Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrolyte and an electrode assembly, wherein the electrolyte and the electrode assembly are accommodated in the shell. The electrode assembly comprises a first pole piece, the first pole piece comprises a current collector and active substance layers, and the active substance layers are arranged on the two opposite surfaces of the current collector in the thickness direction of the current collector. The active material layer comprises a main body region and a thinned region which are arranged along the width direction of the first pole piece, the thickness of the main body region is greater than that of the thinned region, and at least one end of the main body region is connected with the thinned region along the width direction. Wherein in the thickness direction of the current collector, the thinning areas located on the two sides of the current collector are a first thinning area and a second thinning area respectively, the first pole piece is provided with at least one containing part, the at least one containing part penetrates through the first thinning area and the current collector, and a distance exists between the at least one containing part and the surface, away from the current collector, of the second thinning area. A part of the electrolyte is accommodated in the accommodating part. The reliability of the battery monomer is relatively high.

Description

Technical Field

[0001] This application relates to the field of batteries, and more specifically, to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Batteries are widely used in the new energy field, such as in electric vehicles and new energy vehicles, which have become a new trend in the automotive industry. The development of battery technology must consider multiple design factors simultaneously, such as energy density, discharge capacity, and charge / discharge rate. Furthermore, battery reliability also needs to be considered. However, current battery reliability is relatively poor. Utility Model Content

[0003] The purpose of this application is to provide a battery cell, a battery device, and an electrical device, which aims to improve the problem of poor battery reliability in related technologies.

[0004] In a first aspect, embodiments of this application provide a battery cell, the battery cell including a casing, an electrolyte, and an electrode assembly, wherein the electrolyte and the electrode assembly are housed within the casing, the electrode assembly including a first electrode, the first electrode including a current collector and an active material layer, the active material layer being disposed on two opposite surfaces of the current collector along the thickness direction of the current collector, the active material layer including a main body region and a thinned region arranged along the width direction of the first electrode, the thickness of the main body region being greater than the thickness of the thinned region, and at least one end of the main body region being connected to the thinned region along the width direction; wherein, along the thickness direction of the current collector, the thinned regions located on both sides of the current collector are respectively a first thinned region and a second thinned region, the first electrode having at least one receiving portion, at least one receiving portion penetrating the first thinned region and the current collector, and having a distance between it and the surface of the second thinned region facing away from the current collector, a portion of the electrolyte being housed within the receiving portion.

[0005] In the above technical solution, by providing at least one receiving portion on the first electrode, the receiving portion penetrates the first thinned region and the current collector, and is spaced apart from the surface of the second thinned region away from the current collector, a portion of the electrolyte is contained within the receiving portion. On one hand, after providing the receiving portion, the electrolyte can penetrate into the interior of the first and second thinned regions, reducing wetting time and improving wetting effect, thereby reducing the risk of lithium plating. On the other hand, the receiving portion provides an additional channel for lithium ion migration, which helps reduce the resistance to lithium ion diffusion, allowing lithium ions to move from the side with higher concentration to the side with lower concentration through the receiving portion, balancing the lithium ion concentration and reducing the risk of lithium plating. Furthermore, during the charge-discharge cycle of the battery cell, the active material layer expands and contracts. The receiving portion provides expansion space for the active material layer, which helps reduce the internal stress of the active material layer and reduces the risk of cracking and detachment. Moreover, after providing the receiving portion, both the surface and interior of the thinned region can participate in the reaction, making the reaction more uniform at various locations in the thinned region, which helps reduce the risk of lithium plating. In addition, after the housing is set, it can serve as a positioning mark during the manufacturing process, improving alignment accuracy, reducing production errors, and helping to improve the reliability of the battery cell.

[0006] As an optional technical solution in this application embodiment, at least one of the receiving portions penetrates the first thinning zone and the current collector along the thickness direction of the current collector and extends into the second thinning zone.

[0007] In the above technical solution, by extending at least one receiving portion through the first thinned region and the current collector along the thickness direction of the current collector and into the second thinned region, on the one hand, the electrolyte can more easily penetrate into the second thinned region, further reducing the wetting time and improving the wetting effect, thereby reducing the risk of lithium plating. On the other hand, it helps to further reduce the resistance to lithium-ion diffusion, which is beneficial for balancing the lithium-ion concentration and reducing the risk of lithium plating. Furthermore, during the charge-discharge cycle of a single battery cell, the active material layer expands and contracts. The receiving portion can provide expansion space for the expansion of the second thinned region, which helps to reduce the internal stress of the active material layer and reduce the risk of cracking and detachment of the active material layer. Moreover, after the receiving portion extends into the second thinned region, both the surface and interior of the second thinned region can participate in the reaction, making the reaction more uniform at various locations in the second thinned region, which is beneficial for reducing the risk of lithium plating.

[0008] As an optional technical solution in this application embodiment, the cross-sectional area of ​​the first thinning region is larger than the cross-sectional area of ​​the second thinning region, the cross-section is perpendicular to the extension direction of the first electrode and does not pass through the receiving portion; each receiving portion penetrates the first thinning region and the current collector, and has a distance between it and the surface of the second thinning region away from the current collector.

[0009] In the above technical solution, the cross-sectional area of ​​the first thinned region is larger than that of the second thinned region. Therefore, the mass of the active material in the first thinned region is greater than that in the second thinned region. By ensuring that each receiving portion penetrates both the first thinned region and the current collector, and maintains a distance from the surface of the second thinned region away from the current collector, the mass of active material reduced in the first thinned region due to the receiving portion is greater than the mass of active material reduced in the second thinned region due to the receiving portion. When the first electrode is a positive electrode, the amount of lithium ions provided by the first thinned region is reduced, which is beneficial for improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell. Furthermore, the amount of lithium ions provided by the second thinned region is still relatively large, which is beneficial for improving the energy density of the battery cell. When the first electrode is a negative electrode, both the first and second thinned regions have sufficient lithium intercalation space, which is beneficial for reducing the risk of lithium plating and improving the reliability of the battery cell.

[0010] As an optional technical solution in this application embodiment, along the thickness direction of the current collector, at least one end of the receiving portion extends to the surface of the first thinned area away from the current collector, and the other end extends to the surface of the current collector away from the first thinned area.

[0011] In the above technical solution, at least one receiving portion penetrates the first thinning region and the current collector, but does not extend into the second thinning region. When the first electrode is a positive electrode, the mass of the active material in the second thinning region is not reduced, which is beneficial for the battery cell to have a higher energy density. When the first electrode is a negative electrode, the mass of the active material in the second thinning region is not reduced, which is beneficial for maintaining sufficient lithium intercalation space, reducing the risk of lithium plating, and improving the reliability of the battery cell.

[0012] As an optional technical solution in this application embodiment, the first electrode is provided with a plurality of receiving portions, the plurality of receiving portions including a first receiving portion and a second receiving portion; the first receiving portion penetrates the first thinning area and the current collector, and has a distance between it and the surface of the second thinning area away from the current collector; the second receiving portion penetrates the second thinning area and the current collector, and has a distance between it and the surface of the first thinning area away from the current collector.

[0013] In the above technical solution, by setting up the first and second containment portions, on the one hand, the electrolyte can penetrate into the interior of the first and second thinned regions through the first and second containment portions, reducing the wetting time and improving the wetting effect, thereby reducing the risk of lithium plating. On the other hand, the first and second containment portions provide additional channels for lithium ion migration, which helps to reduce the resistance to lithium ion diffusion, allowing lithium ions to move from the side with higher concentration to the side with lower concentration through the first and second containment portions, balancing the lithium ion concentration and reducing the risk of lithium plating. Furthermore, during the charge-discharge cycle of the battery cell, the active material layer will expand and contract. The first and second containment portions provide expansion space for the active material layer, which helps to reduce the internal stress of the active material layer and reduce the risk of cracking and detachment of the active material layer. Moreover, after setting up the first and second containment portions, the surface and interior of the first and second thinned regions can all participate in the reaction, making the reaction more uniform at various locations in the first and second thinned regions, which helps to reduce the risk of lithium plating. In addition, by setting the first and second receiving parts, the first and second receiving parts can serve as positioning marks during the manufacturing process, thereby improving alignment accuracy, reducing production errors, and improving the reliability of the battery cells.

[0014] As an optional technical solution in this application embodiment, the cross-sectional area of ​​the first thinning region is greater than the cross-sectional area of ​​the second thinning region, the cross-section is perpendicular to the extension direction of the first electrode sheet and does not pass through the first receiving portion and the second receiving portion; the number of the first receiving portions is greater than the number of the second receiving portions.

[0015] In the above technical solution, the cross-sectional area of ​​the first thinning region is larger than that of the second thinning region. Therefore, the mass of the active material in the first thinning region is greater than that in the second thinning region. By making the number of first accommodating portions greater than the number of second accommodating portions, the mass of active material reduced in the first thinning region due to the presence of the first accommodating portions is greater than the mass of active material reduced in the second thinning region due to the presence of the second accommodating portions. When the first electrode is a positive electrode, the amount of lithium ions provided by the first thinning region is reduced, which is beneficial to improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell. Furthermore, the amount of lithium ions provided by the second thinning region is still relatively large, which is beneficial to improving the energy density of the battery cell. When the first electrode is a negative electrode, both the first and second thinning regions have sufficient lithium intercalation space, which is beneficial to reducing the risk of lithium plating and improving the reliability of the battery cell.

[0016] As an optional technical solution in this application embodiment, the receiving portion is completely located outside the main body area.

[0017] In the above technical solution, by making the housing completely outside the main body area, it is beneficial to reduce the impact of setting the housing on the capacity of the main body and to make the battery cell have a higher energy density.

[0018] As an optional technical solution in this application embodiment, one end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening; the area of ​​the opening is S, satisfying: 0.007 mm 2 ≤S≤0.785mm 2 .

[0019] In the above technical solution, when S≥0.007mm 2 When the opening area is relatively large, it facilitates the electrolyte to enter the containment and penetrate into the first and second thinning zones, reducing wetting time and improving wetting effect, thereby reducing the risk of lithium plating. On the other hand, during the charge-discharge cycle of a single battery cell, the active material layer expands and contracts. The larger opening provides ample space for the expansion of the active material layer, which helps reduce internal stress and lowers the risk of cracking and detachment. When S≤0.785mm 2 At this time, the opening area should not be too large. On the one hand, this helps to reduce the waste of capacity and allows the battery cell to have a higher energy density. On the other hand, it helps to maintain the structural strength of the first thinning zone and reduces the risk of active material shedding.

[0020] As an optional technical solution in this application embodiment, 0.067mm 2 ≤S≤0.2mm 2 .

[0021] In the above technical solution, when S≥0.067mm 2 When the opening area is larger, it facilitates the electrolyte entering the containment and penetrating the first and second thinning zones, further reducing wetting time, improving wetting effect, and further reducing the risk of lithium plating. On the other hand, during the charge-discharge cycle of a single battery cell, the active material layer expands and contracts. A larger opening provides more space for expansion, which helps reduce internal stress in the active material layer and lowers the risk of cracking and detachment. When S≤0.2mm 2 At this time, the opening area should not be too large. On the one hand, this helps to reduce the waste of capacity and allows the battery cell to have a higher energy density. On the other hand, it helps to maintain the structural strength of the first thinning zone and reduces the risk of active material shedding.

[0022] As an optional technical solution in this application embodiment, the first electrode is provided with a plurality of the receiving portions, and the plurality of receiving portions are spaced apart.

[0023] In the above technical solution, by setting multiple containment portions, on the one hand, the electrolyte can penetrate into the interior of the first and second thinning zones through these portions, reducing wetting time and improving wetting effect, thereby reducing the risk of lithium plating. On the other hand, multiple containment portions provide additional channels for lithium ion migration, which helps reduce the resistance to lithium ion diffusion, allowing lithium ions to move from the side with higher concentration to the side with lower concentration through the containment portions, balancing the lithium ion concentration and reducing the risk of lithium plating. Furthermore, during the charge-discharge cycle of a single battery cell, the active material layer expands and contracts. Multiple containment portions provide expansion space for the active material layer, which helps reduce the internal stress of the active material layer and reduces the risk of cracking and detachment. Moreover, with multiple containment portions, both the surface and interior of the thinning zone can participate in the reaction, making the reaction more uniform at various locations in the thinning zone, which helps reduce the risk of lithium plating.

[0024] As an optional technical solution in this application embodiment, one end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening; the number of openings per unit area on the surface of the first thinned area away from the current collector is P, satisfying: 10 openings / cm 2 ≤P≤100 pieces / cm 2 .

[0025] In the above technical solution, when P ≥ 10 pieces / cm 2 In this case, the number of openings per unit area on the surface of the first thinning zone away from the current collector is relatively large, meaning the density of the containment parts is high. The electrolyte can penetrate into the interior of both the first and second thinning zones through these multiple containment parts, reducing wetting time, improving wetting effect, and thus reducing the risk of lithium plating. When P ≤ 100 openings / cm² 2 At that time, the number of openings per unit area on the surface of the first thinning zone away from the current collector is not too large, that is, the density of the receiving part is not too large, which is conducive to making the effective conductive area of ​​the current collector larger and reducing the resistance.

[0026] As an optional technical solution in this application embodiment, 30 pieces / cm 2 ≤P≤50 pieces / cm 2 .

[0027] In the above technical solution, when P ≥ 30 pieces / cm 2In this case, the number of openings per unit area on the surface of the first thinning zone away from the current collector is greater, meaning the density of the containment portions is higher. The electrolyte can then penetrate into the interior of both the first and second thinning zones through these multiple containment portions, further reducing wetting time, improving wetting effect, and further reducing the risk of lithium plating. When P ≤ 50 openings / cm² 2 At that time, the number of openings per unit area on the surface of the first thinning zone away from the current collector is not too large, that is, the density of the receiving part is not too large, which is conducive to making the effective conductive area of ​​the current collector larger and reducing the resistance.

[0028] As an optional technical solution in this application embodiment, one end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening; the number of openings per unit area on the surface of the first thinned area away from the current collector is P, with the unit being openings / cm. 2 Along the thickness direction of the current collector, the thickness of the main body region is H, in μm, which satisfies: 0.03≤P / H≤0.34.

[0029] In the above technical solution, when the thickness of the main body region is large, the number of openings per unit area on the surface of the first thinned region away from the current collector can also be large. When P / H ≥ 0.03, the ratio of the number of openings per unit area on the surface of the first thinned region away from the current collector to the thickness of the main body region is large, allowing the electrolyte to penetrate into the interior of the first and second thinned regions through multiple containment parts, further reducing the wetting time, improving the wetting effect, and further reducing the risk of lithium plating. When P / H ≤ 0.34, the ratio of the number of openings per unit area on the surface of the first thinned region away from the current collector to the thickness of the main body region is not too large, which is beneficial for maintaining the structural strength of the current collector and the first thinned region, and helps to reduce the risk of active material shedding.

[0030] As an optional technical solution in this application embodiment, one end of the receiving portion extends to the surface of the first thinning area away from the current collector and forms an opening; in the projection plane perpendicular to the thickness direction of the current collector, the minimum distance between the orthographic projections of the hole walls of two adjacent openings is L, satisfying: 1mm≤L≤3mm.

[0031] In the above technical solution, when L≤3mm, the minimum distance between the orthogonal projections of the wall surfaces of two adjacent openings in the projection plane perpendicular to the thickness direction of the current collector is small. This helps to reduce the wetting time, improve the wetting effect, and reduce the risk of lithium plating. When L≥1mm, the minimum distance between the orthogonal projections of the wall surfaces of two adjacent openings in the projection plane perpendicular to the thickness direction of the current collector is not too small. On the one hand, this helps to reduce the waste of capacity and enable the battery cell to have a higher energy density. On the other hand, it helps to maintain the structural strength of the first thinning region and reduces the risk of active material shedding.

[0032] As an optional technical solution in this application embodiment, the electrode assembly includes a positive electrode sheet, and the positive electrode sheet is the first electrode sheet.

[0033] In the above technical solution, when the first electrode is a positive electrode, by setting up a receiving portion, the amount of lithium ions provided by the thinning area can be reduced, which is beneficial to improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell.

[0034] As an optional technical solution in this application embodiment, the electrode assembly includes a positive electrode and a negative electrode, both of which are first electrodes. Along the thickness direction of the current collector, the thinned areas of the positive electrode and the negative electrode are arranged opposite to each other. One end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening. The area of ​​the opening of the receiving portion of the positive electrode is S1, and the area of ​​the opening of the receiving portion of the negative electrode is S2, satisfying: 0.8≤S2 / S1≤0.9.

[0035] In the above technical solution, when S2 / S1≤0.9, the ratio of the area of ​​the opening in the receiving portion of the negative electrode to the area of ​​the opening in the receiving portion of the positive electrode is small, resulting in a larger remaining capacity of the negative electrode, which is beneficial for improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell. When S2 / S1≥0.8, the ratio of the area of ​​the opening in the receiving portion of the negative electrode to the area of ​​the opening in the receiving portion of the positive electrode is not too small, which helps to reduce the wetting time of the negative electrode, improve the wetting effect, and reduce the risk of lithium plating.

[0036] As an optional technical solution in this application embodiment, the electrode assembly includes a positive electrode and a negative electrode, both of which are first electrodes. Along the thickness direction of the current collector, the thinned areas of the positive electrode and the negative electrode are arranged opposite to each other. One end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening. In the positive electrode, the number of openings per unit area on the surface of the first thinned area away from the current collector is P1, and in the negative electrode, the number of openings per unit area on the surface of the first thinned area away from the current collector is P2, satisfying: 0.8≤P2 / P1≤0.9.

[0037] In the above technical solutions, when P2 / P1≤0.9, the remaining capacity of the negative electrode is relatively large, which is beneficial to improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell. When P2 / P1≥0.8, it is beneficial to reduce the wetting time of the negative electrode, improve the wetting effect, and reduce the risk of lithium plating.

[0038] As an optional technical solution in this application embodiment, the receiving portion is a channel disposed in the first electrode sheet.

[0039] In the above technical solution, by making the receiving portion a channel located on the first electrode, it is beneficial to simplify manufacturing and reduce manufacturing costs. Furthermore, during the processing and manufacturing process, the receiving portion can serve as a positioning mark, improving alignment accuracy, reducing production errors, and ultimately enhancing the reliability of the battery cell.

[0040] Secondly, embodiments of this application also provide a battery device, which includes the aforementioned battery cell.

[0041] Thirdly, embodiments of this application also provide an electrical device, which includes the aforementioned battery cell, and the battery cell is used to provide electrical energy to the electrical device. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0044] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0045] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0046] Figure 4 Exploded views of a single battery cell provided in some embodiments of this application;

[0047] Figure 5 This is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application;

[0048] Figure 6 A cross-sectional view of a first electrode provided for some embodiments of this application;

[0049] Figure 7 Cross-sectional view of the first electrode provided for other embodiments of this application;

[0050] Figure 8 Cross-sectional view of a first electrode provided for some embodiments of this application;

[0051] Figure 9 A cross-sectional view of the first electrode provided for some embodiments of this application;

[0052] Figure 10 This application also provides cross-sectional views of the first electrode sheet in some embodiments;

[0053] Figure 11 Cross-sectional view of a first electrode provided for further embodiments of this application;

[0054] Figure 12 This is a top view of the first electrode sheet after it has been unfolded, provided for some embodiments of this application;

[0055] Figure 13 Cross-sectional views of the positive electrode, separator, and negative electrode provided in some embodiments of this application;

[0056] Figure 14 Cross-sectional views of the positive electrode, separator, and negative electrode provided in other embodiments of this application.

[0057] Icons: 10-Box body; 11-First box body; 12-Second box body; 20-Battery cell; 21-Casing; 211-Shell; 212-End cap; 22-Electrode assembly; 221-Main body; 222-Taper; 223-Negative electrode; 224-Positive electrode; 225-Separator; 23-First electrode; 231-Current collector; 232-Active material layer; 2321-Main body area; 2322-Thinned area; 23221-First thinned area; 232211-First surface; 23222-Second thinned area; 232221-Second surface; 233-Receiving part; 2331-First receiving part; 2332-Second receiving part; 2333-Opening; 25-Electrode terminal; 27-Insulator; 100-Battery device; 200-Controller; 300-Motor; 1000-Vehicle. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0060] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0061] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0062] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0063] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0064] In this application, "multiple" means two or more (including two).

[0065] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0066] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0067] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0068] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0069] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0070] As an example, the positive electrode current collector can be a foil or a composite current collector. For example, as a foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0071] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials in battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05At least one of O2 and its modified compounds.

[0072] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0073] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0074] As an example, the negative electrode current collector can be a foil, a foamed metal, or a composite current collector. For example, as a foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, or titanium, etc. The foamed metal can be nickel foam, copper foam, aluminum foam, foam alloy, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0075] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0076] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0077] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0078] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0079] In some embodiments, the separator is a separator membrane. The separator membrane can be any known porous structure separator membrane with good chemical and mechanical stability.

[0080] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0081] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0082] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0083] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0084] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl 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, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0085] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0086] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0087] As an example, polymer solid electrolytes can be polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0088] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0089] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0090] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0091] In some implementations, the electrode assembly is a stacked structure.

[0092] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0093] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0094] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0095] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0096] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0097] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0098] In some implementations, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0099] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, or a composite metal (such as a copper-aluminum composite housing).

[0100] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a sealed structure, it can protect the electrode assembly and prevent, to some extent, electrolyte leakage. When the housing is a non-sealed structure, it can still protect the electrode assembly, and a sealing bag may be included between the housing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag can be a bag-shaped insulating material or an aluminum-plastic film.

[0101] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0102] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0103] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging multiple battery cells and fixing them together to form an independent module.

[0104] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0105] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cell assemblies housed within the housing.

[0106] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0107] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0108] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0109] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0110] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0111] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0112] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0113] The development of battery technology must consider multiple design factors simultaneously, such as energy density, discharge capacity, and charge / discharge rate. Additionally, battery reliability must also be considered. However, current battery reliability is relatively poor.

[0114] The production process of a battery cell involves a coating step, in which a slurry containing active materials is coated onto the current collector by a certain weight to form an active material layer. However, due to the natural fluidity of the slurry, thinning zones will form at the edges of the active material layer. During the cycling process of the battery cell, lithium plating is prone to occur in the thinned zones of the negative electrode, and lithium dendrites can easily pierce the separator and come into contact with the positive electrode, resulting in a short circuit and poor battery reliability.

[0115] Therefore, this application provides a battery cell comprising a casing, an electrolyte, and an electrode assembly, wherein the electrolyte and the electrode assembly are housed within the casing. The electrode assembly includes a first electrode, which includes a current collector and an active material layer. Along the thickness direction of the current collector, the active material layer is disposed on two opposite surfaces of the current collector. The active material layer includes a main body region and a thinned region arranged along the width direction of the first electrode, wherein the thickness of the main body region is greater than the thickness of the thinned region. Along the width direction, at least one end of the main body region is connected to the thinned region. Along the thickness direction of the current collector, the thinned regions located on either side of the current collector are respectively a first thinned region and a second thinned region. The first electrode has at least one receiving portion, which penetrates the first thinned region and the current collector, and is spaced apart from the surface of the second thinned region facing away from the current collector. A portion of the electrolyte is housed within the receiving portion.

[0116] By providing at least one containment portion on the first electrode, penetrating the first thinned region and the current collector, and maintaining a distance from the surface of the second thinned region away from the current collector, a portion of the electrolyte is contained within the containment portion. Firstly, the containment portion allows the electrolyte to penetrate into the interior of both the first and second thinned regions, reducing wetting time and improving wetting effect, thereby reducing the risk of lithium plating. Secondly, the containment portion provides an additional channel for lithium ion migration, reducing resistance to lithium ion diffusion and allowing lithium ions to move from the side with higher concentration to the side with lower concentration, thus balancing the lithium ion concentration and reducing the risk of lithium plating. Furthermore, during the charge-discharge cycle of the battery cell, the active material layer expands and contracts. The containment portion provides expansion space for the active material layer, reducing internal stress and the risk of cracking and detachment. Finally, the containment portion allows both the surface and interior of the thinned region to participate in the reaction, resulting in a more uniform reaction at various locations within the thinned region, further reducing the risk of lithium plating. In addition, after the housing is set, it can serve as a positioning mark during the manufacturing process, improving alignment accuracy, reducing production errors, and helping to improve the reliability of the battery cell.

[0117] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0118] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0119] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0120] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0121] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0122] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 10 and battery cells 20, the housing 10 being used to house the battery cells 20.

[0123] The housing 10 has an enclosed space inside for accommodating the battery cells 20. The housing 10 can have various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, which are interlocked. The first housing body 11 and the second housing body 12 can have various shapes, such as cuboids or cylinders. The first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can also be a hollow structure open on one side. The open side of the second housing body 12 interlocks with the open side of the first housing body 11, thus forming a housing 10 with an enclosed space. Alternatively, the first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can be a plate-like structure, with the second housing body 12 interlocked with the open side of the first housing body 11, thus forming a housing 10 with an accommodating chamber.

[0124] In the battery device 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel. Alternatively, multiple battery cells 20 can be first connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. Another option is that all battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the whole consisting of all battery cells 20 is housed within the housing 10.

[0125] In some embodiments, the battery device 100 may further include a busbar component, through which multiple battery cells 20 can be electrically connected to each other to achieve series, parallel, or mixed connection of the multiple battery cells 20. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0126] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 , Figure 3 This is a schematic diagram of the structure of a battery cell 20 provided in some embodiments of this application. Figure 4 An exploded view of a battery cell 20 provided in some embodiments of this application. Figure 5 This is a schematic diagram of the structure of the electrode assembly 22 provided in some embodiments of this application. Figure 6This is a cross-sectional view of a first electrode 23 provided in some embodiments of this application. Embodiments of this application provide a battery cell 20, which includes a casing 21, an electrolyte, and an electrode assembly 22, all housed within the casing 21. The electrode assembly 22 includes a first electrode 23, which includes a current collector 231 and an active material layer 232. Along the thickness direction of the current collector 231, the active material layer 232 is disposed on two opposite surfaces of the current collector 231. The active material layer 232 includes a main body region 2321 and a thinned region 2322 arranged along the width direction of the first electrode 23, with the thickness of the main body region 2321 being greater than the thickness of the thinned region 2322. Along the width direction, at least one end of the main body region 2321 is connected to the thinned region 2322. The thinned regions 2322 located on both sides of the current collector 231 along the thickness direction are respectively the first thinned region 23221 and the second thinned region 23222. The first electrode 23 is provided with at least one receiving portion 233, which penetrates the first thinning region 23221 and the current collector 231, and has a distance between it and the surface of the second thinning region 23222 away from the current collector 231. A portion of the electrolyte is contained in the receiving portion 233.

[0127] Battery cell 20 refers to the smallest unit that makes up battery device 100.

[0128] The housing 21 includes a housing 211 and an end cap 212. The housing 211 has a receiving space with an opening at one end for accommodating the electrode assembly 22. The end cap 212 is connected to the housing 211 and closes the opening.

[0129] End cap 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap 212 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 212 is not easily deformed under pressure and impact, giving battery cell 20 higher structural strength and improved reliability. The material of end cap 212 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. Battery cell 20 also includes an insulating member 27, which is disposed inside end cap 212. The insulating member 27 can be used to isolate the electrical connection components inside housing 211 from end cap 212 to reduce the risk of short circuit. For example, insulating member 27 can be plastic, rubber, etc.

[0130] The housing 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. An opening can be provided on the housing 211, and the end cap 212 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and the housing 211 can be integrated. Specifically, the end cap 212 and the housing 211 can form a common mating surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 211, the end cap 212 closes the housing 211. The housing 211 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 22. The material of the housing 211 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0131] In some embodiments, the housing 211 may have an opening at only one end, with one end cap 212 correspondingly provided. In other embodiments, the housing 211 may have openings at both ends, with two end caps 212 correspondingly provided, the two end caps 212 respectively closing the two opposite openings of the housing 211. Figure 3 and Figure 4 In the embodiment shown, the housing 211 has an opening at only one end, and an end cap 212 is provided accordingly.

[0132] Electrode terminals 25 may also be provided on the end cap 212 or the housing 211. These terminals are used for electrical connection to the tabs 222 of the electrode assembly 22 to input or output electrical energy from the battery cell 20. The electrode terminals 25 and tabs 222 can be directly connected, for example, by direct welding. Alternatively, they can be indirectly connected, for example, through a current collector. The current collector can be a metallic conductor, such as copper, iron, aluminum, steel, or aluminum alloy.

[0133] Electrode assembly 22 is the component in the battery cell 20 where electrochemical reactions occur. The housing 211 may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive electrode 224 and negative electrode 223, and typically a separator 225 is provided between the positive electrode 224 and the negative electrode 223. The portions of the positive electrode 224 and the negative electrode 223 containing active material constitute the main body 221 of the electrode assembly 22, while the portions of the positive electrode 224 and the negative electrode 223 without active material each constitute a tab 222. The positive and negative tabs may be located together at one end of the main body 221 or separately at both ends of the main body 221. During the charging and discharging process of the battery cell 20, the positive and negative active materials react with the electrolyte.

[0134] The electrode assembly 22 includes a positive electrode 224, a separator 225, and a negative electrode 223, which are wound or stacked. In other words, the electrode assembly 22 can be a wound electrode assembly or a stacked electrode assembly.

[0135] The electrolyte is the liquid electrolyte described above, which will not be repeated here.

[0136] The positive electrode 224 mentioned above can be the first electrode 23, or the negative electrode 223 mentioned above can be the first electrode 23, or both the positive electrode 224 and the negative electrode 223 mentioned above can be the first electrode 23.

[0137] When the aforementioned positive electrode 224 is the first electrode 23, the current collector 231 is the positive current collector, and the active material layer 232 is the positive active material layer, which includes the aforementioned positive active material. When the aforementioned negative electrode 223 is the first electrode 23, the current collector 231 is the negative current collector, and the active material layer 232 is the negative active material layer, which includes the aforementioned negative active material.

[0138] Please refer to Figure 6 The thickness direction of the current collector 231 is the X direction shown in the figure.

[0139] Along the thickness direction of the current collector 231, an active material layer 232 is provided on both opposite surfaces of the current collector 231, that is, both sides of the current collector 231 are coated with an active material layer 232.

[0140] For wound electrode assemblies, the width direction of the first electrode 23 is generally parallel to the winding axis of the electrode assembly 22. For stacked electrode assemblies, both the width and length directions of the first electrode 23 are perpendicular to the thickness direction of the current collector 231. The width of the first electrode 23 is smaller than its length. Generally, the tab 222 is located at one end of the width direction of the first electrode 23, and the width direction of the first electrode 23 can be determined based on the position of the tab 222. Please refer to... Figure 6 The width direction of the first electrode 23 is the Y direction as shown in the figure.

[0141] The active material layer 232 includes a main region 2321 and a thinned region 2322, which are arranged along the width direction of the first electrode 23.

[0142] The main body region 2321 is the main part of the active material layer 232, and it performs the main functions of the active material layer 232. The thinned region 2322 is the thinned portion of the active material layer 232 located at one end of the main body region 2321 along the width direction of the first electrode 23. "The thickness of the main body region 2321 is greater than the thickness of the thinned region 2322" means that the minimum thickness of the main body region 2321 is greater than the maximum thickness of the thinned region 2322, or in other words, the thickness of the main body region 2321 at any position is greater than the thickness of the thinned region 2322 at any position. In some embodiments, the thinned region 2322 is connected to only one end of the main body region 2321 along the width direction of the first electrode 23, that is, the thinned region 2322 is only disposed at one end of the main body region 2321 along the width direction of the first electrode 23. In some other embodiments, the main body region 2321 is connected to both ends of the first electrode 23 along the width direction of the first electrode 23, that is, the thinning region 2322 is disposed at both ends of the main body region 2321 along the width direction of the first electrode 23.

[0143] An active material layer 232 is provided on both opposite surfaces of the current collector 231, and each active material layer 232 includes at least one thinned region 2322. The first thinned region 23221 and the second thinned region 23222 are two thinned regions 2322 located on both sides of the thickness direction of the current collector 231, and the positions of the first thinned region 23221 and the second thinned region 23222 are corresponding.

[0144] The receiving portion 233 is a channel or tank disposed in the first electrode 23, and a portion of the electrolyte is contained within the receiving portion 233. The first electrode 23 may have one, two, three, or more receiving portions 233. In one or more receiving portions 233, at least one receiving portion 233 penetrates through the first thinned region 23221 and the current collector 231 along the thickness direction of the current collector 231, and has a distance between it and the surface of the second thinned region 23222 facing away from the current collector 231. In other words, at least one receiving portion 233 penetrates through the first thinned region 23221 and the current collector 231 along the thickness direction of the current collector 231, and this at least one receiving portion 233 may extend into the second thinned region 23222, but not penetrate through the second thinned region 23222, or it may not extend into the second thinned region 23222.

[0145] Please refer to Figure 6 The first thinning region 23221 has a first surface 232211, which connects the surface of the current collector 231 where the first thinning region 23221 is located and the surface of the main body region 2321 connected to the first thinning region 23221 that is away from the current collector 231. The first surface 232211 is the surface of the first thinning region 23221 that is away from the current collector 231. Similarly, the second thinning region 23222 has a second surface 232221, which connects the surface of the current collector 231 where the second thinning region 23222 is located and the surface of the main body region 2321 connected to the second thinning region 23221 that is away from the current collector 231. The second surface 232221 is the surface of the second thinning region 23222 that is away from the current collector 231.

[0146] "At least one receiving portion 233 penetrates the first thinned area 23221 and the current collector 231, and has a distance between it and the surface of the second thinned area 23222 away from the current collector 231" That is, at least one receiving portion 233 penetrates the first surface 232211 and the surface of the current collector 231 away from the first thinned area 23221, and has a distance between it and the second surface 232221.

[0147] By providing at least one receiving portion 233 on the first electrode 23, the receiving portion 233 penetrates the first thinned region 23221 and the current collector 231, and is spaced away from the surface of the second thinned region 23222 opposite to the current collector 231. A portion of the electrolyte is contained within the receiving portion 233. On the one hand, after providing the receiving portion 233, the electrolyte can penetrate into the interior of the first thinned region 23221 and the second thinned region 23222 through the receiving portion 233, reducing the wetting time and improving the wetting effect, thereby reducing the risk of lithium plating. On the other hand, the receiving portion 233 provides an additional channel for the migration of lithium ions, which helps to reduce the resistance to lithium ion diffusion, allowing lithium ions to move from the side with higher concentration to the side with lower concentration through the receiving portion 233, balancing the lithium ion concentration and reducing the risk of lithium plating. On the other hand, during the charge-discharge cycle of the battery cell 20, the active material layer 232 expands and contracts. The accommodating portion 233 provides expansion space for the active material layer 232, which helps reduce the internal stress of the active material layer 232 and reduces the risk of cracking and detachment. Furthermore, with the accommodating portion 233 provided, both the surface and interior of the thinned area 2322 can participate in the reaction, making the reaction more uniform at various locations in the thinned area 2322, which helps reduce the risk of lithium plating. Additionally, with the accommodating portion 233 provided, during the manufacturing process, the accommodating portion 233 can serve as a positioning mark, improving alignment accuracy, reducing production errors, and ultimately enhancing the reliability of the battery cell 20.

[0148] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 In some embodiments, along the thickness direction of the current collector 231, at least one receiving portion 233 penetrates the first thinning region 23221 and the current collector 231, and extends into the second thinning region 23222.

[0149] "Along the thickness direction of the current collector 231, at least one receiving portion 233 penetrates the first thinning region 23221 and the current collector 231, and extends into the second thinning region 23222." That is, at least one receiving portion 233 penetrates the first thinning region 23221 and the current collector 231 along the thickness direction of the current collector 231, and a portion of the receiving portion 233 is located within the second thinning region 23222. In other words, the receiving portion 233 has a first portion penetrating the first thinning region 23221, a second portion penetrating the current collector 231, and a third portion accommodated in the second thinning region 23222, with the second portion connecting the first portion and the third portion.

[0150] By extending at least one accommodating portion 233 along the thickness direction of the current collector 231 through the first thinned region 23221 and the current collector 231, and into the second thinned region 23222, the electrolyte can more easily penetrate into the second thinned region 23222, further reducing the wetting time and improving the wetting effect, thereby reducing the risk of lithium plating. On the other hand, it helps to further reduce the resistance to lithium-ion diffusion, which is beneficial for balancing the lithium-ion concentration and reducing the risk of lithium plating. Furthermore, during the charge-discharge cycle of the battery cell 20, the active material layer 232 expands and contracts. The accommodating portion 233 provides expansion space for the expansion of the second thinned region 23222, which helps to reduce the internal stress of the active material layer 232 and reduces the risk of cracking and detachment of the active material layer 232. Moreover, after the accommodating portion 233 extends into the second thinned region 23222, both the surface and interior of the second thinned region 23222 can participate in the reaction, making the reaction more uniform at various locations in the second thinned region 23222, which is beneficial for reducing the risk of lithium plating.

[0151] Please refer to Figure 7 , Figure 7 This is a cross-sectional view of the first electrode 23 provided in some other embodiments of this application. In some other embodiments, the cross-sectional area of ​​the first thinned region 23221 is larger than the cross-sectional area of ​​the second thinned region 23222, the cross-section is perpendicular to the extending direction of the first electrode 23, and does not pass through the receiving portion 233. Each receiving portion 233 penetrates the first thinned region 23221 and the current collector 231, and has a distance between it and the surface of the second thinned region 23222 facing away from the current collector 231.

[0152] The extension direction of the first electrode 23 is also the length direction of the first electrode 23. For a wound electrode assembly, the extension direction of the first electrode 23 is also the winding direction of the first electrode 23. For a stacked electrode assembly, both the width direction and the length direction of the first electrode 23 are perpendicular to the thickness direction of the current collector 231. The width direction of the first electrode 23 is smaller than the length direction of the first electrode 23.

[0153] The area of ​​the cross-section of the first thinned region 23221 is greater than the area of ​​the cross-section of the second thinned region 23222. This cross-section is perpendicular to the extension direction of the first electrode 23 and does not pass through the receiving portion 233. In other words, the area of ​​the cross-section of the first thinned region 23221 perpendicular to the extension direction of the first electrode 23 and not passing through the receiving portion 233 is greater than the area of ​​the second thinned region 23222 in the same cross-section. That is, the capacity of the first thinned region 23221 before the receiving portion 233 is installed is greater than the capacity of the second thinned region 23222 before the receiving portion 233 is installed. The capacity of the first thinned region 23221 after the receiving portion 233 is installed can be greater than, equal to, or less than the capacity of the second thinned region 23222 after the receiving portion 233 is installed. The above cross-section can be obtained using CT, and the areas of the first thinned region 23221 and the second thinned region 23222 in the cross-section can be calculated using software. Alternatively, for ease of calculation, a cross-section perpendicular to the extension direction of the first electrode 23 and passing through the receiving portion 233 can be selected for calculation. In the calculation, the cross-sectional area of ​​the remaining part of the first thinned region 23221 after the receiving portion 233 is provided and the cross-sectional area of ​​the portion of the receiving portion 233 located in the first thinned region 23221 are taken as the cross-sectional area of ​​the first thinned region 23221. The cross-sectional area of ​​the remaining part of the second thinned region 23222 after the receiving portion 233 is provided and the cross-sectional area of ​​the portion of the receiving portion 233 located in the second thinned region 23222 are taken as the cross-sectional area of ​​the second thinned region 23222.

[0154] The cross-sectional area of ​​the first thinned region 23221 is larger than that of the second thinned region 23222, so the mass of the active material in the first thinned region 23221 is greater than that in the second thinned region 23222. By making each receiving portion 233 penetrate the first thinned region 23221 and the current collector 231, and having a distance between it and the surface of the second thinned region 23222 away from the current collector 231, the mass of active material reduced in the first thinned region 23221 due to the setting of the receiving portion 233 is greater than the mass of active material reduced in the second thinned region 23222 due to the setting of the receiving portion 233. When the first electrode 23 is a positive electrode 224, the amount of lithium ions that the first thinned region 23221 can provide is reduced, which is beneficial to improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell 20. Furthermore, the amount of lithium ions that the second thinned region 23222 can provide is still relatively large, which is beneficial to improving the energy density of the battery cell 20. When the first electrode 23 is the negative electrode 223, both the first thinning region 23221 and the second thinning region 23222 have sufficient lithium intercalation space, which helps to reduce the risk of lithium plating and improve the reliability of the battery cell 20.

[0155] Please refer to Figure 8 , Figure 8This is a cross-sectional view of a first electrode 23 provided for some embodiments of this application. In some embodiments, along the thickness direction of the current collector 231, at least one end of a receiving portion 233 extends to the surface of the first thinned region 23221 away from the current collector 231, and the other end extends to the surface of the current collector 231 away from the first thinned region 23221.

[0156] "Along the thickness direction of the current collector 231, at least one end of the receiving portion 233 extends to the surface of the first thinned area 23221 away from the current collector 231, and the other end extends to the surface of the current collector 231 away from the first thinned area 23221." At least one end of the receiving portion 233 extends along the thickness direction of the current collector 231 to the first surface 232211, and the other end extends along the thickness direction of the current collector 231 to the surface of the current collector 231 away from the first thinned area 23221, so that the at least one receiving portion 233 only penetrates the first thinned area 23221 and the current collector 231, and does not extend into the second thinned area 23222.

[0157] At least one receiving portion 233 penetrates the first thinning region 23221 and the current collector 231, but does not extend into the second thinning region 23222. When the first electrode 23 is a positive electrode 224, the mass of the active material in the second thinning region 23222 is not reduced, which is beneficial for the battery cell 20 to have a higher energy density. When the first electrode 23 is a negative electrode 223, the mass of the active material in the second thinning region 23222 is not reduced, which is beneficial for maintaining sufficient lithium intercalation space, reducing the risk of lithium plating, and improving the reliability of the battery cell 20.

[0158] Please refer to Figure 9 and Figure 10 , Figure 9 A cross-sectional view of the first electrode 23 provided for some embodiments of this application. Figure 10 This application also provides a cross-sectional view of a first electrode 23 according to some embodiments. In some embodiments, the first electrode 23 is provided with a plurality of receiving portions 233, including a first receiving portion 2331 and a second receiving portion 2332. The first receiving portion 2331 extends through the first thinning region 23221 and the current collector 231, and is spaced apart from the surface of the second thinning region 23222 away from the current collector 231. The second receiving portion 2332 extends through the second thinning region 23222 and the current collector 231, and is spaced apart from the surface of the first thinning region 23221 away from the current collector 231.

[0159] The first electrode 23 may be provided with two, three, four, or more receiving portions 233.

[0160] The first receiving portion 2331 is a receiving portion 233 that penetrates the first thinned region 23221 and the current collector 231 and has a distance between it and the second surface 232221. The number of first receiving portions 2331 can be one, two, three, or more. Please refer to... Figure 9 In some embodiments, the first receiving portion 2331 penetrates the first thinning region 23221 and the current collector 231 and extends into the second thinning region 23222. Please refer to... Figure 10 In some other embodiments, one end of the first receiving portion 2331 extends to the surface of the first thinning region 23221 away from the current collector 231, and the other end extends to the surface of the current collector 231 away from the first thinning region 23221.

[0161] The second receiving portion 2332 is a receiving portion 233 that penetrates the second thinned region 23222 and the current collector 231 and has a distance between it and the first surface 232211. The number of second receiving portions 2332 can be one, two, three, or more. Please refer to... Figure 9 In some embodiments, the second receiving portion 2332 penetrates the second thinning region 23222 and the current collector 231 and extends into the first thinning region 23221. Please refer to... Figure 10 In other embodiments, one end of the second receiving portion 2332 extends to the surface of the second thinning region 23222 away from the current collector 231, and the other end extends to the surface of the current collector 231 away from the second thinning region 23222.

[0162] By providing the first accommodating portion 2331 and the second accommodating portion 2332, on the one hand, the electrolyte can penetrate into the interior of the first thinning region 23221 and the second thinning region 23222 through the first accommodating portion 2331 and the second accommodating portion 2332, reducing the wetting time and improving the wetting effect, thereby reducing the risk of lithium plating. On the other hand, the first accommodating portion 2331 and the second accommodating portion 2332 provide additional channels for lithium ion migration, which helps to reduce the resistance to lithium ion diffusion, allowing lithium ions to move from the side with higher concentration to the side with lower concentration through the first accommodating portion 2331 and the second accommodating portion 2332, balancing the lithium ion concentration and reducing the risk of lithium plating. Furthermore, during the charge-discharge cycle of the battery cell 20, the active material layer 232 will expand and contract. The first accommodating portion 2331 and the second accommodating portion 2332 provide expansion space for the expansion of the active material layer 232, which helps to reduce the internal stress of the active material layer 232 and reduces the risk of cracking and peeling of the active material layer 232. Furthermore, with the first receiving portion 2331 and the second receiving portion 2332 provided, the surface and interior of the first thinning region 23221 and the surface and interior of the second thinning region 23222 can all participate in the reaction, making the reaction more uniform at each position in the first thinning region 23221 and the second thinning region 23222, which helps to reduce the risk of lithium plating. In addition, with the first receiving portion 2331 and the second receiving portion 2332 provided, during the processing and manufacturing process, the first receiving portion 2331 and the second receiving portion 2332 can serve as positioning marks, improving alignment accuracy, reducing production errors, and helping to improve the reliability of the battery cell 20.

[0163] Please refer to Figure 11 , Figure 11 This is a cross-sectional view of a first electrode 23 provided in some other embodiments of this application. In some embodiments, the cross-sectional area of ​​the first thinned region 23221 is larger than the cross-sectional area of ​​the second thinned region 23222, and the cross-section is perpendicular to the extending direction of the first electrode 23 and does not pass through the first receiving portion 2331 and the second receiving portion 2332. The number of first receiving portions 2331 is greater than the number of second receiving portions 2332.

[0164] The area of ​​the cross-section of the first thinning region 23221 is greater than the area of ​​the cross-section of the second thinning region 23222. This cross-section is perpendicular to the extension direction of the first electrode 23 and does not pass through the first receiving portion 2331 or the second receiving portion 2332. In other words, the area of ​​the cross-section of the first thinning region 23221 perpendicular to the extension direction of the first electrode 23 and not passing through the first receiving portion 2331 or the second receiving portion 2332 is greater than the area of ​​the second thinning region 23222 in the same cross-section. That is, the capacity of the first thinning region 23221 before the first receiving portion 2331 and the second receiving portion 2332 are provided is greater than the capacity of the second thinning region 23222 before the first receiving portion 2331 and the second receiving portion 2332 are provided. The capacity of the first thinning region 23221 after the first receiving portion 2331 and the second receiving portion 2332 are provided can be greater than, equal to, or less than the capacity of the second thinning region 23222 after the first receiving portion 2331 and the second receiving portion 2332 are provided. The cross-section can be obtained by CT, and the area of ​​the first thinning region 23221 and the area of ​​the second thinning region 23222 in the cross-section can be calculated by software. Alternatively, for ease of calculation, a cross-section perpendicular to the extension direction of the first electrode 23 and passing through the first receiving portion 2331 and the second receiving portion 2332 can be selected for calculation. In the calculation, the cross-sectional area of ​​the remaining part of the first thinned region 23221 after the first receiving portion 2331 and the second receiving portion 2332 are provided, the cross-sectional area of ​​the portion of the first receiving portion 2331 located in the first thinned region 23221 and the cross-sectional area of ​​the portion of the second receiving portion 2332 located in the first thinned region 23221 are taken as the cross-sectional area of ​​the first thinned region 23221. The cross-sectional area of ​​the remaining part of the second thinned region 23222 after the first receiving portion 2331 and the second receiving portion 2332 are provided, the cross-sectional area of ​​the portion of the first receiving portion 2331 located in the second thinned region 23222 and the cross-sectional area of ​​the portion of the second receiving portion 2332 located in the second thinned region 23222 are taken as the cross-sectional area of ​​the second thinned region 23222.

[0165] If the cross-sectional area of ​​the first thinning region 23221 is greater than the cross-sectional area of ​​the second thinning region 23222, then the mass of the active material in the first thinning region 23221 is greater than the mass of the active material in the second thinning region 23222. By making the number of the first receiving portions 2331 greater than the number of the second receiving portions 2332, the mass of active material reduced in the first thinning region 23221 due to the setting of the first receiving portions 2331 is greater than the mass of active material reduced in the second thinning region 23222 due to the setting of the second receiving portions 2332. When the first electrode 23 is a positive electrode 224, the amount of lithium ions that the first thinning region 23221 can provide is reduced, which is beneficial to improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell 20. Furthermore, the amount of lithium ions that the second thinning region 23222 can provide is still relatively large, which is beneficial to improving the energy density of the battery cell 20. When the first electrode 23 is the negative electrode 223, both the first thinning region 23221 and the second thinning region 23222 have sufficient lithium intercalation space, which helps to reduce the risk of lithium plating and improve the reliability of the battery cell 20.

[0166] Please refer to Figure 11 In some embodiments, the receiving portion 233 is located entirely outside the main body region 2321.

[0167] "The receiving part 233 is completely outside the main body area 2321", meaning that the receiving part 233 does not pass through the main body area 2321.

[0168] By placing the housing 233 entirely outside the main body region 2321, it is beneficial to reduce the impact of the housing 233 on the capacity of the main body region 221 and to enable the battery cell 20 to have a higher energy density.

[0169] In some embodiments, one end of the receiving portion 233 extends to the surface of the first thinned region 23221 away from the current collector 231 and forms an opening 2333. The area of ​​the opening 2333 is S, satisfying: 0.007 mm 2 ≤S≤0.785mm 2 .

[0170] One end of the receiving portion 233 extends to the first surface 232211, and an opening 2333 is formed on the first surface 232211. S represents the area of ​​the opening 2333. For ease of calculation, the projected area of ​​the hole wall of the opening 2333 in the projection plane perpendicular to the thickness direction of the current collector 231 can be taken as S.

[0171] S can be 0.007mm 2 0.01mm 2 0.05mm 2 0.1mm 2 0.15mm 20.2mm 2 0.25mm 2 0.3mm 2 0.35mm 2 0.4mm 2 0.45mm 2 0.5mm 2 0.55mm 2 0.6mm 2 0.65mm 2 0.7mm 2 0.75mm 2 0.785mm 2 wait.

[0172] When S≥0.007mm 2 When the opening 2333 has a relatively large area, on the one hand, it facilitates the electrolyte to enter the receiving portion 233 through the opening 2333 and penetrate into the interior of the first thinning area 23221 and the second thinning area 23222, reducing the wetting time, improving the wetting effect, and thus reducing the risk of lithium plating. On the other hand, during the charge-discharge cycle of the battery cell 20, the active material layer 232 will expand and contract. The larger opening 2333 provides a larger expansion space for the active material layer 232, which helps to reduce the internal stress of the active material layer 232 and reduces the risk of cracking and detachment of the active material layer 232. When S≤0.785mm 2 At this time, the area of ​​the opening 2333 is not too large. On the one hand, this helps to reduce the waste of capacity and allows the battery cell 20 to have a higher energy density. On the other hand, it helps to maintain the structural strength of the first thinning region 23221 and reduces the risk of active material shedding.

[0173] Optionally, 0.067mm 2 ≤S≤0.2mm 2 .

[0174] S can be 0.067mm 2 0.07mm 2 0.08mm 2 0.09mm 2 0.1mm 2 0.11mm 2 0.12mm 2 0.13mm 2 0.14mm 2 0.15mm 2 0.16mm 2 0.17mm 2 0.18mm 2 0.19mm2 0.2mm 2 wait.

[0175] When S≥0.067mm 2 When the opening 2333 has a larger area, on the one hand, it facilitates the electrolyte to enter the receiving portion 233 through the opening 2333 and penetrate into the interior of the first thinning region 23221 and the second thinning region 23222, further reducing the wetting time, improving the wetting effect, and further reducing the risk of lithium plating. On the other hand, during the charge-discharge cycle of the battery cell 20, the active material layer 232 will expand and contract. The larger opening 2333 provides more expansion space for the active material layer 232, which helps to reduce the internal stress of the active material layer 232 and reduces the risk of cracking and detachment of the active material layer 232. When S≤0.2mm 2 At this time, the area of ​​the opening 2333 is not too large. On the one hand, this helps to reduce the waste of capacity and allows the battery cell 20 to have a higher energy density. On the other hand, it helps to maintain the structural strength of the first thinning region 23221 and reduces the risk of active material shedding.

[0176] Please refer to Figure 11 In some embodiments, the first electrode 23 is provided with a plurality of receiving portions 233, which are spaced apart.

[0177] By providing multiple containment portions 233, on the one hand, the electrolyte can penetrate into the interior of the first thinned region 23221 and the second thinned region 23222 through the multiple containment portions 233, reducing the wetting time and improving the wetting effect, thereby reducing the risk of lithium plating. On the other hand, the multiple containment portions 233 provide additional channels for lithium ion migration, which helps to reduce the resistance to lithium ion diffusion, allowing lithium ions to move from the side with higher concentration to the side with lower concentration through the containment portions 233, balancing the lithium ion concentration and reducing the risk of lithium plating. Furthermore, during the charge-discharge cycle of the battery cell 20, the active material layer 232 will expand and contract. The multiple containment portions 233 provide expansion space for the active material layer 232, which helps to reduce the internal stress of the active material layer 232 and reduce the risk of cracking and detachment of the active material layer 232. Moreover, with multiple containment portions 233, both the surface and interior of the thinned region 2322 can participate in the reaction, making the reaction more uniform at all locations in the thinned region 2322, which helps to reduce the risk of lithium plating.

[0178] In some embodiments, one end of the receiving portion 233 extends to the surface of the first thinned region 23221 opposite to the current collector 231 and forms an opening 2333. The number of openings 2333 per unit area on the surface of the first thinned region 23221 opposite to the current collector 231 is P, satisfying: 10 openings / cm.2 ≤P≤100 pieces / cm 2 .

[0179] P represents the number of openings 2333 per unit area on the surface of the first thinned region 23221 away from the current collector 231, that is, the density of the receiving portion 233.

[0180] P can be taken as: 10 units / cm 2 20 pieces / cm 2 30 pieces / cm 2 40 pieces / cm 2 50 pieces / cm 2 60 pieces / cm 2 70 pieces / cm 2 80 pieces / cm 2 90 pieces / cm 2 100 pieces / cm 2 wait.

[0181] When P ≥ 10 cells / cm 2 In this case, the number of openings 2333 per unit area on the surface of the first thinning region 23221 facing away from the current collector 231 is relatively large, that is, the density of the receiving parts 233 is relatively large. The electrolyte can penetrate into the interior of the first thinning region 23221 and the second thinning region 23222 through multiple receiving parts 233, reducing the wetting time, improving the wetting effect, and thus reducing the risk of lithium plating. When P ≤ 100 openings / cm² 2 At the same time, the number of openings 2333 per unit area on the surface of the first thinned region 23221 away from the current collector 231 will not be too large, that is, the density of the receiving part 233 will not be too large, which is conducive to making the effective conductive area of ​​the current collector 231 larger and to reducing the resistance.

[0182] Optionally, 30 pieces / cm 2 ≤P≤50 pieces / cm 2 .

[0183] P can be taken as: 30 pieces / cm 2 32 pieces / cm 2 35 pieces / cm 2 38 pieces / cm 2 40 pieces / cm 2 42 pieces / cm 2 45 pieces / cm 2 48 pieces / cm 2 50 pieces / cm 2 wait.

[0184] When P ≥ 30 cells / cm 2At this time, the number of openings 2333 per unit area on the surface of the first thinning region 23221 facing away from the current collector 231 is greater, that is, the density of the receiving portions 233 is greater. The electrolyte can penetrate into the interior of the first thinning region 23221 and the second thinning region 23222 through multiple receiving portions 233, further reducing the wetting time, improving the wetting effect, and further reducing the risk of lithium plating. When P≤50 openings / cm 2 At the same time, the number of openings 2333 per unit area on the surface of the first thinned region 23221 away from the current collector 231 will not be too large, that is, the density of the receiving part 233 will not be too large, which is conducive to making the effective conductive area of ​​the current collector 231 larger and to reducing the resistance.

[0185] In some embodiments, one end of the receiving portion 233 extends to the surface of the first thinned region 23221 opposite to the current collector 231 and forms an opening 2333. The number of openings 2333 per unit area on the surface of the first thinned region 23221 opposite to the current collector 231 is P, with the unit being openings / cm. 2 Along the thickness direction of the current collector 231, the thickness of the main body region 2321 is H, in μm, which satisfies: 0.03≤P / H≤0.34.

[0186] Please refer to Figure 11 H represents the thickness of the main body region 2321 along the thickness direction of the current collector 231. During measurement, multiple measurements can be taken and the average value can be used as H.

[0187] P / H represents the ratio of the number of openings 2333 per unit area on the surface of the first thinned region 23221 facing away from the current collector 231 to the thickness of the main region 2321 along the thickness direction of the current collector 231.

[0188] P / H can be set to: 0.03, 0.05, 0.08, 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, 0.32, 0.34, etc.

[0189] When the thickness of the main body region 2321 is large, the number of openings 2333 per unit area on the surface of the first thinned region 23221 facing away from the current collector 231 can also be large. When P / H ≥ 0.03, the ratio of the number of openings 2333 per unit area on the surface of the first thinned region 23221 facing away from the current collector 231 to the thickness of the main body region 2321 is large, allowing the electrolyte to penetrate into the interior of the first thinned region 23221 and the second thinned region 23222 through multiple containment portions 233, further reducing the wetting time, improving the wetting effect, and further reducing the risk of lithium plating. When P / H ≤ 0.34, the ratio of the number of openings 2333 per unit area on the surface of the first thinned region 23221 facing away from the current collector 231 to the thickness of the main body region 2321 is not too large, which is beneficial for maintaining the structural strength of the current collector 231 and the first thinned region 23221, and helps reduce the risk of active material shedding.

[0190] Please refer to Figure 12 , Figure 12 This is a top view of the first electrode 23 after unfolding, provided in some embodiments of this application. In some embodiments, one end of the receiving portion 233 extends to the surface of the first thinning region 23221 away from the current collector 231 and forms an opening 2333. In a projection plane perpendicular to the thickness direction of the current collector 231, the minimum distance between the orthographic projections of the hole walls of two adjacent openings 2333 is L, satisfying: 1mm≤L≤3mm.

[0191] L represents the minimum distance between the orthographic projections of the wall surfaces of two adjacent openings 2333 onto a projection plane perpendicular to the thickness direction of the current collector 231.

[0192] L can be 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, etc.

[0193] When L ≤ 3 mm, the minimum distance between the orthogonal projections of the wall surfaces of two adjacent openings 2333 in the projection plane perpendicular to the thickness direction of the current collector 231 is small, which helps to reduce the wetting time, improve the wetting effect, and reduce the risk of lithium plating. When L ≥ 1 mm, the minimum distance between the orthogonal projections of the wall surfaces of two adjacent openings 2333 in the projection plane perpendicular to the thickness direction of the current collector 231 is not too small. On the one hand, this helps to reduce the waste of capacity and allows the battery cell 20 to have a higher energy density. On the other hand, it helps to maintain the structural strength of the first thinning region 23221 and helps to reduce the risk of active material shedding.

[0194] In some embodiments, the electrode assembly 22 includes a positive electrode 224, which is a first electrode 23.

[0195] When the first electrode 23 is the positive electrode 224, by setting the receiving portion 233, the amount of lithium ions provided by the thinning region 2322 can be reduced, which is beneficial to improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell 20.

[0196] Please refer to Figure 13 , Figure 13 This is a cross-sectional view of the positive electrode 224, the separator 225, and the negative electrode 223 provided in some embodiments of this application. In some embodiments, the electrode assembly 22 includes a positive electrode 224 and a negative electrode 223, both of which are first electrodes 23. Along the thickness direction of the current collector 231, the thinned regions 2322 of the positive electrode 224 and the thinned regions 2322 of the negative electrode 223 are disposed opposite to each other. One end of the receiving portion 233 extends to the surface of the first thinned region 23221 away from the current collector 231 and forms an opening 2333. The area of ​​the opening 2333 of the receiving portion 233 of the positive electrode 224 is S1, and the area of ​​the opening 2333 of the receiving portion 233 of the negative electrode 223 is S2, satisfying: 0.8≤S2 / S1≤0.9.

[0197] The thinned regions 2322 of the positive electrode 224 and the negative electrode 223 are arranged opposite to each other along the thickness direction of the current collector 231. In a projection plane perpendicular to the thickness direction of the current collector 231, the orthogonal projection of the thinned region 2322 of the negative electrode 223 can cover the orthogonal projection of the thinned region 2322 of the positive electrode 224, which is beneficial to improving the CB value and reducing the risk of lithium plating.

[0198] S1 represents the area of ​​the opening 2333 of the receiving portion 233 of the positive electrode 224. For ease of calculation, the projected area of ​​the hole wall of the opening 2333 of the receiving portion 233 of the positive electrode 224 in the projection plane perpendicular to the thickness direction of the current collector 231 can be taken as S1.

[0199] S2 represents the area of ​​the opening 2333 of the receiving portion 233 of the negative electrode 223. For ease of calculation, the projected area of ​​the hole wall of the opening 2333 of the receiving portion 233 of the negative electrode 223 in the projection plane perpendicular to the thickness direction of the current collector 231 can be taken as S2.

[0200] S2 / S1 represents the ratio of the area of ​​the opening 2333 of the receiving portion 233 provided in the negative electrode plate 223 to the area of ​​the opening 2333 of the receiving portion 233 provided in the positive electrode plate 224.

[0201] S2 / S1 can take values ​​of: 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, etc.

[0202] When S2 / S1≤0.9, the ratio of the area of ​​the opening 2333 of the receiving portion 233 of the negative electrode 223 to the area of ​​the opening 2333 of the receiving portion 233 of the positive electrode 224 is small, resulting in a larger remaining capacity of the negative electrode 223. This is beneficial for improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell 20. When S2 / S1≥0.8, the ratio of the area of ​​the opening 2333 of the receiving portion 233 of the negative electrode 223 to the area of ​​the opening 2333 of the receiving portion 233 of the positive electrode 224 is not too small, which helps to reduce the wetting time of the negative electrode 223, improve the wetting effect, and reduce the risk of lithium plating.

[0203] Please refer to Figure 14 , Figure 14 This is a cross-sectional view of the positive electrode 224, the separator 225, and the negative electrode 223 provided in other embodiments of this application. The electrode assembly 22 includes a positive electrode 224 and a negative electrode 223, both of which are first electrodes 23. Along the thickness direction of the current collector 231, the thinned regions 2322 of the positive electrode 224 and the negative electrode 223 are disposed opposite to each other. One end of the receiving portion 233 extends to the surface of the first thinned region 23221 away from the current collector 231 and forms an opening 2333. In the positive electrode 224, the number of openings 2333 per unit area on the surface of the first thinned region 23221 away from the current collector 231 is P1, and in the negative electrode 223, the number of openings 2333 per unit area on the surface of the first thinned region 23221 away from the current collector 231 is P2, satisfying: 0.8≤P2 / P1≤0.9.

[0204] P1 represents the number of openings 2333 per unit area on the surface of the first thinned region 23221 away from the current collector 231 in the positive electrode 224. P2 represents the number of openings 2333 per unit area on the surface of the first thinned region 23221 away from the current collector 231 in the negative electrode 223.

[0205] P2 / P1 can take values ​​of: 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, etc.

[0206] When P2 / P1 ≤ 0.9, the remaining capacity of the negative electrode 223 is relatively large, which is beneficial to improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell 20. When P2 / P1 ≥ 0.8, it is beneficial to reduce the wetting time of the negative electrode 223, improve the wetting effect, and reduce the risk of lithium plating.

[0207] In some embodiments, the receiving portion 233 is a channel disposed in the first electrode 23.

[0208] The hole can be round, square, elliptical, etc.

[0209] When the channel is a round hole, the diameter of the channel can be 0.1~1mm. For example, the diameter of the channel can be: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc.

[0210] By making the receiving portion 233 a channel provided in the first electrode 23, it is beneficial to simplify manufacturing and reduce manufacturing costs. Furthermore, during the processing and manufacturing process, the receiving portion 233 can serve as a positioning mark, improving alignment accuracy, reducing production errors, and thus improving the reliability of the battery cell 20.

[0211] This application embodiment also provides a battery device 100, which includes the aforementioned battery cell 20.

[0212] This application embodiment also provides an electrical device, which includes the aforementioned battery cell 20, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0213] According to some embodiments of this application, please refer to Figures 3-14 .

[0214] This application provides a battery cell 20, which includes a casing 21, an electrolyte, and an electrode assembly 22, all housed within the casing 21. The electrode assembly 22 includes a first electrode 23, which comprises a current collector 231 and an active material layer 232. Along the thickness direction of the current collector 231, the active material layer 232 is disposed on two opposite surfaces of the current collector 231. The active material layer 232 includes a main region 2321 and a thinned region 2322 arranged along the width direction of the first electrode 23, with the thickness of the main region 2321 being greater than the thickness of the thinned region 2322. Along the width direction, at least one end of the main region 2321 is connected to the thinned region 2322. The thinned regions 2322 located on either side of the current collector 231 along the thickness direction are respectively the first thinned region 23221 and the second thinned region 23222. The first electrode 23 is provided with at least one receiving portion 233, which penetrates the first thinned region 23221 and the current collector 231, and is spaced apart from the surface of the second thinned region 23222 away from the current collector 231. A portion of the electrolyte is contained within the receiving portion 233. By providing at least one receiving portion 233 on the first electrode 23, penetrating the first thinned region 23221 and the current collector 231, and having a distance between the receiving portion 233 and the surface of the second thinned region 23222 away from the current collector 231, and containing a portion of the electrolyte, on the one hand, after providing the receiving portion 233, the electrolyte can penetrate into the interior of the first thinned region 23221 and the second thinned region 23222 through the receiving portion 233, reducing the wetting time, improving the wetting effect, and thus reducing the risk of lithium plating. On the other hand, the containment portion 233 provides an additional channel for lithium ion migration, which helps reduce the resistance to lithium ion diffusion, allowing lithium ions to move from the side with higher concentration to the side with lower concentration through the containment portion 233, thus balancing the lithium ion concentration and reducing the risk of lithium plating. Furthermore, during the charge-discharge cycle of the battery cell 20, the active material layer 232 expands and contracts. The containment portion 233 provides expansion space for the active material layer 232, which helps reduce the internal stress of the active material layer 232 and reduces the risk of cracking and detachment. Moreover, with the containment portion 233, both the surface and interior of the thinned area 2322 can participate in the reaction, making the reaction more uniform at all locations in the thinned area 2322, which helps reduce the risk of lithium plating. Additionally, with the containment portion 233, during the manufacturing process, the containment portion 233 can serve as a positioning mark, improving alignment accuracy, reducing production errors, and ultimately enhancing the reliability of the battery cell 20.

[0215] In some embodiments, at least one receiving portion 233 penetrates the first thinned region 23221 and the current collector 231 along the thickness direction of the current collector 231 and extends into the second thinned region 23222. By having at least one receiving portion 233 penetrate the first thinned region 23221 and the current collector 231 along the thickness direction of the current collector 231 and extend into the second thinned region 23222, on the one hand, the electrolyte can more easily penetrate into the second thinned region 23222, which can further reduce the wetting time and improve the wetting effect, thereby reducing the risk of lithium plating. On the other hand, it is beneficial to further reduce the resistance to lithium ion diffusion, which is beneficial to equalizing the lithium ion concentration and reducing the risk of lithium plating. Furthermore, during the charge and discharge cycle of the battery cell 20, the active material layer 232 will expand and contract. The receiving portion 233 can provide expansion space for the expansion of the second thinned region 23222, which is beneficial to reduce the internal stress of the active material layer 232 and reduce the risk of cracking and peeling of the active material layer 232. Furthermore, after the receiving portion 233 extends into the second thinning region 23222, both the surface and interior of the second thinning region 23222 can participate in the reaction, making the reaction at each position of the second thinning region 23222 more uniform, which is beneficial to reducing the risk of lithium plating.

[0216] The cross-sectional area of ​​the first thinned region 23221 is larger than that of the second thinned region 23222. The cross-section is perpendicular to the extending direction of the first electrode 23 and does not pass through the receiving portion 233. Each receiving portion 233 penetrates the first thinned region 23221 and the current collector 231, and has a distance between it and the surface of the second thinned region 23222 that is away from the current collector 231. The cross-sectional area of ​​the first thinned region 23221 is larger than that of the second thinned region 23222, so the mass of the active material in the first thinned region 23221 is greater than that in the second thinned region 23222. By making each receiving portion 233 penetrate the first thinned region 23221 and the current collector 231, and having a distance between it and the surface of the second thinned region 23222 away from the current collector 231, the mass of active material reduced in the first thinned region 23221 due to the setting of the receiving portion 233 is greater than the mass of active material reduced in the second thinned region 23222 due to the setting of the receiving portion 233. When the first electrode 23 is a positive electrode 224, the amount of lithium ions that the first thinned region 23221 can provide is reduced, which is beneficial to improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell 20. Furthermore, the amount of lithium ions that the second thinned region 23222 can provide is still relatively large, which is beneficial to improving the energy density of the battery cell 20. When the first electrode 23 is the negative electrode 223, both the first thinning region 23221 and the second thinning region 23222 have sufficient lithium intercalation space, which helps to reduce the risk of lithium plating and improve the reliability of the battery cell 20.

[0217] In other embodiments, along the thickness direction of the current collector 231, at least one end of a receiving portion 233 extends to the surface of the first thinned region 23221 opposite to the current collector 231, and the other end extends to the surface of the current collector 231 opposite to the first thinned region 23221. At least one receiving portion 233 penetrates both the first thinned region 23221 and the current collector 231, and does not extend into the second thinned region 23222. When the first electrode 23 is a positive electrode 224, the mass of the active material in the second thinned region 23222 is not reduced, which is beneficial for the battery cell 20 to have a higher energy density. When the first electrode 23 is a negative electrode 223, the mass of the active material in the second thinned region 23222 is not reduced, which is beneficial for maintaining sufficient lithium intercalation space, reducing the risk of lithium plating, and improving the reliability of the battery cell 20.

[0218] In some embodiments, the first electrode 23 is provided with a plurality of receiving portions 233, including a first receiving portion 2331 and a second receiving portion 2332. The first receiving portion 2331 penetrates through the first thinned region 23221 and the current collector 231, and is spaced apart from the surface of the second thinned region 23222 away from the current collector 231. The second receiving portion 2332 penetrates through the second thinned region 23222 and the current collector 231, and is spaced apart from the surface of the first thinned region 23221 away from the current collector 231. By providing the first receiving portion 2331 and the second receiving portion 2332, on the one hand, the electrolyte can penetrate into the interior of the first thinned region 23221 and the second thinned region 23222 through the first receiving portion 2331 and the second receiving portion 2332, reducing the wetting time, improving the wetting effect, and thus reducing the risk of lithium plating. On the other hand, the first and second accommodating portions 2331 and 2332 provide additional channels for lithium ion migration, which helps reduce the resistance to lithium ion diffusion. This allows lithium ions to move from the side with higher concentration to the side with lower concentration through the first and second accommodating portions 2331 and 2332, thus balancing the lithium ion concentration and reducing the risk of lithium plating. Furthermore, during the charge-discharge cycle of the battery cell 20, the active material layer 232 expands and contracts. The first and second accommodating portions 2331 and 2332 provide expansion space for the active material layer 232, which helps reduce the internal stress of the active material layer 232 and reduces the risk of cracking and detachment. Moreover, with the first and second accommodating portions 2331 and 2332 provided, the surface and interior of the first thinned region 23221 and the surface and interior of the second thinned region 23222 can all participate in the reaction, making the reaction more uniform at each location in the first and second thinned regions 23221 and 23222, which helps reduce the risk of lithium plating. In addition, after the first receiving part 2331 and the second receiving part 2332 are provided, the first receiving part 2331 and the second receiving part 2332 can be used as positioning marks during the processing and manufacturing process, which can improve the alignment accuracy, reduce production errors, and help improve the reliability of the battery cell 20.

[0219] The cross-sectional area of ​​the first thinning region 23221 is larger than the cross-sectional area of ​​the second thinning region 23222. The cross-section is perpendicular to the extension direction of the first electrode 23 and does not pass through the first receiving portion 2331 and the second receiving portion 2332. The number of first receiving portions 2331 is greater than the number of second receiving portions 2332. If the cross-sectional area of ​​the first thinning region 23221 is greater than the cross-sectional area of ​​the second thinning region 23222, then the mass of the active material in the first thinning region 23221 is greater than the mass of the active material in the second thinning region 23222. By making the number of the first receiving portions 2331 greater than the number of the second receiving portions 2332, the mass of active material reduced in the first thinning region 23221 due to the setting of the first receiving portions 2331 is greater than the mass of active material reduced in the second thinning region 23222 due to the setting of the second receiving portions 2332. When the first electrode 23 is a positive electrode 224, the amount of lithium ions that the first thinning region 23221 can provide is reduced, which is beneficial to improving the CB value, reducing the risk of lithium plating, and improving the reliability of the battery cell 20. Furthermore, the amount of lithium ions that the second thinning region 23222 can provide is still relatively large, which is beneficial to improving the energy density of the battery cell 20. When the first electrode 23 is the negative electrode 223, both the first thinning region 23221 and the second thinning region 23222 have sufficient lithium intercalation space, which helps to reduce the risk of lithium plating and improve the reliability of the battery cell 20.

[0220] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: shell; An electrolyte and an electrode assembly are housed within the housing. The electrode assembly includes a first electrode, which includes a current collector and an active material layer. Along the thickness direction of the current collector, the active material layer is disposed on two opposite surfaces of the current collector. The active material layer includes a main body region and a thinned region arranged along the width direction of the first electrode. The thickness of the main body region is greater than the thickness of the thinned region. Along the width direction, at least one end of the main body region is connected to the thinned region. Along the thickness direction of the current collector, the thinning areas located on both sides of the current collector are respectively the first thinning area and the second thinning area. The first electrode is provided with at least one receiving portion, at least one of the receiving portions penetrates the first thinning area and the current collector, and has a distance between it and the surface of the second thinning area away from the current collector. A portion of the electrolyte is contained in the receiving portion.

2. The battery cell according to claim 1, characterized in that, Along the thickness direction of the current collector, at least one of the receiving portions penetrates the first thinning zone and the current collector, and extends into the second thinning zone.

3. The battery cell according to claim 2, characterized in that, The cross-sectional area of ​​the first thinning region is larger than the cross-sectional area of ​​the second thinning region, and the cross-section is perpendicular to the extension direction of the first electrode and does not pass through the receiving portion; Each of the receiving portions extends through the first thinned area and the current collector, and has a distance between it and the surface of the second thinned area facing away from the current collector.

4. The battery cell according to claim 1, characterized in that, Along the thickness direction of the current collector, at least one end of the receiving portion extends to the surface of the first thinned area away from the current collector, and the other end extends to the surface of the current collector away from the first thinned area.

5. The battery cell according to claim 1, characterized in that, The first electrode is provided with a plurality of the aforementioned receiving portions, including a first receiving portion and a second receiving portion; The first receiving portion extends through the first thinned area and the current collector, and has a distance between it and the surface of the second thinned area facing away from the current collector; The second receiving portion extends through the second thinning zone and the current collector, and has a distance between it and the surface of the first thinning zone facing away from the current collector.

6. The battery cell according to claim 5, characterized in that, The cross-sectional area of ​​the first thinning region is larger than the cross-sectional area of ​​the second thinning region. The cross-section is perpendicular to the extension direction of the first electrode and does not pass through the first receiving portion and the second receiving portion. The number of the first accommodating parts is greater than the number of the second accommodating parts.

7. The battery cell according to any one of claims 1-6, characterized in that, The receiving portion is located entirely outside the main body area.

8. The battery cell according to any one of claims 1-6, characterized in that, One end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening; The area of ​​the opening is S, which satisfies: 0.007 mm² 2 ≤S≤0.785mm 2 .

9. The battery cell according to claim 8, characterized in that, 0.067mm 2 ≤S≤0.2mm 2 。 10. The battery cell according to any one of claims 1-6, characterized in that, The first electrode is provided with a plurality of receiving portions, which are spaced apart.

11. The battery cell according to claim 10, characterized in that, One end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening; The number of openings per unit area on the surface of the first thinning zone away from the current collector is P, satisfying: 10 openings / cm. 2 ≤P≤100 pieces / cm 2 .

12. The battery cell according to claim 11, characterized in that, 30 pieces / cm 2 ≤P≤50 pieces / cm 2 .

13. The battery cell according to claim 10, characterized in that, One end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening; The number of openings per unit area on the surface of the first thinning zone away from the current collector is P, with units of openings / cm. 2 Along the thickness direction of the current collector, the thickness of the main body region is H, in μm, which satisfies: 0.03≤P / H≤0.

34.

14. The battery cell according to claim 10, characterized in that, One end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening; In the projection plane perpendicular to the thickness direction of the current collector, the minimum distance between the orthographic projections of the hole walls of two adjacent openings is L, which satisfies: 1mm≤L≤3mm.

15. The battery cell according to any one of claims 1-6, characterized in that, The electrode assembly includes a positive electrode, which is the first electrode.

16. The battery cell according to any one of claims 1-6, characterized in that, The electrode assembly includes a positive electrode and a negative electrode, both of which are first electrodes. Along the thickness direction of the current collector, the thinned regions of the positive electrode and the negative electrode are arranged opposite to each other. One end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening; The area of ​​the opening in the receiving portion of the positive electrode is S1, and the area of ​​the opening in the receiving portion of the negative electrode is S2, satisfying: 0.8≤S2 / S1≤0.

9.

17. The battery cell according to any one of claims 1-6, characterized in that, The electrode assembly includes a positive electrode and a negative electrode, both of which are first electrodes. Along the thickness direction of the current collector, the thinned regions of the positive electrode and the negative electrode are arranged opposite to each other. One end of the receiving portion extends to the surface of the first thinned area away from the current collector and forms an opening; In the positive electrode sheet, the number of openings per unit area on the surface of the first thinned region away from the current collector is P1, and in the negative electrode sheet, the number of openings per unit area on the surface of the first thinned region away from the current collector is P2, satisfying: 0.8≤P2 / P1≤0.

9.

18. The battery cell according to any one of claims 1-6, characterized in that, The receiving portion is a channel disposed in the first electrode.

19. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-18.

20. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-18, the battery cell being used to provide electrical energy to the electrical device.

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