Battery cells, batteries and power consuming devices

Abstract

The present invention provides a battery cell (30), a battery (40), and a power consumption device. The battery cell (30) is an electrode assembly (10) including a first polarity sheet (11), a second polarity sheet (12), and an isolating member (13), the first polarity sheet (11) and the second polarity sheet (12) having opposite polarities, the isolating member (13) being located between the first polarity sheet (11) and the second polarity sheet (12), the first polarity sheet (11), the second polarity sheet (12), and the isolating member (13) being wound along a winding direction to form a wound structure (100), the first polarity sheet (11) including a plurality of first tabs (11B) bent at an end of the wound structure (100) to form a first tab stack structure (111), and the second polarity sheet (11) (12) includes an electrode assembly (10) including a plurality of second tabs (12B) bent at an end of the wound structure (100) to form a second tab stack structure (121), a first conductive member (21) welded to the first tab stack structure (111), and a second conductive member (22) welded to the second tab stack structure (121), and in a first direction (d1) parallel to the extension direction of the winding axis of the wound structure (100), 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 between it and the isolation member (13) in the first direction (d1).

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from Chinese patent application No. 202310955457.7, filed August 1, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] TECHNICAL FIELD The present disclosure relates to the field of battery technology, and more particularly to battery cells, batteries, and power consuming devices. [Background technology]

[0003] Secondary batteries, especially lithium ion batteries, have advantages such as high voltage, large energy density, long cycle life, environmental friendliness and pollution-free operation, a wide operating temperature range, and low self-discharge, and are widely used in the fields of power devices in portable electronic devices and large new energy electric vehicles, which are of great significance in solving mankind's environmental pollution and energy crisis. With the widespread application of lithium ion batteries, the safety of battery use has become a major concern for users. Summary of the Invention

[0004] In one aspect of the present disclosure, there is provided a battery cell including an electrode assembly including a first polarity sheet, a second polarity sheet, and an isolating member, wherein the first polarity sheet and the second polarity sheet have opposite polarities and the isolating member is located between the first polarity sheet and the second polarity sheet, the first polarity sheet, the second polarity sheet, and the isolating member are wound along a winding direction to form a wound structure, the first polarity sheet includes a plurality of first tabs folded at an end of the wound structure to form a first tab stack structure, and the second polarity sheet includes a plurality of second tabs folded at an end of the wound structure to form a second tab stack structure; and a first conductive member welded to the first tab stack structure and a second conductive member welded to the second tab stack structure, wherein at least one of the bending positions of the plurality of first tabs and the bending positions of the plurality of second tabs has a gap between it and the isolating member in a first direction parallel to an extension direction of a winding axis of the wound structure.

[0005] The multiple first tabs and the multiple second tabs are respectively folded at the ends of the wound structure to form a first tab stack structure and a second tab stack structure, and at least one of the folding positions of the multiple first tabs and the multiple second tabs has a gap between it and the isolation member in the first direction. This reduces the risk of the heat emitted from the tabs being conducted to the isolation member and causing the isolation member to heat up during the welding process between the tab stack structure and the conductive member, thereby improving product yield and safety in use.

[0006] In some embodiments, a first minimum distance L1 is defined as a minimum distance of a gap between the bending positions of the first tabs and the isolation member in the first direction, a second minimum distance L2 is defined as a minimum distance of a gap between the bending positions of the second tabs and the isolation member in the first direction, a melting point of a material of the first tabs is lower than a melting point of a material of the second tabs, and the first minimum distance L1 is less than or equal to the second minimum distance L2.

[0007] In battery cell embodiments in which the melting point of the first tab material is lower than the melting point of the second tab material, the second tab material with a higher melting point requires a larger amount of welding heat to form the weld pool, and correspondingly, a higher amount of heat is generated when welding the second tab stack structure. By further increasing the second minimum distance L2, the risk of the isolator member corresponding to the second tab stack structure becoming hot and the isolator member becoming hot due to heat radiation due to being too close to the second tab stack structure can be reduced.

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

[0009] In battery cell embodiments in which the melting point of the first tab material is higher than the melting point of the second tab material, the first tab material with a higher melting point requires a larger amount of welding heat to form the weld pool, and correspondingly, a larger amount of heat is generated when welding the first tab stack structure. By making the first minimum distance L1 greater than or equal to the second minimum distance L2, the risk of the isolator member corresponding to the first tab stack structure becoming hot and the risk of the isolator member becoming hot due to thermal radiation due to being too close to the first tab stack structure can be reduced.

[0010] In some embodiments, the bending positions of the first plurality of tabs are at the bases of the cuts of the first plurality of tabs, and / or the bending positions of the second plurality of tabs are at the bases of the cuts of the second plurality of tabs.

[0011] The bending positions of the plurality of first tabs may be cut positions where the tabs are cut at portions of the current collector substrate of the first polar sheet that are not covered with the active material layer, and the corresponding first minimum distance L1 is the distance in the first direction between the cutting bases of the plurality of first tabs and the separator. The bending positions of the plurality of second tabs may be cut positions where the tabs are cut at portions of the current collector substrate of the second polar sheet that are not covered with the active material layer, and the corresponding second minimum distance L2 is the distance in the first direction between the cutting bases of the plurality of second tabs and the separator.

[0012] In some embodiments, in the first direction, there is a third minimum distance L3 between the bending positions of the plurality of first tabs and the tab tops of the plurality of first tabs, there is a fourth minimum distance L4 between the bending positions of the plurality of second tabs and the tab tops of the plurality of second tabs, a first thickness t1 of the plurality of first tabs in the thickness direction of the first tabs is smaller than a second thickness t2 of the plurality of second tabs in the thickness direction of the second tabs, and the third minimum distance L3 is greater than or equal to the fourth minimum distance L4.

[0013] The third minimum distance L3 and the fourth minimum distance L4 represent the lengths of the first tab and the second tab involved in folding and stacking, respectively. The longer the length of the tab involved in stacking, the greater the degree of overlap of the tabs. The first thickness t1 of the first tab represents the thickness of the single-layer first tab, and the second thickness t2 of the second tab represents the thickness of the single-layer second tab. The thicker the single-layer tab, the thicker the tab stack structure after stacking. In battery cell embodiments in which the first thickness t1 is smaller than the second thickness t2, setting the third minimum distance L3 to be equal to or greater than the fourth minimum distance L4 allows the thicknesses of the first tab stack structure and the second tab stack structure to be closer together, which helps reduce the risk of the isolator portion being burned or heated due to differences in welding heat when forming the weld pool.

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

[0015] The third minimum distance L3 and the fourth minimum distance L4 represent the lengths of the first tab and the second tab involved in folding and stacking, respectively. The longer the length of the tab involved in stacking, the greater the degree of overlap of the tabs. The first thickness t1 of the first tab represents the thickness of the single-layer first tab, and the second thickness t2 of the second tab represents the thickness of the single-layer second tab. The thicker the single-layer tab, the thicker the tab stack structure after stacking. In battery cell embodiments in which the first thickness t1 is greater than the second thickness t2, setting the third minimum distance L3 to be equal to or less than the fourth minimum distance L4 allows the thicknesses of the first tab stack structure and the second tab stack structure to be closer together, which helps reduce the risk of the isolator portion being burned or heated due to differences in welding heat when forming the weld pool.

[0016] In some embodiments, a ratio A / B of a product A of a first thickness t1 of the plurality of first tabs in a thickness direction of the first tabs and the third minimum distance L3 to a product B of a second thickness t2 of the plurality of second tabs in a thickness direction of the second tabs and the fourth minimum distance L4 satisfies 0.2≦A / B≦4, and the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 have the same unit.

[0017] The product A of the first thickness t1 and the third minimum distance L3 represents the lamination thickness of the first tab lamination structure, and the product B of the second thickness t2 and the fourth minimum distance L4 represents the lamination thickness of the second tab lamination structure. The ratio of the products A and B represents the degree of difference in lamination thickness between the first tab lamination structure and the second tab lamination structure. If the ratio A / B is too large, the first tab lamination structure is thick, requiring higher welding power during welding. The high welding heat increases the risk of the isolating member portion corresponding to the first tab lamination structure being burned or overheated compared to the second tab lamination structure. If the ratio A / B is too small, the second tab lamination structure is thick, requiring higher welding power during welding. The high welding heat increases the risk of the isolating member portion corresponding to the second tab lamination structure being burned or overheated compared to the first tab lamination structure. Therefore, by ensuring that the ratio A / B satisfies 0.2≦A / B≦4, the difference in lamination thickness between the first tab lamination structure and the second tab lamination structure is reduced, thereby reducing the risk of the isolation member portions corresponding to the first tab lamination structure and the second tab lamination structure being burned or overheated.

[0018] In some embodiments, the ratio A / B satisfies 0.5≦A / B≦2.

[0019] By further restricting the ratio A / B to satisfy 0.5≦A / B≦2, the difference in lamination thickness between the first tab lamination structure and the second tab lamination structure is further reduced, thereby effectively reducing the risk of the isolation member portions corresponding to the first tab lamination structure and the second tab lamination structure being burned or heated.

[0020] In some embodiments, a ratio A / B of a product A of a first thickness t1 of the plurality of first tabs in a thickness direction of the first tabs and the third minimum distance L3 to a product B of a second thickness t2 of the plurality of second tabs in a thickness direction of the second tabs and the fourth minimum distance L4 satisfies A / B<1, and a third thickness t3 of the first conductive member in the first direction is smaller than a fourth thickness t4 of the second conductive member in the first direction.

[0021] The product A of the first thickness t1 and the third minimum distance L3 represents the lamination thickness of the first tab lamination structure, and the product B of the second thickness t2 and the fourth minimum distance L4 represents the lamination thickness of the second tab lamination structure. In battery cell embodiments where product A is less than product B, the thicker second tab lamination structure must be welded using a higher welding power, which generates laser pulses that are more likely to form a deep weld pool, thereby increasing the risk of the isolator being burned or heated. Therefore, using a thicker second conductive member increases the welding tolerance and reduces the likelihood of a deep weld pool, thereby reducing the risk of the isolator being burned or heated in the portion of the second tab lamination structure that corresponds to the second tab lamination structure. Alternatively, a thinner first conductive member may be combined with a thinner first tab lamination structure and welded using a lower welding power, which correspondingly increases the likelihood of a deep weld pool and reduces the risk of the isolator being burned or heated in the portion of the isolator that corresponds to the first tab lamination structure.

[0022] In some embodiments, a ratio A / B of a product A of a first thickness t1 of the plurality of first tabs in a thickness direction of the first tabs and the third minimum distance L3 to a product B of a second thickness t2 of the plurality of second tabs in a thickness direction of the second tabs and the fourth minimum distance L4 satisfies A / B>1, the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 have the same unit, 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.

[0023] The product A of the first thickness t1 and the third minimum distance L3 represents the lamination thickness of the first tab lamination structure, and the product B of the second thickness t2 and the fourth minimum distance L4 represents the lamination thickness of the second tab lamination structure. In battery cell embodiments where the product B is less than the product A, the first tab lamination structure with a greater lamination thickness must be welded using a higher welding power, which generates laser pulses that are more likely to form a deep weld pool, thereby increasing the risk of the isolator being burned or heated. Therefore, using a thicker first conductive member allows for greater welding tolerances and reduces the likelihood of a deep weld pool, thereby reducing the risk of the isolator being burned or heated in the portion of the isolator corresponding to the first tab lamination structure. Alternatively, a thinner second conductive member may be combined with a second tab lamination structure with a smaller lamination thickness and welded using a lower welding power, which is more likely to form a deep weld pool and reduce the risk of the isolator being burned or heated in the portion of the isolator corresponding to the second tab lamination structure.

[0024] In some embodiments, the first tab stack structure and the second tab stack structure are both located at the same end of the wound structure in the first direction.

[0025] The plurality of first tabs and the plurality of second tabs may be arranged at the same end of the wound structure, and the folded and stacked first tab stack structure and second tab stack structure may be at different angle ranges on the end of that side, and correspondingly, the first conductive member and the second conductive member are also both installed on the same side of the wound structure and are welded to the first tab stack structure and the second tab stack structure, respectively.

[0026] In some embodiments, the first tab stack structure and the second tab stack structure are located at opposite ends of the wound structure, respectively, in the first direction.

[0027] The plurality of first tabs and the plurality of second tabs may be arranged on opposite ends of the wound structure, and the folded and stacked plurality of first tabs and the plurality of second tabs form a first tab stack structure and a second tab stack structure, respectively, at both ends of the wound structure, and correspondingly, the first conductive member and the second conductive member are also respectively installed on both sides of the wound structure and welded to the first tab stack structure and the second tab stack structure, respectively.

[0028] In some embodiments, the battery cell further includes an outer case having a cavity that accommodates the electrode assembly, the first conductive member, and the second conductive member, and an electrode terminal installed on a wall of the outer case and electrically connected to the first conductive member or the second conductive member.

[0029] The first tab laminate structure and the second tab laminate structure formed at the end of the wound 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 installed on the wall of the outer case via the first conductive member or the second conductive member. The laminated multi-layer tab structure has a higher thickness, so it is less likely to burn through when welded to the conductive member, reducing the risk of the isolation member in the electrode assembly being burned or heated during welding, thereby improving the welding quality of the welded area and increasing safety in use.

[0030] In some embodiments, the outer case includes a housing and an end cover, one end of the housing has an opening, the end cover covers the opening, the housing includes side walls and a bottom wall, the side walls surround the outside of the electrode assembly, the bottom wall is positioned opposite the opening, and the wall of the outer case is the end cover or the bottom wall.

[0031] The first and second tab stack structures formed at the ends of the wound structure of the electrode assembly are welded to the first and second conductive members, respectively, and are electrically connected to the electrode terminals installed on the end cover or the bottom wall of the housing via the first or second conductive member, which can effectively reduce the risk of the isolation members in the electrode assembly being burned or overheated during welding, improve the welding quality of the welding area, and increase the safety of use.

[0032] In some embodiments, the first polar sheet further includes a first current collector substrate, the plurality of first tabs being connected to the first current collector substrate and spaced apart along the winding direction, and the bending positions of the plurality of first tabs being located on a side of the separator away from the first current collector substrate in the first direction; and the second polar sheet further includes a second current collector substrate, the plurality of second tabs being connected to the second current collector substrate and spaced apart along the winding direction, and the bending positions of the plurality of second tabs being located on a side of the separator away from the second current collector substrate in the first direction.

[0033] At least some of the first tabs connected to the first current-collector substrate and spaced apart along the winding direction can be bent at an end of the wound structure to form a first tab stack structure with a tight fit and a uniform thickness, which can be welded to a first conductive member to achieve a reliable electrical connection. Similarly, at least some of the second tabs connected to the second current-collector substrate and spaced apart along the winding direction can be bent at an end of the wound structure to form a second tab stack structure with a tight fit and a uniform thickness, which can be welded to a second conductive member to achieve a reliable electrical connection.

[0034] In one aspect of the present disclosure, a battery including the battery cell is provided.

[0035] A battery using the battery cell can effectively improve the safety of use.

[0036] One aspect of the present disclosure provides a power consuming device including the battery.

[0037] The safety of the battery-powered power consumption device can be effectively improved.

[0038] In order to more clearly describe the technical solutions in the embodiments of the present disclosure, the following briefly describes the drawings required for the embodiments of the present disclosure. It should be understood that the drawings shown below are only some embodiments of the present disclosure, and those skilled in the art can further obtain other drawings based on the drawings without any creative efforts.

[0039] The present disclosure can be more clearly understood based on the following detailed description and with reference to the drawings. [Brief explanation of the drawings]

[0040] [Figure 1] 1A-1D are structural schematic diagrams of some embodiments of power consuming devices according to the present disclosure; [Figure 2] 1A-1C are exploded schematic views of some embodiments of batteries according to the present disclosure. [Figure 3] 1 is a schematic diagram of the connection of multiple battery cells in some embodiments of a battery according to the present disclosure. [Figure 4] 1A-1C are exploded schematic views of some embodiments of a battery cell according to the present disclosure. [Figure 5] 1 is a schematic longitudinal cross-sectional view of some embodiments of a battery cell according to the present disclosure, taken along a winding axis CL. [Figure 6] 1A-1C are cross-sectional schematic diagrams of winding structures in some embodiments of electrode assemblies according to the present disclosure. [Figure 7] 1 is an exploded schematic view of an electrode assembly and conductive members in some embodiments of a battery cell according to the present disclosure. FIG. [Figure 8] FIG. 10 is an exploded schematic view of an electrode assembly and conductive members in yet another embodiment of a battery cell according to the present disclosure. [Figure 9] and [Figure 10]9A and 9B are schematic diagrams of an assembled structure and a cross section of the conductive member in FIG. 8, respectively. [Figure 11] 1A-1C are schematic diagrams of deployed polar sheets and tabs in some embodiments of electrode assemblies according to the present disclosure. [Figure 12] FIG. 10 is a schematic diagram of the deployed state of polar sheets and tabs in yet another embodiment of an electrode assembly according to the present disclosure. [Figure 13] 1 is a cross-sectional schematic diagram of a structure in which a tab stack structure and a conductive member are welded together in some embodiments of an electrode assembly according to the present disclosure.

[0041] It should be understood that the dimensions of the various parts shown in the drawings are not drawn to scale, and the same or similar reference numerals refer to the same or similar components. [Explanation of symbols]

[0042] 10 Electrode Assembly 11 First polarity sheet 11A First current collector substrate 11B Tab 1 11C 1st active material layer 111 first tab laminated structure 11f First tab folding position 11r First tab cut base 11t Top of the first tab 12 Second polarity sheet 12B 2nd tab 12C 2nd active material layer 121 Second tab laminate structure 12f Second tab folding position 12r Cut base of second tab 12t Top of the second tab 13 Isolation member 100 winding structure 21 First conductive member 22 Second conductive member 23 Second insulating member 30 battery cells 31 Outer case 311 Housing 311B side wall 311C bottom wall 311A Aperture 311D through hole 312 End cover 32 Electrode terminal 33 First insulating member 34 Electrode lead-out section 35 Pressure reducing member 40 batteries 41 Case 42 Housing cover 43 Busbar 50 vehicles wd Winding direction CL winding shaft d1 1st direction d2 2nd direction DETAILED DESCRIPTION OF THE INVENTION

[0043] The embodiments of the present disclosure will be described in more detail below with reference to the drawings and examples. The detailed description of the following examples and the drawings are used to exemplarily explain the principles of the present disclosure, but are not intended to limit the scope of the present disclosure, and the present disclosure is not limited to the described examples.

[0044] It should be explained that in the description of this disclosure, unless otherwise specified, "multiple" means two or more, and the orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "inner," and "outer" are merely for the purpose of facilitating and simplifying the description of this disclosure, and do not indicate or imply that the subject devices or elements have a particular orientation or should be configured and operated in a particular orientation, and therefore should not be understood as limiting this disclosure. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. "Perpendicular" does not mean perpendicular in the strict sense, but within a tolerance range. "Parallel" does not mean parallel in the strict sense, but within a tolerance range.

[0045] Any directional expressions appearing in the following description are directions shown in the drawings and do not limit the specific structure of the present disclosure. It should be further explained that, unless otherwise clearly specified and limited, the terms "attached," "connected," and "connect" should be understood broadly, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection. They may be directly connected or indirectly connected via an intermediate medium. Those skilled in the art can understand the specific meanings of the above terms in the present disclosure according to specific circumstances.

[0046] Some embodiments of the present invention will be described in detail below with reference to the drawings. The features in the embodiments described below can be combined with each other unless they are inconsistent.

[0047] The term "plurality" as used herein refers to two or more (including two).

[0048] In the embodiments of the present disclosure, the battery cell may be a secondary battery, which is a battery cell that can be continuously used by activating the active material in a manner that the battery cell is discharged and then charged.

[0049] The battery cells may be lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel metal hydride batteries, nickel cadmium batteries, lead acid batteries, etc., and the embodiments of the present application are not limited thereto.

[0050] The battery cell includes an electrode assembly. The electrode assembly includes a first polarity sheet and a second polarity sheet having opposite polarities, and further includes a separator disposed between the first polarity sheet and the second polarity sheet. In some embodiments, the first polarity sheet is a positive electrode sheet, and the second polarity sheet is a negative electrode sheet. In other embodiments, the first polarity sheet is a negative electrode sheet, and the second polarity sheet is a positive electrode sheet. During the charge and discharge process of the battery cell, active ions (e.g., lithium ions) are inserted and removed back and forth between the positive electrode sheet and the negative electrode sheet. The separator disposed between the positive electrode sheet and the negative electrode sheet prevents short-circuiting between the positive and negative electrodes while allowing the active ions to pass through.

[0051] In some embodiments, the positive electrode sheet can 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.

[0052] As an example, the positive electrode current collector substrate has two surfaces opposing each other in the thickness direction, and the positive electrode active material layer is provided on one or both of the two opposing surfaces of the positive electrode current collector substrate.

[0053] As an example, the positive electrode current collector substrate can be a metal foil or a composite current collector. For example, the metal foil can be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The composite current collector can include a polymer substrate layer and a metal layer. The composite current collector can be formed by placing a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0054] As an example, the positive electrode active material may include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound thereof. However, the present disclosure is not limited to these materials, and other conventional materials usable as a positive electrode active material layer in a battery may also be used. These positive electrode active material layers may be used alone or in combination of two or more. Examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium ferric phosphate (e.g., LiFePO4 (also known as LFP)), a composite of lithium ferric phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite of lithium manganese iron phosphate and carbon. Examples of lithium transition metal oxides include lithium cobalt oxide (LiCoO2, etc.), lithium nickel oxide (LiNiO2, etc.), lithium manganese oxide (LiMnO2, LiMn2O4, etc.), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(NCM 333 (also called LiNi) 0.5 Co 0.2 Mn 0.3 O2(NCM 523 (also called) LiNi 0.5 Co 0.25 Mn 0.25 O2(NCM 211 (also called LiNi) 0.6 Co 0.2 Mn 0.2 O2(NCM 622 (also called LiNi) 0.8 Co 0.1 Mn 0.1 O2(NCM 811 Also called lithium nickel cobalt aluminum oxide (LiNi 0.85 Co 0.15 Al 0.05 O2) and / or modifying compounds thereof.

[0055] In some embodiments, the negative electrode sheet may include a negative electrode current collector substrate.

[0056] For example, the negative electrode current collector substrate can be a metal foil, a metal foam, or a composite current collector. For example, the metal foil can be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The metal foam can be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector can include a polymer substrate layer and a metal layer. The composite current collector can be formed by placing a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0057] In some embodiments, the negative electrode sheet can 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.

[0058] As an example, the negative electrode current collector substrate has two surfaces that face each other in the thickness direction of the negative electrode current collector substrate, and the negative electrode active material layer is provided on either one or both of the two facing surfaces of the negative electrode current collector substrate.

[0059] For example, the negative electrode active material layer may be a negative electrode active material layer for a battery cell known in the art. For example, the negative electrode active material layer may include at least one of 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 silicon element, silicon oxide, silicon carbon composite, silicon nitrogen composite, and silicon alloy. The tin-based material may be selected from at least one of tin element, tin oxide compound, and tin alloy. However, the present disclosure is not limited to these materials, and other conventional materials that can be used as a negative electrode active material layer for a battery may also be used. These negative electrode active material layers may be used alone or in combination of two or more types.

[0060] In some embodiments, the positive current collector substrate material may be aluminum, and the negative current collector substrate material may be copper.

[0061] In some embodiments, the isolating member is a separator. The present disclosure does not particularly limit the type of separator, and any known porous structure separator having good chemical stability and mechanical stability can be selected.

[0062] For example, the main material of the separator can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator may be a single-layer film or a multi-layer composite film, and is not particularly limited. When the separator is a multi-layer composite film, the materials of each layer may be the same or different, and are not particularly limited. The separator may be a single member located between the positive electrode sheet and the negative electrode sheet, or may 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.

[0063] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive and negative electrode sheets and simultaneously serves to transfer ions and separate the positive and negative electrodes.

[0064] In some embodiments, the battery cell further includes an electrolyte, which serves to conduct ions between the positive electrode and the negative electrode. The present disclosure does not particularly limit the type of electrolyte, and it can be selected as needed. The electrolyte may be liquid, gel-like, or solid.

[0065] As an example, a liquid electrolyte includes an electrolyte salt and a solvent.

[0066] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bistrifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium bisoxalatoborate, lithium difluorobisoxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0067] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl 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, sulfolane, dimethyl sulfone, ethyl methyl sulfone, and diethyl sulfone. The solvent may optionally be an ether-based solvent. The ether-based solvent may 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, methyl tetrahydrofuran, diphenyl ether, and crown ether.

[0068] As an example, a gel electrolyte contains a skeletal network of polymer electrolytes combined with an ionic liquid-lithium salt.

[0069] By way of example, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0070] By way of example, the polymer solid electrolyte may be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, single ionic polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0071] By way of example, the inorganic solid electrolyte may be one or more of oxide solid electrolytes (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superionic conductors (lithium germanium phosphate sulfur, sulfur silver germanite), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0072] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler in a polymer solid electrolyte.

[0073] In some embodiments, the electrode assembly includes a wound structure. The wound structure is formed by winding a positive electrode sheet, a negative electrode sheet, and a separator. One or more positive electrode sheets and one or more negative electrode sheets are provided. For example, multiple positive electrode sheets and multiple negative electrode sheets are provided alternately along the thickness direction of the polar sheets.

[0074] In some embodiments, the electrode assembly may have a cylindrical, flat, or polygonal prism shape, or the like.

[0075] In some embodiments, the positive electrode sheet includes a positive electrode tab, and the negative electrode sheet includes a negative electrode tab, and the positive electrode tab and negative electrode tab are used to conduct current from the electrode assembly. The positive electrode tab and negative electrode tab are connected to the positive electrode current collector substrate and the negative electrode current collector substrate, respectively. The tabs may be formed by dividing or cutting the current collector substrate, or may be connected to the side edges of the current collector substrate by welding.

[0076] In some embodiments, the battery cell may include an outer case. The outer case is used to enclose components such as the electrode assembly and the electrolyte. The outer case may be a steel case, an aluminum case, a plastic case (e.g., polypropylene), a composite metal case (e.g., a copper-aluminum composite case), an aluminum-plastic film, or the like.

[0077] As an example, the battery cells may be cylindrical battery cells, prismatic battery cells, soft-pack battery cells, or other shaped battery cells, where prismatic battery cells include rectangular battery cells, blade-shaped battery cells, polygonal prismatic batteries, and polygonal prismatic batteries are hexagonal prismatic batteries, etc.

[0078] A battery as referred to in the embodiments of this disclosure refers to a single physical module that contains one or more battery cells to provide higher voltage and capacity.

[0079] In some embodiments, the battery may be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module. The battery module may include multiple battery cells connected in series, parallel, or series-parallel.

[0080] In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, or battery modules, housed within the housing.

[0081] In some embodiments, the housing may be part of a chassis structure of a vehicle, for example, the housing portion may be at least a portion of the floor of the vehicle, or at least a portion of the cross beams and longitudinal beams of the vehicle.

[0082] In some embodiments, the battery may be an energy storage device, which may include an energy storage container, an energy storage cabinet, or the like.

[0083] In some related art, the polar sheet in the electrode assembly is mainly composed of a current collector substrate and an active material layer disposed on the surface of the current collector substrate, and the portion of the polar sheet extending beyond the active material layer of the current collector substrate in the width direction is the current collector output region, which is cut to obtain a plurality of small tabs located on the side edges of the current collector substrate, with breaks cut between adjacent tabs, making each tab independent of each other.

[0084] These small tabs are folded and flattened at the end of the wound electrode assembly to form a dense tab laminate structure. However, when the tab laminate structure and the current collecting disk are welded using a laser or other method, the heat generated from the tab laminate structure heats up the separator that contacts the tab through thermal conduction, which can cause breakage or defects in the separator, potentially affecting product yield and safety.

[0085] In view of this, embodiments of the present disclosure provide a battery cell including an electrode assembly, a first conductive member, and a second conductive member. The electrode assembly includes a first polarity sheet, a second polarity sheet, and an isolation member, wherein the first polarity sheet and the second polarity sheet have opposite polarities, and the isolation member is located between the first polarity sheet and the second polarity sheet, the first polarity sheet, the second polarity sheet, and the isolation member are wound along a winding direction to form a wound structure, the first polarity sheet includes a plurality of first tabs folded along an end of the wound structure to form a first tab stack structure, the second polarity sheet includes a plurality of second tabs folded along an end of the wound structure to form a second tab stack structure, a first conductive member is welded to the first tab stack structure, and a second conductive member is welded to the second tab stack structure, and in a first direction parallel to an extension direction of a winding axis of the wound structure, at least one of the bending positions of the plurality of first tabs and the bending positions of the plurality of second tabs has a gap between it and the isolation member in the first direction.

[0086] The multiple first tabs and the multiple second tabs are respectively folded at the ends of the wound structure to form a first tab stack structure and a second tab stack structure, and at least one of the folding positions of the multiple first tabs and the multiple second tabs has a gap between it and the isolation member in the first direction. This reduces the risk of the heat emitted from the tabs being conducted to the isolation member and causing the isolation member to heat up during the welding process between the tab stack structure and the conductive member, thereby improving product yield and safety in use.

[0087] The battery cell of the embodiment of the present disclosure can be applied to various types of batteries. The battery includes a housing that provides a storage space for a battery module, and the battery module mounted in the housing. The housing may be made of a metal material. The battery module may include multiple battery cells connected in series, parallel, or series-parallel. A battery cell is the smallest unit that constitutes a battery. The battery cell includes an electrode assembly capable of generating an electrochemical reaction.

[0088] The battery of the embodiments of the present disclosure can be applied to various power-consuming devices that use batteries. The power-consuming devices can be mobile phones, portable devices, laptops, battery cars, electric vehicles, boats, spacecraft, electric toys, and power tools. For example, spacecraft include aircraft, rockets, spaceplanes, and spaceships. Electric toys include stationary or mobile electric toys such as game consoles, electric car toys, electric boat toys, and electric aircraft toys. Electric tools include metal cutting power tools, polishing power tools, assembly power tools, and railroad power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drivers, concrete vibrators, and electric planers. The embodiments of the present disclosure are not particularly limited to the above-mentioned power-consuming devices. The battery is used to supply power to power-consuming devices such as vehicles, for example, to supply power for control or driving the vehicle.

[0089] 1 is a structural schematic diagram of some embodiments of a power consumption device according to the present disclosure. For convenience of explanation, a vehicle will be taken as an example of the power consumption device. The vehicle 50 may be a gasoline vehicle, a natural gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, etc. The battery 40 may be installed at the bottom of the vehicle 50 or at the front or rear of the vehicle.

[0090] The battery 40 is used to supply power to the vehicle 50; for example, the battery 40 can be used as an operating power source for the circuit systems of the vehicle 50, for example, to meet the operating power needs for starting, navigating, and driving the vehicle 50. The battery 40 can not only serve as an operating power source for the vehicle 50, but also as a driving power source for the vehicle 50, providing driving power to the vehicle 50 in place of or partially replacing fuel or natural gas.

[0091] The vehicle 50 may further include an axle, wheels, a motor, and a controller, and the controller is used to control the battery 40 and supply power to the motor. For example, if the vehicle 50 uses the battery 40 as its driving power source, the battery 40 supplies the motor with the power required for constant speed and acceleration, instead of or partially replacing fuel or natural gas. The motor is used to drive the rotation of the axle, which in turn moves and rotates the wheels.

[0092] Figure 2 is an exploded schematic view of some embodiments of a battery according to the present disclosure. Figure 3 is a schematic view of the connections of multiple battery cells in some embodiments of a battery according to the present disclosure.

[0093] 2, in some embodiments, a battery 40 includes a housing 41, a housing cover 42 that covers the open side of the housing 41, and one or more battery cells 30 installed in the housing 41. The housing 41 and the housing cover 42 provide an accommodating space for the battery cells 30, and can provide functions such as cooling, sealing, and collision prevention, and can also prevent liquids or other foreign objects from adversely affecting the charging / discharging or safety of the battery cells.

[0094] The housing 41 and the housing cover 42 may have various shapes, such as a rectangular parallelepiped or a cylindrical shape. The housing 41 may have a hollow structure with one side open, and the housing cover 42 has a plate-like structure. The housing cover 42 covers the open side of the housing 41 to form an internal storage space. In another embodiment, the housing 41 has a hollow structure with one side open, and the housing cover 42 also has a hollow structure with one side open, and the open side of the housing cover 42 covers the open side of the housing 41 to form an internal storage space.

[0095] 2 and 3, the battery cells 30 are electrically connected in series, parallel, or series-parallel connection, etc., thereby achieving the required electrical characteristic parameters of the battery 40. A series-parallel connection refers to multiple battery cells 30 being connected in parallel as well as in series. Adjacent battery cells 30 may be electrically connected via a bus bar 43. The multiple battery cells 30 are installed in a row, and one or more rows of battery cells 30 can be installed in the housing 41 as needed.

[0096] In some embodiments, the battery cells 30 of the battery 40 may be arranged along at least one of the length direction and the width direction of the housing 41. At least one row or one column of the battery cells 30 may be installed according to actual needs. Furthermore, one or more layers of the battery cells 30 may be installed in the height direction of the battery 40 according to needs.

[0097] In some embodiments, a plurality of battery cells 30 may first be connected in series, in parallel, or in series-parallel to form a battery module, and then the plurality of battery modules may be further connected in series, in parallel, or in series-parallel to form an integrated unit, which may then be housed in the housing 41. In other embodiments, all of the battery cells 30 may be connected in series, in parallel, or in series-parallel directly, and the integrated unit made up of all of the battery cells 30 may then be housed in the housing.

[0098] Figure 4 is an exploded schematic view of some embodiments of a battery cell according to the present disclosure. Figure 5 is a longitudinal cross-sectional schematic view passing through a winding axis CL of some embodiments of a battery cell according to the present disclosure. Figure 6 is a cross-sectional schematic view of a winding structure of some embodiments of an electrode assembly according to the present disclosure. Figure 7 is an exploded schematic view of an electrode assembly and a conductive member of some embodiments of a battery cell according to the present disclosure.

[0099] 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 polar sheet 11, a second polar sheet 12, and an isolating member 13, the first polar sheet 11 and the second polar sheet 12 having opposite polarities, the isolating member 13 being positioned between the first polar sheet 11 and the second polar sheet 12, and the first polar sheet 11, the second polar sheet 12, and the isolating member 13 being wound along a winding direction wd to form a wound structure 100.

[0100] 6, the polar sheet wound rings formed in the wound structure 100 of the first polar sheet 11 and the second polar sheet 12 may be at least partially alternately arranged from the outside to the inside. An isolating member 13 in the form of a separator may be installed between the first polar sheet 11 and the second polar sheet 12.

[0101] The first polar sheet 11 may include a first current collector substrate 11A and a plurality of first tabs 11B, which are connected to the first current collector substrate 11A and spaced apart along the winding direction wd, and at least some of the first tabs 11B are folded at an end of the wound structure 100 to form a first tab stack structure 111.

[0102] The second polar sheet 12 may include a second current collector substrate 12A and a plurality of second tabs 12B, which are connected to the second current collector substrate 12A and spaced apart along the winding direction wd, and at least some of the second tabs 12B are folded at an end of the wound structure 100 to form a second tab stack structure 121.

[0103] The first conductive member 21 is welded to the first tab laminate structure 111, and the second conductive member 22 is welded to the second tab laminate structure 121. The welding between the conductive member and the tab laminate structure may be performed using a method such as a laser, and the weld area is heated to form a liquid metal portion that melts into a certain geometric shape, i.e., a weld pool.

[0104] 4 and 5 , in some embodiments, the battery cell 30 may further include an outer case 31 and an electrode terminal 32. The outer case 31 has a cavity that accommodates the electrode assembly 10, the first conductive member 21, and the second conductive member 22. The electrode terminal 32 is installed on a wall of the outer case 31 and is electrically connected to the first conductive member 21 or the second conductive member 22.

[0105] The cavity of the outer case 31 not only accommodates the electrode assembly 10 but can also accommodate an electrolyte. The shape of the outer case 31 may be determined based on the shape of one or more electrode assemblies 10 to be accommodated in the cavity, for example, the shape of the outer case 31 is a hollow rectangular parallelepiped, a hollow cube, or a hollow cylinder.

[0106] 4 and 5, the outer case 31 may include a housing 311 and an end cover 312. The housing 311 is a hollow structure with an opening 311A ​​at one or both ends, and may be made of one or more materials, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc. The end cover 312 may be made of a metal or non-metal material, and may be fixedly connected to the housing 311 by welding, adhesive bonding, fastening, or other methods.

[0107] One end of the housing 311 has an opening 311A, and an end cover 312 covers the opening 311A. In Fig. 5, the housing 311 may include a side wall 311B and a bottom wall 311C. The side wall 311B surrounds the outside of the electrode assembly 10, and the bottom wall 311C is located opposite the opening 311A. The wall of the outer case 31 is the end cover 312 or the bottom wall 311C. Correspondingly, the electrode terminal 32 may be located on the end cover 312 or the bottom wall 311C.

[0108] In the case of a cylindrical battery cell, the housing 311 may be a cylindrical hollow structure with an opening 311A ​​at one end, and the end cover 312 may be a disc-shaped structure that fits into the opening 311A. The electrode terminals 32 may be installed on the bottom wall 311C of the housing 311 away from the end cover 312.

[0109] In FIG. 4, a through-hole 311D may be formed in the bottom wall 311C. Referring to FIG. 5, the electrode terminal 32 may be installed in the through-hole 311D via an electrode lead-out portion 34 and a first insulating member 33. The electrode lead-out portion 34 may protrude at least partially from the outer surface of the bottom wall 311C, thereby achieving electrical connection between different battery cells 30 via a bus bar 43 (shown in FIG. 3). The first insulating member 33 is used to achieve insulation between the electrode lead-out portion 34 and the housing 311, and may be made of rubber or plastic. Preferably, openings are formed on both ends of the housing, and both are covered by end covers, and the electrode lead-out portion and electrode terminal may be installed in the end covers.

[0110] 4 and 5, a pressure reducing member 35 may be installed on the end cover 312. The pressure reducing member is an element or component that operates to release the internal pressure or temperature of the battery cell when the internal pressure or temperature reaches a predetermined threshold. The design of the threshold varies depending on design requirements. The threshold may depend on one or more of the materials of the positive electrode sheet, the negative electrode sheet, the electrolyte, and the separator in the battery cell. The pressure reducing member may take the form of an explosion-proof valve, an air valve, a pressure reducing valve, a safety valve, etc., and may specifically be a pressure- or temperature-sensitive element or structure. That is, when the internal pressure or temperature of the battery cell reaches a predetermined threshold, the pressure reducing member operates or a weak structure provided in the pressure reducing member breaks, forming an opening or flow path for releasing the internal pressure or temperature.

[0111] The discharged materials from battery cells referred to herein include, but are not limited to, electrolyte, dissolved or split positive and negative electrode sheets, separator fragments, high-temperature and high-pressure gases produced by reactions (e.g., flammable gases such as CH4 and CO), flames, etc.

[0112] 5 and 7, in some embodiments, in the first direction d1, the first tab laminate structure 111 and the second tab laminate structure 121 are respectively located at opposite ends of the wound structure 100. In the case of a cylindrical wound structure 100, the first direction d1 and the extension direction of the winding axis CL of the wound structure 100 are parallel to each other.

[0113] Correspondingly, 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 welded to the first tab stack structure 111 and the second tab stack structure 121, respectively, at the ends of both sides of the electrode assembly 10, and are also welded to the electrode lead portion 34 and the end cover 312, respectively. The first conductive member 21 and the second conductive member 22 function as current collecting members and can respectively realize electrical connection between the electrode assembly 10 and the electrode terminal 32, and further between the electrode assembly 10 and structures such as the end cover 312.

[0114] At least one of the first conductive member 21 and the second conductive member 22 is a metallic conductor, such as copper, iron, aluminum, steel, an aluminum alloy, etc. In some embodiments, at least one of the first conductive member 21 and the second conductive member 22 may include a current collecting disk or other structure.

[0115] Figure 8 is an exploded schematic view of an electrode assembly and conductive members in yet another embodiment of a battery cell according to the present disclosure. Figures 9 and 10 are schematic views of the assembled structure and cross section of the conductive members in Figure 8, respectively.

[0116] 8, 9, and 10, in some embodiments, the first tab stack structure 111 and the second tab stack structure 121 are both located at the end of the same side of the wound structure 100 in the first direction d1. Correspondingly, the multiple first tabs 11B and the multiple second tabs 12B may be located at the same end of the wound structure 100, and the folded and stacked first tab stack structure 111 and second tab stack structure 121 may be located at different angular ranges of the end of that side. The first conductive member 21 and the second conductive member 22 are also both located on the same side of the wound structure 100 and are welded to the first tab stack structure 111 and the second tab stack structure 121, respectively.

[0117] Referring to FIG. 8, the first conductive member 21 and the second conductive member 22 may both be fan-shaped, and a second insulating member 23 may be further installed at the end of that side of the wound structure to insulate the first conductive member 21 and the second conductive member 22 from each other, and 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 FIG. 8 is welded to the first tab laminate structure 111 and the second tab laminate structure 121.

[0118] 9 and 10, the second insulating member 23 may have a hollow portion and an opening penetrating along the first direction d1, the opening being used to accommodate the first conductive member 21, and the hollow portion accommodating the second conductive member 22. The second insulating member 23 may be made of rubber or plastic.

[0119] Fig. 11 is a schematic diagram of a deployed state of polar sheets and tabs in some embodiments of an electrode assembly according to the present disclosure. Fig. 12 is a schematic diagram of a deployed state of polar sheets and tabs in yet another embodiment of an electrode assembly according to the present disclosure. Fig. 13 is a schematic cross-sectional view of a structure in which a tab stack structure and a conductive member are welded in some embodiments of an electrode assembly according to the present disclosure.

[0120] Fig. 11 corresponds to an embodiment in which a plurality of first tabs 11B and a plurality of second tabs 12B are arranged at opposite ends of the wound structure 100, and Fig. 12 corresponds to an embodiment in which a plurality of first tabs 11B and a plurality of second tabs 12B are arranged at the same end of the wound structure 100. In Fig. 11 and Fig. 12, the second direction d2 and the length direction of the first polar sheet 11 or the second polar sheet 12 are parallel and correspond to the winding direction wd after unfolding, and the first direction d1 and the winding axis CL of the wound structure 100 are parallel and also parallel to the width direction of the first polar sheet 11 or the second polar sheet 12.

[0121] Referring to Figures 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 11f of the multiple first tabs 11B are located on the side of the isolation member 13 away from the first current collector substrate 11A, and the bending positions 12f of the multiple second tabs 12B are located on the side of the isolation member 13 away from the second current collector substrate 12A.

[0122] 11 and 12, the bending positions of the first tab 11B and the second tab 12B are indicated by dashed dotted lines. In an embodiment in which multiple tabs are cut in the current collector substrate using a method such as a laser, the bending position 11f of the multiple first tabs 11B may be at the cut base portions 11r of the multiple first tabs 11B or may be closer to the tab upper portions 11t of the first tabs 11B than the cut base portions 11r of the first tabs 11B, and the bending position 12f of the multiple second tabs 12B may be at the cut base portions 12r of the multiple second tabs 12B or may be closer to the tab upper portions 12t of the second tabs 12B than the cut base portions 12r of the second tabs 12B.

[0123] The plurality of first tabs 11B are at least partially folded at the end of the wound structure 100 to form a first tab laminate structure 111, and the plurality of second tabs 12B are at least partially folded at the end of the wound structure 100 to form a second tab laminate structure 121.

[0124] The bending positions 11f of the plurality of first tabs 11B have a gap between them and the isolation member 13 in the first direction d1, thereby reducing the risk that heat released from the first tab stack structure during welding will be conducted to the isolation member 13 and cause the isolation member 13 to become hot. Correspondingly, the minimum distance of the gap between the bending positions 11f of the plurality of first tabs 11B and the isolation member 13 in the first direction d1 is defined as a first minimum distance L1.

[0125] The bending positions 12f of the second tabs 12B have a gap between them and the isolation member 13 in the first direction d1, thereby reducing the risk that heat released from the second tab stack structure during welding will be conducted to the isolation member 13 and cause the isolation member 13 to become hot. Correspondingly, the minimum distance of the gap between the bending positions 12f of the second tabs 12B and the isolation member 13 in the first direction d1 is defined as a second minimum distance L2.

[0126] When bending positions 11f of the multiple first tabs 11B are positions where the tabs are cut in a portion of first current collector substrate 11A that is not covered with first active material layer 11C, first minimum distance L1 is the minimum distance in first direction d1 between cutting bases 11r of the multiple first tabs 11B and separator 13. When bending positions 12f of the multiple second tabs 12B are positions where the tabs are cut in a portion of the second current collector substrate that is not covered with an active material layer, second minimum distance L2 is the minimum distance in first direction d1 between cutting bases 12r of the multiple second tabs 12B and separator 13.

[0127] In some embodiments, the melting point of the material of the first tabs 11B is lower than the melting point of the material of the second tabs 12B, and the first minimum distance L1 is equal to or less than the second minimum distance L2. For example, if the first tabs 11B are made of aluminum metal with a melting point of 660°C and the second tabs 12B are made of copper metal with a melting point of 1083°C, the first minimum distance L1 in this embodiment is set to be equal to or less than the second minimum distance L2.

[0128] In a battery cell embodiment in which the melting point of the material of the first tab 11B is lower than the melting point of the material of the second tab 12B, the higher melting point material of the second tab 12B requires a greater amount of welding heat to form the weld pool, and correspondingly, the second tab laminate structure 121 generates a greater amount of heat during welding. If the amount of heat generated by the second tab laminate structure 121 is large, there is a risk that the isolation member 13 will be burned due to thermal radiation even if it is not in contact with the second tab laminate structure 121. Therefore, by making the second minimum distance L2 equal to or greater than the first minimum distance L1, the risk of the isolation member 13 corresponding to the second tab laminate structure 121 becoming partially heated and the risk of the isolation member 13 being burned due to thermal radiation due to being too close to the second tab laminate structure 121 can be reduced.

[0129] In some embodiments, the melting point of the material of the first tabs 11B is higher than the melting point of the material of the second tabs 12B, and the second minimum distance L2 is equal to or less than the first minimum distance L1. For example, if the first tabs 11B are made of metallic copper with a melting point of 1083°C and the second tabs 12B are made of metallic aluminum with a melting point of 660°C, the second minimum distance L2 in this embodiment is set to be equal to or less than the first minimum distance L1.

[0130] In battery cell embodiments in which the melting point of the material of the first tab 11B is higher than the melting point of the material of the second tab 12B, the higher melting point material of the first tab 11B requires a greater amount of welding heat to form the weld pool, and correspondingly, the first tab laminate structure 111 generates a greater amount of heat during welding. If the amount of heat generated by the first tab laminate structure 111 is large, there is a risk that the isolation member 13 will be burned due to thermal radiation even if it is not in contact with the first tab laminate structure 111. Therefore, by setting the first minimum distance L1 to be equal to or greater than the second minimum distance L2, the risk of the isolation member corresponding to the first tab laminate structure 111 being partially heated and the risk of the isolation member being burned due to thermal radiation due to being too close to the first tab laminate structure 111 can be reduced.

[0131] Referring to Figures 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 tabs 11B and the tab upper portions 11t of the plurality of first tabs 11B, and there is a fourth minimum distance L4 between the bending positions 12f of the plurality of second tabs 12B and the tab upper portions 12t of the plurality of second tabs 12B.

[0132] When bending positions 11f of the multiple first tabs 11B are positions where the tabs are cut in a portion of first current collector substrate 11A that is not covered with first active material layer 11C, third minimum distance L3 is the minimum distance between cutting bases 11r of the multiple first tabs 11B and tab upper portions 11t of the multiple first tabs 11B in first direction d1, and corresponds to the height of the first tabs 11B. When bending positions 12f of the multiple second tabs 12B are positions where the tabs are cut in a portion of the current collector substrate that is not covered with an active material layer, fourth minimum distance L4 is the minimum distance between cutting bases 12r of the multiple second tabs 12B and tab upper portions 12t of the multiple second tabs 12B in first direction d1, and corresponds to the height of the second tabs 12B.

[0133] FIG. 13 is a cross-sectional schematic diagram of a tab stack structure and a welded conductive member in some embodiments of an electrode assembly according to the present disclosure.

[0134] Referring to Figures 11, 12 and 13, in some embodiments, a first thickness t1 of the plurality of first tabs 11B in the thickness direction of the first tabs 11B is smaller than a second thickness t2 of the plurality of second tabs 12B in the thickness direction of the second tabs 12B, and the third minimum distance L3 is greater than or equal to the fourth minimum distance L4.

[0135] The third minimum distance L3 and the fourth minimum distance L4 represent the lengths of the first tab 11B and the second tab 12B involved in folding and stacking, respectively. The longer the length of the tab involved in stacking, the greater the degree of overlap of the tabs. The first thickness t1 of the first tab 11B represents the thickness of the single-layer first tab 11B, and the second thickness t2 of the second tab 12B represents the thickness of the single-layer second tab 12B. The thicker the single-layer tab, the thicker the tab stack structure after stacking.

[0136] In the case of an embodiment of the battery cell 30 in which the first thickness t1 is smaller than the second thickness t2, by making the third minimum distance L3 equal to or greater than the fourth minimum distance L4, the thicknesses of the first tab stack structure 111 and the second tab stack structure 121 can be made closer, which helps reduce the risk of the isolation member portion being burned or heated due to differences in the amount of welding heat when forming the weld pool mp.

[0137] In some other embodiments, a first thickness t1 of the plurality of first tabs 11B in the thickness direction of the first tabs 11B is greater than a second thickness t2 of the plurality of second tabs 12B in the thickness direction of the second tabs 12B, and the third minimum distance L3 is less than or equal to the fourth minimum distance L4.

[0138] In the case of an embodiment of the battery cell 30 in which the first thickness t1 is greater than the second thickness t2, by making the third minimum distance L3 equal to or less than the fourth minimum distance L4, the thicknesses of the first tab stack structure 111 and the second tab stack structure 121 can be made closer, which helps reduce the risk of the isolation member portion being burned or heated due to differences in the amount of welding heat when forming the weld pool mp.

[0139] In each of the above embodiments, the ratio A / B of the product A of the first thickness t1 of each 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 each of the plurality of second tabs 12B in the thickness direction of the second tab 12B and the fourth minimum distance L4 satisfies 0.2≦A / B≦4, and the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 are all expressed in the same unit, for example, mm or cm.

[0140] The product A of the first thickness t1 and the third minimum distance L3 represents the lamination thickness of the first tab lamination structure 111, and the product B of the second thickness t2 and the fourth minimum distance L4 represents the lamination thickness of the second tab lamination structure 121. The ratio of the product A to the product B represents the degree of difference in lamination thickness between the first tab lamination structure 111 and the second tab lamination structure 121.

[0141] If the ratio A / B is too large, the first tab laminate structure 111 will be thick, and a high welding power will need to be used during welding. If the welding heat is high, there will be a higher risk of the isolation member corresponding to the first tab laminate structure 111 being partially burned or heated compared to the second tab laminate structure 121.

[0142] If the ratio A / B is too small, the second tab laminate structure 121 will be thick, and a high welding power will need to be used during welding. If the welding heat is high, there will be a higher risk of the isolation member corresponding to the second tab laminate structure 121 being partially burned or heated compared to the first tab laminate structure 111.

[0143] Therefore, by ensuring that the ratio A / B satisfies 0.2≦A / B≦4, the difference in lamination thickness between the first tab lamination structure 111 and the second tab lamination structure 121 is reduced, thereby reducing the risk of the isolation member portions corresponding to the first tab lamination structure 111 and the second tab lamination structure 121 being burned or overheated.

[0144] 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.

[0145] By further restricting the ratio A / B to satisfy 0.5≦A / B≦2, the difference in lamination thickness between the first tab lamination structure 111 and the second tab lamination structure 121 is further reduced, thereby effectively reducing the risk of the isolation member portions corresponding to the first tab lamination structure 111 and the second tab lamination structure 121 being burned or heated.

[0146] 13 , in some embodiments, a ratio A / B of a product A of a first thickness t1 of each of the first tabs 11B in the thickness direction and the third minimum distance L3 to a product B of a second thickness t2 of each of the second tabs 12B in the thickness direction and the fourth minimum distance L4 satisfies A / B<1, and the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 are all expressed in the same unit, such as mm or cm. Correspondingly, a third thickness t3 of the first conductive member 21 in the first direction d1 is smaller than a fourth thickness t4 of the second conductive member 22 in the first direction d1.

[0147] The product A of the first thickness t1 and the third minimum distance L3 represents the lamination thickness of the first tab lamination structure 111, and the product B of the second thickness t2 and the fourth minimum distance L4 represents the lamination thickness of the second tab lamination structure 121. In battery cell embodiments where the product A is smaller than the product B, the second tab lamination structure 121, which has a greater lamination thickness, must be welded using a higher welding power, because the higher laser power generates waves that are likely to form a weld pool that is too deep, thereby increasing the risk of the isolation member being burned or heated.

[0148] Therefore, using a thicker second conductive member 22 allows for greater welding tolerances and reduces the likelihood of a weld pool being too deep, thereby reducing the risk of burning or overheating the portion of the isolation member corresponding to the second tab laminate structure 121. Alternatively, a thinner first conductive member 21 may be combined with a first tab laminate structure 111 having a smaller laminate thickness and welded at a lower welding power, which will likely result in a weld pool of appropriate depth and reduce the risk of burning or overheating the portion of the isolation member corresponding to the first tab laminate structure 111.

[0149] In some other embodiments, a ratio A / B of a product A of a first thickness t1 of each of the first tabs 11B in the thickness direction and the third minimum distance L3 to a product B of a second thickness t2 of each of the second tabs 12B in the thickness direction and the fourth minimum distance L4 satisfies A / B>1, and the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 are all expressed in the same unit, such as mm or cm. Correspondingly, a third thickness t3 of the first conductive member 21 in the first direction d1 is greater than a fourth thickness t4 of the second conductive member 22 in the first direction d1.

[0150] The product A of the first thickness t1 and the third minimum distance L3 represents the lamination thickness of the first tab lamination structure 111, and the product B of the second thickness t2 and the fourth minimum distance L4 represents the lamination thickness of the second tab lamination structure 121. For embodiments of the battery cell 30 in which the product B is smaller than the product A, the first tab lamination structure 111, which has a larger lamination thickness, must be welded using a higher welding power, because the higher laser power generates waves that are likely to form a weld pool that is too deep, thereby increasing the risk of the isolation member being burned or overheated.

[0151] Therefore, using a thicker first conductive member 21 allows for greater welding tolerances and reduces the likelihood of a weld pool being too deep, thereby reducing the risk of burning or overheating the portion of the isolator corresponding to the first tab laminate structure 111. Alternatively, a thinner second conductive member 22 may be combined with a second tab laminate structure 121 having a smaller laminate thickness and welded at a lower welding power, which will likely result in a weld pool of appropriate depth and reduce the risk of burning or overheating the portion of the isolator corresponding to the second tab laminate structure 121.

[0152] Based on each of the embodiments of the battery cell, and referring to Fig. 2, an embodiment of the present disclosure provides a battery 40 including the battery cell 30 of any one of the embodiments. A battery using the battery cell can effectively improve safety during use.

[0153] Based on each of the embodiments of the battery cell, and referring to Fig. 1, an embodiment of the present disclosure provides a power consumption device including the battery 40 of any one of the embodiments, which can effectively improve the safety of use of the power consumption device using the battery.

[0154] In some specific embodiments, as shown in FIGS. 5 to 7 and 11, the battery cell 30 has a cylindrical shape and includes an electrode assembly 10, a first conductive member 21, a second conductive member 22, an outer case 31, and an electrode terminal 32. The outer case 31 has a cavity that accommodates the electrode assembly 10, the first conductive member 21, and the second conductive member 22. The outer case 31 may include a housing 311 and an end cover 312. One end of the housing 311 has an opening 311A, and the end cover 312 covers the opening 311A. The housing 311 includes a side wall 311B and a bottom wall 311C. The side wall 311B surrounds the outside of the electrode assembly 10, and the bottom wall 311C is disposed opposite the opening 311A. A through-hole 311D is formed in the bottom wall 311C. The electrode terminal 32 is installed in the through hole 311D via the electrode lead portion 34 and the first insulating member 33.

[0155] 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 polar sheet 11, a second polar sheet 12, and an isolating member 13, the first polar sheet 11 and the second polar sheet 12 having opposite polarities, the isolating member 13 being positioned between the first polar sheet 11 and the second polar sheet 12, and the first polar sheet 11, the second polar sheet 12, and the isolating member 13 being wound along a winding direction wd to form a cylindrical wound structure 100. The isolating member 13 is in the form of a separator and is disposed between the first polar sheet 11 and the second polar sheet 12.

[0156] The first polar sheet 11 includes a first current collector substrate 11A and a plurality of first tabs 11B, which are connected to the first current collector substrate 11A and arranged at intervals along the winding direction wd, and at least some of the first tabs 11B are folded at the end of the wound structure 100 to form a first tab stack structure 111.

[0157] The second polar sheet 12 includes a second current collector substrate 12A and a plurality of second tabs 12B, which are connected to the second current collector substrate 12A and spaced apart along the winding direction wd, and at least some of the second tabs 12B are folded at the end of the wound structure 100 to form a second tab stack structure 121.

[0158] The first conductive member 21 is welded to the first tab laminate structure 111 and to the electrode lead portion 34, thereby achieving electrical connection with the electrode terminal 32. The second conductive member 22 is welded to the second tab laminate structure 121 and to the end cover 312.

[0159] In the first direction d1, the first tab laminate structure 111 and the second tab laminate structure 121 are respectively located at opposite ends of the wound structure 100. The first conductive member 21 and the second conductive member 22 are located on opposite sides of the electrode assembly 10 along the first direction d1.

[0160] The first polar sheet 11 is a positive electrode sheet, and the first current collector substrate 11A and the first tab 11B obtained by cutting the portion of the first current collector substrate 11A that is not covered by the first active material layer 11C are both made of metallic aluminum. The second polar sheet 12 is a negative electrode sheet, and the second current collector substrate 12A and the second tab 12B obtained by cutting the portion of the second current collector substrate 12A that is not covered by the second active material layer 12C are both made of metallic copper.

[0161] The melting point of metallic aluminum is lower than that of metallic copper, and 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 greater than the first thickness t1 of the first tab 11B, and the third minimum distance L3 is greater than the fourth minimum distance L4.

[0162] Although the present disclosure has been described with reference to preferred embodiments, various modifications may be made and equivalents may be substituted for the components thereof without departing from the scope of the present disclosure. In particular, the technical features recited in each embodiment may be combined in any manner as long as there is no structural contradiction. The present disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions encompassed by the claims.

Claims

1. an electrode assembly (10) comprising a first polar sheet (11), a second polar sheet (12), and an isolating member (13), wherein the polarities of the first polar sheet (11) and the second polar sheet (12) are opposite, the isolating member (13) is located between the first polar sheet (11) and the second polar sheet (12), the first polar sheet (11), the second polar sheet (12), and the isolating member (13) are wound along a winding direction (wd) to form a wound structure (100), the first polar sheet (11) comprises a plurality of first tabs (11B) folded at an end of the wound structure (100) to form a first tab laminated structure (111), and the second polar sheet (12) comprises a plurality of second tabs (12B) folded at an end of the wound structure (100) to form a second tab laminated structure (121); a first conductive member (21) welded to the first tab laminate structure (111); a second conductive member (22) welded to the second tab laminate structure (121); In a first direction (d1) parallel to the extension direction of the winding axis of the wound structure (100), 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 between itself and the isolation member (13) in the first direction (d1).

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

3. 2. The battery cell (30) of claim 1, wherein a minimum distance of a gap between the bending positions (11f) of the plurality of first tabs (11B) and the isolation member (13) in the first direction (d1) is defined as a first minimum distance L1, a minimum distance of a gap between the bending positions (12f) of the plurality of second tabs (12B) and the isolation member (13) in the first direction (d1) is defined as a second minimum distance L2, a melting point of a material of the plurality of first tabs (11B) is higher than a melting point of a material of the plurality of second tabs (12B), and the second minimum distance L2 is less than or equal to the first minimum distance L1.

4. 2. The battery cell (30) of claim 1, wherein the bending positions (11f) of the plurality of first tabs (11B) are at the cutting bases (11r) of the plurality of first tabs (11B), and / or the bending positions (12f) of the plurality of second tabs (12B) are at the cutting bases (12r) of the plurality of second tabs (12B).

5. In the first direction (d1), there is a third minimum distance L3 between the bending positions (11f) of the plurality of first tabs (11B) and the tab upper portions (11t) of the plurality of first tabs (11B), and there is a fourth minimum distance L4 between the bending positions (12f) of the plurality of second tabs (12B) and the tab upper portions (12t) of the plurality of second tabs (12B); 2. The battery cell (30) of claim 1, wherein a first thickness t1 of the plurality of first tabs (11B) in the thickness direction of the first tabs (11B) is smaller than a second thickness t2 of the plurality of second tabs (12B) in the thickness direction of the second tabs (12B), and the third minimum distance L3 is greater than or equal to the fourth minimum distance L4.

6. In the first direction (d1), there is a third minimum distance L3 between the bending positions (11f) of the plurality of first tabs (11B) and the tab upper portions (11t) of the plurality of first tabs (11B), and there is a fourth minimum distance L4 between the bending positions (12f) of the plurality of second tabs (12B) and the tab upper portions (12t) of the plurality of second tabs (12B); 2. The battery cell (30) of claim 1, wherein a first thickness t1 of the plurality of first tabs (11B) in the thickness direction of the first tabs (11B) is greater than a second thickness t2 of the plurality of second tabs (12B) in the thickness direction of the second tabs (12B), and the third minimum distance L3 is less than or equal to the fourth minimum distance L4.

7. 6. The battery cell (30) of claim 5, wherein a ratio A / B of a product A of a first thickness t1 of the plurality of first tabs (11B) in the thickness direction of the first tabs (11B) and the third minimum distance L3 to a product B of a second thickness t2 of the plurality of second tabs (12B) in the thickness direction of the second tabs (12B) and the fourth minimum distance L4 satisfies 0.2≦A / B≦4, with the proviso that the first thickness t1, the second thickness t2, the third minimum distance L3, and the fourth minimum distance L4 have the same unit.

8. The battery cell (30) of claim 7, wherein the ratio A / B satisfies 0.5≦A / B≦2.

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

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

11. 2. The battery cell (30) of claim 1, wherein in the first direction (d1), the first tab stack structure (111) and the second tab stack structure (121) are both located at the ends on the same side of the wound structure (100).

12. 2. The battery cell (30) of claim 1, wherein in the first direction (d1), the first tab stack structure (111) and the second tab stack structure (121) are both located at opposite ends of the wound structure (100).

13. an outer case (31) having a cavity for accommodating the electrode assembly (10), the first conductive member (21), and the second conductive member (22); 2. The battery cell (30) according to claim 1, further comprising: an electrode terminal (32) installed on a wall portion of the outer case (31) and electrically connected to the first conductive member (21) or the second conductive member (22).

14. 14. The battery cell (30) of claim 13, wherein the outer case (31) includes a housing (311) and an end cover (312), one end of the housing (311) has an opening (311A), the end cover (312) covers the opening (311A), the housing (311) includes a side wall (311B) and a bottom wall (311C), the side wall (311B) surrounds the outside of the electrode assembly (10), the bottom wall (311C) is located opposite the opening (311A), and the wall portion of the outer case (31) is the end cover (312) or the bottom wall (311C).

15. the first polar sheet (11) further includes a first current collector substrate (11A), the plurality of first 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), folding positions (11f) of the plurality of first tabs (11B) are located on a side of the separator (13) away from the first current collector substrate (11A); 2. The battery cell (30) according to claim 1, wherein the second polar sheet (12) further includes a second current collector substrate (12A), the plurality of second tabs (12B) are connected to the second current collector substrate (12A) and are arranged at intervals along the winding direction (wd), and folding positions (12f) of the plurality of second tabs (12B) are located on a side of the separator (13) away from the second current collector substrate (12A) in the first direction (d1).

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

17. A power consuming device comprising the battery (40) of claim 16.

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