Battery cell and electric device

Abstract

The application provides an electric core and an electric device. The electric core comprises a laminated electrode assembly, the electrode assembly comprises a plurality of first pole pieces and a plurality of second pole pieces which are arranged in a first direction, one corner of each first pole piece is provided with a first notch and a first empty foil area, one corner of each second pole piece is provided with a second notch and a second empty foil area, the first empty foil area and the second notch at least partially overlap when viewed in the first direction, the second empty foil area and the first notch at least partially overlap, and the first empty foil area and the second empty foil area are arranged at intervals. The plurality of first empty foil areas are arranged in the first direction, and the plurality of second empty foil areas are arranged in the first direction. The space reserved between the electrode assembly and the shell for accommodating the first empty foil area and the second empty foil area can be reduced, the energy density of the electric core can be improved, and the possibility of the electrode assembly shaking relative to the shell and the possibility of the electric core short-circuiting are smaller when the electric core is subjected to external force or falls.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery cell and a power consumption device. BACKGROUND

[0002] With the rapid development of electronic information technology, various electronic devices are also developing towards intelligence and multifunction, and the requirements for various performances of batteries are also becoming higher and higher.

[0003] At present, the tab of the electrode assembly is generally led out from one end of the length direction of the electrode sheet, so that a larger space needs to be reserved between the shell for accommodating the electrode assembly and the one end of the electrode assembly provided with the tab to accommodate the tab, which affects the energy density of the battery cell, and causes the electrode assembly to easily shake relative to the shell when the battery cell is subjected to external force or falls, which may cause the tab to contact the electrode sheet and short circuit, thereby increasing the risk of thermal runaway of the battery cell. SUMMARY

[0004] The present application provides a battery cell and a power consumption device, which can improve the energy density of the battery cell and reduce the possibility of short circuit of the battery cell.

[0005] In a first aspect, the present application provides a battery cell, comprising an electrode assembly, the electrode assembly being a stacked plate structure, the electrode assembly comprising a plurality of first electrode sheets and a plurality of second electrode sheets stacked in a first direction, the first electrode sheets and the second electrode sheets being opposite in polarity; one corner position of each first electrode sheet has a first notch and a first empty foil area, and one corner position of each second electrode sheet has a second notch and a second empty foil area, as viewed in the first direction, the first empty foil area and the second notch at least partially overlap, the second empty foil area and the first notch at least partially overlap, and the first empty foil area and the second empty foil area are spaced apart; the first empty foil areas of the plurality of first electrode sheets are stacked in the first direction, and the second empty foil areas of the plurality of second electrode sheets are stacked in the first direction.

[0006] In the technical scheme, one corner of each first pole piece has a first gap and a first foil-free area, one corner of each second pole piece has a second gap and a second foil-free area, the first foil-free area and the second gap at least partially overlap when viewed in the first direction, the second foil-free area and the first gap at least partially overlap, the volume of the first foil-free area and the second foil-free area protruding from the first pole piece and the second pole piece can be reduced, the space reserved between the electrode assembly and the shell for accommodating the first foil-free area and the second foil-free area is reduced, the energy density of the battery cell can be improved, and when the battery cell is subjected to an external force or falls, the electrode assembly is less likely to shake relative to the shell, and the first foil-free area and the second pole piece and the second foil-free area and the first pole piece are less likely to contact and short circuit, thereby reducing the risk of thermal runaway of the battery cell. Moreover, the first foil-free area and the second foil-free area are located at the same corner of the electrode assembly, which can further reduce the space occupied by the first foil-free area and the second foil-free area and further improve the energy density of the battery cell; the first foil-free area and the second foil-free area are arranged at intervals, which can reduce the possibility of short circuit caused by contact between the first foil-free area and the second foil-free area; the first foil-free areas of the plurality of first pole pieces are arranged in a stack in the first direction, and the second foil-free areas of the plurality of second pole pieces are arranged in a stack in the first direction, which facilitates the connection of the plurality of first foil-free areas and the connection of the plurality of second foil-free areas, so that the external device can be electrically connected to the plurality of first pole pieces through the first foil-free area and electrically connected to the plurality of second pole pieces through the second foil-free area.

[0007] In some embodiments of the present application, the first gap and the second gap partially overlap when viewed in the first direction.

[0008] In the technical scheme, the first gap and the second gap partially overlap when viewed in the first direction, which can reserve a spacing space between the first foil-free area and the second foil-free area and reduce the possibility of short circuit caused by contact between the first foil-free area and the second foil-free area.

[0009] In some embodiments of the present application, the first pole piece has a first coating area, the first foil-free area does not exceed the first coating area in the length direction of the first pole piece, and the first foil-free area does not exceed the first coating area in the width direction of the first pole piece; the second pole piece has a second coating area, the second foil-free area does not exceed the second coating area in the length direction of the second pole piece, and the second foil-free area does not exceed the second coating area in the width direction of the second pole piece.

[0010] In the technical solution, along the length direction of the first pole piece, the first empty foil area does not exceed the first coating area, and along the width direction of the first pole piece, the first empty foil area does not exceed the first coating area, so that the first empty foil area does not protrude from the first pole piece, no space needs to be reserved between the electrode assembly and the shell for accommodating the first empty foil area, the energy density of the battery cell can be further improved, the possibility of the electrode assembly shaking relative to the shell when the battery cell is subjected to external force or falls is further reduced, the possibility of the first empty foil area being in contact with the second pole piece and short-circuiting is also further reduced, and thus the risk of the battery cell generating thermal runaway can be further reduced.

[0011] Along the length direction of the second pole piece, the second empty foil area does not exceed the second coating area, and along the width direction of the second pole piece, the second empty foil area does not exceed the second coating area, so that the second empty foil area does not protrude from the second pole piece, no space needs to be reserved between the electrode assembly and the shell for accommodating the second empty foil area, the energy density of the battery cell can be further improved, the possibility of the electrode assembly shaking relative to the shell when the battery cell is subjected to external force or falls is further reduced, the possibility of the second empty foil area being in contact with the first pole piece and short-circuiting is also further reduced, and thus the risk of the battery cell generating thermal runaway can be further reduced.

[0012] In some embodiments of the present application, the first coating area has a first edge in the length direction of the first pole piece, the first empty foil area has a second edge in the length direction of the first pole piece, and the first edge is flush with the second edge; and / or, the second coating area has a third edge in the width direction of the second pole piece, the second empty foil area has a fourth edge in the width direction of the second pole piece, and the third edge is flush with the fourth edge.

[0013] In the technical solution, by making the first edge flush with the second edge, the preparation of the first empty foil area can be facilitated; by making the third edge flush with the fourth edge, the preparation of the second empty foil area can be facilitated.

[0014] In some embodiments of the present application, the interval distance between the first empty foil area and the second empty foil area is D1, and 0.4mm≤D1≤1mm is satisfied.

[0015] In the technical solution, when the interval distance D1 between the first foil-free area and the second foil-free area is greater than or equal to 0.4 mm, the interval distance between the first foil-free area and the second foil-free area is relatively large, the possibility of short circuit between the first foil-free area and the second foil-free area is relatively small, and the risk of thermal runaway of the battery cell can be reduced; when the interval distance D1 between the first foil-free area and the second foil-free area is less than or equal to 1 mm, the interval distance between the first foil-free area and the second foil-free area is relatively small, the occupied interval space is relatively small, and the energy density of the battery cell can be improved; when the interval distance D1 between the first foil-free area and the second foil-free area is 0.4 mm-1 mm, the possibility of short circuit between the first foil-free area and the second foil-free area is relatively small, the risk of thermal runaway of the battery cell can be reduced, and the energy density of the battery cell can be improved.

[0016] In some embodiments of the present application, the battery cell further comprises a first insulating member, at least part of the first insulating member is arranged between the first foil-free area and the second foil-free area.

[0017] In the technical solution, by arranging the first insulating member between the first foil-free area and the second foil-free area, the possibility of short circuit between the first foil-free area and the second foil-free area can be reduced, and the risk of thermal runaway of the battery cell can be further reduced.

[0018] In some embodiments of the present application, the first insulating member wraps at least part of the plurality of first foil-free areas.

[0019] In the technical solution, by wrapping at least part of the plurality of first foil-free areas with the first insulating member, the insulation effect between the first foil-free area and the second foil-free area can be better, the possibility of short circuit between the first foil-free area and the second foil-free area can be further reduced, and the risk of thermal runaway of the battery cell can be further reduced.

[0020] In some embodiments of the present application, the battery cell further comprises a housing, the electrode assembly is arranged in the housing; viewed in the first direction, the first insulating member comprises a first insulating part and a second insulating part, the first insulating part is arranged between the first foil-free area and the second foil-free area, and the second insulating part is arranged between the first foil-free area and the inner wall of the housing.

[0021] In the technical solution, viewed in the first direction, the first insulating member comprises a first insulating part and a second insulating part, the first insulating part is arranged between the first foil-free area and the second foil-free area, and the second insulating part is arranged between the first foil-free area and the inner wall of the housing, so that the first insulating part can play an insulation role between the first foil-free area and the second foil-free area, the second insulating part can play an insulation role between the first foil-free area and the housing, the possibility of short circuit between the first foil-free area and the first foil-free area and between the first foil-free area and the housing can be reduced, and the risk of thermal runaway of the battery cell can be reduced.

[0022] In some embodiments of the present application, the battery cell further comprises an electrode terminal and a first adapter, the first adapter is connected with the plurality of first empty foil areas, the shell comprises a first wall, the electrode terminal is arranged on the first wall, a second insulating part is arranged between the first wall and the first empty foil areas, the electrode terminal passes through the second insulating part and is connected with the first adapter.

[0023] In the above technical solution, the battery cell further comprises an electrode terminal and a first adapter, the first adapter is connected with the plurality of first empty foil areas, the shell comprises a first wall, the electrode terminal is arranged on the first wall, a second insulating part is arranged between the first wall and the first empty foil areas, the electrode terminal passes through the second insulating part and is connected with the first adapter, so that the plurality of first empty foil areas can be electrically connected with external devices through the first adapter and the electrode terminal, the second insulating part can play an insulating role between the electrode terminal and the shell, reducing the possibility of contact short circuit between the first empty foil areas and the shell, and reducing the risk of thermal runaway of the battery cell.

[0024] In some embodiments of the present application, the first insulating part further comprises a third insulating part, the third insulating part is arranged on one side of the plurality of first empty foil areas along the first direction, and the third insulating part is connected with the first insulating part and the second insulating part.

[0025] In the above technical solution, by arranging the third insulating part on one side of the plurality of first empty foil areas along the first direction, and connecting the third insulating part with the first insulating part and the second insulating part, the first empty foil areas and the shell can be insulated in the first direction, reducing the possibility of contact short circuit between the first empty foil areas and the shell, and reducing the risk of thermal runaway of the battery cell.

[0026] In some embodiments of the present application, along the first direction, the first empty foil areas of the plurality of first pole pieces are gathered towards the middle to form a first gathered part, and the third insulating part bears the first gathered part.

[0027] In the above technical solution, along the first direction, the first empty foil areas of the plurality of first pole pieces are gathered towards the middle to form a first gathered part, which can make the connection mode of the plurality of first empty foil areas simpler and easier to operate, facilitate the connection of the plurality of first empty foil areas with the first adapter, and make the size of the first empty foil areas in the extension direction smaller, so that the first empty foil areas occupy less space, which is beneficial to improve the energy density of the battery cell; the third insulating part bears the first gathered part, which can facilitate the connection of the first adapter with the electrode terminal.

[0028] In some embodiments of the present application, along the first direction, the second empty foil areas of the plurality of second pole pieces are gathered towards the middle to form a second gathered part; the battery cell further comprises a second adapter, the second adapter is connected with the shell and the second gathered part.

[0029] In the technical solution, along the first direction, the second foil-free areas of the plurality of second tabs are folded towards the middle to form a second folded part, and the battery cell further comprises a second adapter, the second adapter connecting the shell and the second folded part, so that the connection mode of the plurality of second foil-free areas is simple, easy to operate, and convenient for the connection of the plurality of second foil-free areas with the first adapter, and the size of the second foil-free area in the extension direction thereof is small, so that the second foil-free area occupies a small space, which is beneficial to improve the energy density of the battery cell; and the plurality of second foil-free areas can be electrically connected with external devices through the second adapter and the shell.

[0030] In some embodiments of the present application, the second notch and the second foil-free area are located at one end of the second tab in the length direction of the second tab; the battery cell further comprises a shell, and the electrode assembly is accommodated in the shell; along the length direction of the second tab, the distance between the one end of the second tab provided with the second foil-free area and the second notch and the inner wall of the shell is D2, and 0.4mm≤D2≤1mm is satisfied.

[0031] In the technical solution, the second notch and the second foil-free area are located at one end of the second tab in the length direction of the second tab, so that the first foil-free area and the second foil-free area can be led out from the one end of the second tab in the length direction, which is convenient for the electrical connection of the battery cell with external devices through the first foil-free area and the second foil-free area; when along the length direction of the second tab, the distance D2 between the one end of the second tab provided with the second foil-free area and the second notch and the inner wall of the shell is greater than or equal to 0.4mm, the assembly of the electrode assembly and the shell is facilitated, and the shell is convenient for accommodating electrolyte; when along the length direction of the second tab, the distance D2 between the one end of the second tab provided with the second foil-free area and the second notch and the inner wall of the shell is less than or equal to 1mm, the spacing between the electrode assembly and the shell is small, and the energy density of the battery cell is high; therefore, when along the length direction of the second tab, the distance D2 between the one end of the second tab provided with the second foil-free area and the second notch and the inner wall of the shell is 0.4mm-1mm, the assembly of the electrode assembly and the shell is facilitated, the shell is convenient for accommodating electrolyte, and the energy density of the battery cell is high.

[0032] In some embodiments of the present application, the first notch is triangularly arranged; and / or, the second notch is triangularly arranged.

[0033] In the technical solution, the first notch is triangularly arranged, which is convenient for the preparation of the first notch, and the first notch occupies a small space, which is beneficial to improve the energy density of the battery cell; the second notch is triangularly arranged, which is convenient for the preparation of the second notch, and the second notch occupies a small space.

[0034] In some embodiments of the present application, the first foil-free area is triangularly arranged; and / or, the second foil-free area is triangularly arranged.

[0035] In the technical solution, the first foil-free area is triangular, which is convenient for preparation of the first foil-free area, convenient for folding of multiple first foil-free areas, and occupies a small space, which is conducive to improving the energy density of the battery cell.

[0036] In some embodiments of the present application, the first pole piece is a positive pole piece, and the second pole piece is a negative pole piece.

[0037] In a second aspect, the present application provides a power-using device, which comprises the battery cell as described above and is used to provide electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained from these drawings.

[0039] Figure 1 The three-dimensional structure schematic diagram of the battery cell provided for some embodiments of the present application is shown in the figure.

[0040] Figure 2 The exploded structure schematic diagram of the battery cell provided for some embodiments of the present application is shown in the figure.

[0041] Figure 3 The exploded structure schematic diagram of the electrode assembly of the battery cell provided for some embodiments of the present application is shown in the figure.

[0042] Figure 4 The structure schematic diagram of the first pole piece of the battery cell provided for some embodiments of the present application is shown in the figure.

[0043] Figure 5 The structure schematic diagram of the second pole piece of the battery cell provided for some embodiments of the present application is shown in the figure.

[0044] Figure 6 The local enlarged schematic diagram of the partial structure of the battery cell provided for some embodiments of the present application is shown in the figure.

[0045] Figure 7 The structure schematic diagram of the battery cell from one perspective provided for some embodiments of the present application is shown in the figure.

[0046] Figure 8 The local enlarged structure schematic diagram of the partial structure of the battery cell provided for some embodiments of the present application is shown in the figure.

[0047] Figure 9 The three-dimensional structure schematic diagram of the battery cell provided for some embodiments of the present application is shown in the figure. Figure 7Fig. 6 is a partial enlarged schematic view of a sectional structure of a middle battery cell along the A-A direction;

[0048] Figure 10 Fig. 7 is a partial enlarged schematic view of a sectional structure of a middle battery cell along the B-B direction; Figure 7

[0049] Figure 11 Fig. 8 is a partial enlarged schematic view of a sectional structure of a battery cell provided by another embodiment of the present application;

[0050] Figure 12 Fig. 9 is a partial enlarged schematic view of a sectional structure of a middle battery cell along the C-C direction; Figure 7

[0051] Figure 13 Fig. 10 is a structural schematic view of a separator of a battery cell provided by some embodiments of the present application;

[0052] Figure 14 Fig. 11 is a partial enlarged schematic view of a sectional structure of a middle battery cell along the E-E direction. Figure 7

[0053] Fig. 1 is a structural schematic view of a battery cell provided by some embodiments of the present application; DETAILED DESCRIPTION

[0054] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0055] ​​​Unless otherwise defined, all technical and scientific terms used in the present application have the same meanings as those commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The use of the terms "including," "comprising," or "having" in the description of the application herein is not intended to exclude or require the presence of any

[0056] The terms "first", "second", and the like, as used in the specification and claims of the application, are used for distinguishing between similar elements and not necessarily for describing a specific sequential or chronological order. Unless explicitly stated otherwise, the terms "first", "second", and the like are not intended to imply that a commitment to one of the referenced claims.

[0057] Reference throughout this application to "example" means that a particular feature, structure, or characteristic described in connection with the example is included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of other embodiments.

[0058] In the present application, "flush" does not mean strictly flush, but generally flush, as long as the tolerance is within 0.2mm, it can be considered as "flush".

[0059] In the embodiments of the present application, the same reference signs indicate the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the present application.

[0060] The battery cell includes a shell and an electrode assembly, the electrode assembly is accommodated in the shell, the electrode assembly includes a tab and a tab, the tab generally extends out of the shell from one end of the length direction of the tab to connect with an external device. Therefore, a larger space needs to be reserved between the shell and the one end of the electrode assembly provided with the tab to accommodate part of the tab, which causes the space in the shell for accommodating the tab to be compressed, affecting the energy density of the battery cell. Moreover, due to the larger spacing between the electrode assembly and the shell, when the battery cell is subjected to external force or falls, the electrode assembly is prone to shaking relative to the shell, while the tab is fixed relative to the shell, which may cause the tab to move relative to the tab and thus contact the tab, resulting in an increased risk of thermal runaway of the battery cell.

[0061] In order to improve the energy density of the battery cell and reduce the possibility of short circuit of the battery cell, the battery cell provided in the application includes an electrode assembly, the electrode assembly has a laminated structure, the electrode assembly includes a plurality of first pole pieces and a plurality of second pole pieces stacked along a first direction, the first pole pieces and the second pole pieces have opposite polarities; one corner position of each first pole piece has a first notch and a first empty foil area, one corner position of each second pole piece has a second notch and a second empty foil area, the first empty foil area and the second notch at least partially overlap when viewed along the first direction, the second empty foil area and the first notch at least partially overlap, and the first empty foil area and the second empty foil area are arranged in a spaced manner; the first empty foil areas of the plurality of first pole pieces are stacked along the first direction, and the second empty foil areas of the plurality of second pole pieces are stacked along the first direction.

[0062] In the battery cell with the above structure, one corner position of each first pole piece has a first notch and a first empty foil area, one corner position of each second pole piece has a second notch and a second empty foil area, the first empty foil area and the second notch at least partially overlap when viewed along the first direction, the second empty foil area and the first notch at least partially overlap, the volume of the first empty foil area and the second empty foil area protruding from the first pole pieces and the second pole pieces can be reduced, the space reserved between the electrode assembly and the shell for accommodating the first empty foil area and the second empty foil area is reduced, the energy density of the battery cell can be improved, and when the battery cell is subjected to external force or falls, the electrode assembly is less likely to shake relative to the shell, the first empty foil area is less likely to contact the second pole piece and the second empty foil area is less likely to contact the first pole piece, and the risk of thermal runaway of the battery cell can be reduced. In addition, the first empty foil area and the second empty foil area are located at the same corner position of the electrode assembly, which can further reduce the space occupied by the first empty foil area and the second empty foil area and further improve the energy density of the battery cell; the first empty foil area and the second empty foil area are arranged in a spaced manner, which can reduce the possibility of short circuit caused by contact between the first empty foil area and the second empty foil area; the first empty foil areas of the plurality of first pole pieces are stacked along the first direction, and the second empty foil areas of the plurality of second pole pieces are stacked along the first direction, which facilitates the connection of the plurality of first empty foil areas and the connection of the plurality of second empty foil areas, so that an external device can be electrically connected to the plurality of first pole pieces through the first empty foil area and electrically connected to the plurality of second pole pieces through the second empty foil area.

[0063] The battery cell provided in the embodiments of the application can be a secondary battery or a primary battery, for example, can be a lithium ion battery, a sodium ion battery or a magnesium ion battery, etc., and the embodiments of the application are not limited in this regard. The electrochemical device can have a cylindrical shape, a flat shape, a cuboid shape or other shapes, and the embodiments of the application are not limited in this regard.

[0064] The embodiments of the application provide a power consumption device using the battery cell as a power source, and the power consumption device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, etc.

[0065] Referring to Figures 1 to 5 , Figure 1 A perspective structural schematic diagram of an electric core provided for some embodiments of the present application is shown in FIG. 1A. Figure 2 An exploded structural schematic diagram of an electric core provided for some embodiments of the present application is shown in FIG. 1B. Figure 3 An exploded structural schematic diagram of an electrode assembly of an electric core provided for some embodiments of the present application is shown in FIG. 1C. Figure 4 A structural schematic diagram of a first pole piece of an electric core provided for some embodiments of the present application is shown in FIG. 1D. Figure 5 A structural schematic diagram of a second pole piece of an electric core provided for some embodiments of the present application is shown in FIG. 1E.

[0066] An electric core 10 provided by an embodiment of the present application includes an electrode assembly 100, the electrode assembly 100 is of a laminated structure, and the electrode assembly 100 includes a plurality of first pole pieces 110 and a plurality of second pole pieces 120 stacked along a first direction X, the first pole pieces 110 and the second pole pieces 120 are of opposite polarities; one corner position of each first pole piece 110 is provided with a first notch 111 and a first empty foil area 112, and one corner position of each second pole piece 120 is provided with a second notch 121 and a second empty foil area 122; as viewed along the first direction X, the first empty foil area 112 and the second notch 121 at least partially overlap, the second empty foil area 122 and the first notch 111 at least partially overlap, and the first empty foil area 112 and the second empty foil area 122 are spaced apart; the first empty foil areas 112 of the plurality of first pole pieces 110 are stacked along the first direction X, and the second empty foil areas 122 of the plurality of second pole pieces 120 are stacked along the first direction X.

[0067] By making one corner position of each first tab 110 have a first notch 111 and a first empty foil area 112, and one corner position of each second tab 120 have a second notch 121 and a second empty foil area 122, the first empty foil area 112 and the second notch 121 at least partially overlap, and the second empty foil area 122 and the first notch 111 at least partially overlap when viewed along the first direction X, the volume of the first empty foil area 112 and the second empty foil area 122 protruding from the first tab 110 and the second tab 120 can be reduced, the space reserved for accommodating the first empty foil area 112 and the second empty foil area 122 between the electrode assembly 100 and the shell 300 is reduced, the energy density of the battery cell 10 can be improved, and when the battery cell 10 is subjected to external force or falls, the electrode assembly 100 is less likely to shake relative to the shell 300, and the first empty foil area 112 is less likely to contact the second tab 120 and the second empty foil area 122 is less likely to contact the first tab 110, thereby reducing the risk of thermal runaway of the battery cell 10. In addition, the first empty foil area 112 and the second empty foil area 122 are located at the same corner position of the electrode assembly 100, which can further reduce the space occupied by the first empty foil area 112 and the second empty foil area 122, and further improve the energy density of the battery cell 10. The first empty foil area 112 and the second empty foil area 122 are arranged in a spaced manner, which can reduce the possibility of short circuit caused by contact between the first empty foil area 112 and the second empty foil area 122. The first empty foil areas 112 of the plurality of first tabs 110 are arranged in a stacked manner along the first direction X, and the second empty foil areas 122 of the plurality of second tabs 120 are arranged in a stacked manner along the first direction X, which facilitates the connection of the plurality of first empty foil areas 112 and the connection of the plurality of second empty foil areas 122, so that an external device can be electrically connected to the plurality of first tabs 110 through the first empty foil area 112, and can be electrically connected to the plurality of second tabs 120 through the second empty foil area 122.

[0068] In some embodiments, the first notch 111 and the second notch 121 partially overlap when viewed along the first direction X.

[0069] By making the first notch 111 and the second notch 121 partially overlap when viewed along the first direction X, a spacing space can be reserved between the first empty foil area 112 and the second empty foil area 122, and the possibility of short circuit caused by contact between the first empty foil area 112 and the second empty foil area 122 can be reduced.

[0070] In some embodiments, the first tab 110 has a first coating area 113, and the first empty foil area 112 does not exceed the first coating area 113 along the length direction Y of the first tab, and the first empty foil area 112 does not exceed the first coating area 113 along the width direction Z of the first tab.

[0071] The first coating area 113 can refer to an active material coating area, or can refer to an area coated with other coatings such as ceramic.

[0072] By making the first empty foil area 112 not protrude from the first pole piece 110 along the length direction Y of the first pole piece, and along the width direction Z of the first pole piece, the first empty foil area 112 does not need to reserve space for accommodating the first empty foil area 112 between the electrode assembly 100 and the shell 300, which can further improve the energy density of the battery cell 10, and when the battery cell 10 is subjected to external force or falls, the possibility of the electrode assembly 100 shaking relative to the shell 300 is further reduced, and the possibility of the first empty foil area 112 being in contact with the second pole piece 120 and short-circuiting is also further reduced, thereby further reducing the risk of thermal runaway of the battery cell 10.

[0073] In some embodiments, the second pole piece 120 has a second coated area 123, and along the length direction of the second pole piece, the second empty foil area 122 does not protrude from the second coated area 123, and along the width direction of the second pole piece, the second empty foil area 122 does not protrude from the second coated area 123.

[0074] By making the second empty foil area 122 not protrude from the second pole piece 120 along the length direction of the second pole piece, and along the width direction of the second pole piece, the second empty foil area 122 does not need to reserve space for accommodating the second empty foil area 122 between the electrode assembly 100 and the shell 300, which can further improve the energy density of the battery cell 10, and when the battery cell 10 is subjected to external force or falls, the possibility of the electrode assembly 100 shaking relative to the shell 300 is further reduced, and the possibility of the second empty foil area 122 being in contact with the first pole piece 110 and short-circuiting is also further reduced, thereby further reducing the risk of thermal runaway of the battery cell 10.

[0075] In some embodiments, the length direction of the second pole piece is parallel to the length direction Y of the first pole piece, and the width direction of the second pole piece is parallel to the width direction Z of the first pole piece.

[0076] In some embodiments, the pole piece includes a current collector and an active material layer, and the coated area can refer to an area coated with an active material, or an area coated with other coatings, such as ceramic, and the empty foil area refers to an area where the current collector is not coated with an active material layer.

[0077] In some embodiments, the first coated area 113 has a first edge 1131 in the length direction Y of the first pole piece, the first empty foil area 112 has a second edge 1121 in the length direction Y of the first pole piece, and the first edge 1131 is flush with the second edge 1121.

[0078] By making the first edge 1131 flush with the second edge 1121, the preparation of the first empty foil area 112 can be facilitated.

[0079] In some embodiments, the second coating region 123 has a third edge 1231 in the width direction of the second tab, and the second empty-foil region 122 has a fourth edge 1221 in the width direction of the second tab, and the third edge 1231 is flush with the fourth edge 1221.

[0080] By making the third edge 1231 flush with the fourth edge 1221, the preparation of the second empty-foil region 122 can be facilitated.

[0081] Referring to Figure 6 , Figure 6 A partial enlarged view of a part of the structure of the battery cell is provided for some embodiments of the present application.

[0082] In some embodiments, the interval distance between the first empty-foil region 112 and the second empty-foil region 122 is D1, and 0.4mm≤D1≤1mm is satisfied. For example, D1 can be 0.4mm, 0.7mm or 1mm, etc. The interval distance here refers to the distance between the two shortest points between the first empty-foil region 112 and the second empty-foil region 122.

[0083] When the interval distance D1 between the first empty-foil region 112 and the second empty-foil region 122 is greater than or equal to 0.4mm, the interval distance between the first empty-foil region 112 and the second empty-foil region 122 can be made larger, and the possibility of short circuit between the first empty-foil region 112 and the second empty-foil region 122 can be made smaller, thereby reducing the risk of thermal runaway of the battery cell 10. When the interval distance D1 between the first empty-foil region 112 and the second empty-foil region 122 is less than or equal to 1mm, the interval distance between the first empty-foil region 112 and the second empty-foil region 122 can be made smaller, and the interval space occupied can be made smaller, which is beneficial to improve the energy density of the battery cell 10. When the interval distance D1 between the first empty-foil region 112 and the second empty-foil region 122 is 0.4mm-1mm, both the possibility of short circuit between the first empty-foil region 112 and the second empty-foil region 122 can be made smaller, and the risk of thermal runaway of the battery cell 10 can be reduced, and the energy density of the battery cell 10 can be improved.

[0084] Referring to Figure 7 and Figure 8 , Figure 7 A structure view of the battery cell from one perspective is provided for some embodiments of the present application, Figure 8 A partial enlarged view of a part of the structure of the battery cell is provided for some embodiments of the present application.

[0085] In some embodiments, the battery cell 10 further comprises a first insulating member 200, and at least part of the first insulating member 200 is arranged between the first empty-foil region 112 and the second empty-foil region 122.

[0086] By arranging the first insulating piece 200 between the first empty foil area 112 and the second empty foil area 122, the possibility of short circuit between the first empty foil area 112 and the second empty foil area 122 can be reduced, and the risk of thermal runaway of the battery cell 10 can be reduced.

[0087] In some embodiments, the first insulating piece 200 can be made of a high molecular insulating material such as polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), etc.

[0088] In some embodiments, the first insulating piece 200 wraps at least part of the plurality of first empty foil areas 112.

[0089] By wrapping at least part of the plurality of first empty foil areas 112 with the first insulating piece 200, the insulation effect between the first empty foil area 112 and the second empty foil area 122 can be better, and the possibility of short circuit between the first empty foil area 112 and the second empty foil area 122 can be further reduced, and the risk of thermal runaway of the battery cell 10 can be further reduced.

[0090] Referring to Figures 8 to 10 , Figure 9 For Figure 7 the partial enlarged schematic view of the cross-sectional structure of the battery cell along the A-A direction, Figure 10 For Figure 7 the partial enlarged schematic view of the cross-sectional structure of the battery cell along the B-B direction.

[0091] In some embodiments, the battery cell 10 further includes a shell 300, and the electrode assembly 100 is arranged in the shell 300. When viewed along the first direction X, the first insulating piece 200 includes a first insulating portion 210 and a second insulating portion 220, the first insulating portion 210 is arranged between the first empty foil area 112 and the second empty foil area 122, and the second insulating portion 220 is arranged between the first empty foil area 112 and the inner wall of the shell 300.

[0092] By arranging the first insulating piece 200 between the first empty foil area 112 and the second empty foil area 122, the possibility of short circuit between the first empty foil area 112 and the second empty foil area 122 can be reduced, and the risk of thermal runaway of the battery cell 10 can be reduced.

[0093] In some embodiments, the shell 300 can be made of a material with high strength, such as steel, aluminum alloy, or other metal materials, so that the shell 300 has high stress resistance, and thus the shell 300 is less likely to deform or break due to stress or environmental changes, and thus the reliability of the battery cell 10 is higher.

[0094] In other embodiments, the shell 300 can also be made of a non-metal material with high strength, such as carbon fiber or hard plastic.

[0095] In some embodiments, the battery cell 10 further includes an electrode terminal 410 and a first adapter 420, the first adapter 420 is connected to the plurality of first empty foil areas 112, the shell 300 includes a first wall 311, the electrode terminal 410 is arranged on the first wall 311, the second insulating part 220 is arranged between the first wall 311 and the first empty foil area 112, and the electrode terminal 410 passes through the second insulating part 220 and is connected to the first adapter 420.

[0096] By connecting the first adapter 420 to the plurality of first empty foil areas 112, the shell 300 includes a first wall 311, the electrode terminal 410 is arranged on the first wall 311, the second insulating part 220 is arranged between the first wall 311 and the first empty foil area 112, and the electrode terminal 410 passes through the second insulating part 220 and is connected to the first adapter 420, so that the plurality of first empty foil areas 112 can be electrically connected to external devices through the first adapter 420 and the electrode terminal 410, and the second insulating part 220 can insulate the electrode terminal 410 from the shell 300, reducing the possibility of short circuit between the first empty foil area 112 and the shell 300, and reducing the risk of thermal runaway of the battery cell 10.

[0097] In some embodiments, the first adapter 420 is bent, part of the first adapter 420 is perpendicular to the first wall 311, facilitating connection with the first empty foil area 112, and another part of the first adapter 420 is parallel to the first wall 311, facilitating connection with the electrode terminal 410.

[0098] In some embodiments, part of the first adapter 420 is arranged between two adjacent first empty foil areas 112 of the plurality of first empty foil areas 112, so that the first adapter 420 has a larger connection area with the plurality of first empty foil areas 112 and higher connection reliability.

[0099] In other embodiments, the first adapter 420 can also be arranged on one side of the plurality of first empty foil areas 112 along the first direction X.

[0100] In some embodiments, the battery cell 10 further includes a second insulating part 440 arranged between the electrode terminal 410 and the outside of the first wall 311.

[0101] By arranging the second insulating member 440 between the electrode terminal 410 and the outside of the first wall 311, the possibility of the electrode terminal 410 contacting the shell 300 and short-circuiting can be reduced, and the risk of the battery cell 10 generating thermal runaway can be reduced.

[0102] In some embodiments, the second insulating member 440 can be made of a high-molecular insulating material such as polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), or the like.

[0103] In some embodiments, the first insulating member 200 further includes a third insulating portion 230, the third insulating portion 230 being arranged on one side of the plurality of first foil-free areas 112 along the first direction X, and the third insulating portion 230 being connected with the first insulating portion 210 and the second insulating portion 220.

[0104] By arranging the third insulating portion 230 and connecting the third insulating portion 230 with the first insulating portion 210 and the second insulating portion 220, the third insulating portion 230 can play an insulating role for the first foil-free areas 112 and the shell 300 along the first direction X, the possibility of the first foil-free areas 112 contacting the shell 300 and short-circuiting can be reduced, and the risk of the battery cell 10 generating thermal runaway can be reduced.

[0105] In some embodiments, along the first direction X, the first foil-free areas 112 of the plurality of first pole pieces 110 are gathered toward the middle to form a first gathered portion 112a.

[0106] By gathering the first foil-free areas 112 of the plurality of first pole pieces 110 toward the middle along the first direction X to form the first gathered portion 112a, the connection mode of the plurality of first foil-free areas 112 can be made simpler and easier to operate, and the plurality of first foil-free areas 112 can be connected with the first adapter 420 more easily. Since some of the first foil-free areas 112 need to be bent and extended for a certain length before being connected with adjacent first foil-free areas 112, by gathering the plurality of first foil-free areas 112 toward the middle, the size of the first foil-free areas 112 in the extension direction (i.e., the vertical direction of the bent edge of the first foil-free areas 112) can be made smaller, so that the first foil-free areas 112 occupy less space, which is conducive to improving the energy density of the battery cell 10.

[0107] Referring to Figure 11 , Figure 11 A partial enlarged schematic view of a cross-sectional structure of a battery cell according to another embodiment of the present application is provided.

[0108] In another embodiment, the third insulating portion 230 carries the first gathered portion 112a.

[0109] The shell 300 comprises a shell body 310 and a shell cover 320. During assembly of the battery cell 10, the electrode assembly 100 is first assembled into the shell body 310, and after the first adapter 420 is connected to the electrode terminal 410, the shell cover 320 is arranged on the shell body 310. Since the electrode assembly 100 is assembled into the shell body 310, if the first folding portion 112a is in a suspended state, when the first adapter 420 is connected to the electrode terminal 410, the first folding portion 112a may be forced to cause positional deviation, affecting the connection of the first adapter 420 to the electrode terminal 410. Therefore, by allowing the third insulating portion 230 to bear the first folding portion 112a, the first adapter 420 can be conveniently connected to the electrode terminal 410.

[0110] Referring to Figure 12 , Figure 12 for Figure 7 a partial enlarged schematic view of a sectional structure of the battery cell along the C-C direction.

[0111] In some embodiments, along the first direction X, the second empty foil regions 122 of the plurality of second tabs 120 are folded inward to form a second folding portion 122a. The battery cell 10 further comprises a second adapter 430 connecting the shell 300 and the second folding portion 122a.

[0112] By allowing the second empty foil regions 122 of the plurality of second tabs 120 to be folded inward along the first direction X to form a second folding portion 122a, and by further comprising a second adapter 430 connecting the shell 300 and the second folding portion 122a, the connection mode of the plurality of second empty foil regions 122 can be made simpler and easier to operate, and the plurality of second empty foil regions 122 can be conveniently connected to the first adapter 420. In addition, the size of the second empty foil region 122 in its extension direction can be made smaller, so that the second empty foil region 122 occupies less space, which is beneficial to improve the energy density of the battery cell 10. Furthermore, the plurality of second empty foil regions 122 can be electrically connected to external devices through the second adapter 430 and the shell 300.

[0113] In some embodiments, the shell 300 comprises a second wall 312, and the second adapter 430 is connected to the second wall 312.

[0114] In some embodiments, the second adapter 430 is bent, and a portion of the second adapter 430 is perpendicular to the second wall 312 to facilitate connection with the second empty foil region 122, and another portion of the second adapter 430 is parallel to the second wall 312 to facilitate connection with the second wall 312.

[0115] In some embodiments, the second adapter 430 is arranged between two adjacent second empty foil areas 122 of the plurality of second empty foil areas 122, so that the second adapter 430 has a larger connection area with the plurality of second empty foil areas 122 and has a higher connection reliability.

[0116] In other embodiments, the second adapter 430 can also be arranged on one side of the plurality of second empty foil areas 122 along the first direction X.

[0117] Referring to Figure 13 , Figure 13 A structure diagram of a separator of a battery cell is provided for some embodiments of the present application.

[0118] In some embodiments, the electrode assembly 100 further includes a separator 130 arranged between the first electrode tab 110 and the second electrode tab 120. The separator 130 has a third gap 131. Along the first direction X, the first empty foil area 112 at least partially overlaps the third gap 131, and the second empty foil area 122 at least partially overlaps the third gap 131.

[0119] By arranging the first empty foil area 112 and the second empty foil area 122 to at least partially overlap the third gap 131 along the first direction X, the third gap 131 can be used to accommodate the first empty foil area 112 and the second empty foil area 122, which can facilitate the connection of the plurality of first empty foil areas 112 and the plurality of second empty foil areas 122, respectively.

[0120] Referring to Figure 14 , Figure 14 A partial enlarged view of a cross-sectional structure of a battery cell along the E-E direction is provided for Figure 7 some embodiments of the present application.

[0121] In some embodiments, the second gap 121 and the second empty foil area 122 are located at one end of the second electrode tab in the length direction of the second electrode tab. The battery cell 10 further includes a housing 300, and the electrode assembly 100 is accommodated in the housing 300. Along the length direction of the second electrode tab, the distance between the end of the second electrode tab 120 provided with the second empty foil area 122 and the second gap 121 and the inner wall of the housing 300 is D2, which satisfies 0.4mm≤D2≤1mm. For example, D2 can be 0.4mm, 0.6mm or 1mm, etc.

[0122] By locating the second gap 121 and the second empty foil area 122 at one end of the length direction of the second tab, the first empty foil area 112 and the second empty foil area 122 can be led out from one end of the length direction of the second tab, which facilitates the electrical connection between the battery cell 10 and the external device through the first empty foil area 112 and the second empty foil area 122. When the distance D2 between the one end of the second tab 120 provided with the second empty foil area 122 and the second gap 121 and the inner wall of the shell 300 along the length direction of the second tab is greater than or equal to 0.4 mm, the assembly of the electrode assembly 100 and the shell 300 is facilitated, and the shell 300 can accommodate electrolyte; when the distance D2 between the one end of the second tab 120 provided with the second empty foil area 122 and the second gap 121 and the inner wall of the shell 300 along the length direction of the second tab is less than or equal to 1 mm, the spacing between the electrode assembly 100 and the shell 300 is small, and the energy density of the battery cell 10 is high; therefore, when the distance D2 between the one end of the second tab 120 provided with the second empty foil area 122 and the second gap 121 and the inner wall of the shell 300 along the length direction of the second tab is 0.4 mm-1 mm, the assembly of the electrode assembly 100 and the shell 300 is facilitated, the shell 300 can accommodate electrolyte, and the energy density of the battery cell 10 is high.

[0123] In some embodiments, the first gap 111 is triangularly arranged.

[0124] By arranging the first gap 111 in a triangular shape, the preparation of the first gap 111 is facilitated, and the first gap 111 occupies less space, which is beneficial to improve the energy density of the battery cell 10.

[0125] In some embodiments, the second gap 121 is triangularly arranged.

[0126] By arranging the second gap 121 in a triangular shape, the preparation of the second gap 121 is facilitated, and the second gap 121 occupies less space.

[0127] In other embodiments, the first gap 111 and the second gap 121 can also be arranged in a trapezoidal shape.

[0128] In some embodiments, the first empty foil area 112 is triangularly arranged.

[0129] By arranging the first empty foil area 112 in a triangular shape, the preparation of the first empty foil area 112 is facilitated, the multiple first empty foil areas 112 can be gathered, and the first empty foil area 112 occupies less space, which is beneficial to improve the energy density of the battery cell 10.

[0130] In some embodiments, the third insulation part 230 is arranged in a triangular shape, so that the first insulation part 200 can wrap the first empty foil area 112, and the first insulation part 200 occupies a smaller space, which is conducive to improving the energy density of the battery cell 10.

[0131] In some embodiments, the second empty foil area 122 is arranged in a triangular shape.

[0132] By arranging the second empty foil area 122 in a triangular shape, the preparation of the second empty foil area 122 is facilitated, the multiple second empty foil areas 122 are easily gathered, and the second empty foil area 122 occupies a smaller space, which is conducive to improving the energy density of the battery cell 10.

[0133] In some embodiments, the first tab 110 is a positive electrode tab, and the second tab 120 is a negative electrode tab.

[0134] The battery cell 10 includes an electrode assembly 100, a shell 300, and an electrolyte. The shell 300 is used to accommodate the electrode assembly 100 and the electrolyte. The electrode assembly 100 is composed of a positive electrode tab, a negative electrode tab, and a separator. The battery cell 10 mainly relies on the movement of metal ions between the positive electrode tab and the negative electrode tab to work. The positive electrode tab includes a positive electrode current collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode current collector. The part of the positive electrode current collector that is not coated with the positive electrode active material layer serves as a positive electrode lug (i.e., the first empty foil area 112) to realize the input or output of electric energy of the positive electrode tab through the positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary material, or lithium manganate, etc. The negative electrode tab includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector. The part of the negative electrode current collector that is not coated with the negative electrode active material layer serves as a negative electrode lug (i.e., the second empty foil area 122) to realize the input or output of electric energy of the negative electrode tab through the negative electrode lug. The material of the negative electrode current collector can be copper, and the negative electrode active material can be a carbon material or a silicon material, etc. The material of the separator can be polypropylene (PP) or polyethylene (PE), etc. The electrolyte can include an organic solvent, an electrolyte lithium salt, etc.

[0135] The embodiments of the present application provide a kind of electric equipment, and the electric equipment includes the battery cell 10 provided in any of the above embodiments, and the battery cell 10 is used to provide electric energy.

[0136] The electric equipment can be the device or system of any of the above applications of the battery cell 10.

[0137] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0138] The above merely provides preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. An electric cell, characterized by, The electrode assembly comprises a plurality of first pole pieces and a plurality of second pole pieces stacked in a first direction, the first pole pieces and the second pole pieces being opposite in polarity; Each of the first pole pieces has a first corner position with a first notch and a first foil-free area, and each of the second pole pieces has a second corner position with a second notch and a second foil-free area, the first foil-free area and the second notch at least partially overlapping, and the second foil-free area and the first notch at least partially overlapping when viewed in the first direction, the first foil-free area and the second foil-free area being spaced apart; The first foil-free areas of the plurality of first pole pieces are stacked in the first direction, and the second foil-free areas of the plurality of second pole pieces are stacked in the first direction.

2. The electric cell of claim 1, wherein, The first notch and the second notch partially overlap when viewed in the first direction.

3. The electric cell of claim 1, wherein, The first pole pieces have a first coating area, the first foil-free area not exceeding the first coating area in the length direction of the first pole pieces, and the first foil-free area not exceeding the first coating area in the width direction of the first pole pieces; The second pole pieces have a second coating area, the second foil-free area not exceeding the second coating area in the length direction of the second pole pieces, and the second foil-free area not exceeding the second coating area in the width direction of the second pole pieces.

4. The electric cell of claim 3, wherein, The first coating area has a first edge in the length direction of the first pole pieces, and the first foil-free area has a second edge in the length direction of the first pole pieces, the first edge being flush with the second edge; And / or, The second coating area has a third edge in the width direction of the second pole pieces, and the second foil-free area has a fourth edge in the width direction of the second pole pieces, the third edge being flush with the fourth edge.

5. The electric cell of claim 1, wherein, The spacing distance between the first foil-free area and the second foil-free area is D1, satisfying 0.4mm≤D1≤1mm.

6. The cell of any of claims 1-5, wherein, The battery cell further comprises a first insulating member, at least part of the first insulating member being arranged between the first foil-free area and the second foil-free area.

7. The electric cell of claim 6, wherein, The first insulating member wraps at least part of the plurality of first foil-free areas.

8. The electric cell of claim 6, wherein, The battery cell further comprises a housing, and the electrode assembly is arranged in the housing; Viewed in the first direction, the first insulating member comprises a first insulating portion and a second insulating portion, the first insulating portion being arranged between the first foil-free area and the second foil-free area, and the second insulating portion being arranged between the first foil-free area and an inner wall of the housing.

9. The electric cell of claim 8, wherein, The battery cell further comprises an electrode terminal and a first adapter, the first adapter being connected to the plurality of first foil-free areas, the housing comprising a first wall, the electrode terminal being arranged on the first wall, the second insulating portion being arranged between the first wall and the first foil-free area, the electrode terminal penetrating through the second insulating portion and being connected to the first adapter.

10. The electric cell of claim 8, wherein, The first insulating member further comprises a third insulating portion, the third insulating portion being arranged on one side of the plurality of first foil-free areas in the first direction, and the third insulating portion being connected to the first insulating portion and the second insulating portion.

11. The electric cell of claim 10, wherein, Along the first direction, the first empty foil area of the plurality of first pole pieces converges to the middle to form a first converging part, and the third insulating part bears the first converging part.

12. The cell of any one of claims 1-5, wherein, The battery cell further comprises a shell, and the electrode assembly is arranged in the shell. Along the first direction, the second empty foil area of the plurality of second pole pieces converges to the middle to form a second converging part; the battery cell further comprises a second adapter, and the second adapter connects the shell and the second converging part.

13. The cell of any of claims 1-5, wherein: The second notch and the second empty foil area are located at one end of the second pole piece in the length direction of the second pole piece. The battery cell further comprises a shell, and the electrode assembly is arranged in the shell; along the length direction of the second pole piece, the distance between the one end of the second pole piece provided with the second empty foil area and the second notch and the inner wall of the shell is D2, and 0.4mm≤D2≤1mm is satisfied.

14. The cell of any one of claims 1-5, wherein: The first notch is triangularly arranged; and / or, the second notch is triangularly arranged.

15. The cell of any one of claims 1-5, wherein: The first empty foil area is triangularly arranged; and / or, the second empty foil area is triangularly arranged.

16. The battery cell of any one of claims 1-5, wherein, The first pole piece is a positive pole piece, and the second pole piece is a negative pole piece.

17. An electrical device, characterized by The electrical equipment comprises the battery cell according to any one of claims 1-16, and the battery cell is used to provide electric energy.

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