Battery cells, batteries, and power consumption devices

Abstract

Battery cell, battery and power consumption device. A battery cell (40) comprising an electrode assembly (10), an outer case (4A), electrode terminals (42), and conductive members (21, 22), wherein the electrode assembly (10) includes a plurality of polarity sheets (10a, 10b) and isolation members (10c) placed between adjacent polarity sheets (10a, 10b) with opposite polarity in the plurality of polarity sheets (10a, 10b), the plurality of polarity sheets (10a, 10b) and the isolation members (10c) are wound along a winding direction (wd) and form a wound structure (100), and at least one of the plurality of polarity sheets (10a, 10b) includes a current collector base material (11) and a plurality of tabs (13), the plurality of tabs (1 3) is connected to at least one side of the current collector substrate (11) extending along the winding direction (wd) and is spaced apart along the winding direction (wd), at least a portion of the plurality of tabs (13) are bent along a direction adjacent to the winding axis (CL) of the winding structure (100) and a tab stacking structure (130) is formed at the end of the winding structure (100), the outer case (4A) has a cavity for housing the electrode assembly (10), the electrode terminals (42) are installed on the wall of the outer case (4A), and the conductive members (21, 22) are welded to the tab stacking structure (130) and electrically connected to the electrode terminals (42).

Description

[Technical Field]

[0001] This disclosure relates to the battery technology field, and more particularly to battery cells, batteries, and power consumption devices. [Background technology]

[0002] Rechargeable batteries, especially lithium-ion batteries, have advantages such as high voltage, high energy density, long cycle life, environmental friendliness, low pollution, wide operating temperature range, and low self-discharge. They are widely used in the powertrains of portable electronic devices and large new energy electric vehicles, and are of great significance in solving humanity's environmental pollution and energy crises. As lithium-ion batteries are widely applied, safety in battery use is a matter of great concern to users. [Overview of the project]

[0003] One aspect of this disclosure provides a battery cell including an electrode assembly, an outer case, electrode terminals, and a conductive member. The electrode assembly includes a plurality of polarity sheets and isolation members placed between adjacent polarity sheets of opposite polarity in the plurality of polarity sheets, the plurality of polarity sheets and the isolation members are wound along the winding direction and form a wound structure, at least one of the plurality of polarity sheets includes a current collector substrate and a plurality of tabs, the plurality of tabs are connected to at least one side of the current collector substrate extending along the winding direction and are spaced apart along the winding direction, at least a portion of the plurality of tabs are bent toward the winding axis of the wound structure and form a tab stacking structure at the end of the wound structure. The outer case has a cavity for housing the electrode assembly, The electrode terminals are installed on the wall of the outer case, and The conductive member is welded to the tab-laminated structure and electrically connected to the electrode terminals.

[0004] The electrode terminals are electrically connected to the outer case wall via a conductive member, and are welded to multiple tabs stacked at the ends of the wound structure of the electrode assembly. The stacked multi-layer tab structure has a higher thickness, making it less prone to melt-through when welded to the conductive member. This avoids the risk of short circuits caused by the separator or polarity sheet in the electrode assembly overheating during welding, thereby improving the welding quality of the welded area and reducing the risk of short circuits in the battery cell, thus improving safety during use.

[0005] In some embodiments, the tab stacking structure includes a first tab stacking region and a second tab stacking region arranged from the outside to the inside along the direction adjacent to the winding axis, wherein the number of tabs in the first tab stacking region increases along the direction adjacent to the winding axis, and the number of tabs in the second tab stacking region remains the same along the direction adjacent to the winding axis, and at least a portion of the welding area of ​​the conductive member and the tab stacking structure is located in the second tab stacking region.

[0006] The number of tabs in the second tab lamination region is the same along the direction adjacent to the winding axis. Therefore, when a conductive member is welded to the tab lamination structure formed at the end of the winding structure, the number of tabs in the second tab lamination region is greater and the lamination thickness is greater compared to other tab lamination regions. This makes it less likely for the conductive member to burn through when welded, thereby improving the welding quality of the welded region and reducing the risk of the separator or polarity sheet overheating and causing a short circuit during welding.

[0007] In some embodiments, the welding region includes a first portion located in the second tab stacking region and a second portion located in the first tab stacking region.

[0008] By welding the second tab stacking region and the first tab stacking region to the conductive member via the first and second portions of the welding region, respectively, the overall dimensions of the welding region can be increased, thereby improving the welding strength, reducing the electrical resistance of the welding region, and lowering the risk of overcurrent.

[0009] In some embodiments, the tab stacking structure further includes a third tab stacking region located on the side of the second tab stacking region adjacent to the winding axis, and the welded region further includes a third portion located in the third tab stacking region.

[0010] By welding the conductive member through the third tab stacking region, the overall dimensions of the weld area can be increased, thereby improving the weld strength, reducing the electrical resistance of the weld area, and lowering the risk of overcurrent.

[0011] In some embodiments, the ratio S1 / S of the area S1 of the first portion to the area S of the welding region satisfies S1 / S ≥ 70%.

[0012] By setting the S1 / S ratio to 70% or higher, the welding quality of the weld area can be improved, reducing the risk of tab burn-through or welding defects.

[0013] In some embodiments, the ratio S1 / S of the area S1 of the first portion to the area S of the welding region satisfies S1 / S ≥ 90%.

[0014] By further limiting the S1 / S ratio to over 90%, the welding quality of the weld area can be further improved, effectively reducing the risk of tab burn-through or welding defects.

[0015] In some embodiments, the winding structure is a cylindrical winding structure, and the ratio L1 / L of the maximum radial length L1 of the cylindrical winding structure in the first portion to the maximum radial length L of the cylindrical winding structure in the welding region satisfies L1 / L ≥ 70%.

[0016] By setting the L1 / L ratio to 70%, the welding quality of the weld area can be improved, reducing the risk of tab burn-through or welding defects.

[0017] In some embodiments, the ratio L1 / L of the maximum radial length L1 in the radial direction of the cylindrical winding structure of the first part to the maximum radial length L in the radial direction of the cylindrical winding structure of the welding region satisfies L1 / L≥90%.

[0018] By further limiting the ratio L1 / L to 90% or more, the welding quality of the welding region can be further improved, and the risk of tab detachment or welding defects can be effectively reduced.

[0019] In some embodiments, the minimum distance d between the winding start end in the winding direction of the current collector substrate and the second tab satisfies d≤1200 mm, The second tab is defined as the tab welded to the conductive member among the plurality of tabs and closest to the winding start end.

[0020] By setting the minimum distance d to 1200 mm or less, the range of tabs directly connected to the conductive member through the welding region can be increased, the risk of overcurrent generation in the second tab can be reduced, and thereby the influence of tab overheating on the properties of the chemical substances in the electrode assembly can be avoided as much as possible.

[0021] In some embodiments, the minimum distance d satisfies d≤800 mm.

[0022] By further limiting the minimum distance d to 800 mm or less, the range of tabs directly connected to the conductive member through the welding region can be further increased, the risk of overcurrent generation in the first tab can be further reduced, and thereby the influence of tab overheating on the properties of the chemical substances in the electrode assembly can be more effectively avoided.

[0023] In some embodiments, in the extending direction of the winding axis, the maximum value Hmax of the depth H of the welding region between the conductive member and the tab laminate structure and the thickness t of the conductive member satisfy 1.5*t≤Hmax≤1.9*t.

[0024] By setting the ratio of the maximum depth Hmax of the weld area to the thickness t of the conductive material within a specific range, the risk of tab burn-through and welding defects can be reduced as much as possible.

[0025] In some embodiments, in the extending direction of the winding axis, the maximum value Hmax of the depth H of the welding region and the thickness t of the conductive member satisfy 1.6*t ≤ Hmax ≤ 1.8*t.

[0026] By further limiting the selectable range of the ratio between the maximum depth Hmax of the weld area and the thickness t of the conductive member, the risk of tab burn-through and welding defects can be effectively reduced.

[0027] In some embodiments, in the extending direction of the winding axis, the minimum value Hmin of the depth H of the welded region between the conductive member and the tab laminated structure and the thickness t of the conductive member satisfy 1.1*t ≤ Hmin ≤ 1.5*t.

[0028] By setting the ratio of the minimum welding depth Hmin to the thickness t of the conductive material within a specific range, the risk of tab burn-through and welding defects can be reduced as much as possible.

[0029] In some embodiments, in the extending direction of the winding axis, the minimum value Hmin of the depth H of the welding region and the thickness t of the conductive member satisfy 1.2*t ≤ Hmin ≤ 1.4*t.

[0030] By further limiting the selectable range of the ratio between the minimum welding area depth Hmin and the thickness t of the conductive member, the risk of tab burn-through and welding defects can be effectively reduced.

[0031] In some embodiments, in the extending direction of the winding axis, the difference between the maximum value Hmax and the minimum value Hmin of the welding region H between the conductive member and the tab laminated structure (Hmax-Hmin), and the thickness t of the conductive member satisfy 0.2*t ≤ (Hmax-Hmin) ≤ 0.8*t.

[0032] By limiting the ratio of the difference (Hmax-Hmin) to the thickness t of the conductive member to a specific range, the risk of localized burn-through or welding defects in the tab can be reduced.

[0033] In some embodiments, in the extending direction of the winding axis, the difference between the maximum value Hmax and the minimum value Hmin of the depth H of the welding region (Hmax-Hmin) and the thickness t of the conductive member satisfy 0.3*t ≤ (Hmax-Hmin) ≤ 0.6*t.

[0034] By further limiting the selectable range of the ratio between the difference (Hmax-Hmin) and the thickness t, the risk of localized burn-through or welding defects in the tab can be further reduced.

[0035] In some embodiments, in the winding direction, the spacing e between the tops of adjacent tabs among the plurality of tabs satisfies e ≤ 0.5 mm.

[0036] By setting the spacing e at the top of adjacent tabs to 0.5 mm or less, the degree of tab stacking can be increased, thereby achieving a greater tab stacking thickness and reducing the risk of tab burnout.

[0037] In some embodiments, in the winding direction, the spacing e between the tops of adjacent tabs among the plurality of tabs satisfies e ≤ 0.2 mm.

[0038] By further limiting the spacing e at the top of the tabs to 0.2 mm or less, the thickness of the tab layer can be effectively increased, further reducing the risk of tab melt-off.

[0039] In some embodiments, the welded region of the conductive member and the tab stacking structure includes a first portion located in the second tab stacking region, and in the extending direction of the winding axis, the depth of the first portion increases toward the winding axis.

[0040] As the winding axis approaches, the curvature of the polar sheet winding layer increases, the overlap of the connected tabs increases, and the thickness of the tab stack gradually increases from the outside to the inside. As a result, the welding power also increases from the outside to the inside, thereby forming a weld area where the depth increases from the outside to the inside, which can improve the welding quality of the weld area.

[0041] In some embodiments, the welded region of the conductive member and the tab stacking structure includes a first portion located in the second tab stacking region and a second portion located in the first tab stacking region, wherein the depth of the first portion is less than the depth of the second portion in the extending direction of the winding axis.

[0042] Considering the small number of tabs in the first tab stacking region, if there is no burn-through, the depth of the weld pool will be relatively small. Therefore, the welding power used when welding the first tab stacking region will be lower than the welding power used when welding the second tab stacking region, thereby improving the welding quality of the second part of the first tab stacking region and reducing the risk of tab burn-through.

[0043] In some embodiments, at least some of the tabs are rectangular or parallelograms.

[0044] Considering that rectangular or parallelogram-shaped tabs allow for smaller spacing between the tops of the tabs, this helps to improve the degree to which adjacent tabs overlap, thereby increasing the thickness of the tab stack and reducing the risk of tab melt-off.

[0045] In some embodiments, the winding structure is a cylindrical winding structure, the cylindrical winding structure has a central hole, and the minimum distance r1 between the winding axis and the tab root of the first tab is Satisfying r1≧h0+0.8*R, Here, h0 is the height of the first tab in the direction of extension of the winding axis when it is not bent, and R is the radius of the hole cross-section at the end of the winding structure of the central hole.

[0046] The minimum distance r1 is greater than or equal to the sum of the height h0 of the first tab and the radius R of the central hole, which is 0.8 times the height of the first tab. This corresponds to the radius range covering the central hole not exceeding 20% ​​after the first tab closest to the winding axis is folded from the outside to the inside, thereby reducing the obstruction of the central hole after the tab is folded, avoiding interference with electrolyte injection, and reducing the risk of the tab being inserted downward or rupturing during injection, causing a short circuit.

[0047] In some embodiments, the minimum distance r1 between the winding shaft and the tab root of the first tab satisfies r1 ≥ h0 + R.

[0048] The minimum distance r1 is greater than or equal to the sum of the height h0 of the first tab and the radius R of the central hole, which corresponds to the first tab closest to the winding axis not covering the central hole after being folded from the outside to the inside, thereby more effectively preventing the tab from blocking the central hole and affecting the injection of the electrolyte.

[0049] In some embodiments, the plurality of tabs include a first group of tabs and a second group of tabs, the plurality of polar sheet winding rings on which the first group of tabs is located are located outside of at least one polar sheet winding ring on which the second group of tabs is located, and in the direction of extension of the winding axis, the minimum height h1 of the unbent first group of tabs is greater than the maximum height h2 of the unbent second group of tabs.

[0050] By making the maximum height h2 of the second tab group, located inside the first tab group, smaller than the minimum height h1 of the first tab group, the first tab connected to the welding area can be brought closer to the winding start end, which is advantageous in reducing the risk of overcurrent of the first tab. Furthermore, the smaller tab height of the first tab group reduces or avoids covering the central hole, effectively preventing the tab from blocking the central hole and affecting the injection of the electrolyte.

[0051] In some embodiments, the second group of tabs includes the first tab, and in the direction extending along the winding axis, the height h2 of the unbent second group of tabs decreases toward the direction approaching the winding axis.

[0052] As the height of each tab in the first tab group decreases from the outside to the inside, the second tab stacking region can extend more toward the winding axis, thereby increasing the extent of the second tab stacking region and helping to increase the dimensions of the first portion of the second tab stacking region in the weld area, improving the weld quality of the weld area and reducing the risk of tab burn-through or welding defects.

[0053] 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 a side wall and a bottom wall, the side wall surrounds the outside of the electrode assembly, the bottom wall is positioned opposite the opening, and the wall portion of the outer case is either the end cover or the bottom wall.

[0054] The conductive members are electrically connected to electrode terminals installed on the end cover or the bottom wall of the housing, and welded to the tab-laminate structure of the electrode assembly, improving the welding quality of the welded area while simultaneously reducing the risk of short circuits in the battery cells and improving safety during use.

[0055] One aspect of this disclosure provides a battery including the battery cell. The battery using the battery cell can effectively improve safety in use.

[0056] One aspect of this disclosure provides a power consumption device including the battery. The power consumption device using the battery can effectively improve safety during use. [Brief explanation of the drawing]

[0057] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the drawings required for the embodiments of this disclosure are briefly described below. It should be understood that the drawings shown below represent only a few embodiments of this disclosure, and those skilled in the art can obtain further drawings based on these drawings without requiring any creative effort.

[0058] This disclosure can be better understood by referring to the drawings and the detailed description below.

[0059] [Figure 1] These are schematic diagrams of the structures of several embodiments based on the power consumption device of this disclosure. [Figure 2] This is an exploded schematic diagram of several embodiments based on the battery of this disclosure. [Figure 3] This is a schematic diagram illustrating the connection of multiple battery cells in several embodiments based on the battery of this disclosure. [Figure 4A] This is an exploded schematic diagram of several embodiments based on the battery cell of this disclosure. [Figure 4B] This is a schematic longitudinal cross-sectional view passing through the winding axis of several embodiments based on the battery cell of the present disclosure. [Figure 4C] This is an exploded schematic diagram of electrode assemblies and conductive members in several embodiments based on the battery cell of this disclosure. [Figure 5] This is a schematic cross-sectional view of a wound structure in several embodiments based on the battery cell of the present disclosure. [Figure 6] This is a schematic diagram showing the unfolded state of the polarity sheet and tabs in several embodiments based on the battery cell of this disclosure. [Figure 7] This is a schematic cross-sectional view of a structure in which a tab stacked structure and conductive member are welded together in several embodiments based on the battery cell of this disclosure. [Figure 8] These are schematic cross-sectional views of multiple tab stacking regions of a tab stacking structure in several embodiments based on the battery cell of this disclosure. [Figure 9] This is a schematic diagram showing the distribution of multiple tab stacking regions in a tab stacking structure of a welded region in several embodiments based on the battery cell of this disclosure. [Figure 10] These are schematic diagrams showing the dimensions of various parts of the welding area in several embodiments based on the battery cell of this disclosure. [Figure 11] This is a schematic diagram of the overlap of adjacent tabs in different tab stacking regions in some embodiments based on the battery cell of the present disclosure. [Figure 12] [Figure 13] These are schematic dimensional diagrams of polarity sheets with tab connections of different shapes in several embodiments based on the battery cell of the present disclosure. [Figure 14] This is a schematic diagram showing the dimensions of the bent tab and central hole in some embodiments based on the battery cell of the present disclosure. [Figure 15] This is a schematic diagram of the height of the tab in an unfolded state in another embodiment based on the battery cell of the present disclosure. [Figure 16] Figure 15 is a schematic cross-sectional view of multiple tab stacking regions after the tabs have been folded toward the central hole.

[0060] Please understand that the dimensions of each part shown in the drawings are not drawn according to actual proportions. Also, identical or similar reference numerals indicate identical or similar components. [Explanation of Symbols]

[0061] 10-Electrode assembly, 10a-First polarity sheet, 10b-Second polarity sheet, 10c-Isolation member, 100-Wound structure, 110-Central hole, 11-Current collector substrate, 12-Active material layer, 13-Tab, 130-Tab stacking structure, 130a-First tab stacking region, 130b-Second tab stacking region, 130c-Third tab stacking region, 131-First tab, 132-Second tab, 13a-First tab group, 13b-Second tab group, 21, 22 - Conductive members, 30 - welding area, 31 - first part, 32 - second part, 33 - third part, 40-Battery cell, 4A-Outer case, 41-Housing, 411-Opening, 412-Through hole, 42-End cover, 421-Pressure reducing member, 43-Electrode terminal, 44-Insulating member, 45-Electrode lead-out section, 46-Bus bar, 50-Battery, 51-Housing, 52-Housing cover, 60-vehicles, wd-winding direction, CL-winding axis, WS-winding start end [Modes for carrying out the invention]

[0062] 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 embodiments and drawings are used to illustrate 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 embodiments described.

[0063] Unless otherwise stated, in this disclosure, “multiple” means two or more; terms such as “up,” “down,” “left,” “right,” “inside,” and “outside” refer to directions or positional relationships that are merely intended to facilitate and simplify the explanation of this disclosure, and do not indicate or imply that the devices or elements in question have a specific direction, or that they are composed of and should be operated in a specific direction, and therefore should not be understood as limiting this disclosure. Furthermore, terms such as “first,” “second,” and “third” are used solely for explanatory purposes and should not be understood as indicating or implying relative importance. “Perpendicular” does not mean perpendicular in the strict sense, but is within an acceptable margin of error. “Parallel” does not mean parallel in the strict sense, but is within an acceptable margin of error.

[0064] All directional expressions appearing in the following description refer to the directions shown in the figures and do not limit the specific structure of the disclosure. Further explanation is required in this disclosure that, unless otherwise explicitly provided and limited, the terms “attached,” “connected,” and “connected” should be understood broadly, for example, as fixed connections, removable connections, or integral connections. Connections may be direct or indirect, via an intermediate medium. Those skilled in the art will be able to understand the specific meaning of these terms in this disclosure depending on the specific circumstances.

[0065] Several embodiments of the present invention will be described in detail below with reference to the drawings. The features of the embodiments described below can be combined with each other, as long as they do not contradict each other.

[0066] In this disclosure, "multiple" refers to two or more (including two).

[0067] In the embodiments of this disclosure, the battery cell may be a secondary battery, which is a battery cell that can continue to be used by activating the active material through a charging method after the battery cell has been discharged.

[0068] The battery cell may be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited thereto.

[0069] A battery cell generally includes an electrode assembly. The electrode assembly includes multiple polarity sheets and isolation members placed between adjacent polarity sheets. The multiple polarity sheets may include positive and negative electrode sheets with opposite polarities. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) reciprocate between the positive and negative electrode sheets, being inserted and removed. The isolation members are placed between the positive and negative electrode sheets and serve to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

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

[0071] As an example, the positive electrode current collector substrate has two opposing surfaces 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.

[0072] As an example, the positive electrode current collector substrate can be a metal foil or a composite current collector. For example, as the metal foil, silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium can be used. The composite current collector may 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, and silver alloy) on a polymer material substrate (for example, a substrate such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0073] As an example, the positive electrode active material may include at least one of lithium-containing phosphates, lithium transition metal oxides, and modified compounds thereof. However, the present disclosure is not limited to these materials, and other conventional materials that can be used as the positive electrode active material layer of the battery may also be used. These positive electrode active material layers may be used alone or in combination of two or more. As the lithium-containing phosphate, for example, at least one of lithium iron phosphate (e.g., LiFePO4 (also called LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon may be included, but is not limited thereto. Examples of the lithium transition metal oxide include lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4, etc.), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also called NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also called NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also called NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also called NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also called NCM 811 ), lithium nickel cobalt aluminum oxide (LiNi 0.85 Co 0.15 Al 0.05 O2, etc.) and at least one of its modified compounds may be included, but is not limited thereto.

[0074] In some embodiments, the negative electrode sheet may include a negative electrode current collector substrate.

[0075] As an example, the negative electrode current collector substrate can be a metal foil, foamed metal, or a composite current collector. For example, as the metal foil, silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium can be used. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon. The composite current collector may 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 alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys) on a polymer material substrate (for example, a substrate such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0076] As an example, the negative electrode sheet may include a negative electrode current collector substrate and a negative electrode active material layer installed on at least one surface of the negative electrode current collector substrate.

[0077] As an example, the negative electrode current collector substrate has two opposing surfaces in its own thickness direction, and the negative electrode active material layer is provided on one or both of the two opposing surfaces of the negative electrode current collector substrate.

[0078] As an example, the negative electrode active material layer can be a negative electrode active material layer for battery cells 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. Silicon-based materials can be selected from at least one of elemental silicon, silicon oxide, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials can be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this disclosure is not limited to these materials, and other conventional materials that can be used as the negative electrode active material layer of a battery may be used. These negative electrode active material layers may be used individually or in combination of two or more types.

[0079] In some embodiments, the material of the positive electrode current collector substrate may be aluminum, and the material of the negative electrode current collector substrate may be copper.

[0080] In some embodiments, the electrode assembly further includes an isolation member positioned between the positive and negative electrodes.

[0081] In some embodiments, the separating member is a separator. The disclosure does not particularly limit the type of separator, and any known porous structure separator having good chemical and mechanical stability can be selected.

[0082] As an 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 multilayer composite film, and is not particularly limited. If the separator is a multilayer composite film, the materials of each layer may be the same or different, and are not particularly limited. The isolation member may be a single member positioned between the positive electrode sheet and the negative electrode sheet, or it may be attached to the surface of the positive electrode sheet and / or the surface of the negative electrode sheet.

[0083] In some embodiments, the isolation member is a solid electrolyte. The solid electrolyte is placed between the positive electrode sheet and the negative electrode sheet and serves both the role of ion transfer and isolation of the positive and negative electrodes.

[0084] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The disclosure does not particularly limit the type of electrolyte, which can be selected as needed. The electrolyte may be liquid, gel-like, or solid.

[0085] For example, a liquid electrolyte includes an electrolyte salt and a solvent.

[0086] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluoride phosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoride arsenate, lithium bisfluorosulfonylimide, lithium bistrifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium bisoxalate borate, lithium difluorobisoxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0087] 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 is selectively 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, methyltetrahydrofuran, diphenyl ether, and crown ether.

[0088] For example, a gel-like electrolyte contains a polymer-based skeletal network and can be combined with an ionic liquid-lithium salt.

[0089] As an example, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0090] As an example, the polymer solid electrolyte may be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymer, polyionic liquid lithium salt, cellulose, etc.

[0091] As an example, the inorganic solid electrolyte may be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON film), sulfide solid electrolytes (crystalline lithium superionic conductor (lithium germanium phosphate sulfur, silver sulfur germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0092] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0093] In some embodiments, the electrode assembly includes a wound structure. The positive electrode sheet, the negative electrode sheet, and the isolation member are wound together to form the wound structure.

[0094] For example, one or more positive electrode sheets and negative electrode sheets may be installed, and multiple positive electrode sheets and multiple negative electrode sheets may be stacked alternately.

[0095] For example, multiple positive electrode sheets may be installed, and the negative electrode sheets may be folded to form multiple stacked folded sections, with the positive electrode sheets sandwiched between adjacent folded sections.

[0096] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form multiple stacked folded sections.

[0097] For example, multiple isolation members may be installed, each placed between any adjacent positive or negative electrode sheets.

[0098] For example, the isolation members may be installed in a continuous manner, and may be installed between any adjacent positive or negative electrode sheets by folding or rolling them up.

[0099] In some embodiments, the shape of the electrode assembly may be cylindrical, flattened, or polygonal prism-shaped, etc.

[0100] In some embodiments, the electrode assembly includes tabs from which current can be drawn away from the electrode assembly. The tabs include a positive electrode tab and a negative electrode tab, which are connected to the positive electrode current collector substrate and the negative electrode current collector substrate, respectively. The tabs may be formed by splitting or cutting the current collector substrate, or they may be connected to the sides of the current collector substrate by welding.

[0101] 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 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), or an aluminum-plastic film, etc.

[0102] For example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft pack battery cell, or a battery cell of other shape. A prismatic battery cell includes a rectangular battery cell, a blade-shaped battery cell, and a polygonal prismatic battery, and a polygonal prismatic battery is a hexagonal prismatic battery, etc., and this disclosure is not particularly limited.

[0103] The batteries referred to in the embodiments of this disclosure refer to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0104] In some embodiments, the battery may be a battery module, and if there are multiple battery cells, the multiple battery cells are arranged and fixed to form a single battery module. The battery module may include multiple battery cells connected in series, in parallel, or in series-parallel.

[0105] In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, and the battery cells or battery module are housed within the housing.

[0106] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, the housing portion may be at least part of the vehicle's floor, or at least part of the vehicle's crossbeams and longitudinal beams.

[0107] In some embodiments, the battery may be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, and the like.

[0108] In some related technologies, when welding tabs at the ends of electrode assemblies to the current collector disk, welding quality issues such as burn-through of the tabs or welding defects may occur, affecting the safety of the battery's use.

[0109] In view of this, embodiments of the present disclosure provide a battery cell, a battery, and a power consumption device that can improve the safety of battery use.

[0110] The battery cells of the embodiments of this disclosure can be applied to various types of batteries. A battery includes a housing that provides a space for housing a battery module, and a battery module that is mounted within the housing. The housing may be made of a metal material. The battery module may include a plurality of battery cells connected in series, in parallel, or in series-parallel. A battery cell is the smallest unit that makes up a battery. A battery cell includes an electrode assembly that can generate an electrochemical reaction.

[0111] The batteries in the embodiments of this disclosure are applicable to various power-consuming devices that use batteries. Power-consuming devices may include mobile phones, portable devices, laptop computers, battery cars, electric vehicles, ships, spacecraft, electric toys, and power tools. For example, spacecraft include aircraft, rockets, space shuttles, and spaceships; electric toys include stationary or mobile electric toys such as game consoles, electric toy cars, electric toy ships, and electric toy aircraft; and power tools include metal cutting power tools such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drivers, concrete vibrators, and electric planers, as well as polishing power tools, assembly power tools, and railway power tools. The embodiments of this disclosure are not particularly limited to the above power-consuming devices. The batteries are used to supply power to power-consuming devices such as vehicles, for example, to supply power for control or power for driving the vehicle.

[0112] Figure 1 is a schematic diagram of the structure of several embodiments based on the power consumption device of this disclosure. For convenience of explanation, a vehicle will be used as an example of the power consumption device. The vehicle 60 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 50 can be installed at the bottom of the vehicle 60, or at the front or rear of the vehicle.

[0113] The battery 50 is used to supply power to the vehicle 60. For example, the battery 50 can be used as the operating power source for the vehicle 60's circuit system, meeting the power requirements for starting, navigation, and driving the vehicle 60. The battery 50 can not only serve as the operating power source for the vehicle 60, but also as the driving power source for the vehicle 60, providing driving power to the vehicle 60 in place of or partially replacing fuel or natural gas.

[0114] The vehicle 60 can also be fitted with axles, wheels, a motor, and a controller. The controller is used to control the battery 50 and supply power to the motor. For example, if the vehicle 60 uses the battery 50 as its power source, the battery 50 supplies the motor with the power necessary for constant speed and acceleration, either in place of or in part of the fuel or natural gas. The motor is used to drive the rotation of the axles, thereby moving and rotating the wheels.

[0115] Figure 2 is an exploded schematic diagram of several embodiments based on the battery of the present disclosure. Figure 3 is a schematic diagram of the connections of multiple battery cells in several embodiments based on the battery of the present disclosure.

[0116] Referring to Figure 2, in some embodiments, the battery 50 includes a housing 51, a housing cover 52 that covers the opening side of the housing 51, and one or more battery cells 40 installed inside the housing 51. The housing 51 and housing cover 52 provide a housing space for the battery cells 40 and can provide functions such as cooling, sealing, and collision prevention, and can also prevent liquids or other foreign matter from adversely affecting the charging, discharging, or safety of the battery cells.

[0117] The housing 51 and housing cover 52 may have various shapes, such as a rectangular parallelepiped or a cylinder. The housing 51 may have a hollow structure with one side open, and the housing cover 52 may have a plate-like structure, with the housing cover 52 covering the open side of the housing 51 and forming an internal storage space. In another embodiment, the housing 51 has a hollow structure with one side open, and the housing cover 52 also has a hollow structure with one side open, with the open side of the housing cover 52 covering the open side of the housing 51 and forming an internal storage space.

[0118] Referring to Figures 2 and 3, each battery cell 40 is electrically connected to the others by series connection, parallel connection, or series-parallel connection, thereby realizing the required electrical characteristic parameters of the battery 50. Series-parallel connection refers to the presence of both series and parallel connections among multiple battery cells 40. Adjacent battery cells 40 may be electrically connected via busbars 44. Multiple battery cells 40 are installed in rows, and one or more rows of battery cells 40 can be installed in the housing as needed.

[0119] In some embodiments, each battery cell 40 of the battery 50 may be arranged along at least one of the longitudinal and width directions of the housing. Depending on practical requirements, at least one row or one column of battery cells 40 may be installed. If necessary, an additional layer or multiple layers of battery cells 40 may be installed in the height direction of the battery 50.

[0120] In some embodiments, multiple battery cells 40 are first connected in series, in parallel, or in series-parallel to form a battery module, and then the multiple battery modules are further connected in series, in parallel, or in series-parallel to form an integrated unit which is then housed in the housing 51. In some other embodiments, all the battery cells 40 are directly connected in series, in parallel, or in series-parallel, and then the integrated unit composed of all the battery cells 40 is housed in the housing.

[0121] Figure 4A is an exploded schematic view of several embodiments based on the battery cell of the present disclosure. Figure 4B is a schematic longitudinal section view passing through the winding axis of several embodiments based on the battery cell of the present disclosure. Figure 4C is an exploded schematic view of the electrode assembly and conductive members in several embodiments based on the battery cell of the present disclosure. Figure 5 is a schematic cross-sectional view of the winding structure in several embodiments based on the battery cell of the present disclosure.

[0122] Referring to Figures 3 to 5, in some embodiments, the battery cell 40 includes an electrode assembly 10, an outer case 4A, electrode terminals 42, and conductive members 21, 22. The electrode assembly 10 includes a plurality of polarity sheets 10a, 10b and isolation members 10c placed between adjacent polarity sheets 10a, 10b with opposite polarities. The plurality of polarity sheets 10a, 10b and the isolation members 10c are wound along the winding direction wd and form a wound structure 100.

[0123] In Figure 5, the multiple polar sheets may include polar sheet 10a as a positive electrode sheet and polar sheet 10b as a negative electrode sheet, and the polar sheet winding rings formed within the winding structure 100 of polar sheets 10a and polar sheet 10b may be arranged alternately from the outside to the inside, at least partially. The isolation member 10c is in the form of a separator and can be installed between polar sheet 10a and polar sheet 10b. In some other embodiments, polar sheet 10a may be a negative electrode sheet and polar sheet 10b may be a positive electrode sheet.

[0124] Referring to Figures 4A and 4B, the outer case 4A has a cavity for housing the electrode assembly 10. The electrode terminals 42 are mounted on the wall of the outer case 4A and are electrically connected to the conductive member 21. The electrode terminals 42 may be mounted on the side wall or bottom wall of the outer case 4A.

[0125] The cavity of the outer case 4A houses the electrode assembly 10 and also houses the electrolyte. The shape of the outer case 4A may be determined based on the shape of one or more electrode assemblies 10 housed in the cavity; for example, the shape of the outer case 4A may be a hollow rectangular parallelepiped, a hollow cube, or a hollow cylinder.

[0126] The outer case 4A may include a housing 41 and an end cover 42. The housing 41 is a hollow structure with openings 411 at one or both ends, and its material may be one or more types, such as copper, iron, aluminum, steel, aluminum alloy, or plastic. The end cover 42 can be made of a metallic or non-metallic material and can be fixedly connected to the housing 41 by welding, bonding, or fastening member connection.

[0127] Referring to Figure 4B, one end of the housing 41 has an opening 411, and the end cover 42 covers the opening 411. The housing 41 includes a side wall 414 and a bottom wall 413. The side wall 414 surrounds the outside of the electrode assembly 10, and the bottom wall 413 is installed opposite the opening 411. The wall portion of the outer case 4A is the end cover 42 or the bottom wall 413, and accordingly the electrode terminals 42 may be installed on the end cover 42 or on the bottom wall 413.

[0128] In the case of a cylindrical battery cell, the housing 41 may be a cylindrical hollow structure having an opening 411 at one end, and the end cover 42 may be a disc-shaped structure that fits the opening 411. The electrode terminals 42 may be installed on the bottom wall 413 on the side of the housing 41 away from the end cover 42. In Figures 4A and 4B, a through hole 412 may be provided in the bottom wall 413, and the electrode terminals 42 may be installed in the through hole 412 via an electrode lead-out portion 45 and an insulating member 42. At least a portion of the electrode lead-out portion 45 may protrude from the outer surface of the bottom wall 413, thereby enabling electrical connection between different battery cells 40 via a busbar 46. The insulating member 42 is used to provide insulation between the electrode lead-out portion 45 and the housing 41, and can be made of rubber or plastic. Preferably, openings are provided at both ends of the housing, and both are covered by end covers, and the electrode lead-out portion and electrode terminals may be installed on the end covers.

[0129] Referring to Figure 4A, a pressure reducing member 421 can be installed on the end cover 42. A pressure reducing member is an element or component that operates when the internal pressure or temperature of a battery cell reaches a predetermined threshold, thereby releasing the internal pressure or temperature. The design of the threshold varies depending on the design requirements. The threshold may depend on one or more materials among the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell. The pressure reducing member can take the form of an explosion-proof valve, air valve, pressure reducing valve, or safety valve, and specifically can use a pressure-sensitive or temperature-sensitive element or structure, i.e., when the internal pressure or temperature of the battery cell reaches a predetermined threshold, the pressure reducing member performs an action or a weak structure provided in the pressure reducing member is destroyed, forming an opening or flow path that allows the internal pressure or temperature to escape.

[0130] The emissions from battery cells referred to herein include, but are not limited to, electrolyte, dissolved or fragmented positive and negative electrode sheets, separator fragments, high-temperature and high-pressure gases produced by the reaction (e.g., flammable gases such as CH4 and CO), and flames.

[0131] Referring to Figures 4A to 4C, the conductive members 21 and 22 may be located on both sides of the electrode assembly 10 along the extending direction of the winding axis of the winding structure 100, or on one side of the electrode assembly 10 along the extending direction of the winding axis of the winding structure 100. In Figure 4B, the conductive member 21 is welded to a tab at one end of the electrode assembly 100 and to the electrode lead-out portion 45, and the conductive member 22 is welded to a tab at the other end of the electrode assembly 100 and to the end cover 42. The conductive members 21 and 22 can provide electrical connections between the electrode assembly and structures such as electrode terminals and end covers as current collectors. The conductive members may be metal conductors, such as copper, iron, aluminum, steel, or aluminum alloys. In some embodiments, the conductive members may include current collector discs or other structures.

[0132] Figure 6 is a schematic diagram of the unfolded polarity sheet and tabs in several embodiments based on the battery cell of this disclosure. Figure 7 is a schematic cross-sectional diagram of the structure in which the tab stacked structure and conductive member are welded in several embodiments based on the battery cell of this disclosure. Figure 8 is a schematic cross-sectional diagram of multiple tab stacked regions of the tab stacked structure in several embodiments based on the battery cell of this disclosure.

[0133] Referring to Figure 6, at least one of the multiple polarity sheets of the electrode assembly 10 includes a current collector substrate 11 and multiple tabs 13. The polarity sheet may further include an active material layer 12 covering the surface of at least one side of the current collector substrate 11.

[0134] The plurality of tabs 13 are connected to at least one side of the current collector substrate 11 that extends along the winding direction wd, and are spaced apart along the winding direction wd. The plurality of tabs 13 may be connected to one side of the current collector substrate 11 that extends along the winding direction wd, or they may be connected to two sides of the current collector substrate 11 that extend along the winding direction wd.

[0135] In some embodiments, the multiple tabs 13 may be formed by dividing or cutting the current collector substrate. In another embodiment, each of the multiple tabs 13 may be welded to the side of the current collector substrate 11.

[0136] Referring to Figure 7, at least a portion of the plurality of tabs 13 are bent toward a direction toward the winding axis CL of the winding structure 100, and a tab stacking structure 130 is formed at the end of the winding structure 100. The tab stacking structure 130 may be electrically connected to electrode terminals 42 installed on the wall of the outer case 4A via conductive members 21, 22 (e.g., current collector disks). Specifically, the conductive members 21, 22 are welded to the tab stacking structure 130.

[0137] The conductive members 21 and 22 can form continuous or discrete weld regions 30 with the tab stacked structure 130. When welding the conductive members 21 and 22 to the tab stacked structure 130 using a laser or the like, the weld region 30 is heated and forms a molten liquid metal portion in a certain geometric shape, i.e., a weld pool.

[0138] Referring to Figures 7 and 8, the tab stacking structure 130 includes a first tab stacking region 130a and a second tab stacking region 130b arranged from the outside to the inside along the direction adjacent to the winding axis CL. Figures 7 and 8 show a partial cross-section in which, after the polar sheet has been wound, the tabs to which each winding ring is connected are bent toward the winding axis CL, which is drawn by a dashed line, and are sequentially stacked. For convenience of representation, other polar sheets and isolation members in the winding structure are omitted in the figures.

[0139] The number of stacked tabs in the first tab stacking region 130a increases along the direction approaching the winding axis CL. The number of stacked tabs in the second tab stacking region 130b is the same along the direction approaching the winding axis CL. Here, the number of stacked tabs at a certain position is the number of stacked tabs connected to different polar sheet winding rings at that position in the tab stacking structure 130, that is, the number of turns of the polar sheet winding ring corresponding to each stacked tab at that position.

[0140] Referring to Figure 8, in the first tab stacking region 130a, the number of stacked tabs decreases as you move away from the winding axis CL. For tabs of approximately the same height, the number of stacks gradually increases from the outermost 1 layer to 10 or more layers. The position where the second tab stacking region 130b and the first tab stacking region 130a meet is actually the position where the number of stacked tabs in the first tab stacking region 130a does not increase any further. The number of stacked tabs at each position along the direction approaching the winding axis CL in the second tab stacking region 130b remains the same.

[0141] Referring to Figure 6, the first tab 131 is defined as the tab among the plurality of tabs 13 that is closest to the winding start end WS of the current collector substrate. To illustrate the first tab 131, the polar sheet in Figure 6 is flattened so that its longitudinal direction substantially coincides with the winding direction. The winding start end WS is the starting position when winding the polar sheet and is located at the innermost part of the winding structure. Correspondingly, the second tab stacking region 130 may extend to the polar sheet winding ring where the first tab 131 is located.

[0142] Figure 9 is a schematic diagram showing the distribution of welded areas in multiple tab stacking regions of a tab stacking structure in several embodiments based on the battery cell of the present disclosure. Referring to Figure 9, at least a portion of the welded areas 30 of the conductive members 21, 22 and the tab stacking structure 130 is located in the second tab stacking region 130b. In some embodiments, the entire welded area 30 is located in the second tab stacking region 103b, and in other embodiments, a portion of the welded area 30 is located in the second tab stacking region 103b, with the rest located in other parts of the tab stacking structure other than the second tab stacking region 103b.

[0143] Since the number of tabs in the second tab lamination region 130b is the same, when the conductive members 21 and 22 are welded to the tab lamination structure 130 formed at the end of the wound structure 100, the number of tabs in the second tab lamination region 130b is greater and the lamination thickness is greater compared to other tab lamination regions. Therefore, when welding to the conductive members 21 and 22, burn-through is less likely, thereby improving the welding quality of the welding region 30 and reducing the risk of the separator 10c or polar sheet overheating and causing a short circuit during welding.

[0144] Referring to Figures 7 to 9, in some embodiments, the welding area 30 includes a first portion 31 located in the second tab stacking area 130b and a second portion 32 located in the first tab stacking area 130a. The first tab stacking area 130a is located outside the second tab stacking area 130b, and the number of tab stacks increases from the outside to the inside. By welding the second tab stacking area 130b and the first tab stacking area 130a to the conductive member via the first portion 31 and the second portion 32 of the welding area 30, respectively, the overall dimensions of the welding area 30 can be increased, thereby improving the welding strength, reducing the electrical resistance of the welding area 30, and lowering the risk of overcurrent. The second portion 32 may be connected to the first portion 31 or it may be installed at a distance from the first portion 31.

[0145] In some embodiments, the tab stacking structure 130 further includes a third tab stacking region 130c located on the side of the second tab stacking region 130b adjacent to the winding axis CL, and the welded region 30 further includes a third portion 33 located in the third tab stacking region 130c.

[0146] The third tab stacking region 130c is located inside the second tab stacking region 130b, and the number of tab stacks decreases from the outside to the inside. By welding the third tab stacking region 130c to the conductive members 21 and 22, the overall dimensions of the welded region 30 can be increased, thereby improving the weld strength, reducing the electrical resistance of the welded region 30, and lowering the risk of overcurrent.

[0147] The welding area may be distributed at multiple locations on the conductive member, and this includes continuous or discrete welds at different radial or circumferential locations. Referring to Figure 9, it can be seen that the welding area 30 is composed of multiple parts, and its shape may be a straight section, a curved section, or a straight section and a curved section connected together.

[0148] Figure 10 is a schematic diagram of the dimensions of various parts of a weld area in several embodiments based on the battery cell of the present disclosure. For ease of understanding, the weld areas distributed at each location are exemplaryly set within rectangular areas, and parts of the weld area corresponding to different tab stacking areas are indicated by dashed lines. In Figure 10, the first part 31 corresponds to the second tab stacking area 130b, the second part 32 corresponds to the first tab stacking area 130a, and the third part 33 corresponds to the third tab stacking area 130c.

[0149] Referring to Figure 10, in some embodiments, the ratio S1 / S of the area S1 of the first portion 31 to the area S of the welding region 30 satisfies S1 / S ≥ 70%. Here, area S is the total area of ​​the welding region 30, and in Figure 10, area S is the sum of areas S1, S2, and S3. Referring to the welding region 30 shown in Figure 7, its three-dimensional shape may be irregular, and the area here can be calculated based on the projected area of ​​the surface of the conductive member of the weld pool away from the tab stacked structure.

[0150] Since the welding area 30 includes the first portion 31 and may include other portions, S1 / S represents the occupancy ratio of the first portion 31 in the welding area 30. Because the first portion 31 is more easily able to obtain good welding quality, increasing this occupancy ratio is advantageous in improving the welding quality of the welding area 30. Therefore, by setting the ratio S1 / S to 70% or more, the welding quality of the welding area 30 can be improved, and the risk of tab burn-through or welding defects can be reduced.

[0151] Selectively, the ratio S1 / S of the area S1 of the first portion 31 to the area S of the welding region 30 satisfies S1 / S ≥ 90%, for example, S1 / S is equal to 90%, 95%, 98%, or 100%. By further limiting the ratio S1 / S to 90% or more, the welding quality of the welding region 30 can be further improved, effectively reducing the risk of burn-through of the tab or welding defects.

[0152] Referring to Figures 9 and 10, in some embodiments, the wound structure 100 is a cylindrical wound structure. The ratio L1 / L of the maximum radial length L1 of the cylindrical wound structure in the first portion 31 to the maximum radial length L of the cylindrical wound structure in the welding region 30 satisfies L1 / L ≥ 70%. Here, the maximum radial length L is the maximum radial length of the welding region 30, and the maximum radial length L in Figure 10 is the sum of the maximum radial lengths L1, L2, and L3.

[0153] When determining the maximum radial length of each part, the furthest and closest positions from the winding axis CL of each part of the welding area can be selected, and the difference in the shortest distance from the furthest and closest positions to the winding axis CL can be calculated, which is the maximum radial length of the corresponding part.

[0154] Since the welding area 30 includes the first portion 31 and may include other portions, L1 / L represents the occupancy ratio of the first portion 31 in the welding area 30. Because the first portion 31 is more easily able to obtain good welding quality, increasing this occupancy ratio is advantageous in improving the welding quality of the welding area 30. Therefore, by setting the ratio L1 / L to 70% or more, the welding quality of the welding area 30 can be improved, and the risk of burn-through of the tab or welding defects can be reduced.

[0155] Selectively, the ratio L1 / L of the maximum radial length L1 of the cylindrical wound structure of the first portion 31 to the maximum radial length L of the cylindrical wound structure of the weld area 30 satisfies L1 / L ≥ 90%, for example, L1 / L is equal to 90%, 95%, 98%, or 100%. By further limiting the ratio L1 / L to 90% or more, the weld quality of the weld area 30 can be further improved, effectively reducing the risk of tab burn-through or welding defects.

[0156] Referring to Figure 6, in some embodiments, the minimum distance d between the winding start end WS and the second tab 132 in the winding direction wd of the current collector substrate 11 satisfies d ≤ 1200 mm. The second tab 132 is defined as the tab among the plurality of tabs 13 that is welded to the conductive members 21, 22 and is closest to the winding start end WS. Here, the second tab 132 is located on the side of the first tab 131 that is away from the winding start end WS, and in other embodiments, the second tab 132 may be the first tab 131, i.e., the first tab of the polar sheet is welded to the conductive members 21, 22.

[0157] Here, the minimum distance d is difficult to measure when the polar sheet is wound up, so the value of the minimum distance d can be obtained by measuring the polar sheet in an unfolded state, and in this case the winding direction wd also corresponds to the direction in which the polar sheet is unfolded parallel to the length direction of the polar sheet together with it. The second tab 132 is not only welded to the conductive members 21 and 22, but is also closest to the winding start end WS, so the minimum distance d between it and the winding start end WS can indicate the range of the tab that is directly connected to the conductive members 21 and 22 via the welding area 30.

[0158] Charge on the polar sheet flows to the conductive member through the welding area of ​​multiple tabs and conductive member, and more charge flows to the second tab 132 of the polar sheet between the second tab 132 and the winding start end, thereby making the second tab 132 more susceptible to overcurrent. By setting the minimum distance d to 1200 mm or less, the range of tabs directly connected to the conductive members 21 and 22 via the welding area 30 can be increased, reducing the risk of overcurrent occurring in the second tab 132 and thereby avoiding, as much as possible, overheating of the tabs affecting the properties of the chemicals in the electrode assembly 10.

[0159] Selectively, the minimum distance d satisfies d ≤ 800 mm, for example, d is equal to 800 mm, 680 mm, 540 mm, 500 mm, etc. By further limiting the selectable range of the minimum distance d, the range of tabs directly connected to the conductive members 21, 22 via the welding area 30 can be further increased, further reducing the risk of overcurrent occurring in the first tab 131, thereby more effectively avoiding overheating of the tab affecting the properties of the chemicals in the electrode assembly 10.

[0160] Referring to Figure 7, in some embodiments, in the extending direction of the winding axis CL, the maximum value Hmax of the depth H of the welding region 30 and the thickness t of the conductive members 21 and 22 satisfy 1.5*t ≤ Hmax ≤ 1.9*t. When welding the conductive members 21 and 22 to the laminated tab, a weld pool is formed extending from the surface of the conductive members 21 and 22 toward one side of the tab, and based on factors such as the output and overlap thickness used during welding, the ratio between the depth of the welding region 30 (i.e., the weld pool) and the thickness of the conductive members 21 and 22 can satisfy a certain numerical range.

[0161] Here, the depth H of the welding region 30 can be measured relative to a surface of the conductive members 21 and 22 away from one side of the electrode assembly, and for a given location of the weld pool, the distance from the deepest point of the weld pool to the surface of the conductive member along the extending direction of the winding axis CL is the depth of the weld pool. The maximum value Hmax and minimum value Hmin of the depth of the welding region 30 are the maximum and minimum distances from the deepest point of each part of the entire welding region 30 to the surface of the conductive member along the extending direction of the winding axis CL.

[0162] If the ratio of the maximum depth Hmax of the welding area 30 to the thickness t of the conductive members 21 and 22 is too large, the risk of tab burn-through increases, and if the ratio is too small, the risk of welding defects in the tab increases. Therefore, by setting the ratio of the maximum depth Hmax of the welding area 30 to the thickness t of the conductive members 21 and 22 within a specific range, the risk of tab burn-through and welding defects can be reduced as much as possible.

[0163] Selectively, in the extending direction of the winding axis CL, the maximum value Hmax of the depth H of the welding region 30 and the thickness t of the conductive members 21 and 22 satisfy 1.6*t ≤ Hmax ≤ 1.8*t, for example, Hmax being 1.6*t, 1.65*t, 1.7*t, 1.8*t, etc. By further limiting the selectable range of the ratio between the maximum value Hmax of the depth of the welding region 30 and the thickness t of the conductive members 21 and 22, the risk of tab burn-through and welding defects can be effectively reduced.

[0164] In some embodiments, in the extending direction of the winding axis CL, the minimum value Hmin of the depth H of the welding region 30 and the thickness t of the conductive members 21 and 22 satisfy the condition 1.1*t ≤ Hmin ≤ 1.5*t. If the ratio of the minimum value Hmin of the depth of the welding region 30 to the thickness t of the conductive members 21 and 22 is too large, the risk of tab burn-through increases, and if the ratio is too small, the risk of welding defects in the tab increases. Therefore, by setting the ratio of the minimum value Hmin of the depth of the welding region 30 to the thickness t of the conductive members 21 and 22 within a specific range, the risk of tab burn-through and welding defects can be reduced as much as possible.

[0165] Selectively, in the extending direction of the winding axis CL, the minimum value Hmin of the depth H of the welding region 30 and the thickness t of the conductive members 21 and 22 satisfy 1.2*t ≤ Hmin ≤ 1.4*t, for example, Hmin being 1.2*t, 1.25*t, 1.3*t, 1.4*t, etc. By further limiting the selectable range of the ratio between the minimum value Hmin of the depth of the welding region 30 and the thickness t of the conductive members 21 and 22, the risk of tab burn-through and welding defects can be effectively reduced.

[0166] The difference between the maximum value Hmax and the minimum value Hmin of the depth H of the welding area 30 can represent the range of variation in the depth of the welding area 30. If the difference is too large, it indicates that the depth of the welding area 30 is large, which may increase the risk of localized burn-through or welding defects. If the difference is too small, it indicates that the depth of the welding area 30 is relatively uniform, but considering that there are differences in the thickness of the tab layer, the risk of localized burn-through or welding defects increases in areas where the layer thickness is thin or thick.

[0167] Therefore, in some embodiments, in the extending direction of the winding axis CL, the difference between the maximum value Hmax and the minimum value Hmin of the depth H of the welding region 30 (Hmax-Hmin) and the thickness t of the conductive members 21 and 22 satisfy 0.2*t ≤ (Hmax-Hmin) ≤ 0.8*t, which helps to reduce the risk of localized burn-through or welding defects of the tab.

[0168] Selectively, in the extending direction of the winding axis CL, the difference between the maximum value Hmax and the minimum value Hmin of the depth H of the welding region 30 (Hmax-Hmin) and the thickness t of the conductive members 21 and 22 satisfy 0.3*t ≤ (Hmax-Hmin) ≤ 0.6*t, for example, (Hmax-Hmin) being 0.3*t, 0.4*t, 0.5*t, 0.6*t, etc. By further limiting the selectable range of the ratio between the difference (Hmax-Hmin) and the thickness t, the risk of localized burn-through or welding defects of the tab can be further reduced.

[0169] Figure 11 is a schematic diagram of the overlap of adjacent tabs in different tab stacking regions in several embodiments based on the battery cell of the present disclosure. Figures 12 and 13 are schematic dimensional diagrams of different shapes of tab connections in the polar sheet in several embodiments based on the battery cell of the present disclosure, respectively. Referring to Figure 11, the curvature of the polar sheet winding ring at different radial positions of the winding structure 100 changes with the size of the radius, with the curvature of the polar sheet winding ring increasing as the radius decreases.

[0170] The aforementioned number of tab stacks is the number of tabs stacked that are connected to different polarity sheet winding rings. Considering the possibility of overlap between two or more adjacent tabs connected to the same polarity sheet winding ring, if the number of tab stacks in the second tab stacking region 130a is the same along the direction approaching the winding axis CL, the degree to which adjacent tabs overlap increases as the position approaches the winding axis. Therefore, the thickness of the tab stack increases along the direction approaching the winding axis in the second tab stacking region 130a.

[0171] In Figure 11, the radius of the polar sheet winding ring where the tab root of the first tab closest to the winding start end WS (i.e., the first tab 131) is located is r1, and the radius of the polar sheet winding ring where the tab root of the tab furthest from the winding start end WS is located is r2. Among the multiple tabs to which each polar sheet winding ring is connected, adjacent tabs may overlap after being folded inward. The greater the curvature of the polar sheet winding ring, the greater the overlap of adjacent tabs in the multiple tabs 13 to which it is connected, and correspondingly the thickness of the tab stack increases.

[0172] In Figures 12 and 13, the tab 13 may be bent at its base 13r, and the base 13r of the tab 13 may be the position where the tab 13 is cut in the current collector substrate. The width of the upper part 13t of the tab 13 is defined as w, and the spacing between the upper parts 13t of adjacent tabs is defined as e. Referring to Figures 12 and 13, in some embodiments, in the winding direction wd, the spacing e between the upper parts of adjacent tabs among the plurality of tabs 13 satisfies e ≤ 0.5 mm.

[0173] The larger the gap e at the top of adjacent tabs, the less or no overlap there will be after the adjacent tabs are folded inward. Conversely, the smaller the gap e at the top of adjacent tabs, the greater the overlap there will be after the adjacent tabs are folded inward. Therefore, by setting the gap e at the top of adjacent tabs to 0.5 mm or less, the degree of tab lamination can be increased, thereby obtaining a greater tab lamination thickness and reducing the risk of tab melt-off.

[0174] Selectively, in the winding direction wd, the spacing e between the tops of adjacent tabs among the plurality of tabs 13 satisfies e ≤ 0.2 mm, for example, values ​​that e can take are 0.2 mm, 0.18 mm, 0.12 mm, 0.06 mm, etc. By further limiting the spacing e between the tops of the tabs to 0.2 mm or less, the thickness of the tab stack can be effectively increased, and the risk of tab melt-off can be further reduced.

[0175] Considering that rectangular or parallelogram-shaped tabs can reduce the spacing between the tops of the tabs, this helps to improve the degree to which adjacent tabs overlap. Referring to Figures 12 and 13, in some embodiments, at least some of the plurality of tabs 13 have a rectangular or parallelogram shape, which can increase the thickness of the tab stack and reduce the risk of tab melt-off.

[0176] As the polar sheet winding layer approaches the winding axis CL, the curvature increases, and the overlap of the connected tabs increases, causing the thickness of the tab stack to gradually increase from the outside to the inside. This allows the welding output to also increase from the outside to the inside during welding, and therefore, in some embodiments, the depth of the first portion 31 in the direction extending from the winding axis CL increases in the direction approaching the winding axis CL. A welding region 30 in which the depth increases from the outside to the inside is advantageous for improving the welding quality of the welding region 30.

[0177] In embodiments where the welding region 30 further includes a second portion 32 located in the first tab stacking region 130a, considering that the number of stacked tabs in the first tab stacking region 130a is small, if there is no burn-through, the depth of the weld pool is relatively small, and the welding power used when welding the first tab stacking region 130a is lower than the welding power used when welding the second tab stacking region 130b. Therefore, in some embodiments, the depth of the first portion 31 in the direction of extension of the winding axis CL is smaller than the depth of the second portion 32, thereby improving the welding quality of the second portion 32 of the first tab stacking region 130a and reducing the risk of burn-through of the tabs.

[0178] Figure 14 is a schematic diagram of the dimensions of the bent tab and central hole in several embodiments based on the battery cell of the present disclosure. Referring to Figures 5, 9, 12, 13 and 14, in some embodiments the winding structure 100 is a cylindrical winding structure, and the cylindrical winding structure has a central hole 110. The minimum distance r1 between the winding axis CL and the tab root of the first tab 131 satisfies r1 ≥ h0 + 0.8 * R, where h0 is the height of the first tab 131 in the direction of extension of the winding axis CL in the unbent state, and R is the radius of the hole cross-section at the end of the winding structure 100 of the central hole 110.

[0179] In the winding direction wd, the first tab 131 is closest to the winding start end WS of the current collector substrate 11. When the first tab 131 is folded inward, it is more likely to cover part or more of the central hole 110 compared to a tab connected to a polar sheet winding ring with a larger radius. By making the minimum distance r1 greater than or equal to the sum of the height h0 of the first tab 131 and the radius R of the central hole 110 multiplied by 0.8, it is equivalent to ensuring that the radius range covering the central hole 110 after the first tab 131 closest to the winding axis CL is folded from the outside to the inside does not exceed 20%, thereby reducing the obstruction of the central hole 110 after the tab is folded, avoiding interference with electrolyte injection, and reducing the risk of the tab being inserted downward or rupturing during injection, causing a short circuit.

[0180] Selectively, the minimum distance r1 between the winding shaft CL and the tab root of the first tab 131 satisfies r1 ≥ h0 + R. The minimum distance r1 is greater than or equal to the sum of the height h0 of the first tab 131 and the radius R of the central hole 110, which corresponds to the first tab 131 closest to the winding shaft CL not covering the central hole 110 after being folded from the outside to the inside, thereby more effectively avoiding the tab blocking the central hole 110 and affecting the injection of the electrolyte.

[0181] Figure 15 is a schematic diagram of the height of the tabs in an unfolded state in another embodiment based on the battery cell of the present disclosure. Figure 16 is a schematic cross-sectional view of the multiple tab stacking regions after the tabs have been folded toward the central hole in Figure 15. Referring to Figures 15 and 16, in some embodiments, the multiple tabs 13 include a first tab group 13a and a second tab group 13b. The multiple polar sheet winding rings in which the first tab group 13a is located are located outside of at least one polar sheet winding ring in which the second tab group 13b is located.

[0182] In the extending direction of the winding axis CL, the minimum height h1 of the unbent first tab group 13a is greater than the maximum height h2 of the unbent second tab group 13b. By making the maximum height h2 of the second tab group 13b, which is located inside the first tab group 13a, smaller than the minimum height h1 of the first tab group 13a, the first tab 131 connected to the welding area 30 can be brought closer to the winding start end WS, which is advantageous in reducing the risk of overcurrent of the first tab 131, and the small tab height of the first tab group 13a reduces or avoids covering the central hole 110, effectively preventing the tab from blocking the central hole 110 and affecting the injection of the electrolyte.

[0183] Referring to Figures 15 and 16, the second tab group 13b includes the first tab 131, and in the direction of extension of the winding axis CL, the height h2 of the unbent second tab group 13b decreases toward the direction approaching the winding axis CL. In Figure 15, the tab height of the second tab group 13b gradually decreases toward the direction approaching the winding axis CL, thereby bringing the first tab 131 closer to the winding axis CL in Figure 16 and expanding the extent of the second tab stacking region 130b.

[0184] As the height of each tab in the first tab group 13a decreases from the outside to the inside, the second tab stacking region 130b can extend further toward the winding axis CL, thereby increasing the extent of the second tab stacking region 130b, which helps to increase the dimensions of the first portion 31 of the second tab stacking region 130b in the welding region 30, improving the welding quality of the welding region 30 and reducing the risk of tab burn-through or welding defects.

[0185] Based on each embodiment of the battery cell described herein, the Disclosure further provides embodiments of a battery using the embodiments of the battery cell. The battery comprises the battery cell of any of the embodiments described herein. A battery using the embodiments of the battery cell can obtain better safety in use.

[0186] One aspect of this disclosure provides a power consumption device including the battery. The power consumption device using the battery can achieve better safety in use.

[0187] While this disclosure has been described with reference to preferred embodiments, various improvements and substitutions of components with equivalents can be made without departing from the scope of this disclosure. In particular, each technical feature mentioned in each embodiment can be combined in any way, provided that there is no structural inconsistency. This disclosure is not limited to the specific embodiments disclosed herein and includes all technical solutions included in the claims.

Claims

1. A battery cell (40) comprising an electrode assembly (10), an outer case (4A), electrode terminals (42), and conductive members (21, 22), The electrode assembly (10) includes a plurality of polarity sheets (10a, 10b) and a separator member (10c) placed between adjacent polarity sheets (10a, 10b) with opposite polarities in the plurality of polarity sheets (10a, 10b), the plurality of polarity sheets (10a, 10b) and the separator member (10c) are wound along the winding direction (wd) and form a wound structure (100), and at least one of the plurality of polarity sheets (10a, 10b) is The current collector substrate (11) and a plurality of tabs (13) are connected to at least one side of the current collector substrate (11) extending along the winding direction (wd) and are spaced apart along the winding direction (wd), at least a portion of the plurality of tabs (13) are bent along a direction close to the winding axis (CL) of the winding structure (100), and a tab stacking structure (130) is formed at the end of the winding structure (100). The outer case (4A) has a cavity for housing the electrode assembly (10), The electrode terminal (42) is installed on the wall of the outer case (4A), and The conductive members (21, 22) are welded to the tab stacked structure (130) and electrically connected to the electrode terminals (42) to form a battery cell (40).

2. The battery cell (40) according to claim 1, wherein the tab stacking structure (130) includes a first tab stacking region (130a) and a second tab stacking region (130b) arranged from the outside to the inside along a direction approaching the winding axis (CL), the number of tabs in the first tab stacking region (130a) increases along a direction approaching the winding axis (CL), the number of tabs in the second tab stacking region (130b) is the same along a direction approaching the winding axis (CL), and at least a portion of the conductive members (21, 22) and the welding region (30) of the tab stacking structure (130) is located in the second tab stacking region (130b).

3. The battery cell (40) according to claim 2, wherein the welding region (30) includes a first portion (31) located in the second tab stacking region (130b) and a second portion (32) located in the first tab stacking region (130a).

4. The battery cell (40) according to claim 2 or 3, wherein the tab stacking structure (130) further includes a third tab stacking region (130c) located on the side of the second tab stacking region (130b) adjacent to the winding axis (CL), and the welding region (30) further includes a third portion (33) located in the third tab stacking region (130c).

5. The battery cell (40) according to any one of claims 2 to 4, wherein the ratio S1 / S of the area S1 of the first portion (31) to the area S of the welding region (30) satisfies S1 / S ≥ 70%.

6. The battery cell (40) according to claim 5, wherein the ratio S1 / S of the area S1 of the first portion (31) to the area S of the welding region (30) satisfies S1 / S ≥ 90%.

7. The winding structure (100) is a cylindrical winding structure, and the ratio L1 / L of the maximum radial length L1 of the cylindrical winding structure in the first portion (31) to the maximum radial length L of the cylindrical winding structure in the welding region (30) satisfies L1 / L ≥ 70%, as described in any one of claims 2 to 6.

8. The battery cell (40) according to claim 7, wherein the ratio L1 / L of the maximum radial length L1 in the radial direction of the cylindrical wound structure of the first portion (31) to the maximum radial length L in the radial direction of the cylindrical wound structure of the welded region (30) satisfies L1 / L ≥ 90%.

9. The minimum distance d between the winding start end (WS) and the second tab (132) in the winding direction (wd) of the current collector substrate (11) satisfies d ≤ 1200 mm. The battery cell (40) according to any one of claims 1 to 8, wherein the second tab (132) is defined as the tab among the plurality of tabs (13) that is welded to the conductive member (21, 22) and is closest to the winding start end (WS).

10. The battery cell (40) according to claim 9, wherein the minimum distance d satisfies d ≤ 800 mm.

11. In the extending direction of the winding axis (CL), the maximum value Hmax of the depth H of the welded region (30) between the conductive members (21, 22) and the tab laminated structure (130) and the thickness t of the conductive members (21, 22) satisfy 1.5 * t ≤ Hmax ≤ 1.9 * t, the battery cell (40) according to any one of claims 1 to 10.

12. In the extending direction of the winding axis (CL), the maximum value Hmax of the depth H of the welding region (30) and the thickness t of the conductive members (21, 22) satisfy 1.6 * t ≤ Hmax ≤ 1.8 * t, the battery cell (40) according to claim 11.

13. In the extending direction of the winding axis (CL), the minimum value Hmin of the depth H of the welded region (30) between the conductive members (21, 22) and the tab laminated structure (130) and the thickness t of the conductive members (21, 22) satisfy 1.1 * t ≤ Hmin ≤ 1.5 * t, as described in any one of claims 1 to 12, the battery cell (40).

14. In the extending direction of the winding axis (CL), the minimum value Hmin of the depth H of the welding region (30) and the thickness t of the conductive members (21, 22) satisfy 1.2 * t ≤ Hmin ≤ 1.4 * t, the battery cell (40) according to claim 13.

15. In the extending direction of the winding axis (CL), the difference between the maximum value Hmax and the minimum value Hmin of the depth H of the welded region (30) between the conductive members (21, 22) and the tab laminated structure (130) (Hmax - Hmin), and the thickness t of the conductive members (21, 22) satisfy 0.2 * t ≤ (Hmax - Hmin) ≤ 0.8 * t, as described in any one of claims 1 to 14.

16. In the extending direction of the winding axis (CL), the difference between the maximum value Hmax and the minimum value Hmin of the depth H of the welding region (30) (Hmax - Hmin) and the thickness t of the conductive members (21, 22) satisfy 0.3 * t ≤ (Hmax - Hmin) ≤ 0.6 * t, as described in claim 15, the battery cell (40).

17. In the winding direction (wd), the spacing e between the upper parts of adjacent tabs (13) satisfies e ≤ 0.5 mm, as described in any one of claims 1 to 16.

18. The battery cell (40) according to claim 17, wherein, in the winding direction (wd), the spacing e between the upper parts of adjacent tabs (13) satisfies e ≤ 0.2 mm.

19. The battery cell (40) according to any one of claims 1 to 18, wherein the welded region (30) of the conductive members (21, 22) and the tab stacked structure (130) includes a first portion (31) located in the second tab stacked region (130b), and in the direction of extension of the winding axis (CL), the depth of the first portion (31) increases toward the direction approaching the winding axis (CL).

20. The battery cell (40) according to any one of claims 1 to 19, wherein the conductive members (21, 22) and the welded region (30) of the tab stacking structure (130) include a first portion (31) located in the second tab stacking region (130b) and a second portion (32) located in the first tab stacking region (130a), and in the extending direction of the winding axis (CL), the depth of the first portion (31) is less than the depth of the second portion (32).

21. The battery cell (40) according to any one of claims 1 to 20, wherein at least some of the plurality of tabs (13) are rectangular or parallelograms.

22. The winding structure (100) is a cylindrical winding structure, the cylindrical winding structure has a central hole (110), and the minimum distance r1 between the winding axis (CL) and the base of the tab of the first tab (131) is Satisfying r1 ≥ h0 + 0.8 * R, The battery cell (40) according to any one of claims 1 to 21, wherein h0 is the height of the first tab in the direction of extension of the winding axis (CL) in an unfolded state, and R is the radius of the hole cross-section at the end of the winding structure (100) of the central hole (110).

23. The battery cell (40) according to claim 22, wherein the minimum distance r1 between the winding shaft (CL) and the base of the tab of the first tab (131) satisfies r1 ≥ h0 + R.

24. The battery cell (40) according to any one of claims 1 to 23, wherein the plurality of tabs (13) include a first tab group (13a) and a second tab group (13b), the plurality of polar sheet winding rings in which the first tab group (13a) is located are located outside of at least one polar sheet winding ring in which the second tab group (13b) is located, and in the direction of extension of the winding axis (CL), the minimum height h1 of the unbent first tab group (13a) is greater than the maximum height h2 of the unbent second tab group (13b).

25. The battery cell (40) according to claim 24, wherein the second tab group (13b) includes the first tab (131), and in the direction of extension of the winding axis (CL), the height h2 of the unbent second tab group (13b) decreases toward the direction approaching the winding axis (CL).

26. The battery cell (40) according to any one of claims 1 to 25, wherein the outer case (4A) includes a housing (41) and an end cover (42), one end of the housing (41) has an opening (411), the end cover (42) covers the opening (411), the housing (41) includes a side wall (414) and a bottom wall (413), the side wall (414) surrounds the outside of the electrode assembly (10), the bottom wall (413) is installed opposite the opening (411), and the wall portion of the outer case (4A) is the end cover (42) or the bottom wall (413).

27. A battery (50) comprising a battery cell (40) according to any one of claims 1 to 26.

28. A power consumption device including the battery (50) according to claim 27.

Images