Battery monomer, battery and electric device

Abstract

A battery cell (30), a battery (40), and an electric device. The battery monomer (30) comprises: an electrode assembly (10) comprising a first pole piece (11), a second pole piece (12) and a separator (13), the first pole piece (11) and the second pole piece (12) being opposite in polarity, the separator (13) being located between the first pole piece (11) and the second pole piece (12), the first pole piece (11), the second pole piece (12) and the separator (13) being wound along a winding direction and forming a winding structure (100), the first pole piece (11) comprises a plurality of first tabs (11B) which are bent at the end part of the winding structure (100) and form a first tab stacking structure (111), and the second pole piece (12) comprises a plurality of second tabs (12B) which are bent at the end part of the winding structure (100) and form a second tab stacking structure (121); the first conductive piece (21) is welded with the first tab stacking structure (111); and a second conductive member (22) welded to the second tab stack structure (121), in which, in a first direction (d1) parallel to the direction in which the winding axis of the winding structure (100) extends, at least one of the bending positions (11f) of the plurality of first tabs (11B) and the bending positions (12f) of the plurality of second tabs (12B) has a gap with the separator (13) in the first direction (d1).

Description

Battery cells, batteries and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on and claims priority to the Chinese patent application with application number 202310955457.7 and application date August 1, 2023. The disclosed content of the Chinese patent application is hereby introduced as a whole into this application. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] Secondary batteries, especially lithium-ion batteries, offer advantages such as high voltage, high specific energy, long cycle life, environmental friendliness, a wide operating temperature range, and low self-discharge. They are widely used in portable electronic devices and powering large electric vehicles, playing a significant role in addressing environmental pollution and the energy crisis. With the widespread use of lithium-ion batteries, battery safety has become a matter of close concern to users.

[0005] Summary of the Invention

[0006] In one aspect of the present disclosure, a battery cell is provided, comprising: an electrode assembly, comprising a first pole sheet, a second pole sheet and an isolating member, the first pole sheet and the second pole sheet having opposite polarities, the isolating member being located between the first pole sheet and the second pole sheet, the first pole sheet, the second pole sheet and the isolating member being wound along a winding direction and forming a winding structure, the first pole sheet comprising a plurality of first pole tabs that are bent at the end of the winding structure and form a first pole tab stacking structure, the second pole sheet comprising a plurality of second pole tabs that are bent at the end of the winding structure and form a second pole tab stacking structure; a first conductive member welded to the first pole tab stacking structure; and a second conductive member welded to the second pole tab stacking structure, wherein, in a first direction parallel to an extension direction of a winding axis of the winding structure, at least one of the bending positions of the plurality of first pole tabs and the bending positions of the plurality of second pole tabs has a gap with the isolating member in the first direction.

[0007] Multiple first pole tabs and multiple second pole tabs are bent at the ends of the winding structure to form a first pole tab stacking structure and a second pole tab stacking structure, respectively. By ensuring that at least one of the bending positions of the multiple first pole tabs and the bending positions of the multiple second pole tabs has a gap with the insulating member in the first direction, the risk of heat generated by the pole tabs being conducted to the insulating member and causing burns to the insulating member during the welding process between the pole tab stacking structure and the conductive member can be reduced, thereby improving product yield and safety of use.

[0008] In some embodiments, the minimum distance between the bending positions of the multiple first pole ears and the gap between the insulating member in the first direction is defined as a first minimum distance L1, and the minimum distance between the bending positions of the multiple second pole ears and the gap between the insulating member in the first direction is defined as a second minimum distance L2; the melting point of the material of the multiple first pole ears is less than the melting point of the material of the multiple second pole ears, and the first minimum distance L1 is less than or equal to the second minimum distance L2.

[0009] For the battery cell embodiment in which the melting point of the first pole tab material is lower than that of the second pole tab material, the second pole tab material with a larger melting point requires a larger welding heat to form a welding pool. Correspondingly, the heat generated by the second pole tab stacking structure during welding is higher. By making the second minimum distance L2 larger, the risk of partial scalding of the isolation member corresponding to the second pole tab stacking structure and the risk of burns due to heat radiation caused by the isolation member being too close to the second pole tab stacking structure can be reduced.

[0010] In some embodiments, the minimum distance between the bending positions of the multiple first pole ears and the gap between the insulating member in the first direction is defined as a first minimum distance L1, and the minimum distance between the bending positions of the multiple second pole ears and the gap between the insulating member in the first direction is defined as a second minimum distance L2; the melting point of the material of the multiple first pole ears is greater than the melting point of the material of the multiple second pole ears, and the second minimum distance L2 is less than or equal to the first minimum distance L1.

[0011] For the battery cell embodiment in which the melting point of the first pole tab material is greater than the melting point of the second pole tab material, the first pole tab material with a larger melting point requires a larger welding heat to form a welding pool. Correspondingly, the heat generated by the first pole tab stacking structure during welding is higher. By ensuring that the first minimum distance L1 is not lower than the second minimum distance L2, the risk of partial scalding of the isolation member corresponding to the first pole tab stacking structure and the risk of burns due to heat radiation caused by the isolation member being too close to the first pole tab stacking structure can be reduced.

[0012] In some embodiments, the bending positions of the plurality of first electrode tabs are the cut roots of the plurality of first electrode tabs, and / or the bending positions of the plurality of second electrode tabs are the cut roots of the plurality of second electrode tabs.

[0013] The bending position of the multiple first tabs can be the cutting position of the tabs in the portion of the current collector substrate of the first electrode sheet not covered by the active material layer. Accordingly, the first minimum distance L1 is the distance between the cutting root of the multiple first tabs and the separator in the first direction. The bending position of the multiple second tabs can be the cutting position of the tabs in the portion of the current collector substrate of the second electrode sheet not covered by the active material layer. Accordingly, the second minimum distance L2 is the distance between the cutting root of the multiple second tabs and the separator in the first direction.

[0014] In some embodiments, in the first direction, there is a third minimum distance L3 between the bending positions of the multiple first pole tabs and the tops of the pole tabs of the multiple first pole tabs, and there is a fourth minimum distance L4 between the bending positions of the multiple second pole tabs and the tops of the pole tabs of the multiple second pole tabs; the first thickness t1 of the multiple first pole tabs in the thickness direction of the first pole tab is less than the second thickness t2 of the multiple second pole tabs in the thickness direction of the second pole tab, and the third minimum distance L3 is greater than or equal to the fourth minimum distance L4.

[0015] The third minimum distance L3 and the fourth minimum distance L4 respectively reflect the lengths of the first and second tabs that are bent and stacked. The longer the tabs are stacked, the greater the degree of tab overlap. The first thickness t1 of the first tab reflects the thickness of the first tab in a single layer, and the second thickness t2 of the second tab reflects the thickness of the second tab in a single layer. The thicker the tabs in a single layer, the thicker the stacked tab structure. For battery cell embodiments where the first thickness t1 is less than the second thickness t2, ensuring that the third minimum distance L3 is greater than or equal to the fourth minimum distance L4 allows the thicknesses of the first and second tab stacks to be closer, helping to reduce the risk of partial burns or scalding of the separator due to differences in welding heat during the formation of the weld pool.

[0016] In some embodiments, in the first direction, there is a third minimum distance L3 between the bending positions of the multiple first pole tabs and the tops of the pole tabs of the multiple first pole tabs, and there is a fourth minimum distance L4 between the bending positions of the multiple second pole tabs and the tops of the pole tabs of the multiple second pole tabs; the first thickness t1 of the multiple first pole tabs in the thickness direction of the first pole tab is greater than the second thickness t2 of the multiple second pole tabs in the thickness direction of the second pole tab, and the third minimum distance L3 is less than or equal to the fourth minimum distance L4.

[0017] The third minimum distance L3 and the fourth minimum distance L4 respectively reflect the lengths of the first and second tabs that are bent and stacked. The longer the tabs are stacked, the greater the degree of tab overlap. The first thickness t1 of the first tab reflects the thickness of the first tab in a single layer, and the second thickness t2 of the second tab reflects the thickness of the second tab in a single layer. The thicker the tabs in a single layer, the thicker the stacked tab structure. For battery cell embodiments where the first thickness t1 is greater than the second thickness t2, ensuring that the third minimum distance L3 is less than or equal to the fourth minimum distance L4 allows the thicknesses of the first and second tab stacks to be closer, helping to reduce the risk of partial burns or scalding of the separator due to differences in welding heat during the formation of the weld pool.

[0018] In some embodiments, a ratio A / B of a product A of a first thickness t1 of the plurality of first pole tabs in the thickness direction of the first pole tab and the third minimum distance L3 and a product B of a second thickness t2 of the plurality of second pole tabs in the thickness direction of the second pole tab and the fourth minimum distance L4 satisfies: 0.2≤A / B≤4, wherein the units of the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 are the same.

[0019] The product A of the first thickness t1 and the third minimum distance L3 reflects the stacking thickness of the first pole lug stacking structure, the product B of the second thickness t2 and the fourth minimum distance L4 reflects the stacking thickness of the second pole lug stacking structure, and the ratio of the product A to the product B reflects the degree of difference in stacking thickness between the first pole lug stacking structure and the second pole lug stacking structure. If the ratio A / B is too large, the first pole lug stacking structure is thicker, and a higher welding power and welding heat are required during welding. Compared with the second pole lug stacking structure, the risk of partial burning or scalding of the insulating member corresponding to the first pole lug stacking structure is increased. If the ratio A / B is too small, the second pole lug stacking structure is thicker, and a higher welding power and welding heat are required during welding. Compared with the first pole lug stacking structure, the risk of partial burning or scalding of the insulating member corresponding to the second pole lug stacking structure is increased. Therefore, by making the ratio A / B satisfy: 0.2≤A / B≤4, the difference in stacking thickness between the first tab stacking structure and the second tab stacking structure is reduced, thereby reducing the risk of partial burning or scalding of the isolation members corresponding to the first tab stacking structure and the second tab stacking structure.

[0020] In some embodiments, the ratio A / B satisfies: 0.5≤A / B≤2.

[0021] By further limiting the ratio A / B to satisfy: 0.5≤A / B≤2, the difference in stacking thickness between the first tab stacking structure and the second tab stacking structure can be further reduced, thereby more effectively reducing the risk of partial burning or scalding of the isolation members corresponding to the first tab stacking structure and the second tab stacking structure.

[0022] In some embodiments, the ratio A / B of the product A of the first thickness t1 of the multiple first pole tabs in the thickness direction of the first pole tab and the third minimum distance L3 and the product B of the second thickness t2 of the multiple second pole tabs in the thickness direction of the second pole tab and the fourth minimum distance L4 satisfies: A / B<1, wherein the units of the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 are the same, and the third thickness t3 of the first conductive member in the first direction is less than the fourth thickness t4 of the second conductive member in the first direction.

[0023] The product A of the first thickness t1 and the third minimum distance L3 reflects the stacking thickness of the first tab stacking structure, and the product B of the second thickness t2 and the fourth minimum distance L4 reflects the stacking thickness of the second tab stacking structure. For the battery cell embodiment in which the product A is less than the product B, the second tab stacking structure with a larger stacking thickness requires the use of a higher welding power for welding. When the higher laser power fluctuates, it is easy to form an overly deep molten pool, resulting in an increased risk of burning or scalding the separator. Therefore, a thicker second conductive member is used to increase the fault tolerance of welding, reduce the possibility of forming an overly deep molten pool, and thus reduce the risk of burning or scalding the separator corresponding to the second tab stacking structure. The thinner first conductive member is combined with the first tab stacking structure with a smaller stacking thickness, and a lower welding power can be used for welding. Accordingly, it is easier to form a molten pool of appropriate depth, reducing the risk of burning or scalding the separator corresponding to the first tab stacking structure.

[0024] In some embodiments, the ratio A / B of the product A of the first thickness t1 of the multiple first pole tabs in the thickness direction of the first pole tab and the third minimum distance L3 and the product B of the second thickness t2 of the multiple second pole tabs in the thickness direction of the second pole tab and the fourth minimum distance L4 satisfies: A / B>1, wherein the units of the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 are the same, and the third thickness t3 of the first conductive member in the first direction is greater than the fourth thickness t4 of the second conductive member in the first direction.

[0025] The product A of the first thickness t1 and the third minimum distance L3 reflects the stacking thickness of the first tab stacking structure, and the product B of the second thickness t2 and the fourth minimum distance L4 reflects the stacking thickness of the second tab stacking structure. For the battery cell embodiment in which the product B is less than the product A, the first tab stacking structure with a larger stacking thickness requires the use of a higher welding power for welding. When the higher laser power fluctuates, it is easy to form an overly deep molten pool, resulting in an increased risk of burning or scalding the separator. Therefore, a thicker first conductive member is used to increase the fault tolerance of welding, reduce the possibility of forming an overly deep molten pool, and thus reduce the risk of burning or scalding the separator portion corresponding to the first tab stacking structure. The thinner second conductive member is combined with the second tab stacking structure with a smaller stacking thickness, and a lower welding power can be used for welding. Accordingly, it is easier to form a molten pool of appropriate depth, reducing the risk of burning or scalding the separator portion corresponding to the second tab stacking structure.

[0026] In some embodiments, in the first direction, the first tab stacking structure and the second tab stacking structure are both located at ends on the same side of the winding structure.

[0027] Multiple first pole tabs and multiple second pole tabs can be distributed at the same end of the winding structure, and the first pole tab stacking structure and the second pole tab stacking structure obtained by bending and stacking can be in different angle ranges at the side end. Accordingly, the first conductive member and the second conductive member are also arranged on the same side of the winding structure and are respectively welded to the first pole tab stacking structure and the second pole tab stacking structure.

[0028] In some embodiments, in the first direction, the first tab stacking structure and the second tab stacking structure are respectively located at opposite side ends of the winding structure.

[0029] Multiple first pole tabs and multiple second pole tabs can be distributed at opposite ends of the winding structure. The bent and stacked multiple first pole tabs and multiple second pole tabs form a first pole tab stacking structure and a second pole tab stacking structure at both ends of the winding structure, respectively. Correspondingly, the first conductive member and the second conductive member are also respectively arranged on both sides of the winding structure, and are respectively welded to the first pole tab stacking structure and the second pole tab stacking structure.

[0030] In some embodiments, the battery cell further includes: a housing having a cavity for accommodating the electrode assembly, the first conductive member, and the second conductive member; and an electrode terminal disposed on a wall of the housing and electrically connected to the first conductive member or the second conductive member.

[0031] The first tab stacking structure and the second tab stacking structure formed at the end of the winding structure of the electrode assembly are welded to the first conductive member and the second conductive member respectively, and are electrically connected to the electrode terminal arranged on the wall of the shell through the first conductive member or the second conductive member. Since the stacked multi-layer tab structure has a higher thickness, it is not easy to be welded through when welding with the conductive member, reducing the risk of burning or scalding the isolation member in the electrode assembly during welding, thereby improving the welding quality of the welding area and improving the safety of use.

[0032] In some embodiments, the shell includes a shell and an end cover, one end of the shell has an opening, the end cover covers the opening, the shell includes a side wall and a bottom wall, the side wall surrounds the outside of the electrode assembly, the bottom wall is arranged opposite to the opening, and the wall portion of the shell is the end cover or the bottom wall.

[0033] The first tab stacking structure and the second tab stacking structure formed at the end of the winding structure of the electrode assembly are welded to the first conductive member and the second conductive member respectively, and are electrically connected to the electrode terminal arranged on the end cover or the bottom wall of the shell through the first conductive member or the second conductive member, which can effectively reduce the risk of burning or scalding the isolation member in the electrode assembly during welding, improve the welding quality of the welding area, and improve the safety of use.

[0034] In some embodiments, the first pole sheet further includes a first current collector substrate, the plurality of first pole tabs are connected to the first current collector substrate and are arranged at intervals along the winding direction, and in the first direction, the bending positions of the plurality of first pole tabs are located on the side of the separator away from the first current collector substrate; the second pole sheet further includes a second current collector substrate, the plurality of second pole tabs are connected to the second current collector substrate and are arranged at intervals along the winding direction, and in the first direction, the bending positions of the plurality of second pole tabs are located on the side of the separator away from the second current collector substrate.

[0035] At least a portion of the plurality of first tabs connected to the first current collector substrate and spaced apart along the winding direction are bent at the ends of the winding structure to form a compact first tab stack structure having a certain thickness, which can be welded to the first conductive member to achieve a reliable electrical connection. Similarly, at least a portion of the plurality of second tabs connected to the second current collector substrate and spaced apart along the winding direction are bent at the ends of the winding structure to form a compact second tab stack structure having a certain thickness, which can be welded to the second conductive member to achieve a reliable electrical connection.

[0036] In one aspect of the present disclosure, a battery is provided, comprising: the aforementioned battery cell.

[0037] The battery using the aforementioned battery cells can effectively improve the safety of use.

[0038] In one aspect of the present disclosure, there is provided an electrical device comprising: the aforementioned battery.

[0039] The electrical device using the above-mentioned battery can effectively improve the safety of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on the drawings without any creative work.

[0041] The present disclosure can be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0042] FIG1 is a schematic structural diagram of some embodiments of an electric device according to the present disclosure;

[0043] FIG2 is an exploded schematic diagram of some embodiments of batteries according to the present disclosure;

[0044] FIG3 is a schematic diagram of the connection of multiple battery cells in some embodiments of the battery according to the present disclosure;

[0045] FIG4 is an exploded schematic diagram of some embodiments of a battery cell according to the present disclosure;

[0046] FIG5 is a schematic longitudinal cross-sectional view of a battery cell according to some embodiments of the present disclosure through a winding axis CL;

[0047] FIG6 is a schematic cross-sectional view of a wound structure according to some embodiments of an electrode assembly of the present disclosure;

[0048] FIG7 is an exploded schematic diagram of an electrode assembly and a conductive member in some embodiments of a battery cell according to the present disclosure;

[0049] FIG8 is an exploded schematic diagram of electrode assemblies and conductive members in other embodiments of battery cells according to the present disclosure;

[0050] 9 and 10 are schematic diagrams of the assembly structure and cross-section of the conductive member in FIG8 , respectively;

[0051] FIG11 is a schematic diagram of electrode sheets and tabs in an unfolded state according to some embodiments of the electrode assembly of the present disclosure;

[0052] FIG12 is a schematic diagram of electrode sheets and tabs in an unfolded state according to other embodiments of the electrode assembly of the present disclosure;

[0053] FIG13 is a schematic cross-sectional view of the structure of welding the tab stacking structure and the conductive member according to some embodiments of the electrode assembly of the present disclosure.

[0054] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components.

[0055] Explanation of the reference numerals: 10-electrode assembly; 11-first pole piece; 11A-first current collector substrate; 11B-first pole tab; 11C-first active material layer; 111-first pole tab stacking structure; 11f-bending position of the first pole tab; 11r-cut root of the first pole tab; 11t-top of the pole tab of the first pole tab; 12-second pole piece; 12B-second pole tab; 12C-second active material layer; 121-second pole tab stacking structure; 12f-bending position of the second pole tab; 12r-cut root of the second pole tab; 12t-top of the pole tab of the second pole tab; 13-isolator; 100-winding structure; 21-first conductive member; 22-second conductive member; 23-second insulating member; 30-battery cell; 31-housing; 311-shell; 311B-side wall; 311C-bottom wall; 311A-opening; 311D- Through hole; 312 - end cap; 32 - electrode terminal; 33 - first insulating member; 34 - electrode lead-out portion; 35 - pressure relief component; 40 - battery; 41 - housing; 42 - housing cover; 43 - busbar; 50 - vehicle; wd - winding direction; CL - winding axis; d1 - first direction; d2 - second direction. DETAILED DESCRIPTION

[0056] The following detailed description of the embodiments of the present disclosure is provided in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of the present disclosure, but are not intended to limit the scope of the present disclosure, that is, the present disclosure is not limited to the described embodiments.

[0057] In the description of the present disclosure, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present disclosure. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly perpendicular, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0058] The directional words appearing in the following description are all directions shown in the figures and do not limit the specific structure of the present disclosure. In the description of the present disclosure, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances.

[0059] The following describes some embodiments of the present invention in detail with reference to the accompanying drawings. In the absence of conflict, the features of the following embodiments can be combined with each other.

[0060] The term "plurality" appearing in the present disclosure refers to two or more (including two).

[0061] In the embodiment of the present disclosure, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0062] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0063] The battery cell includes an electrode assembly. The electrode assembly includes a first electrode sheet and a second electrode sheet with opposite polarities, and also includes an isolating member disposed between the first electrode sheet and the second electrode sheet. In some embodiments, the first electrode sheet is a positive electrode sheet, and the second electrode sheet is a negative electrode sheet. In other embodiments, the first electrode sheet is a negative electrode sheet, and the second electrode sheet is a positive electrode sheet. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode sheet and the negative electrode sheet. The isolating member is disposed between the positive electrode sheet and the negative electrode sheet, which can prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0064] In some embodiments, the positive electrode sheet may include a positive electrode current collector substrate and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector substrate.

[0065] As an example, the positive electrode current collector substrate has two surfaces facing each other in its thickness direction, and the positive electrode active material layer is provided on either or both of the two facing surfaces of the positive electrode current collector substrate.

[0066] As an example, the positive electrode current collector substrate can be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. can be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by placing a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0067] As an example, the positive electrode active material layer may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present disclosure is not limited to these materials, and other traditional materials that can be used as battery positive electrode active material layers may also be used. These positive electrode active material layers may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include but are not limited to lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and at least one of its modified compounds, etc.

[0068] In some embodiments, the negative electrode sheet may include a negative electrode current collector substrate.

[0069] As an example, the negative electrode current collector substrate can be a metal foil, a foamed metal, or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium can be used. The foamed metal can be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by placing a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0070] In some embodiments, the negative electrode sheet may include a negative electrode current collector substrate and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector substrate.

[0071] As an example, the negative electrode current collector substrate has two surfaces facing each other in its thickness direction, and the negative electrode active material layer is provided on either or both of the two facing surfaces of the negative electrode current collector substrate.

[0072] As an example, the negative electrode active material layer may adopt the negative electrode active material layer for battery cells that is well known in the art. As an example, the negative electrode active material layer may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present disclosure is not limited to these materials, and other traditional materials that can be used as negative electrode active material layers for batteries may also be used. These negative electrode active material layers may be used alone or in combination of two or more.

[0073] In some embodiments, the material of the positive electrode current collector substrate may be aluminum, and the material of the negative electrode current collector substrate may be copper.

[0074] In some embodiments, the separator is a separator. The present disclosure has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0075] As an example, the primary material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive electrode sheet and the negative electrode sheet, or it can be located between the positive electrode sheet and the negative electrode sheet and attached to the surface of the positive electrode sheet and / or the surface of the negative electrode sheet.

[0076] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode, and serves to transport ions and isolate the positive and negative electrodes.

[0077] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This disclosure does not specifically limit the type of electrolyte, and the electrolyte may be selected based on needs. The electrolyte may be liquid, gel, or solid.

[0078] As an example, the liquid electrolyte includes an electrolyte salt and a solvent.

[0079] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0080] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent can also be an ether solvent. Ether solvents can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0081] As an example, a gel electrolyte includes a polymer as an electrolyte skeleton network, combined with an ionic liquid-lithium salt.

[0082] As examples, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0083] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, or the like.

[0084] As an example, the inorganic solid electrolyte can be an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0085] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0086] In some embodiments, the electrode assembly comprises a wound structure. A positive electrode sheet, a negative electrode sheet, and a separator are wound into the wound structure. One or more positive and negative electrode sheets may be provided. For example, multiple positive and negative electrode sheets may be arranged alternately along the thickness of the sheet.

[0087] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0088] In some embodiments, the positive electrode sheet includes a positive electrode tab, and the negative electrode sheet includes a negative electrode tab. The positive and negative electrode tabs can be used to conduct current from the electrode assembly. The positive and negative electrode tabs are connected to the positive and negative current collector substrates, respectively. The tabs can be formed by cutting or trimming the current collector substrate, or by welding them to the sides of the current collector substrate.

[0089] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0090] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal prismatic batteries. Polygonal prismatic batteries are, for example, hexagonal prismatic batteries.

[0091] The battery mentioned in the embodiments of the present disclosure refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0092] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module. A battery module may include multiple battery cells connected in series, parallel, or hybrid.

[0093] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0094] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0095] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0096] In some related technologies, the electrode sheet in an electrode assembly primarily consists of a current collector substrate and an active material layer disposed on the surface of the current collector substrate. The portion of the current collector substrate extending beyond the active material layer across the width of the electrode sheet forms the current collection and output region. This region is cut to create multiple, smaller tabs located on the sides of the current collector substrate. Cutouts are provided between adjacent tabs, making each tab independent of the others.

[0097] These smaller tabs are bent and flattened at the ends of the wound electrode assembly to form a denser tab stacking structure. When the tab stacking structure is welded to the collecting plate by laser or other means, the heat generated by the tab stacking structure may burn the isolating parts in contact with the tabs through heat conduction, causing the isolating parts to break and fail, affecting product yield and safety of use.

[0098] In view of this, an embodiment of the present disclosure provides a battery cell, comprising: an electrode assembly, a first conductive member, and a second conductive member. The electrode assembly comprises a first electrode sheet, a second electrode sheet, and a separator, wherein the first electrode sheet and the second electrode sheet have opposite polarities, the separator is located between the first electrode sheet and the second electrode sheet, the first electrode sheet, the second electrode sheet, and the separator are wound along a winding direction to form a winding structure, the first electrode sheet comprises a plurality of first electrode tabs bent at the end of the winding structure to form a first electrode tab stacking structure, and the second electrode sheet comprises a plurality of second electrode tabs bent at the end of the winding structure to form a second electrode tab stacking structure; a first conductive member is welded to the first electrode tab stacking structure; and a second conductive member is welded to the second electrode tab stacking structure, wherein, in a first direction parallel to the direction in which the winding axis of the winding structure extends, at least one of the bending positions of the plurality of first electrode tabs and the bending positions of the plurality of second electrode tabs has a gap with the separator in the first direction.

[0099] Multiple first pole tabs and multiple second pole tabs are bent at the ends of the winding structure to form a first pole tab stacking structure and a second pole tab stacking structure, respectively. By ensuring that at least one of the bending positions of the multiple first pole tabs and the bending positions of the multiple second pole tabs has a gap with the insulating member in the first direction, the risk of heat generated by the pole tabs being conducted to the insulating member and causing burns to the insulating member during the welding process between the pole tab stacking structure and the conductive member can be reduced, thereby improving product yield and safety of use.

[0100] The battery cells of the disclosed embodiments are applicable to various types of batteries. A battery may include a housing and a battery module. The housing provides space for the battery module, which is mounted within the housing. The housing may be made of metal. The battery module may include multiple battery cells connected in series, parallel, or in a hybrid configuration. A battery cell is the smallest unit of a battery. It includes an electrode assembly capable of undergoing an electrochemical reaction.

[0101] The battery of the embodiment of the present disclosure can be applied to various types of battery-using electrical devices. Electrical devices can be mobile phones, portable devices, laptop computers, battery cars, electric cars, ships, spacecraft, electric toys and electric tools, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers. The embodiment of the present disclosure does not impose any special restrictions on the above-mentioned electrical devices. The battery can be used to power electrical devices such as vehicles, for example, to provide power for controlling the vehicle or power for driving the vehicle.

[0102] Figure 1 is a schematic diagram of the structure of some embodiments of the power-consuming device according to the present disclosure. For convenience, the description will be based on a vehicle as an example. Vehicle 50 can be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle or a hybrid vehicle. A battery 40 can be installed at the bottom, front, or rear of vehicle 50.

[0103] The battery 40 can be used to power the vehicle 50. For example, the battery 40 can serve as the operating power source of the vehicle 50 and be used for the circuit system of the vehicle 50, such as the power requirements for starting, navigating, and operating the vehicle 50. The battery 40 can not only serve as the operating power source of the vehicle 50, but also as the driving power source of the vehicle 50, replacing or partially replacing fuel or natural gas to provide driving force for the vehicle 50.

[0104] Vehicle 50 may also be equipped with axles, wheels, a motor, and a controller. The controller is used to control the power supplied by battery 40 to the motor. For example, when vehicle 50 is powered by battery 40, battery 40 replaces or partially replaces fuel or natural gas to provide the motor with the power required for constant speed and acceleration. The motor is used to drive the axles, which in turn drives the wheels.

[0105] Figure 2 is an exploded schematic diagram of some embodiments of the battery according to the present disclosure. Figure 3 is a schematic diagram of the connection of multiple battery cells in some embodiments of the battery according to the present disclosure.

[0106] 2 , in some embodiments, a battery 40 includes a housing 41, a cover 42 covering an open side of the housing 41, and one or more battery cells 30 disposed within the housing 41. The housing 41 and cover 42 provide space for the battery cells 30 and offer cooling, sealing, and impact protection functions. They also prevent liquids or other foreign matter from adversely affecting the charging, discharging, or safety of the battery cells.

[0107] The box body 41 and the box cover 42 can have various shapes, such as a rectangular parallelepiped or a cylinder. The box body 41 can be a hollow structure with one side open, and the box cover 42 can be a plate-like structure. The box cover 42 covers the open side of the box body 41, forming an internal storage space. In another embodiment, the box body 41 is a hollow structure with one side open, and the box cover 42 is also a hollow structure with one side open. The open side of the box cover 42 covers the open side of the box body 41, forming an internal storage space.

[0108] Referring to Figures 2 and 3 , the battery cells 30 are electrically connected, such as in series, parallel, or hybrid, to achieve the desired electrical performance parameters of the battery 40. Hybrid means that multiple battery cells 30 are connected both in series and in parallel. Adjacent battery cells 30 can be electrically connected via busbars 43 . Multiple battery cells 30 are arranged in rows, and one or more rows of battery cells 30 can be arranged within the housing 41 as needed.

[0109] In some embodiments, the battery cells 30 of the battery 40 may be arranged along at least one of the length and width of the housing 41. As needed, at least one row or column of battery cells 30 may be provided. Alternatively, one or more layers of battery cells 30 may be provided along the height of the battery 40.

[0110] In some embodiments, multiple battery cells 30 may be connected in series, parallel, or hybrid to form a battery module, and then the multiple battery modules may be connected in series, parallel, or hybrid to form a whole unit, which is then housed in the housing 41. In other embodiments, all battery cells 30 may be directly connected in series, parallel, or hybrid to form a whole unit, and then all battery cells 30 may be housed in the housing.

[0111] Figure 4 is an exploded schematic diagram of some embodiments of a battery cell according to the present disclosure. Figure 5 is a longitudinal cross-sectional schematic diagram through a winding axis CL according to some embodiments of a battery cell according to the present disclosure. Figure 6 is a cross-sectional schematic diagram of a winding structure in some embodiments of an electrode assembly according to the present disclosure. Figure 7 is an exploded schematic diagram of an electrode assembly and a conductive member in some embodiments of a battery cell according to the present disclosure.

[0112] 3 to 7 , in some embodiments, a battery cell 30 includes an electrode assembly 10, a first conductive member 21, and a second conductive member 22. The electrode assembly 10 includes a first electrode sheet 11, a second electrode sheet 12, and a separator 13. The first electrode sheet 11 and the second electrode sheet 12 have opposite polarities. The separator 13 is located between the first electrode sheet 11 and the second electrode sheet 12. The first electrode sheet 11, the second electrode sheet 12, and the separator 13 are wound along a winding direction wd to form a wound structure 100.

[0113] 6 , the pole piece windings formed by the first pole piece 11 and the second pole piece 12 in the winding structure 100 may be at least partially arranged alternately from outside to inside. The separator 13 may be provided between the first pole piece 11 and the second pole piece 12 in the form of an isolation film.

[0114] The first pole sheet 11 may include a first current collector substrate 11A and a plurality of first pole tabs 11B. The plurality of first pole tabs 11B are connected to the first current collector substrate 11A and are arranged at intervals along the winding direction wd. At least a portion of the plurality of first pole tabs 11B are bent at the end of the winding structure 100 to form a first pole tab stacking structure 111.

[0115] The second pole sheet 12 may include a second current collector substrate 12A and a plurality of second pole tabs 12B. The plurality of second pole tabs 12B are connected to the second current collector substrate 12A and are arranged at intervals along the winding direction wd. At least a portion of the plurality of second pole tabs 12B are bent at the end of the winding structure 100 to form a second pole tab stacking structure 121.

[0116] The first conductive member 21 is welded to the first tab stack 111, and the second conductive member 22 is welded to the second tab stack 121. The welding of the conductive members to the tab stack can be performed using a laser or other method, and the corresponding welding area is represented by a liquid metal portion that is heated and melted into a certain geometric shape, i.e., a weld pool.

[0117] 4 and 5 , in some embodiments, the battery cell 30 may further include a housing 31 and an electrode terminal 32. The housing 31 has a chamber for accommodating the electrode assembly 10, the first conductive member 21, and the second conductive member 22. The electrode terminal 32 is disposed on a wall of the housing 31 and is electrically connected to the first conductive member 21 or the second conductive member 22.

[0118] The cavity of the housing 31 can accommodate not only the electrode assembly 10 but also the electrolyte. The shape of the housing 31 can be determined according to the shape of the one or more electrode assemblies 10 accommodated in the cavity, for example, the shape of the housing 31 is a hollow cuboid, a hollow cube, or a hollow cylinder.

[0119] In Figures 4 and 5 , the housing 31 may include a shell 311 and an end cap 312. The shell 311 is a hollow structure with an opening 311A ​​at one or both ends. It may be made of one or more materials, such as copper, iron, aluminum, steel, aluminum alloy, or plastic. The end cap 312 may be made of metal or non-metal and may be fixedly connected to the shell 311 by welding, bonding, or fasteners.

[0120] One end of the housing 311 has an opening 311A, and an end cap 312 covers the opening 311A. In Figure 5, the housing 311 may include side walls 311B and a bottom wall 311C. The side walls 311B surround the outside of the electrode assembly 10, and the bottom wall 311C is disposed opposite the opening 311A. The wall portion of the outer shell 31 serves as the end cap 312 or the bottom wall 311C. Accordingly, the electrode terminal 32 may be disposed on either the end cap 312 or the bottom wall 311C.

[0121] For cylindrical battery cells, the housing 311 may be a cylindrical hollow structure with an opening 311A ​​at one end, and the end cap 312 may be a disc-shaped structure matching the opening 311A. The electrode terminal 32 may be disposed on the bottom wall 311C of the housing 311 away from the end cap 312.

[0122] In Figure 4, the bottom wall 311C may be provided with a through hole 311D. Referring to Figure 5, the electrode terminal 32 may be provided on the through hole 311D through the electrode lead-out portion 34 and the first insulating member 33. The electrode lead-out portion 34 may at least partially protrude from the outer surface of the bottom wall 311C to facilitate electrical connection between different battery cells 30 through the bus bar 43 (as shown in Figure 3). The first insulating member 33 is used to achieve insulation between the electrode lead-out portion 34 and the shell 311, and may be made of rubber or plastic. Optionally, openings are provided at both ends of the shell, and both are covered by end covers, and the electrode lead-out portion and the electrode terminal may be provided on the end covers.

[0123] 4 and 5 , a pressure relief component 35 may be provided on the end cover 312. A pressure relief component refers to an element or component that is actuated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a predetermined threshold. The threshold design varies according to different design requirements. The threshold may depend on one or more materials of the positive electrode plate, negative electrode plate, electrolyte and isolation membrane in the battery cell. The pressure relief component may take the form of an explosion-proof valve, an air valve, a pressure relief valve or a safety valve, and may specifically adopt a pressure-sensitive or temperature-sensitive element or structure, that is, when the internal pressure or temperature of the battery cell reaches a predetermined threshold, the pressure relief component performs an action or a weak structure provided in the pressure relief component is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released.

[0124] The emissions from battery cells mentioned here include but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of isolation membranes, high-temperature and high-pressure gases produced by the reaction (such as CH4, CO and other combustible gases), flames, etc.

[0125] 5 and 7 , in some embodiments, in a first direction d1, the first tab stacking structure 111 and the second tab stacking structure 121 are located at opposite ends of the wound structure 100. For a cylindrical wound structure 100, the first direction d1 is parallel to the extension direction of the winding axis CL of the wound structure 100.

[0126] Accordingly, the first conductive member 21 and the second conductive member 22 are located on both sides of the electrode assembly 10 along the first direction d1, and are respectively welded to the first tab stack structure 111 and the second tab stack structure 121 at the two side ends of the electrode assembly 10, and are respectively welded to the electrode lead portion 34 and the end cap 312. The first conductive member 21 and the second conductive member 22 can serve as current collectors to respectively achieve electrical connections between the electrode assembly 10 and the electrode terminal 32, and between the electrode assembly 10 and structures such as the end cap 312.

[0127] At least one of the first conductive member 21 and the second conductive member 22 may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc. In some embodiments, at least one of the first conductive member 21 and the second conductive member 22 may include a collecting plate or other structures.

[0128] Figure 8 is an exploded schematic diagram of an electrode assembly and a conductive member in some other embodiments of a battery cell according to the present disclosure. Figures 9 and 10 are respectively an assembled structure and a cross-sectional schematic diagram of the conductive member in Figure 8 .

[0129] With reference to Figures 8, 9, and 10, in some embodiments, in the first direction d1, the first tab stacking structure 111 and the second tab stacking structure 121 are both located at the same end of the wound structure 100. Accordingly, multiple first tabs 11B and multiple second tabs 12B are distributed at the same end of the wound structure 100, and the first tab stacking structure 111 and the second tab stacking structure 121 obtained by bending and stacking can be distributed at different angles at the end of the same side. The first conductive member 21 and the second conductive member 22 are also both disposed on the same side of the wound structure 100 and are welded to the first tab stacking structure 111 and the second tab stacking structure 121, respectively.

[0130] Referring to Figure 8, the first conductive member 21 and the second conductive member 22 can both be fan-shaped, and in order to insulate the first conductive member 21 and the second conductive member 22 from each other, a second insulating member 23 can also be provided at the side end of the winding structure. The first conductive member 21 and the second conductive member 22 are both assembled with the second insulating member 23, and the assembled structure shown in Figure 8 is welded to the first tab stacking structure 111 and the second tab stacking structure 121.

[0131] 9 and 10 , the second insulating member 23 may be provided with a hollow portion and an opening extending along the first direction d1, wherein the opening is used to accommodate the first conductive member 21 and the hollow portion accommodates the second conductive member 22. The second insulating member 23 may be made of rubber or plastic.

[0132] Figure 11 is a schematic diagram of electrode sheets and tabs in an unfolded state according to some embodiments of the electrode assembly of the present disclosure. Figure 12 is a schematic diagram of electrode sheets and tabs in an unfolded state according to other embodiments of the electrode assembly of the present disclosure. Figure 13 is a schematic cross-sectional diagram of the structure of the tab stacking structure welded to the conductive member according to some embodiments of the electrode assembly of the present disclosure.

[0133] FIG11 corresponds to an embodiment in which the plurality of first electrode tabs 11B and the plurality of second electrode tabs 12B are distributed at opposite ends of the wound structure 100, while FIG12 corresponds to an embodiment in which the plurality of first electrode tabs 11B and the plurality of second electrode tabs 12B are distributed at the same end of the wound structure 100. In FIG11 and FIG12 , the second direction d2 is parallel to the length direction of the first electrode sheet 11 or the second electrode sheet 12, and is also equivalent to the winding direction wd after unfolding. The first direction d1 is parallel to the winding axis CL of the wound structure 100, and is also parallel to the width direction of the first electrode sheet 11 or the second electrode sheet 12.

[0134] 11 and 12 , in a first direction d1 parallel to the extension direction of the winding axis CL of the winding structure 100 , the bending positions 11 f of the multiple first pole tabs 11B are located on a side of the separator 13 away from the first current collector substrate 11A, and the bending positions 12 f of the multiple second pole tabs 12B are located on a side of the separator 13 away from the second current collector substrate 12A.

[0135] In Figures 11 and 12 , the dotted lines indicate the bending positions of the first and second electrode tabs 11B, 12B. For embodiments in which multiple electrode tabs are cut from a current collector substrate using a laser or other method, the bending positions 11f of the multiple first electrode tabs 11B may be the cut root portions 11r of the multiple first electrode tabs 11B, or may be closer to the top 11t of the first electrode tab 11B than the cut root portions 11r of the first electrode tab 11B. The bending positions 12f of the multiple second electrode tabs 12B may be the cut root portions 12r of the multiple second electrode tabs 12B, or may be closer to the top 12t of the second electrode tab 12B than the cut root portions 12r of the second electrode tab 12B.

[0136] At least part of the first tabs 11B are bent at the end of the winding structure 100 to form a first tab stacking structure 111 , and at least part of the second tabs 12B are bent at the end of the winding structure 100 to form a second tab stacking structure 121 .

[0137] The bent positions 11f of the multiple first tabs 11B can have a gap with the separator 13 in the first direction d1, thereby reducing the risk of heat generated by the first tab stack structure being transferred to the separator 13 during welding, causing burns to the separator 13. Accordingly, the minimum distance between the bent positions 11f of the multiple first tabs 11B and the separator 13 in the first direction d1 is defined as a first minimum distance L1.

[0138] The bent positions 12f of the plurality of second electrode tabs 12B may have a gap with the separator 13 in the first direction d1, thereby reducing the risk of heat generated by the second electrode tab stack structure being transferred to the separator 13 during welding, causing burns to the separator 13. Accordingly, the minimum distance between the bent positions 12f of the plurality of second electrode tabs 12B and the separator 13 in the first direction d1 is defined as a second minimum distance L2.

[0139] When the bending position 11f of the plurality of first electrode tabs 11B is the position where the electrode tab is cut in the portion of the first current collector substrate 11A not covered by the first active material layer 11C, the first minimum distance L1 is the minimum distance between the cut root 11r of the plurality of first electrode tabs 11B and the separator 13 in the first direction d1. When the bending position 12f of the plurality of second electrode tabs 12B is the position where the electrode tab is cut in the portion of the current collector substrate not covered by the active material layer, the second minimum distance L2 is the minimum distance between the cut root 12r of the plurality of second electrode tabs 12B and the separator 13 in the first direction d1.

[0140] In some embodiments, the melting point of the material of the plurality of first electrode tabs 11B is lower than the melting point of the material of the plurality of second electrode tabs 12B, and the first minimum distance L1 is less than or equal to the second minimum distance L2. For example, when the first electrode tab 11B is made of aluminum with a melting point of 660°C or copper with a melting point of 1083°C, and the second electrode tab 12B is made of aluminum with a melting point of 660°C, the first minimum distance L1 in this embodiment can be set to be less than or equal to the second minimum distance L2.

[0141] For battery cell embodiments in which the melting point of the first tab 11B material is lower than that of the second tab 12B material, the higher melting point of the second tab 12B material requires greater welding heat to form a weld pool. Accordingly, the heat generated by the second tab stack 121 during welding is higher. When the heat generated by the second tab stack 121 is high, there is a risk of burns from thermal radiation even if the separator 13 does not contact the second tab stack 121. Therefore, by ensuring that the second minimum distance L2 is not less than the first minimum distance L1, the risk of burns from the portion of the separator 13 corresponding to the second tab stack 121, as well as the risk of burns from thermal radiation caused by the separator 13 being too close to the second tab stack 121, can be reduced.

[0142] In some embodiments, the melting point of the material of the plurality of first electrode tabs 11B is greater than the melting point of the material of the plurality of second electrode tabs 12B, and the second minimum distance L2 is less than or equal to the first minimum distance L1. For example, when the first electrode tabs 11B are made of copper with a melting point of 1083°C and the second electrode tabs 12B are made of aluminum with a melting point of 660°C, the second minimum distance L2 in this embodiment can be set to be less than or equal to the first minimum distance L1.

[0143] For battery cell embodiments in which the melting point of the first tab 11B material is greater than the melting point of the second tab 12B material, the first tab 11B material with a larger melting point requires a greater welding heat to form a weld pool. Correspondingly, the heat generated by the first tab stack structure 111 during welding is higher. When the heat generated by the first tab stack structure 111 is high, there is a risk of burns from thermal radiation even if the separator 13 is not in contact with the first tab stack structure 111. Therefore, by ensuring that the first minimum distance L1 is not less than the second minimum distance L2, the risk of burns from the separator portion corresponding to the first tab stack structure 111, as well as the risk of burns from thermal radiation caused by the separator being too close to the first tab stack structure 111, can be reduced.

[0144] 11 and 12 , in the first direction d1, there is a third minimum distance L3 between the bending positions 11f of the plurality of first pole tabs 11B and the pole tab tops 11t of the plurality of first pole tabs 11B, and there is a fourth minimum distance L4 between the bending positions 12f of the plurality of second pole tabs 12B and the pole tab tops 12t of the plurality of second pole tabs 12B.

[0145] When the bend position 11f of the plurality of first electrode tabs 11B is the location where the tabs are cut in the portion of the first current collector substrate 11A not covered by the first active material layer 11C, the third minimum distance L3 is the minimum distance between the cut root 11r of the plurality of first electrode tabs 11B and the tab top 11t of the plurality of first electrode tabs 11B in the first direction d1, which is equivalent to the height of the first electrode tab 11B. When the bend position 12f of the plurality of second electrode tabs 12B is the location where the tabs are cut in the portion of the current collector substrate not covered by the active material layer, the fourth minimum distance L4 is the minimum distance between the cut root 12r of the plurality of second electrode tabs 12B and the tab top 12t of the plurality of second electrode tabs 12B in the first direction d1, which is equivalent to the height of the second electrode tab 12B.

[0146] FIG13 is a schematic cross-sectional view of the structure of welding the tab stacking structure and the conductive member according to some embodiments of the electrode assembly of the present disclosure.

[0147] 11 , 12 , and 13 , in some embodiments, a first thickness t1 of the plurality of first pole tabs 11B in the thickness direction of the first pole tabs 11B is less than a second thickness t2 of the plurality of second pole tabs 12B in the thickness direction of the second pole tabs 12B, and the third minimum distance L3 is greater than or equal to the fourth minimum distance L4.

[0148] The third minimum distance L3 and the fourth minimum distance L4 respectively represent the lengths of the first and second tabs 11B, 12B that are bent and stacked. The longer the tabs are stacked, the greater the degree of tab overlap. The first thickness t1 of the first tab 11B represents the thickness of the first tab 11B in a single layer, while the second thickness t2 of the second tab 12B represents the thickness of the second tab 12B in a single layer. The thicker the single tab, the thicker the stacked tab structure.

[0149] For the battery cell 30 embodiment in which the first thickness t1 is less than the second thickness t2, by making the third minimum distance L3 greater than or equal to the fourth minimum distance L4, the thicknesses of the first tab stacking structure 111 and the second tab stacking structure 121 can be made closer, which helps to reduce the risk of partial burning or scalding of the isolation member caused by the difference in welding heat when forming the welding pool mp.

[0150] In other embodiments, the first thickness t1 of the plurality of first pole tabs 11B in the thickness direction of the first pole tabs 11B is greater than the second thickness t2 of the plurality of second pole tabs 12B in the thickness direction of the second pole tabs 12B, and the third minimum distance L3 is less than or equal to the fourth minimum distance L4.

[0151] For the battery cell 30 embodiment in which the first thickness t1 is greater than the second thickness t2, by making the third minimum distance L3 less than or equal to the fourth minimum distance L4, the thicknesses of the first tab stacking structure 111 and the second tab stacking structure 121 can be made closer, which helps to reduce the risk of partial burning or scalding of the isolation member caused by the difference in welding heat when forming the welding pool mp.

[0152] In the above embodiments, a ratio A / B of a product A of a first thickness t1 of the plurality of first pole tabs 11B in the thickness direction of the first pole tab 11B and the third minimum distance L3 and a ratio B of a product B of a second thickness t2 of the plurality of second pole tabs 12B in the thickness direction of the second pole tab 12B and the fourth minimum distance L4 satisfies: 0.2≤A / B≤4, wherein the units of the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 are the same, for example, all are mm or cm.

[0153] The product A of the first thickness t1 and the third minimum distance L3 represents the stacking thickness of the first tab stack structure 111, and the product B of the second thickness t2 and the fourth minimum distance L4 represents the stacking thickness of the second tab stack structure 121. The ratio of the product A to the product B can reflect the degree of difference in stacking thickness between the first tab stack structure 111 and the second tab stack structure 121.

[0154] If the ratio A / B is too large, the first tab stack structure 111 is thicker, and a higher welding power and welding heat are required during welding. Compared with the second tab stack structure 121, the risk of burning or scalding the isolation part corresponding to the first tab stack structure 111 is increased.

[0155] If the ratio A / B is too small, the second tab stacking structure 121 is thicker, and a higher welding power and higher welding heat are required during welding. Compared with the first tab stacking structure 111, the risk of burning or scalding the isolation part corresponding to the second tab stacking structure 121 is increased.

[0156] Therefore, by making the ratio A / B satisfy: 0.2≤A / B≤4, the difference in stacking thickness between the first tab stacking structure 111 and the second tab stacking structure 121 is reduced, thereby reducing the risk of partial burning or scalding of the isolation members corresponding to the first tab stacking structure 111 and the second tab stacking structure 121.

[0157] Furthermore, the ratio A / B may satisfy: 0.5≤A / B≤2, for example, A / B is equal to 0.5, 0.8, 1, 1.2, 1.6 or 2.

[0158] By further limiting the ratio A / B to satisfy: 0.5≤A / B≤2, the difference in stacking thickness between the first tab stacking structure 111 and the second tab stacking structure 121 can be further reduced, thereby more effectively reducing the risk of partial burning or scalding of the isolation members corresponding to the first tab stacking structure 111 and the second tab stacking structure 121.

[0159] With reference to FIG13 , in some embodiments, the ratio A / B of the product A of the first thickness t1 of the plurality of first tabs 11B in the thickness direction of the first tab 11B and the third minimum distance L3 to the product B of the second thickness t2 of the plurality of second tabs 12B in the thickness direction of the second tab 12B and the fourth minimum distance L4 satisfies the following: A / B<1, wherein the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 are in the same unit, for example, mm or cm. Accordingly, the third thickness t3 of the first conductive member 21 in the first direction d1 is less than the fourth thickness t4 of the second conductive member 22 in the first direction d1.

[0160] The product A of the first thickness t1 and the third minimum distance L3 represents the stacking thickness of the first tab stack structure 111, and the product B of the second thickness t2 and the fourth minimum distance L4 represents the stacking thickness of the second tab stack structure 121. For battery cell embodiments where the product A is less than the product B, the thicker second tab stack structure 121 requires higher welding power for welding. Fluctuations in laser power at higher temperatures can easily lead to the formation of an excessively deep molten pool, increasing the risk of burns or scalding of the separator.

[0161] Therefore, a thicker second conductive member 22 is used to increase the tolerance of welding, reduce the possibility of forming an excessively deep molten pool, and thus reduce the risk of burning or scalding the portion of the separator corresponding to the second tab stack structure 121. The thinner first conductive member 21, when combined with the first tab stack structure 111 having a smaller stack thickness, allows for welding using a lower welding power, which in turn makes it easier to form a molten pool of appropriate depth, thereby reducing the risk of burning or scalding the portion of the separator corresponding to the first tab stack structure 111.

[0162] In other embodiments, the ratio A / B of the product A of the first thickness t1 of the plurality of first tabs 11B in the thickness direction of the first tab 11B and the third minimum distance L3 to the product B of the second thickness t2 of the plurality of second tabs 12B in the thickness direction of the second tab 12B and the fourth minimum distance L4 satisfies: A / B>1, wherein the units of the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 are the same, for example, all in mm or cm. Accordingly, the third thickness t3 of the first conductive member 21 in the first direction d1 is greater than the fourth thickness t4 of the second conductive member 22 in the first direction d1.

[0163] The product A of the first thickness t1 and the third minimum distance L3 represents the stacking thickness of the first tab stack structure 111, and the product B of the second thickness t2 and the fourth minimum distance L4 represents the stacking thickness of the second tab stack structure 121. For battery cell 30 embodiments where the product B is less than the product A, the thicker first tab stack structure 111 requires higher welding power for welding. Fluctuations in laser power at higher temperatures can easily lead to the formation of an excessively deep molten pool, increasing the risk of burns or scalding of the separator.

[0164] Therefore, a thicker first conductive member 21 is used to increase the tolerance of welding, reduce the possibility of forming an excessively deep molten pool, and thus reduce the risk of burning or scalding the portion of the separator corresponding to the first tab stack structure 111. The thinner second conductive member 22 is used in conjunction with the second tab stack structure 121 with a smaller stack thickness, allowing for welding at a lower welding power, which in turn makes it easier to form a molten pool of appropriate depth, thereby reducing the risk of burning or scalding the portion of the separator corresponding to the second tab stack structure 121.

[0165] Based on the various embodiments of the aforementioned battery cells, with reference to FIG2 , an embodiment of the present disclosure provides a battery 40 comprising the battery cell 30 of any of the aforementioned embodiments. A battery using the aforementioned battery cells can effectively improve safety in use.

[0166] Based on the various embodiments of the aforementioned batteries, with reference to Figure 1 , an embodiment of the present disclosure provides an electrical device comprising a battery 40 according to any of the aforementioned embodiments. The electrical device using the aforementioned battery can effectively improve safety in use.

[0167] In some specific embodiments, as shown in Figures 5-7 and 11, the battery cell 30 is cylindrical and includes: an electrode assembly 10, a first conductive member 21, a second conductive member 22, a housing 31, and an electrode terminal 32. The housing 31 has a chamber for accommodating the electrode assembly 10, the first conductive member 21, and the second conductive member 22. The housing 31 may include a shell 311 and an end cap 312. One end of the shell 311 has an opening 311A, and the end cap 312 covers the opening 311A. The shell 311 includes side walls 311B and a bottom wall 311C. The side walls 311B surround the outside of the electrode assembly 10, and the bottom wall 311C is arranged opposite the opening 311A. The bottom wall 311C has a through hole 311D. The electrode terminal 32 is disposed on the through hole 311D via the electrode lead 34 and the first insulating member 33.

[0168] The battery cell 30 includes an electrode assembly 10, a first conductive member 21, and a second conductive member 22. The electrode assembly 10 includes a first electrode sheet 11, a second electrode sheet 12, and a separator 13. The first electrode sheet 11 and the second electrode sheet 12 have opposite polarities. The separator 13 is located between the first electrode sheet 11 and the second electrode sheet 12. The first electrode sheet 11, the second electrode sheet 12, and the separator 13 are wound along a winding direction wd to form a cylindrical wound structure 100. The separator 13 is provided between the first electrode sheet 11 and the second electrode sheet 12 in the form of an isolation film.

[0169] The first pole sheet 11 includes a first current collector substrate 11A and a plurality of first pole tabs 11B. The plurality of first pole tabs 11B are connected to the first current collector substrate 11A and are arranged at intervals along the winding direction wd. At least a portion of the plurality of first pole tabs 11B are bent at the end of the winding structure 100 to form a first pole tab stacking structure 111.

[0170] The second pole piece 12 includes a second current collector substrate 12A and a plurality of second pole tabs 12B. The plurality of second pole tabs 12B are connected to the second current collector substrate 12A and are arranged at intervals along the winding direction wd. At least a portion of the plurality of second pole tabs 12B are bent at the end of the winding structure 100 to form a second pole tab stacking structure 121.

[0171] The first conductive member 21 is welded to the first tab stack structure 111 and to the electrode lead portion 34 to achieve electrical connection to the electrode terminal 32. The second conductive member 22 is welded to the second tab stack structure 121 and to the end cap 312.

[0172] In the first direction d1, the first tab stacking structure 111 and the second tab stacking structure 121 are respectively located at opposite ends of the winding structure 100. The first conductive member 21 and the second conductive member 22 are located at both sides of the electrode assembly 10 along the first direction d1.

[0173] The first electrode sheet 11 is a positive electrode sheet, and its first current collector substrate 11A and the first electrode tab 11B obtained by cutting the portion of the first current collector substrate 11A not covered by the first active material layer 11C are both made of metal aluminum. The second electrode sheet 12 is a negative electrode sheet, and its second current collector substrate 12A and the second electrode tab 12B obtained by cutting the portion of the second current collector substrate 12A not covered by the second active material layer 12C are both made of metal copper.

[0174] The melting point of aluminum is lower than that of copper. Referring to Figure 11 , the first minimum distance L1 is smaller than the second minimum distance L2. The second thickness t2 of the second tab 12B is larger than the first thickness t1 of the first tab 11B. The third minimum distance L3 is larger than the fourth minimum distance L4.

[0175] While the present disclosure has been described with reference to preferred embodiments, various modifications may be made thereto and equivalent components may be substituted without departing from the scope of the present disclosure. In particular, the various technical features described in the various embodiments may be combined in any manner, provided no structural conflicts exist. The present disclosure is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A battery cell (30), comprising: An electrode assembly (10), comprising a first pole piece (11), a second pole piece (12) and a separator (13), wherein the first pole piece (11) and the second pole piece (12) have opposite polarities, the separator (13) is located between the first pole piece (11) and the second pole piece (12), the first pole piece (11), the second pole piece (12) and the separator (13) are wound along a winding direction (wd) to form a winding structure (100), the first pole piece (11) comprises a plurality of first pole tabs (11B) bent at the end of the winding structure (100) to form a first pole tab stacking structure (111), and the second pole piece (12) comprises a plurality of second pole tabs (12B) bent at the end of the winding structure (100) to form a second pole tab stacking structure (121); A first conductive member (21) is welded to the first electrode tab stack structure (111); and A second conductive member (22) is welded to the second electrode tab stack structure (121). In which, in a first direction (d1) parallel to the extension direction of the winding axis of the winding structure (100), at least one of the bending positions (11f) of the plurality of first pole ears (11B) and the bending positions (12f) of the plurality of second pole ears (12B) has a gap with the isolation member (13) in the first direction (d1).

2. The battery cell (30) according to claim 1, wherein: The minimum distance between the bending positions (11f) of the multiple first pole ears (11B) and the gap between the insulating member (13) in the first direction (d1) is defined as a first minimum distance L1, and the minimum distance between the bending positions (12f) of the multiple second pole ears (12B) and the gap between the insulating member (13) in the first direction (d1) is defined as a second minimum distance L2; the melting point of the material of the multiple first pole ears (11B) is lower than the melting point of the material of the multiple second pole ears (12B), and the first minimum distance L1 is lower than or equal to the second minimum distance L2.

3. The battery cell (30) according to claim 1, wherein: The minimum distance between the bending positions (11f) of the multiple first pole ears (11B) and the gap between the insulating member (13) in the first direction (d1) is defined as a first minimum distance L1, and the minimum distance between the bending positions (12f) of the multiple second pole ears (12B) and the gap between the insulating member (13) in the first direction (d1) is defined as a second minimum distance L2; the melting point of the material of the multiple first pole ears (11B) is greater than the melting point of the material of the multiple second pole ears (12B), and the second minimum distance L2 is less than or equal to the first minimum distance L1.

4. The battery cell (30) according to any one of claims 1 to 3, wherein: The bending positions (11f) of the plurality of first pole tabs (11B) are the cut roots (11r) of the plurality of first pole tabs (11B), and / or the bending positions (12f) of the plurality of second pole tabs (12B) are the cut roots (12r) of the plurality of second pole tabs (12B).

5. The battery cell (30) according to any one of claims 1 to 4, wherein: In the first direction (d1), there is a third minimum distance L3 between the bending positions (11f) of the plurality of first pole tabs (11B) and the pole tab tops (11t) of the plurality of first pole tabs (11B), and there is a fourth minimum distance L4 between the bending positions (12f) of the plurality of second pole tabs (12B) and the pole tab tops (12t) of the plurality of second pole tabs (12B); The first thickness t1 of the plurality of first pole tabs (11B) in the thickness direction of the first pole tab (11B) is smaller than the second thickness t2 of the plurality of second pole tabs (12B) in the thickness direction of the second pole tab (12B), and the third minimum distance L3 is greater than or equal to the fourth minimum distance L4.

6. The battery cell (30) according to any one of claims 1 to 4, wherein: In the first direction (d1), there is a third minimum distance L3 between the bending positions (11f) of the plurality of first pole tabs (11B) and the pole tab tops (11t) of the plurality of first pole tabs (11B), and there is a fourth minimum distance L4 between the bending positions (12f) of the plurality of second pole tabs (12B) and the pole tab tops (12t) of the plurality of second pole tabs (12B); A first thickness t1 of the plurality of first pole tabs (11B) in the thickness direction of the first pole tab (11B) is greater than a second thickness t2 of the plurality of second pole tabs (12B) in the thickness direction of the second pole tab (12B), and the third minimum distance L3 is less than or equal to the fourth minimum distance L4.

7. The battery cell (30) according to claim 5 or 6, wherein: A ratio A / B of a product A of a first thickness t1 of the plurality of first pole tabs (11B) in the thickness direction of the first pole tabs (11B) and the third minimum distance L3 and a ratio B of a product B of a second thickness t2 of the plurality of second pole tabs (12B) in the thickness direction of the second pole tabs (12B) and the fourth minimum distance L4 satisfies: 0.2≤A / B≤4, wherein the units of the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 are the same.

8. The battery cell (30) according to claim 7, wherein: The ratio A / B satisfies: 0.5≤A / B≤2.

9. The battery cell (30) according to claim 5 or 6, wherein: The ratio A / B of the product A of the first thickness t1 of the plurality of first pole tabs (11B) in the thickness direction of the first pole tab (11B) and the third minimum distance L3 and the product B of the second thickness t2 of the plurality of second pole tabs (12B) in the thickness direction of the second pole tab (12B) and the fourth minimum distance L4 satisfies: A / B<1, wherein the units of the first thickness t1, the second thickness t2, the third minimum distance L3 and the fourth minimum distance L4 are the same, and the third thickness t3 of the first conductive member (21) in the first direction (d1) is less than the fourth thickness t4 of the second conductive member (22) in the first direction (d1).

10. The battery cell (30) according to claim 5 or 6, wherein: The ratio A / B of the product A of the first thickness t1 of the plurality of first pole tabs (11B) in the thickness direction of the first pole tab (11B) and the third minimum distance L3 and the product B of the second thickness t2 of the plurality of second pole tabs (12B) in the thickness direction of the second pole tab (12B) and the fourth minimum distance L4 satisfies: A / B>1, wherein the units of the first thickness t1, the second thickness t2, the third minimum distance L3 and the fourth minimum distance L4 are the same, and the third thickness t3 of the first conductive member (21) in the first direction (d1) is greater than the fourth thickness t4 of the second conductive member (22) in the first direction (d1).

11. The battery cell (30) according to any one of claims 1 to 10, wherein: In the first direction (d1), the first electrode tab stacking structure (111) and the second electrode tab stacking structure (121) are both located at the same side end of the winding structure (100).

12. The battery cell (30) according to any one of claims 1 to 10, wherein: In the first direction (d1), the first electrode tab stacking structure (111) and the second electrode tab stacking structure (121) are respectively located at opposite side ends of the winding structure (100).

13. The battery cell (30) according to any one of claims 1 to 12, further comprising: A housing (31) having a chamber for accommodating the electrode assembly (10), the first conductive member (21) and the second conductive member (22); and An electrode terminal (32) is arranged on the wall of the housing (31) and is electrically connected to the first conductive member (21) or the second conductive member (22).

14. The battery cell (30) according to claim 13, wherein: The shell (31) comprises a shell (311) and an end cover (312); one end of the shell (311) has an opening (311A); the end cover (312) covers the opening (311A); the shell (311) comprises a side wall (311B) and a bottom wall (311C); the side wall (311B) surrounds the outer side of the electrode assembly (10); the bottom wall (311C) is arranged opposite to the opening (311A); and the wall portion of the shell (31) is the end cover (312) or the bottom wall (311C).

15. The battery cell (30) according to any one of claims 1 to 14, wherein: The first pole piece (11) further comprises a first current collector substrate (11A), the plurality of first pole tabs (11B) are connected to the first current collector substrate (11A) and are arranged at intervals along the winding direction (wd), and in the first direction (d1), the bending positions (11f) of the plurality of first pole tabs (11B) are located on a side of the separator (13) away from the first current collector substrate (11A); The second pole piece (12) further comprises a second current collector substrate (12A), the plurality of second pole tabs (12B) being connected to the second current collector substrate (12A) and arranged at intervals along the winding direction (wd), and in the first direction (d1), the bending positions (12f) of the plurality of second pole tabs (12B) are located on a side of the separator (13) away from the second current collector substrate (12A).

16. A battery (40), comprising: The battery cell (30) according to any one of claims 1 to 15.

17. An electrical device, comprising: The battery (40) as claimed in claim 16.

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