, resulting in structural deformation of the wound electrode assembly, which could lead to a short circuit. Summary of the Invention

[0010] Technical issues

[0011] The present invention aims to solve the above-mentioned problems, and its purpose is to provide battery cells and battery packs with enhanced shock resistance to external impacts.

[0012] Solution to the problem

[0013] A battery cell according to one embodiment of the present invention includes: an electrode assembly; a battery case for housing the electrode assembly; and a cover assembly disposed on an upper portion of the battery case and including a top cover; wherein the top cover includes a folded-back portion that bends from an edge of the top cover and extends toward the center of the top cover.

[0014] In addition, the folded-back portion of the top cover is formed along the circumferential direction of the top cover.

[0015] In addition, the folding section is integrated with the top cover.

[0016] In addition, the cover assembly also includes a cover plate disposed on the underside of the top cover.

[0017] Additionally, the end of the cover plate can wrap around the folded-back portion from the outside.

[0018] In addition, the cover assembly also includes a gasket between the cover plate and the battery compartment.

[0019] In addition, the battery box portion surrounding the electrode assembly is formed by a double-wall structure including an outer wall and an inner wall disposed inside the outer wall.

[0020] In addition, the inner wall is formed by multiple interconnected arched columns.

[0021] In addition, the plurality of the arched columns are arranged along the circumferential direction of the electrode assembly.

[0022] Additionally, the arched column includes a concave portion that is recessed towards the outside of the battery cell.

[0023] In addition, the battery cell of this embodiment also includes a filler material filled between the inner wall and the outer wall.

[0024] Alternatively, the filler material can be foam material.

[0025] Alternatively, the filler material can be rubber.

[0026] The battery cell may include multiple elastic spheres surrounding the electrode assembly inside the battery case.

[0027] Multiple of the aforementioned elastic spheres can be stacked vertically.

[0028] The aforementioned elastic sphere can recover through elasticity.

[0029] The electrode assembly can contact the inside of the elastic sphere, and the battery box can contact the outside of the elastic sphere.

[0030] The aforementioned elastic sphere can be made of rubber.

[0031] The aforementioned elastic sphere can be made of foam material.

[0032] The aforementioned battery cell can be a cylindrical battery cell.

[0033] The battery pack of the present invention includes multiple battery cells.

[0034] Effects of the present invention

[0035] The battery cell and battery pack according to the present invention have the effect of enhanced impact resistance against external impact (squeezing). Attached Figure Description

[0036] Figure 1 This is a diagram illustrating a cylindrical battery cell according to one embodiment of the present invention.

[0037] Figure 2 This is a diagram used to explain the structure of a cylindrical battery cell in one embodiment of the present invention.

[0038] Figure 3 This is a diagram illustrating an electrode assembly according to one embodiment of the present invention.

[0039] Figure 4 This is a diagram illustrating the appearance of the electrode assembly before winding in one embodiment of the present invention.

[0040] Figure 5 This is a diagram illustrating the winding configuration of an electrode assembly in one embodiment of the present invention.

[0041] Figure 6 This is a longitudinal cross-sectional view of the cylindrical battery cell in the first embodiment of the present invention.

[0042] Figure 7 It is by Figure 6 The circle in the image indicates a detailed view of the portion.

[0043] Figure 8 It is along Figure 6 A cross-sectional view of line B-B' in the diagram.

[0044] Figure 9 yes Figure 8 A partial detailed view.

[0045] Figure 10 This is a diagram showing an external force being applied to a cylindrical battery cell in a first embodiment of the present invention.

[0046] Figure 11 This is a longitudinal cross-sectional view of the cylindrical battery cell in the second embodiment of the present invention.

[0047] Figure 12 It is along Figure 11 The cross-sectional view taken by line B-B' in the diagram.

[0048] Figure 13 yes Figure 12 A partial detailed view.

[0049] Figure 14 This is a diagram illustrating the application of an external force to a cylindrical battery cell in a second embodiment of the present invention.

[0050] Figure 15 This is a diagram illustrating a battery pack according to one embodiment of the present invention.

[0051] Figure 16 The diagram illustrates an electric vehicle equipped with a battery pack according to one embodiment of the present invention. Detailed Implementation

[0052] The advantages and features of the present invention, as well as the methods for achieving these advantages and features, will become apparent from the following detailed description of embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various other forms; embodiments are provided only to ensure a complete disclosure of the invention and to fully inform those skilled in the art of its scope. The invention is defined only by the scope of the claims. Therefore, in some embodiments, well-known process steps, well-known apparatus structures, and well-known techniques are not described in detail so as not to obscure the invention. Throughout the specification, the same reference numerals refer to the same elements.

[0053] In the accompanying drawings, the thickness of layers and regions may be exaggerated for clarity. Throughout the specification, similar parts are designated using the same reference numerals. When an element such as a layer, film, region, or plate is referred to as being "on" another element, the element may be directly on the other element or there may be intermediate elements present. Conversely, when a portion is referred to as being "directly" on another portion, it should be understood that there are no intermediate portions. Furthermore, when an element is referred to as being "below" another element, the element may be directly disposed below the other element, or there may be one or more intermediate elements therein. Conversely, when a portion is referred to as being "directly" below another portion, it means that there are no intermediate portions.

[0054] A battery cell and a battery pack including the battery cell according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0055] Figure 1 This is a diagram illustrating a cylindrical battery cell according to one embodiment of the present invention. Figure 2 This is a diagram used to explain the structure of a cylindrical battery cell in one embodiment of the present invention. Figure 3 This is a diagram illustrating an electrode assembly according to one embodiment of the present invention. Figure 4 This is a diagram showing the electrode assembly before winding in one embodiment of the present invention. Figure 5 This is a diagram illustrating the winding configuration of an electrode assembly in one embodiment of the present invention. Figure 6 This is a longitudinal cross-sectional view of the cylindrical battery cell in the first embodiment of the present invention. Figure 7 It is by Figure 6 A detailed view of the portion indicated by the circle in the image. Figure 8 It is along Figure 6 A cross-sectional view of line B-B' in the diagram. Figure 9 yes Figure 8 Partial detailed view, and Figure 10 This is a diagram showing an external force being applied to a cylindrical battery cell in a first embodiment of the present invention.

[0056] In the first embodiment of the present invention, reference is made to Figures 1 to 10 Battery cell 100 is described.

[0057] The battery cell 100 may be a cylindrical battery cell 100 in which the electrode assembly 110 is built into a cylindrical can.

[0058] The cylindrical battery cell 100 may include a wound electrode assembly 110 and a battery case 120 for accommodating the electrode assembly 110. An upper insulating member 150 may be provided on the upper side of the electrode assembly 110, and a lower insulating member 160 may be provided on the lower side of the electrode assembly 110.

[0059] The electrode assembly 110 has a wound structure in which a first electrode 111, a second electrode 113 and a spacer 112 arranged therebetween are wound, and a center pin 140 can be inserted into the center of the electrode assembly.

[0060] A cylindrical battery cell 100 can be formed by housing an electrode assembly 110 in a battery case 120, injecting an electrolyte into the battery case 120, and then attaching a cover assembly 130 to the top of the battery case 120. The battery case 120 can be a cylindrical container, and the wound electrode assembly 110 can be housed in the cylindrical battery case 120 to realize a cylindrical secondary battery.

[0061] The battery box 120 may include a rolled edge portion 122 and a crimped portion 123.

[0062] The rolled edge portion 122 is used for stable connection of the cover assembly 130. It can be formed on the upper outer surface of the battery case 120 in the circumferential direction and can be recessed on the outer circumferential surface of the battery case 120 toward the center of the electrode assembly 110. The rolled edge portion 122 can prevent movement of the electrode assembly 110.

[0063] The crimping portion 123 can be disposed above the rolled edge portion 122 and is formed to wrap around the edge portion of the cover assembly 130 in the circumferential direction. The crimping portion 123 can ensure a stable connection of the cover assembly 130.

[0064] The cover assembly 130 may include a top cover 131 forming electrode terminals, a cover plate 132, and a gasket 133 for maintaining airtightness.

[0065] The top cover 131 can form a positive terminal.

[0066] Gasket 133 can be installed on the upper inner surface of crimp portion 123 and the upper inner surface of rolled edge portion 122 to increase the sealing force between cover assembly 130 and battery box 120.

[0067] The second electrode contact 111c can extend upward from the electrode assembly 110. Specifically, the second electrode contact 111c can extend from the second electrode 111 of the electrode assembly 110. The second electrode contact 111c can be a positive electrode contact.

[0068] The second electrode contact 111c is connected to the cover plate 132, so that the top cover 131 can be used as an electrode terminal (positive terminal). An opening 151 is formed in the upper insulating member 150, and the second electrode contact 111c can be connected to the cover plate 132 through the opening 151.

[0069] The center pin 140 typically comprises a metallic material to impart strength and is formed by a cylindrical structure made by bending a plate into a circular shape. In addition to self-heating, the center pin 140 also serves as a channel for fixing and supporting the electrode assembly 110 and for releasing gases generated by internal reactions during charging, discharging, and operation.

[0070] The electrolyte injected into the battery box 120 can be a non-aqueous electrolyte containing lithium salts, and the non-aqueous electrolyte containing lithium salts includes both non-aqueous electrolytes and lithium salts. Non-aqueous electrolytes include, but are not limited to, non-aqueous organic solvents, organic solid electrolytes, and inorganic solid electrolytes.

[0071] The battery cell 100 does not necessarily have to be a cylindrical battery cell 100, and can be a battery cell of another shape, such as a prismatic battery cell.

[0072] Figure 4 This diagram shows the appearance of the electrode assembly 110 before winding. The electrode assembly 110 can be formed in a wound form by winding a first electrode 113, a second electrode 111, and a spacer 112 together in an elongated shape. The spacer 112 can be located between the first electrode 113 and the second electrode 111. In addition, to prevent the first electrode 113 and the second electrode 111 from contacting each other when wound into a wound shape, the spacer 112 can be additionally placed below the second electrode 111.

[0073] The first electrode 113 may include a first electrode current collector 113a and a first active material layer 113b on the first electrode current collector 113a. The first active material layer 113b may be formed by applying electrode active material to one or both sides of the first electrode current collector 113a. In addition, a first electrode tab 113c may be attached to a region of the first electrode current collector 113a where no electrode active material is applied.

[0074] As an example, as shown, the electrode active material may not be applied to the core-side end of the first electrode current collector 113a, and the first electrode tab 113c may be attached to this region. The first electrode 113 may be a negative electrode, and the first electrode tab 113c may be a negative electrode tab.

[0075] The exposed portion 113d without the application of electrode active material can also be located in the region at the outer periphery of the electrode assembly 110 of the first electrode current collector 113a. The exposed portion 113d can be the uncoated portion of the negative electrode.

[0076] The second electrode 111 may include a second electrode current collector 111a and a second active material layer 111b on the second electrode current collector 111a. The second active material layer 111b may be formed by applying electrode active material to one or both sides of the second electrode current collector 111a. Additionally, a second electrode tab 111c may be attached to a region of the second electrode current collector 111a where no electrode active material is applied. As an example, as illustrated, the second electrode tab 111c may be attached to the center of the second electrode current collector 111a, and the second active material layer 111b may be disposed on both sides of the second electrode tab 111c. The second electrode 111 may be a positive electrode, and the second electrode tab 111c may be a positive electrode tab.

[0077] The sealing strip 170 can be disposed on the outer peripheral surface of the electrode assembly 110. In one embodiment of the invention, the sealing strip 170 can be placed on the upper and lower portions of the outer peripheral surface of the electrode assembly 110, such as... Figure 4 As shown. That is, the sealing tape 170 can be arranged on the outer surface of the wound electrode assembly 110 in the circumferential direction, and can be attached to the outer surface of the electrode assembly 110 by the adhesive layer on the lower surface of the sealing tape 170.

[0078] The sealing strip 170 can be attached to the outer peripheral surface of the first electrode 113 (negative electrode) disposed at the outer periphery of the electrode assembly 110. Furthermore, the sealing strip 170 can be placed across the end 113e of the first electrode 113.

[0079] The sealing strip 170 can be disposed on the exposed portion 113d of the first electrode 113 (negative electrode) disposed at the outer periphery of the electrode assembly 110.

[0080] The sealing tape 170 can be placed on the outer surface of the electrode assembly 110 to prevent the wound electrode assembly 110 from loosening.

[0081] In this embodiment, such as Figure 6 and Figure 7As shown, the top cover 131 in the cover assembly 130 includes a folded-back portion 131a at its edge. The top cover 131 may be generally circular.

[0082] The folded-back portion 131a can be bent from the edge of the top cover 131 and can extend towards the center of the top cover 131. The folded-back portion 131a can be formed by bending it into a "ㄷ" shape at the edge of the top cover 131 and can be formed along the circumferential direction at the edge of the top cover 131. The folded-back portion 131a of the top cover 131 can be integrally formed with the top cover 131.

[0083] When the edge of the top cover 131 is formed into a straight shape, there is a problem that when an external force is applied to the battery cell 100 or the top cover 131, the edge of the top cover 131 penetrates the cover plate 132 and / or the gasket 133 and comes into contact with the outer wall of the can, which serves as the battery box 120, thus causing a short circuit.

[0084] However, in this embodiment, since the folded-back portion 131a is arranged at the edge of the top cover 131 in this manner, even when an external force is applied to the battery cell 100 or the top cover 131, the edge of the top cover does not penetrate the cover plate 132 and / or the gasket 133, so that a short circuit will not occur.

[0085] The end of the cover plate 132, which is placed on the lower side of the top cover 131, can wrap around the folded-back portion 131a from the outside. The cover plate 132 can be generally circular.

[0086] The edge of the cover plate 132 can be formed to extend along the folded portion 131a from the outside of the folded portion 131a. That is, the end 132a of the cover plate 132 can be bent at the edge of the cover plate 132, and can extend toward the center of the cover plate 132 while wrapping the folded portion 131a, and can be formed along the circumferential direction at the edge of the cover plate 132.

[0087] The gasket 133 for maintaining airtightness can be placed between the cover plate 132 and the battery box 120 (press-fit portion 123), located on the outside of the cover plate 132.

[0088] In this embodiment, such as Figure 8 As shown, the inner wall 200 can be placed inside the cylindrical can-shaped battery box 120. The inner wall 200 can be arranged along the circumferential direction of the electrode assembly 110 and can surround the electrode assembly 110. The inner wall 200 can be placed inside the battery box 120 portion surrounding the electrode assembly 110. Therefore, the battery box 120 portion surrounding the electrode assembly 110 can be constructed as a double-wall structure including an outer wall 125 and an inner wall 200.

[0089] The inner wall 200 may include a plurality of arched columns 210. In this embodiment, the inner wall 200 may be formed by arranging the plurality of arched columns 210 along the periphery of the electrode assembly 110. Alternatively, the inner wall 200 may be formed by arranging the plurality of arched columns 210 along the inner circumferential surface of the outer wall 125.

[0090] The inner wall 200 can be formed by connecting multiple arched columns 210 to each other.

[0091] Each arched column 210 can extend vertically, and the lower part of each arched column 210 can be placed on the bottom of the battery box 120.

[0092] The arched column may include a concave portion 210a formed concavely on the outer side of the battery cell 100. The concave portion 210a may have an arcuate shape or a semi-circular shape. The two ends of the arched column 210 may be connected to one end of an adjacent arched column 210, and one end of the arched column 210 may be bent and connected to one end of an adjacent arched column 210. For example... Figure 9 As shown, the lowest point 210b located in the middle of the concave portion 210a can be positioned to contact the outer wall 125.

[0093] Therefore, the inner wall 200 can be formed by repeatedly bending a single plate outward in a concave shape along the circumferential direction of the electrode assembly 110, and the multiple arched columns 210 can be integrally formed. The material of the inner wall 200 can be metal, such as stainless steel (SUS).

[0094] In this embodiment, the battery box 120 portion surrounding the electrode assembly 110 is formed as a double-wall structure with an inner wall 200 and an outer wall 125 continuously connected and arranged with arched columns 210, such that when an external force is applied to the battery cell 100, as Figure 10 As shown, the impact resistance, such as the crush resistance, is enhanced, and the electrode assembly 110 is protected from external forces.

[0095] In this embodiment, the space between the inner wall 200 and the outer wall 125 can be filled with a filling material 300.

[0096] The filler material 300 can be, for example, a foam material. The foam material can be polyurethane foam, synthetic resin foam, or expanded foam.

[0097] In addition, the filler material 300 can be an elastic component, such as rubber, or it can be silicone resin or synthetic resin.

[0098] In this way, in this embodiment, the space between the inner wall 200 and the outer wall 125 is filled with a filler material 300 so that when an external force such as compression is applied, the external force or impact received by the wall of the battery box 120 can be mitigated.

[0099] Next, the battery cell 100 according to the second embodiment of the present invention will be described. Figure 11 This is a longitudinal cross-sectional view of the cylindrical battery cell in the second embodiment of the present invention. Figure 12 It is along Figure 11 A cross-sectional view taken from line B-B' in the diagram. Figure 13 yes Figure 12 Partial detailed view, and Figure 14 This is a diagram illustrating the application of an external force to a cylindrical battery cell in a second embodiment of the present invention.

[0100] The difference between the second embodiment and the first embodiment is that a buffer portion is placed instead of the inner wall 200 in the first embodiment.

[0101] In this embodiment, such as Figure 11 As shown, the buffer portion can be placed inside the cylindrical can-shaped battery box 120. The buffer portion may include a plurality of elastic spheres 400. The plurality of elastic spheres 400 may be arranged along the circumferential direction of the electrode assembly 110 and may surround the electrode assembly 110. The buffer portion composed of the plurality of elastic spheres 400 may be placed on the inner side wall of the battery box 120 and surround the electrode assembly 110.

[0102] The elastic sphere 400 can be elastic and elastically recoverable. In this embodiment, a plurality of elastic spheres 400 can be arranged along the circumferential direction of the electrode assembly 110. Additionally, as... Figure 11 As shown, multiple elastic spheres 400 can be arranged to be vertically stacked on the outer periphery of the electrode assembly 110 from bottom to top.

[0103] The elastic sphere 400 can be formed into a generally spherical shape. The material of the elastic sphere 400 can be made of an elastic body. For example, the elastic sphere 400 can be an elastic component, such as rubber, foam material, expanded foam, polyurethane foam, sponge, or soft synthetic resin. The inner portion of the elastic sphere 400 can contact the electrode assembly 110, and the outer portion of the elastic sphere 400 can contact the inner surface of the battery box 120.

[0104] In this embodiment, a plurality of elastic spheres 400 are arranged along the circumferential direction of the electrode assembly 110 inside the battery case 120 and surrounding the electrode assembly 110, such that when an external force is applied to the battery cell 100, as Figure 14As shown, the elastic sphere 400 absorbs and mitigates external forces, thereby enhancing impact resistance, such as compression resistance, and protecting the electrode assembly 110 from external forces. Additionally, external forces in the vertical direction can be mitigated by the elastic sphere 400 laminated on the outer side of the electrode assembly 110.

[0105] As for other configurations and effects, they are the same as in the previous embodiment, so their detailed description is omitted here.

[0106] Meanwhile, multiple cylindrical battery cells 100 can be housed in the housing 2100 to form a battery pack 2000 (see [link]). Figure 15 ).

[0107] The battery pack 2000 may also include various control and protection systems, such as a BMS (Battery Management System), and can be applied to a variety of devices. Specifically, the battery pack can be applied to transportation vehicles, such as electric bicycles, electric vehicles, and hybrid vehicles, or to energy storage systems (ESS), but is not limited to these, and can be applied to various devices that can use rechargeable batteries.

[0108] Figure 16 This is a view illustrating an electric vehicle (V) equipped with a battery pack 2000. In the electric vehicle (V), the wheels are driven by motors powered by the battery pack 2000, thereby enabling the electric vehicle to operate.

[0109] Although the present invention has been described with reference to preferred embodiments, the present invention is not limited to the above embodiments, and those skilled in the art can make various changes and modifications without departing from the spirit of the present invention.

[0110] Industrial applicability

[0111] The present invention can provide battery cells and battery packs with enhanced impact resistance to external impacts (squeezing).

Claims

1. A battery cell, comprising: Electrode assembly; A battery case for housing the electrode assembly; as well as A cover assembly, the cover assembly being disposed on the upper portion of the battery compartment and including a top cover; in, The top cover includes a folded portion that bends from the edge of the top cover and extends toward the center of the top cover.

2. The battery cell according to claim 1, wherein, The folded portion of the top cover is formed along the circumferential direction of the top cover.

3. The battery cell according to claim 1, wherein, The folded-back portion is integrally formed with the top cover.

4. The battery cell according to claim 1, wherein, The cover assembly also includes a cover plate disposed on the underside of the top cover.

5. The battery cell according to claim 4, wherein, The end of the cover plate surrounds the folded portion from the outside.

6. The battery cell according to claim 4, wherein, The cover assembly also includes a gasket between the cover plate and the battery compartment.

7. The battery cell according to claim 1, wherein, The battery compartment surrounding the electrode assembly has a double-wall structure consisting of an outer wall and an inner wall disposed inside the outer wall.

8. The battery cell according to claim 7, wherein, The inner wall is formed by connecting multiple arched columns to each other.

9. The battery cell according to claim 8, wherein, The plurality of the arched columns are arranged along the circumferential direction of the electrode assembly.

10. The battery cell according to claim 9, wherein, The arched column includes a concave portion that is recessed towards the outside of the battery cell.

11. The battery cell according to claim 7, wherein, It also includes a filling material between the inner wall and the outer wall.

12. The battery cell according to claim 11, wherein, The filling material is foam material.

13. The battery cell according to claim 1, further comprising: Multiple elastic spheres surround the electrode assembly from the inside of the battery box.

14. The battery cell according to claim 13, wherein, Multiple elastic spheres are stacked vertically.

15. The battery cell according to claim 13, wherein, The elastic sphere can recover through elasticity.

16. The battery cell according to claim 13, wherein, The electrode assembly contacts the inner side of the elastic sphere, and the battery box contacts the outer side of the elastic sphere.

17. The battery cell according to claim 13, wherein, The elastic sphere is made of rubber.

18. The battery cell according to claim 13, wherein, The elastic sphere is made of foam material.

19. The battery cell according to claim 1, wherein, The battery cell is a cylindrical battery cell.

20. A battery pack comprising a plurality of battery cells according to claim 1.

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