Battery cell and electric device

Abstract

A battery cell (10) and an electric device. The battery cell (10) comprises a housing (100), an electrode assembly (200) disposed in the housing (100), and an electrode terminal (310) disposed at a wall portion of the housing (100), wherein the electrode assembly (200) comprises a plurality of first electrode sheets (210) and a plurality of second electrode sheets (220) which stacked in a first direction (X), a first empty foil area (211) is formed at a first corner of each first electrode sheet (210), each second electrode sheet (220) is provided with a first notch (221), and when observed in the first direction (X), the first empty foil areas (211) at least partially overlap with the first notches (221); and the electrode terminal (310) is electrically connected to the first empty foil areas (211), and the electrode terminal (310) does not protrude from the housing (100) in a length direction (Y), a width direction (Z) and a thickness direction of the housing (100). A space that is reserved between the electrode assembly (200) and the housing (100) and used for accommodating the first empty foil areas (211) is small, so that the energy density of the battery cell (10) can be improved, and when the battery cell (10) is subjected to an external force or falls, the possibility of a short circuit caused by the first empty foil areas (211) coming into contact with the second electrode sheets (220) is also smaller. The electrode terminal (310) does not protrude from the housing (100) in the length direction (Y) of the housing (100), the width direction (Z) of the housing (100) and the thickness direction of the housing (100), so that the possibility of the electrode terminal (310) interfering with other components can be reduced, thereby facilitating a reduction in the complexity of subsequent preparation processes.

Description

Battery cells and electrical equipment CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese patent application CN202410181711.7, entitled “Battery Cells and Electrical Equipment,” filed on February 18, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery cell and an electrical device. Background Art

[0003] With the rapid development of electronic information technology, various electronic devices are also developing towards intelligence and multi-functions, and the requirements for battery energy density are becoming higher and higher.

[0004] At present, the electrode terminals of battery cells are generally set to pass through the shell in the length direction or width direction of the shell. Part of the electrode terminal is accommodated between the inner wall of the shell and the electrode assembly, occupying a large space inside the shell, affecting the energy density of the battery cell; the other part of the electrode terminal protrudes from the shell, which is easy to interfere with other components. Summary of the Invention

[0005] The present application provides a battery cell and electrical equipment, which can improve the energy density of the battery cell and reduce interference with other components.

[0006] In a first aspect, the present application provides a battery cell comprising a casing, an electrode assembly and an electrode terminal. The electrode assembly is disposed in the casing and comprises a plurality of first pole pieces and a plurality of second pole pieces stacked along a first direction. The polarity of the first pole piece is opposite to that of the second pole piece. A first empty foil area is formed at a first corner of the first pole piece. The second pole piece has a first notch. When viewed along the first direction, the first empty foil area at least partially overlaps with the first notch. The electrode terminal is disposed on a wall portion of the casing and is electrically connected to the first empty foil area. The electrode terminal does not protrude from the casing along the length direction, width direction and thickness direction of the casing, and the first direction is the thickness direction of the casing.

[0007] In the above technical solution, the electrode assembly is arranged in the shell, so that the shell can play a protective role for the electrode assembly; the electrode assembly includes a plurality of first electrode sheets and a plurality of second electrode sheets stacked along a first direction, the polarity of the first electrode sheet is opposite to that of the second electrode sheet, a first empty foil area is formed at the first corner of the first electrode sheet, and the second electrode sheet has a first notch. When viewed along the first direction, the first empty foil area and the first notch at least partially overlap. The first direction is the thickness direction of the shell, which can reduce the volume of the first empty foil area protruding from the first electrode sheet. The space reserved between the electrode assembly and the shell for accommodating the first empty foil area is small, which can provide The energy density of the battery cell is high, and when the battery cell is subjected to external force or falls, the electrode assembly is less likely to shake relative to the shell, and the possibility of short-circuiting between the first empty foil area and the second electrode piece is also smaller, thereby reducing the risk of thermal runaway of the battery cell; by locating the first empty foil area at the first corner of the first electrode piece, the preparation of the first empty foil area can be facilitated; the electrode terminal is arranged on the wall of the shell and is electrically connected to the first empty foil area. Along the length, width and thickness directions of the shell, the electrode terminal does not protrude from the shell, which can reduce the possibility of interference between the electrode terminal and other components, and is conducive to reducing the complexity of the subsequent preparation process.

[0008] In some embodiments of the present application, the housing has a first surface and a second surface opposite to each other along a first direction, and a groove recessed toward the second surface is formed at the second corner of the first surface; when viewed along the first direction, the groove at least partially overlaps with the first empty foil area; and the electrode terminal is arranged on the bottom wall of the groove.

[0009] In the above technical solution, the shell has a first surface and a second surface opposite to each other along a first direction, and a groove is formed at the second corner of the first surface, which is recessed toward the second surface. When viewed along the first direction, the groove at least partially overlaps with the first empty foil area, and the electrode terminal is arranged on the bottom wall of the groove, so that the portion of the electrode terminal located outside the shell can be accommodated in the groove, thereby ensuring that the electrode terminal does not protrude from the shell in the length direction, width direction and thickness direction of the shell.

[0010] In some embodiments of the present application, the housing includes a shell and a cover, the shell includes a first surface and an opening is formed on a side opposite to the first surface, and the cover includes a second surface and covers the opening.

[0011] In the above technical solution, the outer shell includes a shell and a cover. The shell includes a first surface and an opening is formed on the side opposite to the first surface. The cover is the second surface. The cover covers the opening, so that the electrode terminal is spaced farther apart from the cover. When the cover and the shell are welded, the heat transferred to the electrode terminal is small, and the impact on the sealing between the electrode terminal and the shell is small.

[0012] In some embodiments of the present application, the plurality of first empty foil areas are gathered along the first direction and electrically connected to the electrode terminals.

[0013] In the above technical solution, multiple first empty foil areas are gathered along the first direction and electrically connected to the electrode terminals, which can make the connection method of the multiple first empty foil areas simpler and easier to operate, and facilitate the connection of the multiple first empty foil areas to the electrode terminals. In addition, the size of the first empty foil areas in their extension direction can be smaller, so that the space occupied by the first empty foil areas is smaller, which is beneficial to improving the energy density of the battery cell; and the first empty foil areas can be directly connected to the electrode terminals without bending, which can further reduce the internal space of the shell occupied by the first empty foil areas, which is beneficial to further improving the energy density of the battery cell.

[0014] In some embodiments of the present application, the housing has a first side wall at one end in the length direction, a second side wall at one end in the width direction, and a third side wall connecting the first side wall and the second side wall, and the electrode terminal is arranged on the third side wall.

[0015] In the above technical solution, the portion of the electrode terminal located outside the shell does not protrude from the first side wall in the length direction of the shell, and does not protrude from the second side wall in the width direction of the shell, and the first empty foil area can extend to the electrode terminal in a direction perpendicular to the thickness direction of the third side wall. The first empty foil area occupies a smaller space in the shell, which is conducive to improving the energy density of the battery cell.

[0016] In some embodiments of the present application, the third sidewall is disposed at an obtuse angle to the first sidewall, and the third sidewall is disposed at an obtuse angle to the second sidewall.

[0017] In the above technical solution, the third side wall is set at an obtuse angle to the first side wall, and the third side wall is set at an obtuse angle to the second side wall, so that a gap can be formed at the corner of the shell, so that the part of the electrode terminal located outside the shell can be accommodated in the gap, thereby making it possible for the electrode terminal to not protrude from the shell along the length, width and thickness directions of the shell.

[0018] In some embodiments of the present application, the plurality of first empty foil areas are gathered and bent along a first direction, and the plurality of first empty foil areas are electrically connected to the electrode terminals.

[0019] In the above technical solution, multiple first hollow foil areas are gathered and bent along a first direction, and the multiple first hollow foil areas are electrically connected to the electrode terminals. This simplifies the connection method of the multiple first hollow foil areas, makes operation easier, and facilitates the electrical connection of the multiple first hollow foil areas to the electrode terminals. Furthermore, the dimensions of the first hollow foil areas in their extension direction are reduced, thereby reducing the space occupied by the first hollow foil areas and facilitating improved energy density of the battery cell. Furthermore, after the first hollow foil areas are bent and electrically connected to the electrode terminals, the connection area between the first hollow foil areas and the electrode terminals is increased, resulting in a higher connection strength.

[0020] In some embodiments of the present application, the electrode assembly further includes a diaphragm, which is disposed between the first electrode plate and the second electrode plate. The diaphragm has a second notch. When viewed along the first direction, the first empty foil area at least partially overlaps with the second notch.

[0021] In the above technical solution, the electrode assembly also includes a diaphragm, which is arranged between the first electrode plate and the second electrode plate. The diaphragm has a second notch. When viewed along the first direction, the first empty foil area and the second notch at least partially overlap, so that the second notch can be used to accommodate the first empty foil area, which can facilitate the folding and connection of multiple first empty foil areas.

[0022] In some embodiments of the present application, the second electrode is provided with a second empty foil area, and a plurality of second empty foil areas are gathered and bent, and the plurality of second empty foil areas are electrically connected to the housing.

[0023] In the above technical solution, the second electrode sheet is provided with a second empty foil area, and multiple second empty foil areas are gathered and bent. The multiple second empty foil areas are electrically connected to the shell, so that the load can be electrically connected to the electrode assembly through the shell and the electrode terminal, which facilitates the battery cell to provide electrical energy to the load.

[0024] In some embodiments of the present application, the first electrode is a positive electrode, and the second electrode is a negative electrode.

[0025] In some embodiments of the present application, a first through hole is provided on the wall of the shell, and the battery cell further includes a connecting plate and a sealing member. The connecting plate is a metal plate, which is arranged at the first through hole and connected to the shell. A second through hole is provided on the connecting plate, and the electrode terminal is provided through the second through hole. The sealing member is arranged between the connecting plate and the electrode terminal.

[0026] In the above technical solution, a first through hole is provided on the wall of the shell, and the battery cell also includes a connecting piece and a sealing member. The connecting piece is a metal piece, which is provided at the first through hole and connected to the shell, so that the electrode terminal can be directly installed on the shell. The preparation and installation of the electrode terminal are less difficult and have better versatility. A second through hole is provided on the connecting piece, and the electrode terminal is provided through the second through hole. The sealing member is provided between the connecting piece and the electrode terminal, so that the sealing member can realize the sealing of the electrode terminal. The connection between the connecting piece and the wall can realize the sealing of the shell and the electrode terminal, thereby making the sealing effect of the battery cell better.

[0027] In some embodiments of the present application, the electrode terminal includes a first conductive member, a second conductive member, and a third conductive member, wherein the first conductive member is located on a first side of the connecting sheet along a thickness direction thereof, the second conductive member is located on a second side of the connecting sheet along the thickness direction thereof, opposite to the first side, and the third conductive member is disposed through the second through-hole, and the third conductive member is electrically connected to the first conductive member and the second conductive member;

[0028] The sealing member includes a first sealing member and a second sealing member. The first sealing member is arranged between the first conductive member and the connecting piece, and the second sealing member is arranged between the second conductive member and the connecting piece.

[0029] In the above technical solution, the electrode terminal includes a first conductive member, a second conductive member and a third conductive member. The first conductive member is located on the first side of the connecting piece along the thickness direction thereof, and can be used to achieve electrical connection with other components located on the first side of the connecting piece; the second conductive member is located on the second side of the connecting piece along the thickness direction thereof, which is opposite to the first side, and can be used to achieve electrical connection with other components located on the second side of the connecting piece; the third conductive member is arranged through the second through hole, and the third conductive member electrically connects the first conductive member and the second conductive member, so that the component electrically connected to the first conductive member and the component electrically connected to the second conductive member can be electrically connected; the sealing member includes a first sealing member and a second sealing member. The first sealing member is arranged between the first conductive member and the connecting piece, and can achieve sealing between the first conductive member and the connecting piece; the second sealing member is arranged between the second conductive member and the connecting piece, and can achieve sealing between the second conductive member and the connecting piece. By providing the first sealing member and the second sealing member, the reliability of the sealing can be improved.

[0030] In a second aspect, the present application provides an electrical device, comprising a battery cell as described above, the battery cell being used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can also be obtained based on these drawings.

[0032] FIG1 is a schematic diagram of the three-dimensional structure of a battery cell provided in some embodiments of the present application;

[0033] FIG2 is a schematic diagram of an exploded structure of a battery cell provided in some embodiments of the present application from one perspective;

[0034] FIG3 is a schematic structural diagram of a first electrode piece of a battery cell provided in some embodiments of the present application;

[0035] FIG4 is a schematic structural diagram of a second pole piece of a battery cell provided in some embodiments of the present application;

[0036] FIG5 is a schematic structural diagram of a battery cell provided in some embodiments of the present application from one perspective;

[0037] FIG6 is a schematic cross-sectional view of the battery cell in FIG5 along the AA direction;

[0038] FIG7 is a schematic diagram of a partial enlarged structure of a cell at position C in FIG6 ;

[0039] FIG8 is a schematic diagram of an exploded structure of a battery cell provided in some embodiments of the present application from another perspective;

[0040] FIG9 is a schematic cross-sectional view of a portion of the battery cell structure along line BB in FIG5 ;

[0041] FIG10 is a schematic structural diagram of a first current collector of a battery cell provided in some embodiments of the present application;

[0042] FIG11 is a schematic diagram of the structure of a diaphragm of a battery cell provided in some embodiments of the present application;

[0043] FIG12 is a schematic cross-sectional view of a partial structure of a battery cell provided in some embodiments of the present application;

[0044] FIG13 is an exploded schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0045] FIG14 is a schematic diagram of the three-dimensional structure of battery cells provided in other embodiments of the present application;

[0046] FIG15 is a schematic structural diagram of a battery cell from one perspective provided in other embodiments of the present application.

[0047] Icons: 10-cell; 100-housing; 101-first through hole; 110-housing; 111-first surface; 1111-groove; 112-opening; 120-second surface; 130-first sidewall; 140-second sidewall; 150-third sidewall; 200-electrode assembly; 210-first pole piece; 210a-first current collector; 210b-first active material layer; 211-first empty foil area; 2111-first section; 2112-second section; 212-body; 220-second pole piece; 221-first notch; 222-second empty area Foil area; 230 - diaphragm; 231 - second notch; 310 - electrode terminal; 311 - first conductive member; 312 - second conductive member; 3121 - plug hole; 3122 - second end surface; 3121 - plug hole; 313 - third conductive member; 3131 - first portion; 3132 - second portion; 3133 - step surface; 3134 - first end surface; 320 - connecting piece; 301 - second through hole; 330 - sealing member; 331 - first sealing member; 332 - second sealing member; X - first direction; Y - length direction of the housing; Z - width direction of the housing.

[0048] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0049] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0050] The terms "first", "second" and the like in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0051] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0052] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0053] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0054] With the development of the new energy industry, batteries are gradually developing towards high energy density and high power density. However, at present, the electrode terminals of battery cells are generally set through the shell in the length or width direction of the shell. A portion of the electrode terminal is accommodated between the inner wall of the shell and the electrode assembly. The hollow foil area of ​​the positive or negative electrode sheet of the electrode assembly is folded and bent before being connected to the electrode terminal. Therefore, a large space must be reserved between the electrode assembly and the shell to accommodate the bent hollow foil area and the electrode terminal, which affects the energy density of the battery cell. The other part of the electrode terminal protrudes from the shell and is prone to interference with other components, making the subsequent preparation of the battery cell more complicated.

[0055] In order to improve the energy density of a battery cell and reduce interference with other components, the present application provides a battery cell, which includes a shell, an electrode assembly and an electrode terminal. The electrode assembly is arranged in the shell, and the electrode assembly includes a plurality of first pole pieces and a plurality of second pole pieces stacked along a first direction. The polarity of the first pole piece is opposite to that of the second pole piece. A first empty foil area is formed at a first corner of the first pole piece, and the second pole piece has a first notch. When viewed along the first direction, the first empty foil area and the first notch at least partially overlap; the electrode terminal is arranged on the wall of the shell and is electrically connected to the first empty foil area. The electrode terminal does not protrude from the shell along the length, width and thickness directions of the shell. The first direction is the thickness direction of the shell.

[0056] In a battery cell of this structure, the electrode assembly is arranged in the shell, so that the shell can protect the electrode assembly; the electrode assembly includes a plurality of first pole pieces and a plurality of second pole pieces stacked along a first direction, the polarity of the first pole piece is opposite to that of the second pole piece, a first empty foil area is formed at a first corner of the first pole piece, and the second pole piece has a first notch. When viewed along the first direction, the first empty foil area and the first notch at least partially overlap. The first direction is the thickness direction of the shell, which can reduce the volume of the first empty foil area protruding from the first pole piece. The space reserved between the electrode assembly and the shell for accommodating the first empty foil area is small, which can provide The energy density of the battery cell is high, and when the battery cell is subjected to external force or falls, the electrode assembly is less likely to shake relative to the shell, and the possibility of short-circuiting between the first empty foil area and the second electrode piece is also smaller, thereby reducing the risk of thermal runaway of the battery cell; by locating the first empty foil area at the first corner of the first electrode piece, the preparation of the first empty foil area can be facilitated; the electrode terminal is arranged on the wall of the shell and is electrically connected to the first empty foil area. Along the length, width and thickness directions of the shell, the electrode terminal does not protrude from the shell, which can reduce the possibility of interference between the electrode terminal and other components, and is conducive to reducing the complexity of the subsequent preparation process.

[0057] The battery cells provided in the embodiments of the present application can be secondary batteries or primary batteries, such as lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, and are not limited to this embodiment of the present application. The battery cells can be cylindrical, flat, rectangular, or in other shapes, and are not limited to this embodiment of the present application.

[0058] The embodiments of the present application provide an electrical device that uses a battery cell as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, and the like.

[0059] Referring to Figures 1 to 4, Figure 1 is a schematic diagram of the three-dimensional structure of the battery cell provided in some embodiments of the present application; Figure 2 is a schematic diagram of the exploded structure of the battery cell provided in some embodiments of the present application from one perspective; Figure 3 is a schematic diagram of the structure of the first electrode piece of the battery cell provided in some embodiments of the present application; Figure 4 is a schematic diagram of the structure of the second electrode piece of the battery cell provided in some embodiments of the present application.

[0060] The present embodiment provides a battery cell 10, comprising a housing 100, an electrode assembly 200, and an electrode terminal 310. The electrode assembly 200 is disposed within the housing 100 and includes a plurality of first electrode sheets 210 and a plurality of second electrode sheets 220 stacked along a first direction X. The first electrode sheets 210 and the second electrode sheets 220 have opposite polarities. A first hollow foil region 211 is formed at a first corner of the first electrode sheet 210, and the second electrode sheet 220 has a first notch 221. When viewed along the first direction X, the first hollow foil region 211 at least partially overlaps the first notch 221. The electrode terminal 310 is disposed on a wall of the housing 100 and electrically connected to the first hollow foil region 211. The electrode terminal 310 does not protrude from the housing 100 along the length direction Y, the width direction Z, and the thickness direction of the housing. The first direction X is the thickness direction of the housing.

[0061] By disposing the electrode assembly 200 in the housing 100 , the housing 100 can protect the electrode assembly 200 . The electrode assembly 200 includes a plurality of first electrode sheets 210 and a plurality of second electrode sheets 220 stacked along a first direction X. The polarity of the first electrode sheet 210 is opposite to that of the second electrode sheet 220. A first hollow foil area 211 is formed at a first corner of the first electrode sheet 210, and the second electrode sheet 220 has a first notch 221. When viewed along the first direction X, the first hollow foil area 211 and the first notch 221 at least partially overlap. The first direction X is the thickness direction of the shell, which can reduce the volume of the first hollow foil area 211 protruding from the first electrode sheet 210. The space reserved between the electrode assembly 200 and the shell 100 for accommodating the first hollow foil area 211 is small, which can improve the energy density of the battery cell 10. When the battery cell 10 is subjected to external force or falls, the electrode assembly 200 is less likely to shake relative to the shell 100, and the possibility of short circuit between the first hollow foil area 211 and the second electrode sheet 220 is also less, thereby reducing the risk of thermal runaway of the battery cell 10. By locating the first hollow foil region 211 at the first corner of the first electrode piece 210, the preparation of the first hollow foil region 211 can be facilitated. The electrode terminal 310 is disposed on the wall of the housing 100 and is electrically connected to the first hollow foil region 211. The electrode terminal 310 does not protrude from the housing 100 along the length direction Y, the width direction Z, and the thickness direction of the housing. This reduces the possibility of interference between the electrode terminal 310 and other components, thereby reducing the complexity of subsequent preparation processes.

[0062] In some embodiments, the shell 100 can be made of a material with higher strength, such as metal materials such as steel, aluminum alloy, etc., so that the shell 100 has higher force-bearing performance, and thus the shell 100 is not easily deformed or damaged due to force or environmental changes, thereby making the battery cell 10 more reliable.

[0063] In other embodiments, the housing 100 may also be made of non-metallic materials with relatively high strength, such as carbon fiber, hard plastic, etc.

[0064] 5 to 7 , FIG5 is a schematic structural diagram of a battery cell provided in some embodiments of the present application from one perspective; FIG6 is a schematic cross-sectional structural diagram of the battery cell in FIG5 along the AA direction; and FIG7 is a schematic partial enlarged structural diagram of point C of the battery cell in FIG6 .

[0065] In some embodiments, the housing 100 has a first surface 111 and a second surface 120 that are opposite each other along a first direction X. A groove 1111 is formed at a second corner of the first surface 111 and is recessed toward the second surface 120. When viewed along the first direction X, the groove 1111 at least partially overlaps with the first hollow foil region 211. The electrode terminal 310 is disposed on the bottom wall of the groove 1111.

[0066] The housing 100 has a first surface 111 and a second surface 120 that are opposite to each other along a first direction X. A groove 1111 is formed at a second corner of the first surface 111 and is recessed toward the second surface 120. When viewed along the first direction X, the groove 1111 at least partially overlaps with the first empty foil area 211. The electrode terminal 310 is disposed on the bottom wall of the groove 1111 so that a portion of the electrode terminal 310 located outside the housing 100 can be accommodated in the groove 1111, thereby preventing the electrode terminal 310 from protruding from the housing 100 in the length direction Y, the width direction Z, and the thickness direction of the housing.

[0067] In some embodiments, the groove 1111 can be formed by partial stretching or stamping.

[0068] In some embodiments, the edge of the groove 1111 is straight, so that the groove 1111 occupies a smaller space, which is beneficial for improving the energy density of the battery cell 10 .

[0069] In other embodiments, the edge of the groove 1111 may also be in other shapes such as an arc shape or a broken line shape.

[0070] Please also refer to Figure 8, which is a schematic diagram of the exploded structure of the battery cell provided in some embodiments of the present application from another perspective.

[0071] In some embodiments, the housing 100 includes a shell 110 and a cover. The shell 110 includes a first surface 111 and has an opening 112 formed on a side opposite to the first surface 111 . The cover includes a second surface 120 and covers the opening 112 .

[0072] The housing 100 includes a shell 110 and a cover. The shell 110 includes a first surface 111 and an opening 112 is formed on a side opposite to the first surface 111. The cover includes a second surface 120. The cover covers the opening 112, so that the electrode terminal 310 is spaced farther from the cover. When the cover and the shell 110 are connected by welding, less heat is transferred to the electrode terminal 310, and the impact on the sealing between the electrode terminal 310 and the shell 110 is less.

[0073] In other embodiments, the housing 110 and the cover may be connected by adhesive bonding.

[0074] In other embodiments, the housing 100 includes a shell 110 and a cover. The shell 110 includes a first surface 111 and a second surface 120 , and an opening 112 is formed on one side in the thickness direction of the shell. The cover covers the opening 112 .

[0075] In other embodiments, the housing 100 includes a shell 110 and a cover, the shell 110 includes a first surface 111, and an opening 112 is formed on a side opposite to the first surface 111, the cover includes a second surface 120, and a second opening (not shown in the figure) is formed on a side opposite to the second surface 120, and the second opening of the cover covers the opening 112 of the shell 110.

[0076] Refer to FIG9 , which is a schematic cross-sectional view of a portion of the battery cell structure along line BB in FIG5 .

[0077] In some embodiments, the plurality of first empty foil regions 211 are gathered along the first direction X and electrically connected to the electrode terminal 310 .

[0078] The plurality of first empty foil areas 211 are gathered along the first direction X and electrically connected to the electrode terminal 310, which can make the connection method of the plurality of first empty foil areas 211 simpler and easier to operate, and facilitate the electrical connection of the plurality of first empty foil areas 211 to the electrode terminal 310, and can make the size of the first empty foil areas 211 smaller in the extension direction thereof, so that the space occupied by the first empty foil areas 211 is smaller, which is beneficial to improving the energy density of the battery cell 10; and the first empty foil areas 211 can be directly electrically connected to the electrode terminal 310 without being bent, which can further reduce the internal space of the shell 100 occupied by the first empty foil areas 211, which is beneficial to further improving the energy density of the battery cell 10.

[0079] In some embodiments, the first empty foil area 211 is welded to the electrode terminal 310, which can increase the connection strength between the first empty foil area 211 and the electrode terminal 310. When the battery cell 10 is subjected to external force, the probability of the first empty foil area 211 being separated from the electrode terminal 310 is small, which is beneficial to improving the reliability of the battery cell 10.

[0080] In some embodiments, the first empty foil area 211 and the electrode terminal 310 are made of the same material, which facilitates welding connection between the first empty foil area 211 and the electrode terminal 310 .

[0081] In other embodiments, the first empty foil area 211 and the electrode terminal 310 may also be connected by adhesive bonding.

[0082] In other embodiments, the battery cell 10 may further include a first adapter (not shown in the figure), which is welded to the first empty foil area 211 and the electrode terminal 310, respectively, so that the connection strength between the first adapter and the first empty foil area 211 and the electrode terminal 310 is higher. When the battery cell 10 is subjected to external force, the probability of the first adapter being separated from the first empty foil area 211 and the electrode terminal 310 is small, which is beneficial to improving the reliability of the battery cell 10.

[0083] In some embodiments, the first adapter is made of the same material as the first empty foil area 211 and / or the electrode terminal 310 , which facilitates welding connection between the first adapter and the first empty foil area 211 and / or the electrode terminal 310 .

[0084] 3 and 10 , FIG10 is a schematic structural diagram of a first current collector of a battery cell provided in some embodiments of the present application.

[0085] In some embodiments, the first electrode 210 includes a first current collector 210a and a first active material layer 210b. The first active material layer 210b is arranged on at least one side of the first current collector 210a along its thickness direction. The first current collector 201a includes a first empty foil area 211 and a main body 212.

[0086] In some embodiments, the first empty foil area 211 includes a first section 2111 and a second section 2112. The first section 2111 is connected to the main body 212, and the second section 2112 is connected to the side of the first section 2111 away from the main body 212. The first section 2111 is arranged in a rectangular shape, and the second section 2112 is arranged in a triangular shape, which can facilitate the folding of multiple first empty foil areas 211. In addition, the area of ​​the first empty foil area 211 is large, the connection area between the multiple first empty foil areas 211 is large, and the connection strength is large.

[0087] Before the multiple first empty foil areas 211 are folded together, the first empty foil areas 211 protrude from the main body 212 along the length direction Y of the shell, so that the area of ​​the first empty foil areas 211 is larger, the connection area between the multiple first empty foil areas 211 is larger, and the connection strength is greater.

[0088] See FIG11 , which is a schematic structural diagram of a diaphragm of a battery cell provided in some embodiments of the present application.

[0089] In some embodiments, the electrode assembly 200 further includes a diaphragm 230 , which is disposed between the first electrode piece 210 and the second electrode piece 220 . The diaphragm 230 has a second notch 231 . When viewed along the first direction X, the first empty foil area 211 and the second notch 231 at least partially overlap.

[0090] By arranging the diaphragm 230 between the first electrode 210 and the second electrode 220, the diaphragm 230 has a second notch. When viewed along the first direction X, the first empty foil area 211 and the second notch 231 at least partially overlap, so that the second notch 231 can be used to accommodate the first empty foil area 211, which can facilitate the folding and connection of multiple first empty foil areas 211.

[0091] In some embodiments, the second electrode 220 is provided with a second empty foil area 222 , and a plurality of second empty foil areas 222 are gathered and bent, and the plurality of second empty foil areas 222 are electrically connected to the housing 100 .

[0092] The second electrode sheet 220 is provided with a second empty foil area 222, and multiple second empty foil areas 222 are gathered and bent. The multiple second empty foil areas 222 are electrically connected to the shell 100, so that the load can be electrically connected to the electrode assembly 200 through the shell 100 and the electrode terminal 310, which facilitates the battery cell 10 to provide electrical energy to the load.

[0093] In some embodiments, the second hollow foil area 222 is welded to the outer shell 100, which can increase the connection strength between the second hollow foil area 222 and the outer shell 100. When the battery cell 10 is subjected to external force, the probability of the second hollow foil area 222 being separated from the outer shell 100 is small, which is beneficial to improving the reliability of the battery cell 10.

[0094] In some embodiments, the second empty foil area 222 is made of the same material as the housing 100 , which facilitates welding connection between the second empty foil area 222 and the housing 100 .

[0095] In other embodiments, the second empty foil area 222 and the housing 100 may also be connected by adhesive bonding.

[0096] In other embodiments, the battery cell 10 may further include a second adapter (not shown in the figure), which is welded to the second empty foil area 222 and the outer shell, respectively, so that the connection strength between the second adapter and the second empty foil area 222 and the outer shell 100 is higher. When the battery cell 10 is subjected to external force, the probability of the second adapter being separated from the second empty foil area 222 and the outer shell 100 is small, which is beneficial to improving the reliability of the battery cell 10.

[0097] In some embodiments, the second adapter is made of the same material as the second empty foil area 222 and / or the housing 100 , which facilitates welding connection between the second adapter and the second empty foil area 222 and / or the housing 100 .

[0098] In some embodiments, the first electrode 210 is a positive electrode, and the second electrode 220 is a negative electrode.

[0099] The battery cell 10 includes a housing 100, an electrode assembly 200 and an electrolyte, and the housing 100 is used to accommodate the electrode assembly 200 and the electrolyte. The electrode assembly 200 is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell 10 mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The part of the positive electrode collector that is not coated with the positive electrode active material layer serves as the first empty foil area (i.e., the positive electrode ear) to realize the input or output of electrical energy of the positive electrode sheet through the first empty foil area. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary material or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The portion of the negative electrode current collector not coated with the negative electrode active material layer serves as the negative electrode tab, through which electrical energy is input or output from the negative electrode sheet. The negative electrode current collector can be made of copper, and the negative electrode active material can be made of carbon or silicon. The separator can be made of polypropylene (PP) or polyethylene (PE). The electrolyte can include organic solvents, lithium electrolyte salts, etc.

[0100] In some embodiments, the electrode assembly 200 may be a laminated structure formed by stacking a negative electrode sheet, a separator, and a positive electrode sheet.

[0101] In other embodiments, the electrode assembly 200 may also be a wound structure formed by winding a negative electrode sheet, a separator, and a positive electrode sheet.

[0102] In some embodiments, the electrode terminal 310 may be made of aluminum to facilitate connection with the first empty foil area 211 .

[0103] 1 , 7 , 12 and 13 , FIG12 is a schematic cross-sectional view of a partial structure of a battery cell provided in some embodiments of the present application; FIG13 is an exploded schematic view of a partial structure of a battery cell provided in some embodiments of the present application.

[0104] In some embodiments, a first through hole 101 is provided on the wall of the outer shell 100, and the battery cell 10 further includes a connecting piece 320 and a sealing member 330. The connecting piece 320 is a metal piece. The connecting piece 320 is provided at the first through hole 101 and is connected to the outer shell 100. A second through hole 301 is provided on the connecting piece 320, and the electrode terminal 310 is provided through the second through hole 301. The sealing member 330 is provided between the connecting piece 320 and the electrode terminal 310.

[0105] By setting a first through hole 101 on the wall of the shell 100, the battery cell 10 also includes a connecting piece 320 and a sealing member 330. The connecting piece 320 is a metal piece. The connecting piece 320 is set at the first through hole 101 and is connected to the shell 100, and the electrode terminal 310 can be directly installed on the shell 110. The preparation and installation of the electrode terminal 310 are less difficult and have better versatility; a second through hole 301 is set on the connecting piece 320, and the electrode terminal 310 is set through the second through hole 301. The sealing member 330 is set between the connecting piece 320 and the electrode terminal 310, so that the sealing member 330 can achieve the sealing of the electrode terminal 310. The connection between the connecting piece 320 and the wall can achieve the sealing of the shell 100 and the electrode terminal 310, so that the sealing effect of the battery cell 10 is better.

[0106] In some embodiments, the connecting piece 320 is welded to the shell 100, which can increase the connection strength between the connecting piece 320 and the shell 100. When the battery cell 10 is subjected to external force, the probability of the connecting piece 320 being separated from the shell 100 is small, which is beneficial to improving the reliability of the battery cell 10.

[0107] In some embodiments, the shell 100 may be made of steel, and the connecting piece 320 may be made of steel, so as to facilitate welding connection between the connecting piece 320 and the shell 100 .

[0108] In other embodiments, the shell 100 may be made of nickel-plated steel, and the connecting piece 320 may be made of nickel, so as to facilitate welding connection between the connecting piece 320 and the shell 100 .

[0109] The shell 100 is made of steel or nickel-plated steel, so that the shell 100 has better electrolyte resistance, mechanical properties, and stretch forming ability.

[0110] In some embodiments, the thickness of the connecting sheet 320 is 0.05 mm-0.1 mm, for example, 0.05 mm, 0.08 mm, or 0.1 mm.

[0111] When the thickness of the connecting piece 320 is greater than or equal to 0.05 mm, the strength of the connecting piece 320 can be increased, and the possibility of the connecting piece 320 breaking when the battery cell 10 is subjected to force is reduced; when the thickness of the connecting piece 320 is less than or equal to 0.1 mm, the space occupied by the connecting piece 320 can be reduced, which is beneficial to improving the energy density of the battery cell 10; therefore, when the thickness of the connecting piece 320 is 0.05 mm-0.1 mm, the strength of the connecting piece 320 can be increased, and the possibility of the connecting piece 320 breaking when the battery cell 10 is subjected to force is reduced, and the space occupied by the connecting piece 320 can be reduced, which is beneficial to improving the energy density of the battery cell 10.

[0112] In some embodiments, the electrode terminal 310 includes a first conductive member 311, a second conductive member 312 and a third conductive member 313. The first conductive member 311 is located on a first side of the connecting piece 320 along its thickness direction, the second conductive member 312 is located on a second side of the connecting piece 320 along its thickness direction opposite to the first side, and the third conductive member 313 is arranged through the second through hole 301. The third conductive member 313 electrically connects the first conductive member 311 and the second conductive member 312.

[0113] The electrode terminal 310 includes a first conductive member 311, a second conductive member 312, and a third conductive member 313. The first conductive member 311 is located on a first side of the connecting sheet 320 along its thickness direction and can be used to electrically connect to other components located on the first side of the connecting sheet 320. The second conductive member 312 is located on a second side of the connecting sheet 320, opposite the first side along its thickness direction, and can be used to electrically connect to other components located on the second side of the connecting sheet 320. The third conductive member 313 is disposed through the second through-hole 301 and electrically connects the first conductive member 311 and the second conductive member 312, thereby enabling electrical connection between components electrically connected to the first conductive member 311 and components electrically connected to the second conductive member 312.

[0114] In some embodiments, the seal 330 includes a first seal 331 and a second seal 332 . The first seal 331 is disposed between the first conductive member 311 and the connecting piece 320 , and the second seal 332 is disposed between the second conductive member 312 and the connecting piece 320 .

[0115] The sealing member 330 includes a first sealing member 331 and a second sealing member 332. The first sealing member 331 is disposed between the first conductive member 311 and the connecting piece 320 to achieve a seal between the first conductive member 311 and the connecting piece 320. The second sealing member 332 is disposed between the second conductive member 312 and the connecting piece 320 to achieve a seal between the second conductive member 312 and the connecting piece 320. The provision of the first sealing member 331 and the second sealing member 332 for the two sealing members 330 improves the reliability of the seal.

[0116] In some embodiments, the material of the first sealing member 331 and the second sealing member 332 may be polypropylene (PP), so that the sealing effect of the first sealing member 331 and the second sealing member 332 is better.

[0117] In some embodiments, the first conductive member 311 and the third conductive member 313 are integrally formed, a plug hole 3121 is provided on the second conductive member 312, a portion of the third conductive member 313 is plugged into the plug hole 3121, and is electrically connected to the second conductive member 312 in the plug hole 3121.

[0118] By integrally forming the first and third conductive members 311 and 313, the overall structure of the first and third conductive members 311 and 313 is further stabilized, and the preparation process of the electrode terminal 310 is simplified. By providing the insertion hole 3121 on the second conductive member 312, a portion of the third conductive member 313 is inserted into the insertion hole 3121 and electrically connected to the second conductive member 312 within the insertion hole 3121. This allows the second and third conductive members 312 and 313 to be connected by insertion, and the second conductive member 312 is less likely to move relative to the third conductive member 313. This further stabilizes the overall structure of the electrode terminal 310 and improves the reliability of the electrical connection between the second and third conductive members 312 and 313.

[0119] In other embodiments, the first conductive member 311 , the second conductive member 312 , and the third conductive member 313 may be integrally formed, that is, the electrode terminal 310 may be formed by riveting.

[0120] In some embodiments, the third conductive member 313 includes a first portion 3131 and a second portion 3132 connected to each other, the first portion 3131 is inserted into the plug hole 3121, the second portion 3132 is located between the first portion 3131 and the first conductive member 311, and the cross-sectional area of ​​the first portion 3131 is smaller than the cross-sectional area of ​​the second portion 3132, so that a step surface 3133 is formed between the first portion 3131 and the second portion 3132; the second conductive member 312 abuts against the step surface 3133.

[0121] The cross section of the first portion 3131 is the cross section of the first portion 3131 on a plane parallel to the thickness direction of the connecting piece 320 , and the cross section of the second portion 3132 is the cross section of the second portion 3132 on a plane parallel to the thickness direction of the connecting piece 320 .

[0122] The third conductive member 313 includes a first portion 3131 and a second portion 3132 that are connected. The first portion 3131 is inserted into the insertion hole 3121, and the second portion 3132 is located between the first portion 3131 and the first conductive member 311. The cross-sectional area of ​​the first portion 3131 is smaller than the cross-sectional area of ​​the second portion 3132, so that a step surface 3133 is formed between the first portion 3131 and the second portion 3132; the second conductive member 312 abuts against the step surface 3133, which can fix the distance between the second conductive member 312 and the first conductive member 311. When the second conductive member 312 is inserted into the third conductive member 313, the compression amount of the second conductive member 312 on the first sealing member 331 and the second sealing member 332 can be sufficient to achieve a better sealing effect, and the possibility of the first sealing member 331 and the second sealing member 332 being damaged by excessive squeezing by the second conductive member 312, thereby affecting the sealing effect, can be reduced.

[0123] In some embodiments, the third conductive element 313 has a first end surface 3134 facing away from the first conductive element 311 , and the second conductive element 312 has a second end surface 3122 facing away from the first conductive element 311 . The first end surface 3134 is flush with the second end surface 3122 .

[0124] The third conductive member 313 has a first end face 3134 facing away from the first conductive member 311, and the second conductive member 312 has a second end face 3122 facing away from the first conductive member 311. By making the first end face 3134 flush with the second end face 3122, when the second side of the electrode terminal 310 (the side where the first end face 3134 and the second end face 3122 are located) is electrically connected to other components by bonding, the first end face 3134 and the second end face 3122 can simultaneously serve as connection surfaces, so that the area of ​​the connection surface is larger, the connection force with other components is greater, and the reliability is better.

[0125] Among them, the flushness of the first end face 3134 and the second end face 3122 can be broadly understood, that is, when the distance between the plane where the first end face 3134 is located and the plane where the second end face 3122 is located in the thickness direction of the connecting piece 320 is within the error value range, the error range is generally within 1 mm, and they can be understood as being flush.

[0126] In other embodiments, the first end face 3134 may also be recessed relative to the second end face 3122, so that when the second side of the electrode terminal 310 (the side where the first end face 3134 and the second end face 3122 are located) is electrically connected to other components by bonding, the second end face 3122 can serve as a connection surface.

[0127] In other embodiments, the first end face 3134 may also protrude relative to the second end face 3122, so that when the second side of the electrode terminal 310 (the side where the first end face 3134 and the second end face 3122 are located) is electrically connected to other components by bonding, the first end face 3134 can serve as a connection surface.

[0128] 14 and 15 , FIG14 is a schematic diagram of the three-dimensional structure of battery cells provided in other embodiments of the present application; FIG15 is a schematic diagram of the structure of battery cells provided in other embodiments of the present application from one perspective.

[0129] In other embodiments, the housing 100 has a first side wall 130 at one end in the length direction Y, a second side wall 140 at one end in the width direction Z, and a third side wall 150 connecting the first side wall 130 and the second side wall 140, and the electrode terminal 310 is disposed on the third side wall 150.

[0130] This ensures that the portion of the electrode terminal 310 located outside the outer shell 100 does not protrude beyond the first side wall 130 in the length direction Y of the outer shell, and does not protrude beyond the second side wall 140 in the width direction Z of the outer shell, and the first empty foil area 211 can extend to the electrode terminal 310 in a direction perpendicular to the thickness direction of the third side wall 150. The first empty foil area 211 occupies a smaller space in the outer shell 100, which is beneficial to improving the energy density of the battery cell 10.

[0131] In some embodiments, the third sidewall 150 is disposed at an obtuse angle to the first sidewall 130 , and the third sidewall 150 is disposed at an obtuse angle to the second sidewall 140 .

[0132] By setting the third side wall 150 at an obtuse angle to the first side wall 130, and setting the third side wall 150 at an obtuse angle to the second side wall 140, a notch can be formed at a corner of the shell 100, so that the portion of the electrode terminal 310 located outside the shell 100 can be accommodated in the notch, thereby ensuring that the electrode terminal 310 does not protrude from the shell 100 along the length direction Y, the width direction and the thickness direction of the shell.

[0133] In some embodiments, the plurality of first empty foil regions 211 are gathered and bent along the first direction X, and the plurality of first empty foil regions 211 are electrically connected to the electrode terminal 310 .

[0134] By gathering and bending the plurality of first hollow foil regions 211 along the first direction X, the plurality of first hollow foil regions 211 are electrically connected to the electrode terminal 310. This simplifies the electrical connection of the plurality of first hollow foil regions 211, making it easier to operate and facilitate electrical connection of the plurality of first hollow foil regions 211 to the electrode terminal 310. Furthermore, the dimensions of the first hollow foil regions 211 in their extending direction are reduced, thereby reducing the space occupied by the first hollow foil regions 211 and facilitating improved energy density of the battery cell 10. Furthermore, after the first hollow foil regions 211 are bent and electrically connected to the electrode terminal 310, the connection area between the first hollow foil regions 211 and the electrode terminal 310 is increased, resulting in a higher connection strength.

[0135] An embodiment of the present application provides an electrical device, comprising a battery cell 10 according to any of the above solutions, and the battery cell 10 is used to provide electrical energy to the electrical device.

[0136] The electrical device may be any of the aforementioned devices or systems using the battery cell 10 .

[0137] In some embodiments, the electrical device further includes a protection plate connected to the electrode terminal 310 , and the protection plate does not protrude from the housing 100 along the first direction X. This can make the overall structure of the battery cell 10 and the protection plate in the battery compartment of the electrical device more compact, thereby improving the space utilization of the battery compartment.

[0138] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0139] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: shell; an electrode assembly disposed in the housing, the electrode assembly comprising a plurality of first electrode sheets and a plurality of second electrode sheets stacked along a first direction, the first electrode sheets and the second electrode sheets having opposite polarities, a first hollow foil region formed at a first corner of the first electrode sheet, and a first notch formed in the second electrode sheet, such that when viewed along the first direction, the first hollow foil region at least partially overlaps with the first notch; The electrode terminal is arranged on the wall of the shell and is electrically connected to the first empty foil area. Along the length direction, width direction and thickness direction of the shell, the electrode terminal does not protrude from the shell, and the first direction is the thickness direction of the shell.

2. The battery cell according to claim 1, characterized in that The housing has a first surface and a second surface opposite to each other along the first direction, a groove is formed at the second corner of the first surface and is recessed toward the second surface; when viewed along the first direction, the groove at least partially overlaps with the first empty foil area; The electrode terminal is arranged on the bottom wall of the groove.

3. The battery cell according to claim 2, characterized in that The housing includes a shell and a cover. The shell includes the first surface and has an opening formed on a side opposite to the first surface. The cover includes the second surface and covers the opening.

4. The battery cell according to claim 2, characterized in that The plurality of first empty foil areas are gathered along the first direction and electrically connected to the electrode terminals.

5. The battery cell according to claim 1, characterized in that The housing includes a first side wall at one end in the length direction, a second side wall at one end in the width direction, and a third side wall connecting the first side wall and the second side wall, and the electrode terminal is provided on the third side wall.

6. The battery cell according to claim 5, characterized in that The third side wall is disposed at an obtuse angle to the first side wall, and the third side wall is disposed at an obtuse angle to the second side wall.

7. The battery cell according to claim 5, characterized in that The plurality of first empty foil areas are gathered and bent along the first direction, and the plurality of first empty foil areas are electrically connected to the electrode terminals.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The electrode assembly further includes a diaphragm, which is disposed between the first electrode piece and the second electrode piece. The diaphragm has a second notch. When viewed along the first direction, the first empty foil area at least partially overlaps with the second notch.

9. The battery cell according to any one of claims 1 to 7, characterized in that: The second electrode piece is provided with a second empty foil area, and a plurality of the second empty foil areas are gathered and bent, and the plurality of the second empty foil areas are electrically connected to the shell.

10. The battery cell according to any one of claims 1 to 7, characterized in that: The first pole piece is a positive pole piece, and the second pole piece is a negative pole piece.

11. The battery cell according to claim 1, characterized in that: A first through hole is provided on the wall of the shell, and the battery core also includes a connecting piece and a sealing member. The connecting piece is a metal piece, which is arranged at the first through hole and connected to the shell. A second through hole is provided on the connecting piece, and the electrode terminal is provided through the second through hole. The sealing member is arranged between the connecting piece and the electrode terminal.

12. The battery cell according to claim 11, characterized in that The electrode terminal includes a first conductive member, a second conductive member, and a third conductive member, wherein the first conductive member is located on a first side of the connecting piece along the thickness direction thereof, the second conductive member is located on a second side of the connecting piece along the thickness direction thereof opposite to the first side, and the third conductive member is disposed through the second through hole and electrically connects the first conductive member and the second conductive member; The sealing member includes a first sealing member and a second sealing member. The first sealing member is disposed between the first conductive member and the connecting piece, and the second sealing member is disposed between the second conductive member and the connecting piece.

13. An electrical device, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 12, wherein the battery cell is used to provide electrical energy.

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