Battery, battery pack and energy storage system

Abstract

The utility model provides a battery, a battery pack and an energy storage system, the battery comprises a shell, a pole core, a mylar film, an insulating porous film and a bottom support sheet, and the pole core, the mylar film, the insulating porous film and the bottom support sheet are accommodated in the shell; the bottom surface of the pole core, the mylar film, the insulating porous film and the bottom support sheet are sequentially stacked, and the insulating porous film positioned on the bottom surface comprises a plurality of through holes. The through holes of the insulating porous membrane can reduce the circulation of dust falling from the pole core between the pole core and the shell, and reduce the possibility of micro short circuit between the bottom surface of the pole core and the shell.

Description

[0001] This application claims the priority of the Chinese patent application filed with the State Intellectual Property Office on November 3, 2023, with application number 202322985676.8 and application name “Batteries, Battery Packs and Energy Storage Systems”, all contents of which are incorporated by reference in this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery, a battery pack and an energy storage system. Background Art

[0003] The new energy industry is developing rapidly, and battery energy storage technology has become a key supporting technology for the new energy industry. However, when the battery is in use, the battery shell is charged, which may cause insulation failure between the shell and the battery cell, resulting in safety risks such as positive electrode carbonization, aluminum shell breakdown short circuit, corrosion, and leakage, which reduces the safety and reliability of the battery. Utility Model Content

[0004] The embodiments of the present application provide a battery, a battery pack, and an energy storage system that can help improve safety and reliability.

[0005] In a first aspect, an embodiment of the present application provides a battery, comprising a shell, a pole core, a Mylar film, an insulating porous membrane and a bottom support sheet, wherein the pole core, the Mylar film, the insulating porous membrane and the bottom support sheet are all accommodated in the shell; the bottom surface of the pole core, the Mylar film, the insulating porous membrane and the bottom support sheet are stacked in sequence, and the insulating porous membrane located on the bottom surface comprises a plurality of through holes.

[0006] The pole core includes the pole piece, which is composed of granular materials and binders. However, the particles on the pole piece are easy to fall off and form dust that enters the electrolyte. In this way, a micro short circuit may form between the pole core and the shell, which may easily lead to safety risks such as shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage.

[0007] In the battery provided by the present application, the through holes of the insulating porous membrane can reduce the circulation of dust shed from the electrode piece between the Mylar membrane and the bottom support sheet, and reduce the possibility of a micro short circuit between the bottom surface of the electrode core and the shell, thereby reducing the possibility of shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage, thereby improving the safety and reliability of the battery.

[0008] According to the first aspect, in a possible implementation, the Mylar film located on the bottom surface includes a plurality of first openings, the bottom support sheet includes a second opening, the aperture of the through hole is smaller than the aperture of the first opening, and the aperture of the through hole is smaller than the aperture of the second opening.

[0009] In this possible implementation, by setting the aperture of the through hole to be smaller than the aperture of the first opening and smaller than the aperture of the second opening, the circulation of dust between the bottom surface of the shell and the shell is further reduced.

[0010] According to the first aspect, in a possible implementation manner, the plurality of first openings and the plurality of second openings are arranged non-overlappingly.

[0011] In this possible implementation, the position of the first opening and the position of the second opening are staggered to avoid the first opening and the second opening being arranged along the same straight line, thereby extending the diffusion path of dust from the bottom surface of the pole core to the shell and reducing the possibility of a micro short circuit between the bottom surface and the shell.

[0012] According to the first aspect, in a possible implementation manner, the aperture range of the through hole is [0.01 μm, 50 μm].

[0013] In this possible implementation, the through hole does not allow dust with a particle size greater than 50 μm to pass through, which greatly reduces the flow of dust between the bottom surface and the shell, and greatly reduces the possibility of a micro short circuit between the pole core and the shell.

[0014] According to the first aspect, in a possible implementation manner, the insulating porous film covers the connection between the side surface and the bottom surface.

[0015] In this possible implementation, since the Mylar film and the insulating porous film are wrapped at the connection, the insulating porous film provides enhanced protection at the connection, reducing the possibility of damage to the Mylar film at the connection, which is beneficial to reducing the possibility of micro short circuits between the pole core and the shell.

[0016] According to the first aspect, in a possible implementation, the pole core also includes a top surface and a pole ear, the top surface is arranged opposite to the bottom surface, the side surface is connected between the bottom surface and the top surface, the pole ear is arranged on the top surface and protrudes from the top surface, the Mylar film covers the side surface and the top surface, the insulating porous film covers the surface of the Mylar film away from the side surface and the top surface, the insulating porous film located on the top surface is provided with an avoidance hole, and the pole ear is passed through the avoidance hole.

[0017] In this possible implementation, the insulating porous membrane covers the side of the Mylar membrane away from the side and top surface, thereby increasing the area of ​​the pole core covered by the insulating porous membrane, reducing the flow of dust between the side and top surface of the pole core and the shell, and further reducing the possibility of micro short circuits between the pole core and the shell.

[0018] According to the first aspect, in a possible implementation, the pole core further includes two adjacent side surfaces, the two side surfaces and the bottom surface together form a bottom corner structure, and the Mylar film wraps the bottom corner structure. The battery further includes a protective tape, the protective tape wraps the bottom corner structure and is located on a side of the Mylar film away from the pole core, and the protective tape portion is located between the bottom support sheet and the insulating porous film.

[0019] According to the first aspect, in a possible implementation, the battery also includes a battery cover, which is covered on the shell, and the pole core also includes a top surface, which is arranged opposite to the bottom surface, and an insulating protective film is provided on the side of the battery cover facing the top surface of the pole core.

[0020] The Mylar film at the bottom corner structure of the pole core is easily damaged due to the large stress it is subjected to during bending, which may cause dust in the pole core to leak from the damaged part of the Mylar film at the bottom corner structure.

[0021] In this possible implementation method, the protective tape is wrapped around the bottom corner structure. In this way, the strength of the Mylar film at the bottom corner structure is enhanced, the possibility of damage to the Mylar film at the bottom corner structure is reduced, the flow of dust between the bottom corner structure of the pole core and the shell is reduced, and the possibility of a micro short circuit between the pole core and the shell is further reduced.

[0022] According to the first aspect, in a possible implementation, the battery also includes a battery cover, which is covered on the shell, and the battery cover, the pole core, the insulating porous membrane, and the bottom support are arranged in sequence, and the battery cover includes a cover, an upper insulating plastic part, a lower insulating plastic part and a pole: the cover includes a first surface and a second surface arranged opposite to each other, the second surface is arranged on the side of the cover facing the bottom surface, the cover is provided with a first pole through hole passing through the first surface and the second surface, the upper insulating plastic part at least partially covers the first surface, and the upper insulating plastic part is provided with a second pole through hole; the lower insulating plastic part is located between the second surface and the pole core, the lower insulating plastic part at least partially covers the second surface, and the lower insulating plastic part is provided with a third pole through hole; the pole is passed through the third pole through hole, the first pole through hole and the second pole through hole, and the pole is electrically connected to the pole core.

[0023] According to the first aspect, in one possible implementation, the first surface includes at least one surface pore; the upper insulating plastic part is partially embedded in the surface pore of the first surface, and / or the second surface includes at least one surface pore, and the lower insulating plastic part is partially embedded in the surface pore of the second surface.

[0024] In this possible implementation, the upper insulating plastic part is partially embedded in the surface pores of the first surface, so that the upper insulating plastic part and the cover plate form an integrated structure. While improving the sealing of the battery cover plate, it can also simplify the structure of the battery cover plate and facilitate the assembly of the battery cover plate with other components.

[0025] Part of the lower insulating plastic part is embedded in the surface pores of the second surface, so that the lower insulating plastic part and the cover plate form an integrated structure, which not only improves the sealing of the battery cover plate, but also simplifies the structure of the battery cover plate and facilitates the assembly of the battery cover plate with other components.

[0026] According to the first aspect, in a possible implementation manner, there is a distance between the surface pore and the outer periphery of the first pole through hole, and there is a distance between the surface pore and the outer periphery of the cover plate.

[0027] In this possible implementation, there is a distance between the surface pores and the periphery of the first pole through hole to reduce the possibility of cracking of the hole wall of the first pole through hole and causing cracking of the cover plate. There is a distance between the surface pores and the outer periphery of the cover plate to reduce the possibility of cracking of the outer periphery of the cover plate and causing cracking of the cover plate.

[0028] According to the first aspect, in a possible implementation manner, the diameter range of the surface pores is [10 nm, 500 nm].

[0029] In this possible implementation, the surface pores are nanoscale pores, which can increase the contact area between the cover plate and the upper insulating plastic part or the cover plate and the lower insulating plastic part, and improve the connection strength between the cover plate and the upper insulating plastic part or the cover plate and the lower insulating plastic part.

[0030] According to the first aspect, in a possible implementation manner, the battery cover further includes a sealing member, and the sealing member is located between an inner wall of the first pole through hole and an outer wall of the pole.

[0031] In this possible implementation, the seal is used to achieve a sealed connection between the pole, the lower insulating plastic part and the cover plate, thereby reducing the entry of water vapor, impurities and the like into the interior of the battery.

[0032] According to the first aspect, in a possible implementation, the aperture of the third pole through hole is larger than the aperture of the second pole through hole, the seal includes a first sealing portion and a second sealing portion which are connected and arranged, the outer diameter of the first sealing portion is smaller than the outer diameter of the second sealing portion, the first sealing portion is at least partially located between the inner wall of the first pole through hole and the outer wall of the pole, and the second sealing portion is located between the inner wall of the third pole through hole and the outer wall of the pole.

[0033] In this possible implementation, the upper insulating plastic part, the lower insulating plastic part and the sealing part form a step structure to avoid the risk of electrolyte crystallization and electronic conduction caused by the gap between the upper insulating plastic part, the lower insulating plastic part and the sealing part.

[0034] According to the first aspect, in a possible implementation, the upper insulating plastic part also includes a main body and an extension portion protruding from the main body toward the cover plate, the second pole through hole passes through the main body, the main body covers at least part of the first surface, and the extension portion is located between the inner wall of the first pole through hole and the outer wall of the pole.

[0035] In this possible implementation, the extension portion extends into the first pole through hole, and the extension portion is located between the inner wall of the first pole through hole and the outer wall of the pole to reduce the possibility of a gap between the upper insulating plastic part and the cover plate, thereby improving the sealing of the battery cover plate.

[0036] According to the first aspect, in a possible implementation, the first sealing portion is partially located between the inner wall of the first pole through hole and the outer wall of the pole, the first sealing portion is penetrated through the second pole through hole, and the extension portion is located between the inner wall of the second pole through hole and the outer wall of the first sealing portion, or the end face of the extension portion away from the body is in contact with an end of the first sealing portion away from the second sealing portion.

[0037] In this possible implementation, the extension portion is located between the inner wall of the second pole through hole and the outer wall of the first sealing portion, or the end face of the extension portion away from the main body is in contact with an end of the first sealing portion away from the second sealing portion, thereby reducing the possibility of a gap between the upper insulating plastic part, the sealing part, and the cover plate, and further improving the sealing of the battery cover plate.

[0038] According to the first aspect, in a possible implementation, the sealing member further includes a first recessed portion recessed on a side of the second sealing portion facing the cover plate, and a portion of the cover plate is fixed in the first recessed portion.

[0039] In this possible implementation, the cover plate is partially fixed in the first recessed portion, thereby increasing the connection area between the cover plate and the second sealing portion, reducing the possibility of a gap between the cover plate and the second sealing portion, and improving the sealing and connection strength between the cover plate and the second sealing portion.

[0040] According to the first aspect, in a possible implementation, the seal also includes a second recessed portion, which is recessed on the circumferential wall of the second sealing portion facing the inner wall of the third pole through hole, and the inner wall of the third pole through hole forms a flange toward the pole, and the flange is fixed in the second recessed portion.

[0041] In this possible implementation, since the flange is fixedly received in the second recessed portion, the connection area between the lower insulating plastic part and the second sealing portion is increased, the possibility of a gap between the lower insulating plastic part and the second sealing portion is reduced, and the sealing and connection strength between the lower insulating plastic part and the second sealing portion are improved.

[0042] According to the first aspect, in a possible implementation, a third recess is formed on an end surface of the first sealing portion away from the second sealing portion, and an embedding portion is formed on a surface of the upper insulating plastic part facing the cover, and the embedding portion is fixedly received in the third recess.

[0043] In this possible implementation, an embedded portion is convexly provided on one side of the upper insulating plastic part facing the cover plate, and the embedded portion is at least partially fixedly accommodated in the third recessed portion. In this way, the connection area between the upper insulating plastic part and the first sealing part is increased, the possibility of a gap between the upper insulating plastic part and the first sealing part is reduced, and the sealing and connection strength between the upper insulating plastic part and the first sealing part are improved.

[0044] According to the first aspect, in a possible implementation manner, an insulating coating is provided on the inner wall of the shell facing the pole core.

[0045] In this possible implementation, an insulating coating is provided on the inner wall of the shell, and the insulating coating is used to form insulating protection on the inner wall of the shell to reduce the possibility of a micro short circuit between the shell and the pole core when dust in the pole core falls into the shell, thereby reducing the possibility of shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage, thereby improving the safety and reliability of the battery.

[0046] According to the first aspect, in a possible implementation manner, the inner wall includes a bottom wall, and the bottom supporting sheet is located between the insulating porous membrane and the bottom wall.

[0047] In this possible implementation, when the battery is placed upright, one end of the bottom wall is connected to the support surface for supporting the battery. Dust tends to fall toward the bottom wall due to gravity, and since the insulating coating is coated on the bottom wall, the dust is insulated and isolated from the bottom wall by the insulating coating, reducing the possibility of a micro short circuit between the bottom wall and the pole core through the dust.

[0048] According to the first aspect, in a possible implementation, the inner wall includes a bottom wall and four side walls connected to the bottom wall, the bottom support sheet is located between the insulating porous membrane and the bottom wall, and the insulating coating is coated on two opposite side walls.

[0049] In this possible implementation, when the battery is placed on its side, the side of the shell where the side wall coated with the insulating coating is located is used to connect with the support surface supporting the battery. Dust tends to fall toward the side wall coated with the insulating coating due to gravity, and because the side wall is coated with the insulating coating, the dust is insulated and isolated from the side wall by the insulating coating, reducing the possibility of a micro short circuit between the side wall and the pole core through the dust.

[0050] In a second aspect, the present application further provides a battery, comprising a shell and a pole core accommodated in the shell, wherein an insulating coating is coated on the inner wall of the shell facing the pole core.

[0051] The pole core includes the pole piece, which is composed of granular materials and binders. However, the particles on the pole piece are easy to fall off and form dust that enters the electrolyte. In this way, a micro short circuit may form between the pole core and the shell, which may easily lead to safety risks such as shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage.

[0052] In the battery provided in the second aspect, an insulating coating is provided on the inner wall of the shell, and the insulating coating is used to form insulating protection on the inner wall of the shell to reduce the possibility of a micro short circuit between the shell and the pole core when dust shed from the pole core falls onto the shell, thereby reducing the possibility of shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage, thereby improving the safety and reliability of the battery.

[0053] According to the second aspect, in a possible implementation manner, the inner wall includes a bottom wall, and the bottom supporting sheet is located between the insulating porous membrane and the bottom wall.

[0054] In this possible implementation, when the battery is placed upright, the bottom wall is in contact with the support surface for supporting the battery. Dust tends to fall toward the bottom wall due to gravity, and since the insulating coating is coated on the bottom wall, the dust is insulated and isolated from the bottom wall by the insulating coating, reducing the possibility of a micro short circuit between the bottom wall and the pole core through the dust.

[0055] According to the second aspect, in a possible implementation, the inner wall includes a bottom wall and four side walls connected to the bottom wall, the bottom support sheet is located between the insulating porous membrane and the bottom wall, and the insulating coating is coated on two opposite side walls.

[0056] In this possible implementation, when the battery is placed on its side, the side wall coated with the insulating coating is used to contact the supporting surface of the battery. Dust tends to fall toward the side wall coated with the insulating coating due to gravity, and since the side wall is coated with the insulating coating, the dust is insulated and isolated from the side wall by the insulating coating, reducing the possibility of a micro short circuit between the side wall and the pole core through the dust.

[0057] According to the second aspect, the battery also includes a Mylar film, an insulating porous membrane and a bottom support sheet, which are all accommodated in a shell; the bottom surface of the pole core, the Mylar film, the insulating porous membrane and the bottom support sheet are stacked in sequence, and the insulating porous membrane located on the bottom surface includes multiple through holes.

[0058] Both the positive and negative electrodes are made of granular materials and binders. However, the particles on the positive and negative electrodes are easy to fall off and form dust that enters the electrolyte. In this way, a micro short circuit may form between the electrode core and the shell, which may easily lead to safety risks such as shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage.

[0059] The battery provided in the second aspect of the present application has through holes in the insulating porous membrane that can reduce the circulation of dust between the Mylar membrane and the bottom support sheet, and reduce the possibility of micro short circuits between the bottom surface of the pole core and the shell, thereby reducing the possibility of shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage, thereby improving the safety and reliability of the battery.

[0060] In a third aspect, an embodiment of the present application provides a battery, the battery comprising a shell, a pole core and a battery cover, the pole core is accommodated in the shell, and the battery cover is covered on the shell. The battery cover comprises a cover, an upper insulating plastic part, a lower insulating plastic part and a pole: the cover comprises a first surface and a second surface arranged opposite to each other, the second surface is arranged on the side of the cover facing the bottom surface, the cover is provided with a first pole through hole penetrating the first surface and the second surface, the upper insulating plastic part covers the first surface, and the upper insulating plastic part is provided with a second pole through hole; the lower insulating plastic part is located between the second surface and the pole core, the lower insulating plastic part covers the second surface, and the lower insulating plastic part is provided with a third pole through hole; the pole is penetrated through the third pole through hole, the first pole through hole and the first pole through hole, and at least one surface pore is formed on the first surface; the upper insulating plastic part is partially embedded in the surface pore of the first surface, and / or, the second surface forms at least one surface pore, and part of the lower insulating plastic part is embedded in the surface pore of the second surface.

[0061] In the battery provided by the third aspect, the upper insulating plastic part is partially embedded in the surface pores of the first surface, so that the upper insulating plastic part and the cover plate form an integrated structure. While improving the sealing of the battery cover plate, it can also simplify the structure of the battery cover plate and facilitate the assembly of the battery cover plate with other components.

[0062] Part of the lower insulating plastic part is embedded in the surface pores of the second surface, so that the lower insulating plastic part and the cover plate form an integrated structure, which not only improves the sealing of the battery cover plate, but also simplifies the structure of the battery cover plate and facilitates the assembly of the battery cover plate with other components.

[0063] According to the third aspect, in a possible implementation manner, there is a distance between the surface pore and the periphery of the first pole through hole, and there is a distance between the surface pore and the outer periphery of the cover plate.

[0064] In this possible implementation, there is a distance between the surface pores and the periphery of the first pole through hole to reduce the possibility of cracking of the hole wall of the first pole through hole and causing cracking of the cover plate. There is a distance between the surface pores and the outer periphery of the cover plate to reduce the possibility of cracking of the outer periphery of the cover plate and causing cracking of the cover plate.

[0065] According to the third aspect, in a possible implementation manner, the surface pores are nanoscale pores, and the diameter of the nanoscale pores ranges from [10 nm to 500 nm].

[0066] In this possible implementation, the surface pores are nanoscale pores, which can increase the contact area between the cover plate and the upper insulating plastic part or the cover plate and the lower insulating plastic part, and improve the connection strength between the cover plate and the upper insulating plastic part or the cover plate and the lower insulating plastic part.

[0067] In a fourth aspect, an embodiment of the present application provides a battery, the battery comprising a shell, a pole core and a battery cover, the pole core is accommodated in the shell, and the battery cover is covered on the shell. The battery cover comprises a cover, an upper insulating plastic part, a lower insulating plastic part, a pole and a seal: the cover comprises a first surface and a second surface arranged opposite to each other, the second surface is arranged on the side of the cover facing the bottom surface, the cover is provided with a first pole through hole penetrating the first surface and the second surface, the upper insulating plastic part covers the first surface, and the upper insulating plastic part is provided with a second pole through hole; the lower insulating plastic part is located between the second surface and the pole core, the lower insulating plastic part covers the second surface, and the lower insulating plastic part is provided with a third pole through hole; the pole is passed through the third pole through hole, the first pole through hole and the first pole through hole, the seal is located between the inner wall of the first pole through hole and the outer wall of the pole, and the seal, the upper insulating plastic part, the cover and the lower insulating plastic part are an integrated structure.

[0068] The seal, the upper insulating plastic part, the cover plate and the lower insulating plastic part are an integrated structure, which improves the sealing connection between the seal, the pole, the lower insulating plastic part and the cover plate, and reduces the entry of water vapor, impurities, etc. into the interior of the battery.

[0069] According to the fourth aspect, in a possible implementation, the aperture of the third pole through hole is larger than the aperture of the second pole through hole, the seal includes a first sealing portion and a second sealing portion connected to each other, the outer diameter of the first sealing portion is smaller than the outer diameter of the second sealing portion, the first sealing portion is located between the inner wall of the first pole through hole and the outer wall of the pole, and the second sealing portion is located between the inner wall of the third pole through hole and the outer wall of the pole.

[0070] In this possible implementation, the upper insulating plastic part, the lower insulating plastic part and the sealing part form a step structure, which reduces the risk of electrolyte crystallization caused by the gap between the upper insulating plastic part, the lower insulating plastic part and the sealing part, thereby causing electron conduction.

[0071] According to the fourth aspect, in a possible implementation, the upper insulating plastic part also includes a main body and an extension portion protruding from the main body toward the cover plate, the second pole through hole passes through the main body, the main body covers at least part of the first surface, and the extension portion is located between the inner wall of the first pole through hole and the outer wall of the pole.

[0072] In this possible implementation, the extension portion extends into the first pole through hole, and the extension portion is located between the inner wall of the first pole through hole and the outer wall of the pole to reduce the possibility of a gap between the upper insulating plastic part and the cover plate, thereby improving the sealing of the battery cover plate.

[0073] According to the fourth aspect, in a possible implementation, part of the first sealing portion is located between the inner wall of the first pole through hole and the outer wall of the pole, the rest of the first sealing portion is passed through the second pole through hole, and the extension portion is located between the inner wall of the second pole through hole and the outer wall of the first sealing portion, or, one end of the extension portion close to the lower insulating plastic part is in contact with an end of the first sealing portion away from the second sealing portion.

[0074] In this possible implementation, the extension portion is located between the inner wall of the second pole through hole and the outer wall of the first sealing portion, or the end of the extension portion close to the lower insulating plastic part is in contact with the end of the first sealing part away from the second sealing part, thereby reducing the possibility of a gap between the upper insulating plastic part, the sealing part, and the cover plate, and further improving the sealing of the battery cover plate.

[0075] According to the fourth aspect, in a possible implementation, the sealing member further includes a first recessed portion recessed on a side of the second sealing portion facing the cover plate, and a portion of the cover plate is fixedly embedded in the first recessed portion.

[0076] In this possible implementation, the cover plate is partially fixed in the first recessed portion, thereby increasing the connection area between the cover plate and the second sealing portion, reducing the possibility of a gap between the cover plate and the second sealing portion, and improving the sealing and connection strength between the cover plate and the second sealing portion.

[0077] According to the fourth aspect, in a possible implementation, the seal also includes a second recessed portion, which is recessed on the peripheral wall of the second sealing portion facing the inner wall of the third pole through hole, and the inner wall of the third pole through hole forms a flange toward the pole, and the flange is fixed in the second recessed portion.

[0078] In this possible implementation, since the flange is fixedly received in the second recessed portion, the connection area between the lower insulating plastic part and the second sealing portion is increased, the possibility of a gap between the lower insulating plastic part and the second sealing portion is reduced, and the sealing and connection strength between the lower insulating plastic part and the second sealing portion are improved.

[0079] According to the fourth aspect, in a possible implementation, a third recessed portion is recessed on an end surface of the first sealing portion away from the second sealing portion, and an embedded portion is convexly disposed on a surface of the upper insulating plastic part facing the cover plate, and the embedded portion is fixedly received in the third recessed portion.

[0080] In this possible implementation, an embedded portion is convexly provided on one side of the upper insulating plastic part facing the cover plate, and the embedded portion is at least partially fixedly accommodated in the third recessed portion. In this way, the connection area between the upper insulating plastic part and the first sealing part is increased, the possibility of a gap between the upper insulating plastic part and the first sealing part is reduced, and the sealing and connection strength between the upper insulating plastic part and the first sealing part are improved.

[0081] In a fifth aspect, an embodiment of the present application provides a battery, the battery comprising a shell, a pole core and a battery cover, the pole core is accommodated in the shell, the battery cover is arranged on the shell, and an insulating protective film is provided on the side of the battery cover facing the pole core.

[0082] In a sixth aspect, an embodiment of the present application provides a battery pack, the battery pack comprising a plurality of batteries as described in any one of the first to fifth aspects, the plurality of batteries being connected in series or in parallel.

[0083] In the seventh aspect, an embodiment of the present application also provides an energy storage system, which includes the battery pack and a power converter described in the sixth aspect, the power converter is used to convert the AC power output by an external AC power source into DC power and output it to the battery pack, and / or the power converter is used to convert the DC power output by the battery pack into AC power and output it to a load or a grid.

[0084] In the eighth aspect, the embodiment of the present application provides a battery, the battery includes a shell, a pole core, a Mylar film and a bottom support sheet, the pole core, the Mylar film and the bottom support sheet are all accommodated in the shell, the bottom surface of the pole core, the Mylar film and the bottom support sheet are stacked in sequence, and the insulating porous film includes a plurality of through holes, and the aperture range of the through holes is [1nm-100nm]. In the battery provided by the present application, the through holes of the Mylar film can reduce the circulation of dust falling from the pole piece between the bottom support sheet and the shell, reduce the possibility of a micro short circuit between the bottom surface of the pole core and the shell, thereby reducing the possibility of shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage, and improving the safety and reliability of the battery.

[0085] According to the eighth aspect, in a possible implementation, the bottom support sheet includes a plurality of openings, and the plurality of openings and the plurality of through holes are arranged in a non-overlapping manner. The positions of the plurality of openings and the positions of the plurality of through holes are staggered with each other, so as to avoid the openings of the bottom support sheet and the through holes of the Mylar film being arranged along the same straight line, and to extend the diffusion path of the dust from the bottom surface of the pole core to the shell, so as to reduce the possibility of a micro short circuit between the bottom surface of the pole core and the shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 A schematic diagram of the framework structure of a photovoltaic system is shown;

[0087] Figure 2 A schematic diagram of the structure of a battery pack provided in some embodiments of the present application;

[0088] Figure 3 A three-dimensional exploded schematic diagram of a battery provided in one embodiment of the present application;

[0089] Figure 4 A three-dimensional schematic diagram of a battery provided in an embodiment of the present application with part of the housing removed;

[0090] Figure 5 A three-dimensional schematic diagram of a housing provided in one embodiment of the present application;

[0091] Figure 6 For along Figure 5 The cross-sectional view obtained by the line I1 shown;

[0092] Figure 7 This is a schematic diagram of the battery being used in a vertical placement scenario;

[0093] Figure 8 A schematic diagram of a battery application with a scene on the first side;

[0094] Fig. 9 A schematic diagram of a battery application in a second side placement scenario;

[0095] Fig.10 A three-dimensional schematic diagram of a pole core provided in one embodiment of the present application;

[0096] Fig.11 A side view of a battery with the housing removed provided in one embodiment of the present application;

[0097] Fig.12 A schematic plan view of a Mylar membrane provided in one embodiment of the present application;

[0098] Fig.13 It is a three-dimensional exploded schematic diagram of the Mylar film, the insulating porous film, and the bottom support sheet;

[0099] Fig.14 A schematic plan view of a bottom support sheet, a Mylar film and an insulating porous film stacked together provided in one embodiment of the present application;

[0100] Fig.15 A schematic diagram of a three-dimensional assembly of a battery with the battery housing and battery cover removed;

[0101] Fig.16 A schematic plan view of a bottom support sheet, a Mylar film and an insulating porous film stacked together provided in one embodiment of the present application;

[0102] Fig.17 A three-dimensional schematic diagram of a partial structure of a battery provided in one embodiment of the present application;

[0103] Fig.18 A three-dimensional schematic diagram of a battery cover provided in an embodiment of the present application;

[0104] Fig.19 An embodiment of the present application provides Fig.18 A partial cross-sectional view taken along line I 2-I2;

[0105] Fig. 20 For an embodiment of the present application Fig.18A partial cross-sectional view obtained along line I 2-I 2;

[0106] Fig.21 for Fig. 20 A three-dimensional schematic diagram of a sealing member of a battery cover shown;

[0107] Fig. 22 For along Fig. 20 A radial cross-sectional view of the seal shown;

[0108] Fig.23 For an embodiment of the present application Fig.18 A partial cross-sectional view obtained along line I 2-I 2;

[0109] Fig.24 For an embodiment of the present application Fig.18 A partial cross-sectional view obtained along line I 2-I 2;

[0110] Fig.25 for Fig.24 A three-dimensional schematic diagram of a sealing member of a battery cover shown;

[0111] Fig.26 A partial cross-sectional view of a cover plate, a lower insulating plastic part, and a sealing part assembled together according to an embodiment of the present application;

[0112] Fig. 27 A partial cross-sectional view of a cover plate, a lower insulating plastic part, and a sealing part assembled together according to an embodiment of the present application;

[0113] Fig.28 A partial cross-sectional view of a cover plate, a lower insulating plastic part, and a sealing part assembled together according to an embodiment of the present application;

[0114] Fig.29 A partial cross-sectional view of a cover plate, an upper insulating plastic part, and a sealing part assembled together according to an embodiment of the present application;

[0115] Fig.30 A partial cross-sectional view of a cover plate, an upper insulating plastic part, and a sealing part assembled together according to an embodiment of the present application;

[0116] Fig.31 A partial cross-sectional view of a cover plate, an upper insulating plastic part, and a sealing part assembled together according to an embodiment of the present application;

[0117] Fig.32 A schematic diagram of a battery cover provided with an insulating protective film according to an embodiment of the present application. DETAILED DESCRIPTION

[0118] Figure 1 A schematic diagram of the framework structure of a photovoltaic system is shown. Figure 1As shown, the photovoltaic system includes a photovoltaic array 110, a power grid 130, an external load 140 and an energy storage system 150. Among them, the energy storage system 150 includes a battery pack 100 and a power converter 200. The power converter 200 is used to convert the AC power output by the external AC power source into DC power and output it to the battery pack 100, and / or, the power converter 200 is used to convert the DC power output by the battery pack 100 into AC power and output it to the external load 140 or the power grid 130. The power converter 200 can integrate a DC / DC conversion circuit and a DC / AC conversion circuit, and the battery pack 100 can be located between the DC / DC conversion circuit and the DC / AC conversion circuit. The electric energy generated by the photovoltaic array 110 can be converted into a DC power after being stepped up or stepped down by the DC / DC conversion circuit to charge the battery pack 100. When the electric energy generated by the photovoltaic array 110 is insufficient to supply power to the grid 130 / external load 140, the electric energy stored in the battery pack 100 can be transmitted to the grid 130 / external load 140 through the DC / AC conversion circuit in the power converter 200. On the other hand, the energy storage system 150 can also receive power from the grid 130. The AC power output by the grid 130 is converted into DC power after passing through the DC / AC conversion circuit and transmitted to the battery pack 100, so as to charge the battery pack 100. Alternatively, the power converter 200 only includes a DC / AC conversion circuit, the battery pack 100 has a built-in DC / DC conversion circuit, and the battery pack 100 directly receives the DC power generated by the photovoltaic array 110. It can be understood that the energy storage system 150 can also be used in application scenarios such as wind power systems, and the present application does not limit the application scenarios of the energy storage system 150.

[0119] See also Figure 2 , Figure 2 A schematic diagram of the structure of a battery pack provided for some embodiments of the present application.

[0120] The battery pack 100 includes a plurality of batteries 20. The plurality of batteries 20 are connected in series or in parallel. The battery 20 may be a secondary battery, for example, a lithium ion secondary battery, a sodium ion secondary battery, a potassium ion secondary battery, a magnesium ion secondary battery, a zinc ion secondary battery, an aluminum ion secondary battery, or the like.

[0121] The embodiment of the present application provides a battery, the battery includes a shell, a pole core, a Mylar film and a bottom support sheet, the pole core, the Mylar film and the bottom support sheet are all accommodated in the shell, the bottom surface of the pole core, the Mylar film and the bottom support sheet are stacked in sequence, and the insulating porous film includes a plurality of through holes, and the aperture range of the through holes is [1nm-100nm]. In the battery provided by the present application, the through holes of the Mylar film can reduce the circulation of dust falling from the pole piece between the bottom support sheet and the shell, reduce the possibility of a micro short circuit between the bottom surface of the pole core and the shell, thereby reducing the possibility of shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage, and improving the safety and reliability of the battery.

[0122] According to the eighth aspect, in a possible implementation, the bottom support sheet includes a plurality of openings, and the plurality of openings and the plurality of through holes are arranged in a non-overlapping manner. The positions of the plurality of openings and the positions of the plurality of through holes are staggered with each other, so as to avoid the openings of the bottom support sheet and the through holes of the Mylar film being arranged along the same straight line, and to extend the diffusion path of the dust from the bottom surface of the pole core to the shell, so as to reduce the possibility of a micro short circuit between the bottom surface of the pole core and the shell.

[0123] In another embodiment, the battery further comprises an insulating porous membrane. Figure 3 and Figure 4 , Figure 3 This is a three-dimensional exploded schematic diagram of a battery provided in an embodiment of the present application. Figure 4 A three-dimensional schematic diagram of a battery provided in an embodiment of the present application with part of the shell removed, wherein the battery 20 includes a shell 21, a pole core 23, a Mylar film 24, a bottom support sheet 25, and a battery cover 28. The shell 21 is used to contain an electrolyte (not shown). The pole core 23, the Mylar film 24, and the bottom support sheet 25 are all contained in the shell 21. The shell 21 is an aluminum shell. It can be understood that the shell 21 can be a shell made of other conductive materials. The battery cover 28 is covered on the shell 21 to form a closed cavity with the shell 21.

[0124] The pole core 23 includes a positive electrode sheet and a negative electrode sheet. The positive electrode sheet and the negative electrode sheet can embed and release metal ions (such as lithium ions) to achieve energy storage and release. The positive electrode sheet and the negative electrode sheet are the main energy storage parts of the battery 20, which can reflect the energy density, cycle performance and safety performance of the battery 20. The electrolyte can be a transmission carrier for metal ions. The Mylar film 24 can wrap the pole core 23, that is, the Mylar film 24 covers the pole core 23, which is used to insulate and isolate the pole core 23 from the shell 21. The pole core 23, the Mylar film 24 and the bottom support sheet 25 are stacked in sequence along the first direction. The bottom support sheet 25 is used to support and bear the pole core 23, and the bottom support sheet 25 is used to insulate and separate the pole core 23 from the shell 21. The pole core 23 is a pole core that can be formed by lamination or winding. The first direction can be Figure 3 The Z direction shown in .

[0125] In some embodiments of this application, please refer to Figure 5 , Figure 5A three-dimensional schematic diagram of a shell provided in an embodiment of the present application, wherein the shell 21 is roughly a cubic structure. The shell 21 includes a bottom wall 216 and a plurality of side walls 217 connected to the bottom wall 216. The bottom wall 216 and the bottom support sheet 25 are arranged relative to each other along a first direction, and the plurality of side walls 217 include a first side wall 2171, a second side wall 2172, a third side wall 2173 and a fourth side wall 2174. The area of ​​the first side wall 2171 may be greater than the area of ​​the third side wall 2173. The first side wall 2171 and the second side wall 2172 are arranged relative to each other along a second direction, and the third side wall 2173 and the fourth side wall 2174 are arranged relative to each other along a third direction. The first direction is perpendicular to the second direction, the second direction is perpendicular to the third direction, and the first direction is perpendicular to the third direction. The area of ​​the first side wall 2171 may be equal to the area of ​​the second side wall 2172. The area of ​​the third side wall 2173 may be equal to the area of ​​the fourth side wall 2174. It is understood that the areas of the four side walls 217 may be equal or unequal. It is understood that the present application does not limit the shell 21 to a cubic structure, and the shell 21 may be a regular or irregular shape such as a disc or a sphere. When the shell 21 is circular, the number of the side wall 217 may be one.

[0126] Both the positive and negative electrodes are made of granular materials and binders. However, the particles on the positive and negative electrodes are easy to fall off and form dust that enters the electrolyte. In this way, a micro short circuit may form between the electrode core and the shell, which may easily lead to safety risks such as shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage.

[0127] Based on this, see Figure 5 The battery 20 provided in the present application may also include an insulating coating 218 coated on the inner wall of the shell 21. The insulating coating 218 is used to form insulating protection on the inner wall of the shell 21 to reduce the possibility of a micro short circuit between the shell 21 and the pole core 23 when dust in the pole core 23 falls into the shell 21, thereby reducing the possibility of shell corrosion, positive electrode carbonization, aluminum shell breakdown short circuit, and leakage, thereby improving the safety and reliability of the battery 20. Figure 5 2 shows an exemplary insulating coating 218 coated on the surface of the second side wall 2172 facing the inner cavity of the housing 21. Figure 5The shaded portion in the figure is the insulating coating 218. If the thickness of the insulating coating 218 is too thin, its insulating performance may be poor. If the thickness of the insulating coating 218 is too thick, it will affect the energy density of the battery. Therefore, the thickness range of the insulating coating 218 is [30μm, 200μm], that is, the thickness of the insulating coating 218 is not less than 30μm and not more than 200μm. For example, the thickness of the insulating coating 218 can be 30μm, 35μm, 40μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, 150μm, 200μm, so as to have better insulating performance.

[0128] In some embodiments of the present application, Figure 6 As shown, Figure 6 For along Figure 5 As shown in the cross-sectional view taken along line I1 , the insulating coating 218 is coated on the side of the bottom wall 216 facing the inner cavity of the housing 21 .

[0129] See also Figure 7 , Figure 7 This is a schematic diagram of a battery used in a vertical placement scenario. When the battery 20 is used in a vertical placement scenario, one end of the shell 21 where the bottom wall 216 is located is in contact with or in contact with a support surface 300 for supporting the battery 20. The support surface 300 may be the ground, etc. In a vertical placement scenario, dust easily falls toward the bottom wall 216 due to gravity, and since the insulating coating 218 is coated on the bottom wall 216, the dust is insulated and isolated from the surface of the bottom wall 216 facing the inner cavity of the shell 21 by the insulating coating 218, reducing the possibility of a micro short circuit between the bottom wall 216 and the pole core 23 through the dust.

[0130] In some embodiments of the present application, the insulating coating 218 can be coated on the surface of the first side wall 2171 and the second side wall 2172 facing the inner cavity of the shell 21. When the battery 20 is used in the first side placement scenario, such as Figure 8 As shown, Figure 8The figure is a schematic diagram of a battery application in a first side placement scenario, in which the first side wall 2171 is in contact with the support surface 300 for supporting the battery 20. It can be understood that one of the first side wall 2171 and the second side wall 2172 is in contact with the support surface 300 for supporting the battery 20. In the first side placement scenario, the dust of the battery 20 is easy to fall toward the first side wall 2171 or the second side wall 2172 due to gravity, and since the insulating coating 218 is coated on the surface of the first side wall 2171 and the second side wall 2172 facing the inner cavity of the shell 21, the dust is insulated and isolated from the first side wall 2171 and the second side wall 2172 through the insulating coating 218, reducing the possibility of a micro short circuit between the first side wall 2171, the second side wall 2172 and the pole core 23 through the dust. Since the first side wall 2171 and the second side wall 2172 are coated with an insulating coating 218 on the inner wall facing the shell 21, when the battery 20 is placed on its side, either the first side wall 2171 or the second side wall 2172 can contact the supporting surface of the battery 20, facilitating the use of the battery 20.

[0131] In some embodiments of the present application, the insulating coating 218 is coated on the surface of the third side wall 2173 and the fourth side wall 2174 facing the inner cavity of the shell 21, and the battery 20 is used in the second side placement scenario, such as Fig. 9 As shown, Fig. 9 The schematic diagram of the battery application in the second side placement scenario is shown in which the fourth side wall 2174 is in contact with the support surface 300 for supporting the battery 20. It can be understood that one of the third side wall 2173 and the fourth side wall 2174 is in contact with the support surface 300 for supporting the battery 20. In the second side placement scenario, the dust of the battery 20 is likely to fall toward the third side wall 2173 or the fourth side wall 2174 due to gravity, and since the insulating coating 218 is coated on the third side wall 2173 and the fourth side wall 2174, the dust is insulated and isolated from the third side wall 2173 or the fourth side wall 2174 through the insulating coating 218, reducing the possibility of a micro short circuit between the third side wall 2173, the fourth side wall 2174 and the pole core 23 through the dust. Since the third side wall 2173 and the fourth side wall 2174 are coated with the insulating coating 218, when the battery 20 is placed on its side, the side where either the third side wall 2173 or the fourth side wall 2174 is located can contact the supporting surface of the battery 20, which facilitates the use of the battery 20. It is understood that the present application does not limit the thickness of the insulating coating 218. It is understood that the position of the insulating coating 218 on the inner wall of the housing 21 is not limited. For example, the insulating coating 218 can be coated on the entire area or a partial area of ​​the inner wall of the housing 21.

[0132] It can be understood that the inner wall of the shell 21 includes a bottom wall, and the bottom supporting plate 25 is located between the pole core 23 and the bottom wall of the inner wall. The bottom wall of the inner wall is the surface of the bottom wall 216 facing the inner cavity of the shell 21.

[0133] It can be understood that the inner wall of the shell 21 includes a bottom wall and four side walls connected to the bottom wall, the bottom support plate 25 is located between the pole core 23 and the bottom wall, the insulating coating 218 is coated on the side walls of two opposite inner walls, and the side walls of the inner walls are the surfaces of the side walls 217 facing the inner cavity of the shell 21.

[0134] The insulating coating 218 can be formed on the inner wall of the housing 21 by electrophoretic coating or inner wall spraying. The material of the insulating coating 218 includes organic and / or inorganic materials, and the organic material is not limited to ultraviolet curing coating (UV) spraying material, polyethylene (PE) coating material, polypropylene (PP) aluminum plastic film, silicon coating, organic resin coating of various proportions, etc., and the inorganic material is not limited to ceramic, magnesium oxide, aluminum oxide, water glass, phosphate, talc and other materials.

[0135] The main material in the UV spray material / organic resin coating can be one or more of epoxy resin, acrylic resin, polyurethane resin, hydroxy acrylic resin and other multifunctional resins.

[0136] The auxiliary agent in the UV spray material / organic resin coating can be one or more of a photoinitiator, a reactive diluent, a flame retardant, a wetting agent, a leveling agent, a defoaming agent, and the like.

[0137] In some embodiments of the present application, forming an insulating coating 218 on the inner wall of the shell 21 of the battery 20 may include the following steps: pre-cleaning the battery 20, spraying an insulating coating on the inner wall of the shell 21, and then curing it to form an insulating coating 218 on the inner wall of the shell 21. The step of pre-cleaning the battery 20 includes: surface cleaning the inner wall of the shell 21, which includes but is not limited to plasma cleaning, laser cleaning, water washing, etc.

[0138] When laser cleaning is used to clean the inner wall of the shell 21, the laser cleaning depth is [5μm, 10μm], the laser cleaning power range is [500W, 2000W] (high power), and the laser cleaning speed is [5000mm / s, 15000mm / s] to obtain an excellent cleaning effect. It is understood that the present application does not limit the specific values ​​of the laser cleaning depth, laser cleaning power, and laser cleaning speed when laser cleaning the shell 21.

[0139] When plasma cleaning is used to clean the inner wall of the shell 21, the plasma cleaning power range is [200W, 1500W], the plasma cleaning output frequency range is [20kHz, 40kHz], and the plasma cleaning heats the temperature of the shell 21 to [40°C, 80°C], that is, the temperature of the shell 21 is heated to not less than 40°C and not more than 80°C, so as to obtain an excellent cleaning effect. It can be understood that the present application does not limit the plasma cleaning power, plasma cleaning output frequency, and plasma cleaning heating temperature of the shell 21 when plasma cleaning is performed on the shell 21. It can be understood that the present application does not limit the specific values ​​of the plasma cleaning power, plasma cleaning output frequency range, and plasma cleaning heating temperature of the shell 21 when plasma cleaning is performed on the shell 21.

[0140] The spraying distance of the insulating paint depends on the size of the battery shell. The time range of the insulating paint spraying is [1min, 8min]. It can be understood that the present application does not limit the time range of the insulating paint spraying, and the paint can be sprayed on the inner wall of the shell 21.

[0141] In some embodiments of this application, please refer to Fig.10 , Fig.10 The three-dimensional schematic diagram of the pole core provided in one embodiment of the present application, the pole core 23 includes a bottom surface 231, a plurality of side surfaces 233 and a top surface 235. The plurality of side surfaces 233 are connected between the bottom surface 231 and the top surface 235. The bottom surface 231 and the top surface 235 are arranged opposite to each other along a first direction. The plurality of side surfaces 233 include a first side surface 2331, a second side surface 2332, a third side surface 2333 and a fourth side surface 2334, the first side surface 2331 and the second side surface 2332 are arranged opposite to each other along a second direction, the third side surface 2333 and the fourth side surface 2334 are arranged opposite to each other along a third direction, the first side surface 2331 is connected to the bottom surface 231, the second side surface 2332 is connected to the bottom surface 231, the third side surface 2333 is connected to the bottom surface 231, the fourth side surface 2334 is connected to the bottom surface 231, and the Mylar film 24 wraps the first side surface 2331, the second side surface 2332, the third side surface 2333 and the fourth side surface 2334.

[0142] Please refer to Fig.10 and Fig.11 , Fig.11A side view of a battery with the shell removed is provided in one embodiment of the present application. The Mylar film 24 wraps the bottom surface 231, the side surface 233 and the top surface 235. In some embodiments of the present application, the Mylar film 24 wraps the first side surface 2331, the second side surface 2332, the third side surface 2333, the fourth side surface 2334 and the top surface 235. It can be understood that the Mylar film 24 can wrap at least one of the first side surface 2331, the second side surface 2332, the third side surface 2333 and the fourth side surface 2334. For example, the Mylar film 24 can wrap the first side surface 2331 and the second side surface 2332 without wrapping the third side surface 2333 and the fourth side surface 2334.

[0143] See also Fig.12 , Fig.12 The schematic plan view of the Mylar film provided in one embodiment of the present application shows that the portion of the Mylar film 24 located on the bottom surface 231 includes a plurality of first openings 241 for circulating electrolyte. The region 2413 of the Mylar film 24 is attached to the bottom surface 231 .

[0144] See also Fig.13 , Fig.13 The bottom support sheet 25 includes a second opening 251. The second opening 251 is used to circulate electrolyte. In some embodiments of the present application, the first opening 241 (such as Fig.12 The position of the first opening 241 and the second opening 251 are staggered to avoid the first opening 241 and the second opening 251 being arranged along the same straight line, thereby extending the diffusion path of dust from the bottom surface 231 of the pole core 23 to the shell 21, thereby reducing the possibility of a micro short circuit between the bottom surface 231 and the shell 21.

[0145] The battery 20 further includes an insulating porous membrane 26, which is located between the Mylar membrane 24 and the bottom support sheet 25 in the first direction. The bottom surface 231, the Mylar membrane 24, the insulating porous membrane 26, and the bottom support sheet 25 are stacked in sequence along the first direction. The insulating porous membrane 26 is used to absorb dust. The insulating porous membrane 26 includes a plurality of through holes 261, the aperture of the through hole 261 is smaller than the aperture of the first opening 241, and the aperture of the through hole 261 is smaller than the aperture of the second opening 251. Fig.13 The through hole 261 in FIG. 2 is merely exemplary and does not represent the actual size of the through hole 261 in application.

[0146] The through hole 261 allows the electrolyte to flow, and the aperture of the through hole 261 is smaller than the aperture of the first opening 241, and the aperture of the through hole 261 is smaller than the aperture of the second opening 251. The through hole 261 can reduce the circulation of dust between the Mylar film 24 and the bottom support sheet 25, and reduce the possibility of a micro short circuit between the pole core 23 and the shell 21, thereby reducing the possibility of corrosion of the shell 21, carbonization of the positive electrode, breakdown of the aluminum shell, short circuit, and leakage, and improving the safety and reliability of the battery 20.

[0147] In some embodiments of the present application, the aperture range of the first opening 241 and the second opening 251 is [1mm, 5mm], and the aperture range of the first opening 241 and the second opening 251 is not less than 1mm and not greater than 5mm. For example, the aperture of the first opening 241 can be 1mm, 2mm, 3mm, 4mm and 5mm, and the aperture of the second opening 251 can be 1mm, 2mm, 3mm, 4mm and 5mm. The pore size range of the through hole 261 is [0.01μm, 50μm]. The pore size of the through hole 261 is not less than 0.01μm and not more than 50μm. For example, the pore size of the through hole 261 can be 0.01μm, 0.03μm, 0.05μm, 0.07μm, 0.1μm, 0.3μm, 0.5μm, 0.7μm, 1μm, 3μm, 5μm, 7μm, 10μm, 13μm, 15μm, 17μm, or 20μm. For example, the particle size range of the dust is approximately [10μm, 20μm], and the aperture of the through hole 261 can be set at [0.01μm, 10μm]. The through hole 261 does not allow dust with a particle size greater than 10μm to pass through, which greatly reduces the flow of dust between the bottom surface 231 and the bottom wall 216, and greatly reduces the possibility of a micro short circuit between the pole core 23 and the shell 21.

[0148] The insulating porous membrane 26 can be a multilayer composite membrane, an organic / inorganic composite membrane, a nanofiber coating membrane, an electrospinning membrane, a cellulose-based membrane, and the like. The thickness range of the insulating porous membrane 26 is [2 μm, 200 μm]. The porosity range of the insulating porous membrane 26 is [10%, 90%]. It is understood that the present application does not limit the thickness range of the insulating porous membrane 26, and the present application does not limit the porosity range of the insulating porous membrane 26.

[0149] In some embodiments of the present application, the Mylar film 24, the insulating porous film 26, and the bottom support sheet 25 are an integrated composite structure. The Mylar film 24, the insulating porous film 26, and the bottom support sheet 25 can be formed into an integrated composite structure by hot pressing. The temperature range of the Mylar film 24, the insulating porous film 26, and the bottom support sheet 25 during hot pressing is [100°C, 300°C]. It can be understood that the present application is not limited to forming the Mylar film 24, the insulating porous film 26, and the bottom support sheet 25 into an integrated composite structure by a hot pressing composite process, and the Mylar film 24, the insulating porous film 26, and the bottom support sheet 25 can also be formed into an integrated composite structure by other processes. It can be understood that the Mylar film 24, the insulating porous membrane 26, and the bottom support sheet 25 may not form an integrated composite structure. The Mylar film 24, the insulating porous membrane 26, and the bottom support sheet 25 may also be a separate structure, or the Mylar film 24 and the insulating porous membrane 26 are an integrated structure, or the insulating porous membrane 26 and the bottom support sheet 25 are an integrated structure.

[0150] In the related art, the Mylar film is easily damaged at the connection between the bottom and the side of the pole core due to the relatively large stress caused by bending, causing dust in the pole core to reach the shell from the damaged part of the Mylar film, forming a micro short circuit between the pole core and the shell through the damaged part.

[0151] The Mylar film 24 is located between the insulating porous film 26 and the pole core 23. The area of ​​the bottom surface 231 covered by the Mylar film 24 is 2413 (eg Fig.12 As shown). The bottom surface 231 and the side surface 233 form a connection. In some embodiments of the present application, the bottom surface 231 and the first side surface 2331 intersect to form a first connection, and the bottom surface 231 and the second side surface 2332 intersect to form a second connection. The Mylar film 24 wraps the first connection and the second connection. The insulating porous film 26 extends from the bottom surface 231 to the first side surface 2331 and wraps the first connection. The insulating porous film 26 extends from the bottom surface 231 to the second side surface 2332 and wraps the second connection. Please refer to Fig.13 and Fig.14 As shown, Fig.14 A schematic plan view of a bottom support sheet, a Mylar film and an insulating porous film stacked together provided in an embodiment of the present application, wherein the width of the insulating porous film 26 is substantially the same as the width of the bottom surface 231 in the third direction. The extending length of the insulating porous film 26 in its length direction is greater than the length of the bottom surface 231 in the second direction. The insulating porous film 26 covers the bottom surface 231, the first connection and the second connection. Since the Mylar film 24 and the insulating porous film 26 are wrapped at the first connection and the second connection, the insulating porous film 26 provides enhanced protection for the Mylar film 24 at the first connection and the second connection, thereby reducing the possibility of damage to the Mylar film 24 at the first connection and the second connection, which is beneficial to reducing the possibility of a micro short circuit between the pole core 23 and the shell 21.

[0152] In some implementations of this application, please refer to Fig.10 , Fig.15 , Fig.15The three-dimensional assembly diagram of the battery without the shell and the battery cover is shown in FIG. The insulating porous membrane 26 covers the side of the Mylar membrane 24 away from the third side 2333, and the insulating porous membrane 26 covers the side of the Mylar membrane 24 away from the third side 2333, so as to increase the area of ​​the Mylar membrane 24 covered by the insulating porous membrane 26 and improve the protection area of ​​the Mylar membrane 24 by the insulating porous membrane 26. The top surface 235 is connected to one end of the third side 2333 away from the bottom surface 231, the top surface 235 is connected to one end of the fourth side 2334 away from the bottom surface 231, the top surface 235 and the bottom surface 231 are arranged opposite to each other along the first direction, and the pole core 23 also includes a pole ear 237 protruding from the top surface 235. The insulating porous membrane 26 covers the top surface 235 , thereby increasing the area of ​​the pole core 23 covered by the insulating porous membrane 26 , reducing the flow of dust between the top surface 235 of the pole core 23 and the shell 21 , and further reducing the possibility of a micro short circuit between the pole core 23 and the shell 21 .

[0153] The insulating porous membrane 26 located on the top surface 235 is provided with a avoidance hole 267 (such as Fig.15 As shown), it is used to penetrate the pole ear 237. The pole ear 237 is penetrated in the avoidance hole 267. The pole ear 237 is electrically connected to the battery cover 28 to output electric energy from the battery 20 to the electric device, or to input electric energy into the battery 20. The pole ear 237 includes a positive pole ear and a negative pole ear. The positive pole ear is formed by extending the positive electrode sheet. The negative pole ear is formed by extending the negative electrode sheet. The number of avoidance holes 267 can be two, one avoidance hole 267 is penetrated by the positive pole ear, and the other avoidance hole 267 is penetrated by the negative pole ear. The number of avoidance holes 267 can also be one. Both the positive pole ear and the negative pole ear are penetrated in the avoidance hole 267. Please refer to Fig.15 and Fig.16 , Fig.16 A schematic plan view of a bottom support sheet, a Mylar membrane and an insulating porous membrane stacked together according to an embodiment of the present application, wherein a first groove 2673 is recessed on one side edge of the insulating porous membrane 26, and a second groove 2675 is recessed on one side edge of the insulating porous membrane 26. The first groove 2673 and the second groove 2675 are located on the top surface 235, and the side wall of the first groove 2673 and the side wall of the second groove 2675 together form an avoidance hole 267 (such as Fig.15 shown).

[0154] In the related art, the Mylar film at the bottom corner structure of the pole core is easily damaged due to the large stress it is subjected to during bending, causing dust in the pole core to reach the shell from the damaged part of the Mylar film at the bottom corner structure, forming a micro short circuit between the pole core and the shell through the damaged part.

[0155] Please refer to Fig.10 and Fig.17 , Fig.17A three-dimensional schematic diagram of a partial structure of a battery provided in an embodiment of the present application, wherein the pole core 23 further includes a bottom corner structure 239 formed by a bottom surface 231 and two adjacent side surfaces 233, and the Mylar film 24 wraps the bottom corner structure 239. The battery 20 further includes a plurality of protective tapes 27, each of which wraps a corresponding bottom corner structure 239 and is located on the side of the Mylar film 24 away from the pole core 23. The protective tape 27 is partially located between the bottom support sheet 25 and the insulating porous film 26. The protective tape 27 wraps the bottom corner structure 239, thereby strengthening the strength of the Mylar film 24 at the bottom corner structure 239, reducing the possibility of damage to the Mylar film 24 at the bottom corner structure 239, reducing the amount of dust flowing between the bottom corner structure 239 of the pole core 23 and the shell 21, and further reducing the possibility of a micro short circuit between the pole core 23 and the shell 21.

[0156] For example, the bottom surface 231, the first side surface 2331, and the third side surface 2333 together form a bottom angle structure 239, the bottom surface 231, the first side surface 2331, and the fourth side surface 2334 together form a bottom angle structure 239, the bottom surface 231, the second side surface 2332, and the third side surface 2333 together form a bottom angle structure 239, and the bottom surface 231, the second side surface 2332, and the fourth side surface 2334 together form a bottom angle structure 239. It can be understood that the shape and structure of the pole core 23 are different, and the number of bottom angle structures 239 is different.

[0157] It can be understood that the inner wall of the shell 21 includes a bottom wall, the bottom supporting sheet 25 is located between the insulating porous membrane 26 and the bottom wall of the inner wall, and the bottom wall of the inner wall is the surface of the bottom wall 216 facing the inner cavity of the shell 21.

[0158] It can be understood that the inner wall of the shell 21 includes a bottom wall and four side walls connected to the bottom wall, the bottom support sheet 25 is located between the insulating porous membrane 26 and the bottom wall of the inner wall, and the insulating coating 218 can be coated on the side walls of two opposite inner walls. The side walls of the inner wall are the surfaces of the side walls 217 facing the inner cavity of the shell 21.

[0159] See also Fig.18 and Fig.19 , Fig.18 This is a three-dimensional schematic diagram of a battery cover provided in an embodiment of the present application. Fig.19 An embodiment of the present application provides Fig.18 The battery cover 28 may be an integral structure or a split structure. In some embodiments of the present application, the battery cover 28 includes a cover 281, an upper insulating plastic part 282, a lower insulating plastic part 283 and a pole 285. The cover 281 includes a first surface and a second surface that are oppositely arranged in a first direction. The first surface may be Fig.19 The upper surface 2811 shown in FIG. 1 and the second surface 2812 are Fig.19As shown in the figure, the lower surface 2813 is arranged on the side of the cover plate 281 facing the bottom surface 231. The cover plate 281 can be a metal cover plate. It can be understood that the material of the cover plate 281 is not limited in the present application. The upper insulating plastic part 282 is fixedly covered on a part of the upper surface 2811. The lower insulating plastic part 283 is located between the lower surface 2813 and the top surface 235 of the pole core 23, and the lower insulating plastic part 283 covers a part of the lower surface 2813. The pole 285 is penetrated by the lower insulating plastic part 283, the cover plate 281, and the upper insulating plastic part 282, and the pole 285 is electrically connected to the pole core 23. The upper insulating plastic part 282 and the lower insulating plastic part 283 are used to electrically insulate the cover plate 281 and the pole 285. The pole 285 includes a positive pole and a negative pole, the positive pole is electrically connected to the positive pole ear, and the negative pole is electrically connected to the negative pole ear. The positive electrode column and the negative electrode column are used to be electrically connected to an external device to achieve power transmission between the battery 20 and the external device.

[0160] The upper surface 2811 and the lower surface 2813 each include at least one surface pore. A portion of the upper insulating plastic part 282 is embedded in the surface pore of the upper surface 2811, and a portion of the lower insulating plastic part 283 is embedded in the surface pore of the lower surface 2813, so that the upper insulating plastic part 282, the cover plate 281, and the lower insulating plastic part 283 form an integrated composite structure, which improves the sealing of the battery cover plate 28 while simplifying the structure of the battery cover plate 28 and facilitating the assembly of the battery cover plate 28 with other components. In addition, the upper surface 2811 where the cover plate 281 contacts the upper insulating plastic part 282 is provided with at least one surface pore, and a portion of the upper insulating plastic part 282 is embedded in at least one surface pore of the upper surface 2811, thereby improving the connection stability between the upper insulating plastic part 282 and the cover plate 281. The lower surface 2813 of the cover plate 281 in contact with the lower insulating plastic part 283 has at least one surface pore, and a portion of the lower insulating plastic part 283 is embedded in at least one surface pore of the lower surface 2813, thereby improving the connection stability between the lower insulating plastic part 283 and the cover plate 281.

[0161] It can be understood that one of the upper surface 2811 and the lower surface 2813 is provided with a surface pore, and a portion of the cover plate 281 is embedded in the surface pore.

[0162] In some embodiments of the present application, the surface pores are nanoscale pores, and the diameter range of the nanoscale pores is [10nm, 500nm]. The surface pores are nanoscale pores, which can increase the contact area between the cover plate 281 and the upper insulating plastic part 282, and between the cover plate 281 and the lower insulating plastic part 283, and improve the connection strength between the cover plate 281 and the upper insulating plastic part 282, and between the cover plate 281 and the lower insulating plastic part 283. The width range of the surface pores is [0.05mm, 1mm]. In the first direction, the depth of the surface pores is [0.1mm, 3mm], and the thickness range of the cover plate 281 is [0.1mm, 9mm].

[0163] The cover plate 281 is provided with a first pole through hole 2817 that passes through the upper surface 2811 and the lower surface 2813, and the first pole through hole 2817 is used to pass the pole 285. The surface pores are arranged at the periphery of the first pole through hole 2817, that is, there is a spacing between the surface pores and the outer periphery of the first pole through hole 2817 to reduce the possibility of cracking of the hole wall of the first pole through hole 2817 and causing cracking of the cover plate 281. There is a spacing between the surface pores and the outer periphery of the cover plate 281 to reduce the possibility of cracking of the outer periphery of the cover plate 281 and causing cracking of the cover plate 281. The cover plate 281 is also provided with a liquid injection hole and a mounting hole. The liquid injection hole is used to inject electrolyte. The mounting hole is used to install an explosion-proof valve.

[0164] In some embodiments of the present application, the upper insulating plastic part 282 is injected into the surface pores of the upper surface 2811 of the cover plate 281 by integral injection molding, and the upper insulating plastic part 282 is firmly fixed on the cover plate 281 by an anchor bolt effect; the lower insulating plastic part 283 is injected into the surface pores of the lower surface 2813 of the cover plate 281 by integral injection molding, and the lower insulating plastic part 283 is firmly fixed on the cover plate 281 by an anchor bolt effect. The upper insulating plastic part 282, the cover plate 281 and the lower insulating plastic part 283 form a unique sealed integrated structure design, which improves the sealing performance of the battery cover plate 28 while reducing the use of the sealing structure.

[0165] The material of the upper insulating plastic part 282 and the lower insulating plastic part 283 is selected from polyethylene, polypropylene, polyacetal, polystyrene, modified polyethylene terephthalate, polybutylene terephthalate, polynaphthalate, polyphenylene sulfide, polyimide, polyamide-imide, polyetherimide, polysulfone, polyethersulfone, polyetherketone, polyether magnesium, polycarbonate, polyamide or acrylonitrile-butadiene-styrene copolymer. The material of the cover plate is selected from at least one of aluminum, titanium, aluminum alloy, titanium alloy or stainless steel.

[0166] The material of the upper insulating plastic part 282 and the lower insulating plastic part 283 includes fillers, and the fillers include at least one of glass fiber, carbon fiber, carbon nanotube, carbon black, cement, and ceramic.

[0167] In some embodiments of the present application, the upper insulating plastic part 282 is provided with a second pole through hole 2821 for passing the pole 285. The lower insulating plastic part 283 is provided with a third pole through hole 2831 for passing the pole 285. The pole 285 is passed through the second pole through hole 2821 and the third pole through hole 2831.

[0168] In one possible implementation, Fig. 20 As shown, Fig. 20 For an embodiment of the present application Fig.18 In the partial cross-sectional view taken along the line I2-I2, the upper insulating plastic part 282 also includes a body 2823 and an extension part 2825 protruding from the body 2823 toward the side of the cover plate 281, the second pole through hole 2821 passes through the body 2823 and the extension part 2825, the body 2823 covers a portion of the upper surface 2811, and the outer wall of the extension part 2825 fits the inner wall of the first pole through hole 2817. The extension part 2825 extends into the first pole through hole 2817, and the extension part 2825 is located between the inner wall of the first pole through hole 2817 and the outer wall of the pole 285, so as to reduce the possibility of a gap between the upper insulating plastic part 282 and the cover plate 281.

[0169] Please refer to Fig. 20 , Fig.21 and Fig. 22 , Fig.21 for Fig. 20 A three-dimensional schematic diagram of the sealing member of the battery cover shown in FIG. Fig. 22 For along Fig. 20 In the radial cross-sectional view of the seal shown in FIG. 2 , the battery cover 28 further includes a seal 287, which is inserted into the third pole through hole 2831 and the first pole through hole 2817. The seal 287 is a hollow structure, and the pole 285 is inserted into the hollow structure of the seal 287. The seal 287 is used to achieve a sealed connection between the pole 285, the lower insulating plastic part 283 and the cover 281, and reduce the entry of water vapor, impurities, etc. into the interior of the battery 20.

[0170] The material of the seal 287 is selected from polyethylene, polypropylene, polyacetal, polystyrene, modified polyethylene terephthalate, polybutylene terephthalate, polynaphthalate, polyphenylene sulfide, polyimide, polyamideimide, polyetherimide, polysulfone, polyethersulfone, polyether ketone, polyether magnesium, polycarbonate, polyamide, acrylonitrile-butadiene-styrene copolymer, ceramic, and cement.

[0171] The material of the sealing member 287 includes fillers, and the fillers include glass fiber, carbon fiber, carbon nanotube, carbon black, cement, and ceramic.

[0172] In some possible implementations, the upper insulating plastic part 282 , the sealing part 287 , and the lower insulating plastic part 283 may be made of organic insulating materials or inorganic insulating materials, such as doping-optimized ceramic materials, doping-optimized PPS organic materials, glass, cement, and other materials.

[0173] like Fig. 20 As shown, in some embodiments of the present application, the cross section of the seal 287 along the radial direction of the seal 287 is generally a "T"-shaped step structure, and the seal 287 includes a first sealing portion 2871 and a second sealing portion 2873 connected and arranged along the axial direction of the seal 287. The aperture of the first pole through hole 2817 is smaller than the aperture of the third pole through hole 2831. The aperture of the second pole through hole 2821 is smaller than the aperture of the first pole through hole 2817. The outer diameter of the first sealing portion 2871 is smaller than the outer diameter of the second sealing portion 2873. The first sealing portion 2871 is sequentially penetrated through the first pole through hole 2817 and the second pole through hole 2821. The extension portion 2825 is located between the outer wall of the first sealing portion 2871 and the inner wall of the first pole through hole 2817, and the outer wall of the first sealing portion 2871 is in contact with the inner wall of the second pole through hole 2821. The second sealing portion 2873 is accommodated in the third pole through hole 2831. The second sealing portion 2873 is located between the inner wall of the third pole through hole 2831 and the outer wall of the pole 285. The upper insulating plastic part 282 and the lower insulating plastic part 283 are integrally injected with the sealing part 287 to form a step structure, thereby avoiding the risk of electrolyte crystallization and electron conduction caused by the gap between the upper insulating plastic part 282, the lower insulating plastic part 283 and the sealing part 287.

[0174] It can be understood that the aperture of the first pole through hole 2817 may not be smaller than the aperture of the third pole through hole 2831, and the aperture of the second pole through hole 2821 may not be smaller than the aperture of the first pole through hole 2817. For example, the apertures of the first pole through hole 2817, the second pole through hole 2821, and the third pole through hole 2831 may be the same, or the aperture of the first pole through hole 2817 may be larger than the aperture of the third pole through hole 2831, and the aperture of the second pole through hole 2821 may be larger than the aperture of the first pole through hole 2817.

[0175] It can be understood that the present application does not limit the structure of the seal 287 .

[0176] Please refer to Fig. 20 , Fig.21 and Fig. 22The sealing member 287 further includes a first recessed portion 2876 recessed on the side of the second sealing portion 2873 facing the cover plate 281, and the first recessed portion 2876 is used to be fixedly connected to the cover plate 281. A portion of the cover plate 281 is fixedly embedded in the first recessed portion 2876. The first recessed portion 2876 is arranged along the outer periphery of the second sealing portion 2873, thereby making the second sealing portion 2873 present a step structure.

[0177] The cover plate 281 is partially fixed in the first recessed portion 2876 , thereby increasing the connection area between the cover plate 281 and the second sealing portion 2873 , reducing the possibility of a gap between the cover plate 281 and the second sealing portion 2873 , and improving the sealing and connection strength between the cover plate 281 and the second sealing portion 2873 .

[0178] The sealing member 287 further includes a second recessed portion 2877, which is used to be fixedly connected to the lower insulating plastic member 283. The second recessed portion 2877 is recessed on the inner wall of the second sealing member 2873 facing the inner wall of the third pole through hole 2831, and the inner wall of the third pole through hole 2831 of the lower insulating plastic member 283 forms a flange 2833 (such as Fig. 20 As shown in FIG. 2 , the flange 2833 is fixedly received in the second recessed portion 2877. Since the flange 2833 is fixedly received in the second recessed portion 2877, the connection area between the lower insulating plastic part 283 and the second sealing portion 2873 is increased, the possibility of a gap between the lower insulating plastic part 283 and the second sealing portion 2873 is reduced, and the sealing and connection strength between the lower insulating plastic part 283 and the second sealing portion 2873 are improved.

[0179] It can be understood that the first recessed portion 2876 and the second recessed portion 2877 can be annular grooves or annular recesses extending along the circumference of the second sealing portion 2873, and the first recessed portion 2876 and the second recessed portion 2877 may not extend along the circumference of the second sealing portion 2873. The first recessed portion 2876 and the second recessed portion 2877 can be omitted. The number of the first recessed portions 2876 can be two or more to increase the connection area between the second sealing portion 2873 and the lower insulating plastic part 283 of the cover plate 281, thereby improving the connection stability and sealing of the sealing member 287 and the lower insulating plastic part 283. The number of the second recessed portions 2877 can be two or more to increase the connection area between the second sealing portion 2873 and the lower insulating plastic part 283 of the cover plate 281, thereby improving the connection stability and sealing of the sealing member 287 and the lower insulating plastic part 283.

[0180] like Fig. 22As shown, in some embodiments of the present application, the length D of the second sealing portion 2873 extending along the radial direction R of the second sealing portion 2873 is [50μm, 600μm], so that the second sealing portion 2873 has a larger contact area with the cover plate 281. The height H of the second sealing portion 2873 in the first direction Z is [50μm, 2000μm], so that the second sealing portion 2873 has greater strength. It can be understood that the present application does not limit the length of the second sealing portion 2873 extending along the radial direction R of the second sealing portion 2873, and the present application does not limit the height H of the second sealing portion 2873 along the first direction Z.

[0181] In one possible implementation, Fig.23 As shown, Fig.23 For an embodiment of the present application Fig.18 In the partial cross-sectional view taken along the line I2-I2, the extension portion 2825 is provided through the first pole through hole 2817. The first sealing portion 2871 is provided through the second pole through hole 2821 and is in contact with the inner wall of the second pole through hole 2821. The extension portion 2825 is located between the inner wall of the first pole through hole 2817 and the outer wall of the first sealing portion 2871. The end surface of the extension portion 2825 away from the body 2823 is in contact with the second sealing portion 2873.

[0182] In one possible implementation, Fig.24 , Fig.25 and Fig.26 As shown, Fig.24 For an embodiment of the present application Fig.18 The partial cross-sectional view obtained by the line I2-I2, Fig.25 for Fig.24 A three-dimensional schematic diagram of the sealing member of the battery cover shown in FIG. Fig.26 A partial cross-sectional view of a cover plate, a lower insulating plastic part, and a sealing part assembled together according to an embodiment of the present application, wherein the second sealing part 2873 is a step structure, and the second recessed part 2877 is recessed on a side of the second sealing part 2873 facing the cover plate 281 in the first direction, and the second recessed part 2877 is arranged along the outer periphery of the hollow structure of the second sealing part 2873 away from the sealing part 287. The flange 2833 is fixedly received in the second recessed part 2877. The side of the second sealing part 2873 facing the cover plate 281 is in contact with a part of the lower surface 2813, and the outer wall of the first sealing part 2871 is in contact with the outer wall of the first pole through hole 2817. The end surface of the extension part 2825 away from the body 2823 is in contact with the first sealing part 2871 and the end surface facing away from the second sealing part 2873 is in contact with the end surface.

[0183] In one possible implementation, Fig. 27 As shown, Fig. 27A partial cross-sectional view of the cover plate, the lower insulating plastic part, and the seal provided in an embodiment of the present application are assembled together. The seal 287 omits the first recessed portion, and the second recessed portion 2877 is located on the peripheral wall of the second sealing portion 2873 that is away from the hollow structure. The flange 2833 is fixed in the second recessed portion 2877.

[0184] In one possible implementation, Fig.28 As shown, Fig.28 It is a partial cross-sectional view of the cover plate, the lower insulating plastic part, and the seal provided in an embodiment of the present application, wherein the seal 287 omits the first recessed portion, the second recessed portion 2877 is located at the end of the second sealing portion 2873 away from the cover plate 281 in the first direction, and the flange 2833 is disposed at the end of the third pole through hole 2831 away from the cover plate 281 in the first direction. The flange 2833 is fixed and clamped with the second recessed portion 2877.

[0185] In one possible implementation, Fig.29 As shown, Fig.29 The present invention provides a partial cross-sectional view of the cover plate, the upper insulating plastic part, and the sealing part assembled together according to an embodiment of the present application. The sealing part 287 also includes a third recessed portion 2878, which is recessed in the first sealing part 2871 on the side away from the second sealing part 2873 in the first direction. The third recessed portion 2878 penetrates the outer peripheral wall of the first sealing part 2871 away from the hollow structure. The upper insulating plastic part 282 is provided with an embedded portion 2826 on the side facing the cover plate 281, and the embedded portion 2826 is at least partially fixedly accommodated in the third recessed portion 2878. In this way, the connection area between the upper insulating plastic part 282 and the first sealing part 2871 is increased, the possibility of a gap between the upper insulating plastic part 282 and the first sealing part 2871 is reduced, and the sealing and connection strength between the upper insulating plastic part 282 and the first sealing part 2871 are improved.

[0186] In one possible implementation, Fig.30 As shown, Fig.30 This is a partial cross-sectional view of the cover plate, the upper insulating plastic component, and the sealing component assembled together according to an embodiment of the present application, wherein the third recessed portion 2878 is a groove.

[0187] In one possible implementation, Fig.31 As shown, Fig.31 This is a partial cross-sectional view of the cover plate, the upper insulating plastic part, and the sealing part assembled together according to an embodiment of the present application. The third recessed portion 2878 penetrates the inner peripheral wall of the hollow structure of the first sealing portion 2871 facing the sealing part 287.

[0188] It can be understood that the second pole through hole 2821 may not penetrate the extension portion 2825 , and the extension portion 2825 only needs to be connected to the first sealing portion 2871 .

[0189] It can be understood that the extension portion 2825 of the upper insulating plastic component 282 can be omitted.

[0190] See also Fig.32 , Fig.32 A schematic diagram of a battery cover provided with an insulating protective film in an embodiment of the present application, wherein an insulating protective film 29 is further provided on the side of the battery cover 28 facing the pole core, and the insulating protective film 29 is used to insulate and isolate the electrolyte from the battery cover 28, to prevent the electrolyte from contacting the battery cover 28 and causing corrosion, which is beneficial to improving the safety performance of the battery. In some embodiments of the present application, the insulating protective film 29 is arranged away from the explosion-proof valve mounting hole 2893 and the injection hole 2895.

[0191] The insulating protective film 29 can be made of organic material or inorganic material. The organic material is not limited to polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyimide or polyethylene terephthalate, and the inorganic material is not limited to ceramic, magnesium oxide, aluminum oxide, water glass, phosphate, talc and other materials.

[0192] The insulating protective film 29 can be prepared by one of the following methods: vacuum coating, electroplating, chemical coating, spraying, brushing, scraping or dipping.

[0193] The thickness of the insulating protective film 29 can be [10 μm, 200 μm]. It can be understood that the insulating protective film 29 can be designed for the integrated battery cover 28. When the battery cover 28 is a split design, the insulating protective film 29 also covers the side of the battery cover 28 facing the pole core.

[0194] It should be understood that expressions such as "including" and "may include" that may be used in the present application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In the present application, terms such as "including" and / or "having" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0195] In addition, in the present application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0196] In the present application, expressions including ordinal numbers such as "first" and "second" may modify various elements. However, such elements are not limited by the above expressions. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only used to distinguish one element from other elements. For example, a first user device and a second user device indicate different user devices, although the first user device and the second user device are both user devices. Similarly, without departing from the scope of the present application, a first element may be referred to as a second element, and similarly, a second element may also be referred to as a first element.

[0197] When a component is referred to as being "connected" or "accessed" to another component, it should be understood that the component is not only directly connected to or accessed to the other component, but also another component may exist between the component and the other component. On the other hand, when a component is referred to as being "directly connected" or "directly accessed" to another component, it should be understood that there is no component between them.

[0198] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery, characterized in that: The battery comprises a shell, a core, a Mylar film, an insulating porous film and a bottom support sheet, wherein the core, the Mylar film, the insulating porous film and the bottom support sheet are all accommodated in the shell; The bottom surface of the pole core, the Mylar film, the insulating porous film and the bottom support sheet are stacked in sequence, and the insulating porous film includes a plurality of through holes.

2. The battery according to claim 1, characterized in that The Mylar film located on the bottom surface includes a plurality of first openings, the bottom support sheet includes a plurality of second openings, the aperture of the through hole is smaller than the aperture of the first opening, and the aperture of the through hole is smaller than the aperture of the second opening.

3. The battery according to claim 2, characterized in that The plurality of first openings and the plurality of second openings are arranged not to overlap.

4. The battery according to claim 1, characterized in that The aperture range of the through hole is [0.01 μm-50 μm].

5. The battery according to claim 1, characterized in that The pole core also includes a side surface, and the insulating porous film covers the connection between the side surface and the bottom surface.

6. The battery according to claim 5, characterized in that The pole core further includes a top surface and a pole ear, the top surface is arranged opposite to the bottom surface, the side surface is connected between the bottom surface and the top surface, and the pole ear is arranged on the top surface and protrudes from the top surface; The Mylar film covers the side surface and the top surface; The insulating porous film covers the surface of the Mylar film away from the side surface and the top surface; The insulating porous membrane located on the top surface is provided with an avoidance hole, and the pole tab is passed through the avoidance hole.

7. The battery according to claim 1, characterized in that The pole core further comprises two adjacently connected side surfaces, the two side surfaces and the bottom surface together form a bottom angle structure, and the Mylar film wraps the bottom angle structure; The battery further comprises a protective tape, which covers the bottom corner structure and is located on a side of the Mylar film away from the pole core, and the protective tape is partially located between the bottom support sheet and the insulating porous film.

8. The battery according to claim 1, characterized in that The battery further comprises a battery cover plate, which is arranged on the shell, and the pole core comprises a top surface, which is arranged opposite to the bottom surface, and an insulating protective film is arranged on the side of the battery cover plate facing the top surface of the pole core.

9. The battery according to claim 1, characterized in that The battery further comprises a battery cover plate, which is covered on the housing, and the battery cover plate, the pole core, the insulating porous membrane and the bottom support sheet are arranged in sequence. The battery cover includes a cover, an upper insulating plastic part, a lower insulating plastic part and a pole: The cover plate comprises a first surface and a second surface which are arranged opposite to each other, the second surface is arranged on a side of the cover plate facing the bottom surface, and the cover plate is provided with a first pole through hole which passes through the first surface and the second surface. The upper insulating plastic part at least partially covers the first surface, and the upper insulating plastic part is provided with a second pole through hole; The lower insulating plastic part is located between the second surface and the pole core, the lower insulating plastic part at least partially covers the second surface, and the lower insulating plastic part is provided with a third pole through hole; The pole is inserted into the third pole through hole, the first pole through hole and the second pole through hole, and the pole is electrically connected to the pole core.

10. The battery according to claim 9, characterized in that The first surface includes at least one surface pore; the upper insulating plastic part is partially embedded in the surface pore of the first surface; and / or the second surface includes at least one surface pore, and the lower insulating plastic part is partially embedded in the surface pore of the second surface.

11. The battery according to claim 10, characterized in that There is a distance between the surface pore and the outer periphery of the first pole through hole, and there is a distance between the surface pore and the outer periphery of the cover plate.

12. The battery according to claim 10, characterized in that The diameter range of the surface pores is [10 nm, 500 nm].

13. The battery according to claim 9, characterized in that The battery cover plate further includes a sealing member, and the sealing member is located between the inner wall of the first pole through hole and the outer wall of the pole.

14. The battery according to claim 13, characterized in that The aperture of the third pole through hole is larger than the aperture of the second pole through hole. The seal includes a first sealing portion and a second sealing portion which are connected to each other, wherein the outer diameter of the first sealing portion is smaller than the outer diameter of the second sealing portion, and the first sealing portion is at least partially located between the inner wall of the first pole through hole and the outer wall of the pole; the second sealing portion is located between the inner wall of the third pole through hole and the outer wall of the pole.

15. The battery according to claim 14, characterized in that The upper insulating plastic part also includes a body and an extension portion protruding from the body toward the cover plate, the second pole through hole passes through the body, the body covers at least part of the first surface, and the extension portion is located between the inner wall of the first pole through hole and the outer wall of the pole.

16. The battery according to claim 15, characterized in that The first sealing portion is partially located between the inner wall of the first pole through hole and the outer wall of the pole, and the rest of the first sealing portion is passed through the second pole through hole; the extension portion is located between the inner wall of the second pole through hole and the outer wall of the first sealing portion; or, the end surface of the extension portion away from the body is in contact with an end of the first sealing portion away from the second sealing portion.

17. The battery according to claim 14, characterized in that The sealing member further comprises a first recessed portion, which is recessed on a side of the second sealing portion facing the cover plate, and a portion of the cover plate is fixed in the first recessed portion.

18. The battery according to claim 14, characterized in that The seal also includes a second recessed portion, which is recessed in the outer peripheral wall of the hollow structure of the second seal away from the seal; the inner wall of the third pole through hole of the lower insulating plastic part forms a flange toward the seal, and the flange is embedded in the second recessed portion.

19. The battery according to claim 14, characterized in that The sealing member further comprises a third recessed portion, which is recessed in the end surface of the first sealing member away from the second sealing member; an embedding portion is provided on a surface of the upper insulating plastic member facing the cover plate, and the embedding portion is fixedly received in the recessed portion.

20. The battery according to claim 1, characterized in that An insulating coating is provided on the inner wall of the shell facing the pole core.

21. The battery according to claim 20, characterized in that The inner wall comprises a bottom wall, and the bottom supporting sheet is located between the insulating porous membrane and the bottom wall.

22. The battery according to claim 20, characterized in that The inner wall comprises a bottom wall and four side walls connected to the bottom wall, the bottom supporting sheet is located between the insulating porous membrane and the bottom wall, and the insulating coating is coated on two opposite side walls.

23. A battery pack, characterized in that: The battery pack comprises a plurality of batteries as described in any one of claims 1 to 22, and the plurality of batteries are connected in series or in parallel.

24. An energy storage system, characterized in that: The energy storage system includes the battery pack and power converter described in claim 23 above, wherein the power converter is used to convert the AC power output by an external AC power source into DC power and output it to the battery pack, and / or the power converter is used to convert the DC power output by the battery pack into AC power and output it to a load or a power grid.

25. A battery, characterized in that: The battery comprises a shell, a core, a Mylar film and a bottom support sheet, wherein the core, the Mylar film and the bottom support sheet are all accommodated in the shell; The bottom surface of the pole core, the Mylar film and the bottom support sheet are stacked in sequence, the Mylar film includes a plurality of through holes, and the aperture range of the through holes is [1nm-100nm].

26. The battery according to claim 25, characterized in that The bottom support sheet includes a plurality of openings, and the plurality of openings and the plurality of through holes are arranged in a non-overlapping manner.

Images