Battery cell, battery device and electric device

Abstract

Provided in the embodiments of the present application are a battery cell, a battery device and an electric device. The battery cell comprises a casing, a first electrode terminal, an electrode assembly and a first adapter. The casing has a first wall; the first electrode terminal is disposed on the first wall; the electrode assembly is disposed inside the casing and has a first tab; and the first adapter comprises a first connecting portion, a second connecting portion and a bent portion, the first connecting portion being electrically connected to the first electrode terminal, the second connecting portion being electrically connected to the first tab, the bent portion connecting the first connecting portion and the second connecting portion, and on the same projection plane perpendicular to the direction of thickness of the first wall, the orthographic projection of the first connecting portion at least partially overlapping with the orthographic projection of the second connecting portion. The bent portion comprises at least two first conductive layers arranged in a stacked manner. The technical solution provided in the present application can improve the reliability of the battery cell.

Description

Battery cells, battery packs and electrical devices Technical Field

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

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In the manufacturing process of battery devices, the reliability of the battery device is a crucial issue. Therefore, improving the reliability of battery devices is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] This application provides a battery cell, a battery device, and an electrical device that can improve the reliability of the battery cell.

[0005] This application is achieved through the following technical solution:

[0006] In a first aspect, embodiments of this application provide a battery cell, which includes a housing, a first electrode terminal, an electrode assembly, and a first adapter. The housing has a first wall; the first electrode terminal is disposed on the first wall; the electrode assembly is disposed within the housing and has a first tab; the first adapter includes a first connecting portion, a second connecting portion, and a bending portion. The first connecting portion is electrically connected to the first electrode terminal, the second connecting portion is electrically connected to the first tab, and the bending portion connects the first connecting portion and the second connecting portion. On the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first connecting portion and the orthographic projection of the second connecting portion at least partially overlap. The bending portion includes at least two stacked first conductive layers.

[0007] According to embodiments of this application, in a battery cell, the first adapter is a bent structure, and the first connecting portion and the second connecting portion are connected through the bent portion. The orthographic projections of the first connecting portion and the second connecting portion at least partially overlap. When the battery cell is subjected to vibration, the first adapter can absorb the force generated by the movement of the electrode assembly. Furthermore, the bent portion includes at least two stacked conductive layers, forming a buffer structure between the first electrode terminal and the first tab. This facilitates bending of the first adapter and allows it to absorb the force generated by the movement of the electrode assembly, dispersing the stress at the bent portion of the first tab and reducing the risk of fatigue cracking of the first tab, thus giving the battery cell higher reliability. According to some embodiments of this application, at least one first conductive layer is provided with a weakening portion.

[0008] In the above scheme, the weakening part is provided on at least one first conductive layer, which can reduce the overall strength of the bending part. The bending difficulty of the first adapter is low, which makes it easy for the bending part to bend relative to the first connecting part and the second connecting part, and the processing and manufacturing difficulty is low.

[0009] According to some embodiments of this application, the weakened portion includes at least one of a through hole, a groove, and a notch.

[0010] In the above scheme, through holes, grooves and engravings are all relatively easy to process, making them convenient to manufacture and reducing manufacturing costs.

[0011] According to some embodiments of this application, the weakening portion is disposed on the inner side of the bending portion.

[0012] In the above scheme, the weakened part is located inside the bending part, which facilitates the bending of the first adapter.

[0013] According to some embodiments of this application, in the unfolded state of the first adapter, the first connecting portion, the bent portion, and the second connecting portion are sequentially distributed along the length direction of the first adapter; the length direction of the weakened portion is parallel to the width direction of the first adapter.

[0014] In the above scheme, the length direction of the weakened part is parallel to the width direction of the first adapter, and the weakened part has a large size in the width direction of the first adapter, which further reduces the strength of the bending part and facilitates the bending part to bend relative to the first connecting part and the second connecting part.

[0015] According to some embodiments of this application, there are multiple weakened portions, which are spaced apart along the width direction of the first adapter.

[0016] In the above solution, multiple weakening parts are spaced apart along the width direction of the first adapter. On the one hand, this can reduce the strength of the bending part in the width direction of the first adapter, making it easier to reduce the bending difficulty of the first adapter. On the other hand, it can increase the heat dissipation area of ​​the bending part, so that the bending part has a better heat dissipation effect.

[0017] According to some embodiments of this application, the bending portion has a first end face and a second end face disposed opposite to each other along the width direction of the first adapter, and a plurality of weakening portions including a first weakening portion and a second weakening portion, one end of the first weakening portion extending to the first end face and one end of the second weakening portion extending to the second end face.

[0018] In the above scheme, one end of the first weakening part extends to the first end face, and one end of the second weakening part extends to the second end face, so that the first weakening part and the second weakening part can be manufactured from the end of the first adapter in the width direction of the first adapter, and the manufacturing difficulty is low.

[0019] According to some embodiments of this application, the second connection portion includes multiple layers of second conductive layers stacked together, with the first electrode tab sandwiched between the multiple layers of second conductive layers.

[0020] In the above scheme, the multilayer second conductive layer clamps the first electrode tab to facilitate the welding connection between the multilayer second conductive layer and the first electrode tab, and to facilitate the assembly of the first adapter and the first electrode tab.

[0021] According to some embodiments of this application, the number of layers in the first conductive layer is less than or equal to the number of layers in the second conductive layer.

[0022] In the above scheme, when the number of layers of the first conductive layer is less than the number of layers of the second conductive layer, the bending part has lower strength, which is conducive to bending the bending part; when the number of layers of the first conductive layer is equal to the number of layers of the second conductive layer, the bending part can have higher current carrying capacity, which is conducive to the flow of current on the first adapter.

[0023] According to some embodiments of this application, each first conductive layer is integrally formed with a second conductive layer.

[0024] In the above scheme, the first conductive layer and the second conductive layer are integrally formed, the first conductive layer and the second conductive layer are firmly connected, and it is easy to process and manufacture.

[0025] According to some embodiments of this application, the thickness of the second conductive layer is equal to the thickness of the first conductive layer.

[0026] In the above scheme, the thickness of the second conductive layer is equal to the thickness of the first conductive layer, which facilitates processing and manufacturing.

[0027] According to some embodiments of this application, the first electrode includes a plurality of first sub-electrodes stacked together, with the plurality of first sub-electrodes sandwiched between two adjacent second conductive layers.

[0028] In the above scheme, multiple first sub-tabs are stacked to enable the first tabs to have a high current carrying capacity; multiple first sub-tabs are sandwiched between two adjacent second conductive layers to facilitate the connection between the first tabs and the second connection part, thereby improving the connection reliability between the first tabs and the first adapter.

[0029] According to some embodiments of this application, the number of layers of the second conductive layer on both sides of the first electrode tab of the second connection portion is equal.

[0030] In the above scheme, the number of layers of the second conductive layer on both sides of the first electrode tab of the second connection part is equal, which can improve the welding quality of the multi-layer second conductive layer and the first electrode tab, so that the second connection part and the first electrode tab are firmly connected.

[0031] According to some embodiments of this application, the first connection portion includes at least two stacked third conductive layers.

[0032] In the above scheme, the third conductive layer has a multi-layer structure, and each first conductive layer can be connected to a third conductive layer, which facilitates the connection between the first connecting part and the bending part.

[0033] According to some embodiments of this application, the number of layers in the first conductive layer is less than or equal to the number of layers in the third conductive layer.

[0034] In the above scheme, when the number of layers of the first conductive layer is less than the number of layers of the third conductive layer, the bending part has lower strength, which is beneficial for bending the bending part; when the number of layers of the first conductive layer is equal to the number of layers of the third conductive layer, the bending part can have higher current carrying capacity, which is convenient for current to flow on the first adapter.

[0035] According to some embodiments of this application, each first conductive layer and each third conductive layer are integrally formed.

[0036] In the above scheme, the first conductive layer and the third conductive layer are integrally formed, the first conductive layer and the third conductive layer are firmly connected, and it is easy to process and manufacture.

[0037] According to some embodiments of this application, the thickness of the third conductive layer is equal to the thickness of the first conductive layer.

[0038] In the above scheme, the thickness of the third conductive layer is equal to the thickness of the first conductive layer, which facilitates processing and manufacturing.

[0039] According to some embodiments of this application, the first connecting part is a single-layer structure.

[0040] In the above scheme, the first connection part is a single-layer structure, which is simple and facilitates the flow of current.

[0041] According to some embodiments of this application, the thickness of each first conductive layer is greater than or equal to 0.05 mm and less than or equal to 0.25 mm.

[0042] In the above scheme, the thickness of each first conductive layer satisfies the above relationship (greater than or equal to 0.05mm and less than or equal to 0.25mm). On the one hand, the processing and manufacturing difficulty is low, and it is easy to process and manufacture. On the other hand, the bending difficulty of the bending part is low, and it is easy to bend the first adapter.

[0043] According to some embodiments of this application, the thickness of each first conductive layer is greater than or equal to 0.1 mm and less than or equal to 0.2 mm.

[0044] In the above scheme, when the thickness of each first conductive layer is greater than or equal to 0.1 mm, the first conductive layer has a relatively thick thickness, which further reduces the difficulty of processing and manufacturing; when the thickness of each first conductive layer is less than or equal to 0.2 mm, the first conductive layer has a lower strength, which further reduces the bending difficulty of the bending part.

[0045] According to some embodiments of this application, the first adapter is made of copper, and the maximum thickness of the bent portion is greater than or equal to 0.4 mm and less than or equal to 1.5 mm. mm .

[0046] In the above scheme, the first adapter is made of copper, which has good conductivity. The maximum thickness of the bent part satisfies the above relationship (greater than or equal to 0.4 mm and less than or equal to 1.5 mm). On the one hand, the bent part has a large current flow area and the first adapter has a high current flow capacity. On the other hand, the bent part has low strength, which makes it easy to bend the bent part.

[0047] According to some embodiments of this application, the maximum thickness of the bent portion is greater than or equal to 0.6 mm and less than or equal to 1.2 mm.

[0048] In the above scheme, when the maximum thickness of the bending part is greater than or equal to 0.6 mm, the bending part has a large flow area, which further improves the flow capacity of the first adapter; when the maximum thickness of the bending part is less than or equal to 1.2 mm, the strength of the bending part is low, which further reduces the bending difficulty of the bending part.

[0049] According to some embodiments of this application, the first adapter is made of aluminum, and the maximum thickness of the bent portion is greater than or equal to 0.4 mm and less than or equal to 1.8 mm.

[0050] In the above scheme, the first adapter is made of aluminum, which has low cost and low density, and aluminum has good processing performance; the maximum thickness of the bending part meets the above relationship (greater than or equal to 0.4 mm and less than or equal to 1.8 mm). On the one hand, the bending part has a large flow area, and the first adapter can have a high flow capacity. On the other hand, the bending part has low strength, which makes it easy to bend the bending part.

[0051] According to some embodiments of this application, the maximum thickness of the bent portion is greater than or equal to 0.7 mm and less than or equal to 1.5 mm.

[0052] In the above scheme, when the maximum thickness of the bending part is greater than or equal to 0.7mm, the bending part has a larger flow area, which further improves the flow capacity of the first adapter; when the maximum thickness of the bending part is less than or equal to 1.5mm, the strength of the bending part is lower, which further reduces the bending difficulty of the bending part.

[0053] According to some embodiments of this application, the number of first conductive layers is greater than or equal to 10 and less than or equal to 12; the thickness of each first conductive layer is greater than or equal to 0.05 mm and less than or equal to 0.15 mm.

[0054] In the above scheme, the number of first conductive layers and the thickness of each first conductive layer satisfy the above relationship. On the one hand, it is convenient to process and manufacture the first conductive layer. On the other hand, the bending difficulty of the bending part is low, which is convenient for bending the first adapter.

[0055] According to some embodiments of this application, the minimum cross-sectional area of ​​the bent portion is H1, and the minimum cross-sectional area of ​​the first connecting portion is H2, satisfying 0.1*H2≤H1≤0.5*H2.

[0056] In the above scheme, the minimum cross-sectional area of ​​the bending part and the minimum cross-sectional area of ​​the first connecting part satisfy the above relationship (0.1*H2≤H1≤0.5*H2). On the one hand, it can reduce the bending difficulty of the first adapter, and on the other hand, the bending part has a high flow capacity.

[0057] According to some embodiments of this application, 0.2*H2≤H1≤0.4*H2.

[0058] In the above scheme, when H1≥0.2*H2, the cross-sectional area of ​​the bending part is larger, which further improves the flow capacity of the bending part; when H1≤0.4*H2, the strength of the bending part is lower, which further reduces the bending difficulty of the bending part.

[0059] According to some embodiments of this application, the first adapter includes a plurality of conductive sheets stacked together. Each conductive sheet includes an integrally formed first conductive layer, a second conductive layer and a third conductive layer. Multiple layers of the first conductive layer form a bending portion, multiple layers of the second conductive layer form a second connecting portion, and multiple layers of the third conductive layer form a first connecting portion.

[0060] In the above scheme, the first adapter has a multi-layer structure, with the first conductive layer, the second conductive layer and the third conductive layer integrally formed, which is convenient for processing and manufacturing, and the first conductive layer is firmly connected to the second conductive layer and the third conductive layer.

[0061] According to some embodiments of this application, the thickness of each conductive sheet in the plurality of conductive sheets is equal.

[0062] In the above scheme, the thickness of each conductive sheet in the multiple conductive sheets is equal, which facilitates mass production and reduces processing costs.

[0063] According to some embodiments of this application, adjacent conductive sheets in a plurality of conductive sheets are welded or connected by conductive adhesive.

[0064] In the above scheme, adjacent conductive sheets are welded or connected by conductive adhesive to facilitate electrical connection between the multiple conductive sheets, thereby giving the first adapter a high current carrying capacity.

[0065] According to some embodiments of this application, the housing includes a shell and an end cap, the shell having an opening, the end cap covering the opening, and the end cap being a first wall; the electrode assembly also has a second tab, the polarity of which is opposite to that of the first tab; the battery cell also includes a second electrode terminal, the second electrode terminal being disposed on the end cap or the shell, and the second electrode terminal being electrically connected to the second tab.

[0066] In the above scheme, the end cap serves as the first wall, facilitating the assembly of the first electrode terminal with the first wall, the connection of the first adapter with the first electrode terminal, and the assembly of the battery cell. When the second electrode terminal is located on the end cap, the second tab and the first tab can be located on the same side of the electrode assembly, facilitating the connection of the second electrode terminal and the first electrode terminal with the electrode assembly; when the second electrode terminal is located on the housing, the positions of the second electrode terminal and the first electrode terminal are flexible, facilitating the connection of the battery cell with other components.

[0067] According to some embodiments of this application, the outer casing includes a first end cap, a housing, and a second end cap. The housing has two openings that are disposed opposite to each other. The first end cap and the second end cap cover the two openings respectively. The first end cap is a first wall. The electrode assembly also has a second electrode tab, the polarity of which is opposite to that of the first electrode tab. The battery cell also includes a second electrode terminal, which is disposed on the second end cap and electrically connected to the second electrode tab.

[0068] In the above scheme, the second electrode terminal is disposed on the second end cover, and the first end cover and the second end cover are disposed opposite to each other. The first end cover and the second end cover can be assembled with the housing from both ends of the housing, which facilitates the assembly flexibility of the battery cell and makes it easier to assemble the battery cell.

[0069] According to some embodiments of this application, the electrode assembly has two first tabs; the first adapter includes two second connecting portions and two bending portions, the two second connecting portions are spaced apart along the thickness direction of the electrode assembly, each second connecting portion is connected to a first connecting portion through a bending portion, and each first tab is connected to a second connecting portion.

[0070] In the above scheme, when the electrode assembly is provided with a number of first sub-tabs, the battery cell can have a high energy density. The multiple first sub-tabs can be divided into two first tabs, and the two first tabs can be spaced apart along the thickness direction of the electrode assembly to facilitate the convergence of the multiple first sub-tabs. The first adapter includes two second connecting parts, each of which is connected to the first connecting part through a bending part, which facilitates the connection between the first tab and the first adapter. At the same time, the provision of two second connecting parts and two bending parts helps to disperse the stress of the two first tabs and reduces the risk of cracking of the first tab.

[0071] According to some embodiments of this application, the outer shell is rectangular.

[0072] In the above scheme, the outer shell is rectangular, has high strength, and facilitates the stacking of multiple battery cells to improve the energy density of the battery device composed of these battery cells.

[0073] Secondly, embodiments of this application also provide a battery device, which includes a battery cell provided according to any of the above embodiments.

[0074] Thirdly, embodiments of this application also provide an electrical device, which includes a battery cell or battery device provided according to any of the above embodiments, wherein the battery cell or battery device is used to provide electrical energy.

[0075] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0076] 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.

[0077] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0078] Figure 2 is an exploded view of the structure of a battery device provided in some embodiments of this application;

[0079] Figure 3 is an exploded view of the structure of a battery cell provided in some embodiments of this application;

[0080] Figure 4 is a schematic diagram of the assembly of the first adapter and the first electrode provided in some embodiments of this application;

[0081] Figure 5 is a schematic diagram of a bent portion provided in some embodiments of this application;

[0082] Figure 6 is a schematic diagram of the first adapter in its unfolded state according to some embodiments of this application;

[0083] Figure 7 is a schematic diagram of a bent portion provided in some other embodiments of this application;

[0084] Figure 8 is a schematic diagram of the assembly of the first adapter and the first electrode tab provided in some other embodiments of this application;

[0085] Figure 9 is a schematic diagram of the structure of the first adapter provided in some embodiments of this application;

[0086] Figure 10 is a magnified view of part A in Figure 9;

[0087] Figure 11 is a schematic diagram of the assembly of the first adapter and the first electrode tab provided in some embodiments of this application;

[0088] Figure 12 is an exploded view of the structure of a battery cell provided in some other embodiments of this application;

[0089] Figure 13 is an exploded view of the structure of a battery cell provided in some embodiments of this application;

[0090] Figure 14 is a structural exploded view of a battery cell provided in some embodiments of this application;

[0091] Figure 15 is an exploded view of the structure of a battery cell provided in some embodiments of this application from another perspective.

[0092] Figure 16 is a schematic diagram of the assembly of the electrode assembly and the first adapter provided in some embodiments of this application.

[0093] The accompanying drawings are not drawn to scale.

[0094] Marking Explanation: 100-Battery assembly; 10-Casing; 11-First sub-casing; 12-Second sub-casing; 20-Battery cell; 21-Outer casing; 21a-Housing shell; 21b-End cap; 21c-First end cap; 21d-Second end cap; 211-First wall; 212-First side wall; 213-Second side wall; 22-Electrode assembly; 22a-First electrode tab; 22b-Second electrode tab; 220-Main body; 220a-First edge; 220b-Second edge; 221-First sub-electrode tab; 23a-First electrode terminal; 23b-Second electrode terminal; 24-First adapter; 24a-Conductive sheet; 241- 2411-Third conductive layer; 242-Second connecting part; 2421-Second conductive layer; 243-Bending part; 243a-First end face; 243b-Second end face; 2431-First conductive layer; 244-Weakening part; 244a-First weakening part; 244b-Second weakening part; 25-First insulating component; 26-Second insulating component; 27-Second adapter; 28-Pressure relief mechanism; 29-Third insulating component; 200-Controller; 300-Motor; 1000-Vehicle; K-Width direction; L-Length direction; X-First direction; Y-Thickness direction of electrode assembly; z-Thickness direction of first wall. Detailed Implementation

[0095] 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 and completely 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 fall within the scope of protection of this application.

[0096] 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.

[0097] In this application, the reference to "embodiment" means that a specific 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 throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0098] 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.

[0099] 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.

[0100] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0101] 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.

[0102] 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 and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0103] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0104] 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.

[0105] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0106] As an example, the enclosure may include a first sub-enclosure and a second sub-enclosure. The first and second sub-enclosures are interlocked to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or shutting down; it can be sealed or not sealed. The first sub-enclosure may be a top cover or a bottom plate.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] The battery cell may be, but is not limited to, lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc.

[0112] 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, prevents short circuits while allowing active ions to pass through.

[0113] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0114] 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.

[0115] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be made of stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium with a silver-plated surface. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector 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.).

[0116] 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 for batteries may also be used.

[0117] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0118] As an example, the negative electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, or made of carbon, nickel, or titanium, etc.

[0119] In some embodiments, 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.

[0120] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in batteries. 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 for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0121] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0122] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0123] 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.

[0124] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0125] In some implementations, the electrode assembly is a stacked structure.

[0126] 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, plastic (such as polypropylene), or composite metal (such as a copper-aluminum composite housing).

[0127] In some embodiments, the housing includes an end cap and a casing, the casing having an opening, and the end cap closing the opening to form a sealed space for accommodating substances such as electrode assemblies and electrolytes. The casing may have one or more openings. The end cap may also be provided one or more times.

[0128] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab of the electrode assembly. The electrode terminal can be directly connected to the tab or indirectly connected to the tab via an adapter. The electrode terminal can be located on the end cap or on the housing.

[0129] In some implementations, an explosion-proof valve is provided on the housing. The explosion-proof valve is used to release the internal pressure of the battery cells.

[0130] 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 protects the electrode assembly and prevents leaks such as electrolyte leakage. When the housing is a non-sealed structure, it protects 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.

[0131] As an example, a battery cell can be a prismatic battery cell or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0132] The development of battery device technology must take into account multiple design factors, such as performance parameters like energy density, discharge capacity, and charge / discharge rate. In addition, the reliability of the battery device also needs to be considered.

[0133] In some embodiments, a battery cell includes a housing, electrode terminals, an electrode assembly, and an adapter. The electrode terminals are disposed on the first wall of the housing, and the electrode assembly is disposed within the housing, having tabs. The adapter electrically connects the electrode terminals and the tabs. To facilitate battery cell assembly, the tabs are relatively long. After the tabs are connected to the adapter, they are bent, and the electrode assembly is inserted into the housing. Because the adapter has high strength, and one end of the adapter is welded to the tab, and the other end is welded to the electrode terminal, during battery cell transportation or operation of the electrical device, when the battery cell is subjected to vibration, the electrode assembly is prone to movement relative to the housing. The bent portion of the tab is susceptible to fatigue cracking, resulting in poor current-carrying capacity of the battery cell. Furthermore, the cracked tabs can easily puncture the separator, causing a short circuit between the positive and negative electrodes, affecting the reliability of the battery cell.

[0134] In view of this, in order to solve the problem of fatigue cracking at the bending position of the electrode tab due to vibration of the battery cell, resulting in low reliability of the battery cell, this application provides a battery cell including a shell, a first electrode terminal, an electrode assembly, and a first adapter. The shell has a first wall; the first electrode terminal is disposed on the first wall; the electrode assembly is disposed inside the shell, and the electrode assembly has a first electrode tab; the first adapter includes a first connecting portion, a second connecting portion, and a bending portion. The first connecting portion is electrically connected to the first electrode terminal, the second connecting portion is electrically connected to the first electrode tab, and the bending portion connects the first connecting portion and the second connecting portion. On the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first connecting portion and the orthographic projection of the second connecting portion at least partially overlap. The bending portion includes at least two stacked first conductive layers. This battery cell has high reliability.

[0135] In such a battery cell, the first adapter is a bent structure, and the first connecting part and the second connecting part are connected through the bent part. The orthographic projection of the first connecting part and the orthographic projection of the second connecting part at least partially overlap. When the battery cell is subjected to vibration, the first adapter can absorb the force generated by the movement of the electrode assembly. Furthermore, the bent part includes at least two stacked first conductive layers, which can form a buffer structure between the first electrode terminal and the first tab. This facilitates the bending of the first adapter and the absorption of the force generated by the movement of the electrode assembly. It can also disperse the stress at the bent part of the first tab, reduce the risk of fatigue cracking of the first tab, and make the battery cell have high reliability.

[0136] The battery device disclosed in this application can be used, but is not limited to, in electrical equipment such as vehicles, ships, or aircraft. A power system for such electrical equipment can be constructed using the battery device disclosed in this application.

[0137] 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.

[0138] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of this application.

[0139] Please refer to Figure 1, which is a schematic diagram of the vehicle structure provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can 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's electrical system, such as meeting the power requirements for starting, navigation, and operation of the vehicle 1000.

[0140] 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.

[0141] 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.

[0142] Please refer to Figure 2, which is an exploded view of the structure of a battery device provided in some embodiments of this application. The battery device 100 includes a housing 10 and battery cells 20, with the battery cells 20 housed within the housing 10.

[0143] The housing 10 provides a space for housing the battery cell 20, and the housing 10 can adopt various structures. In some embodiments, the housing 10 may include a first sub-housing 11 and a second sub-housing 12, which overlap each other, and together define a space for housing the battery cell 20. The second sub-housing 12 may be a hollow structure with one end open, and the first sub-housing 11 may be a plate-like structure, with the first sub-housing 11 covering the open side of the second sub-housing 12 so that the first sub-housing 11 and the second sub-housing 12 together define the space; the first sub-housing 11 and the second sub-housing 12 may also be hollow structures with one side open, with the open side of the first sub-housing 11 covering the open side of the second sub-housing 12.

[0144] In the battery device 100, there can be multiple battery cells 20. These multiple battery cells 20 can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also be composed of multiple battery cells 20 first connected in series, in parallel, or in a mixed configuration to form a battery module, and then multiple battery modules are connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10.

[0145] The battery device 100 may also include other structures, such as a busbar for making electrical connections between multiple battery cells 20.

[0146] Please refer to Figure 3, which is an exploded view of the structure of a battery cell provided in some embodiments of this application. As shown in Figure 3, the battery cell 20 includes a housing 21, an electrode assembly 22, and other functional components. The housing 21 includes a shell 21a and an end cap 21b. The shell 21a has an opening, and the end cap 21b closes the opening to isolate the internal environment of the battery cell 20 from the external environment.

[0147] The housing 21a is a component used to cooperate with the end cap 21b to form the internal environment of the battery cell 20, wherein the formed internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 21a and the end cap 21b can be independent components. The housing 21a can have various shapes and sizes. Specifically, the shape of the housing 21a can be determined according to the specific shape and size of the electrode assembly 22. The housing 21a can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0148] End cap 21b refers to a component that covers the opening of housing 21a to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21b can be adapted to the shape of housing 21a to fit it. Optionally, end cap 21b can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 21b is not easily deformed under pressure and impact, giving battery cell 20 higher structural strength and improved reliability. Functional components such as electrode terminals and pressure relief mechanisms can be provided on end cap 21b. Electrode terminals can be used for electrical connection with electrode assembly 22 to output or input electrical energy to battery cell 20. The material of end cap 21b can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose special limitations on this. In some embodiments, an insulating structure may be provided on the inner side of the end cap 21b. The insulating structure can be used to isolate the electrical connection components within the housing 21a from the end cap 21b to reduce the risk of short circuits. For example, the insulating structure may be made of plastic, rubber, etc.

[0149] Electrode assembly 22 is the component in the battery cell 20 where the electrochemical reaction takes place. The housing 21a may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode plates, and usually a separator is provided between the positive and negative electrode plates to separate the positive and negative electrode plates to prevent internal short circuits between the positive and negative electrode plates.

[0150] Please refer to Figure 3 and further to Figure 4. Figure 4 is a schematic diagram of the assembly of the first adapter and the first tab provided in some embodiments of this application. This application provides a battery cell 20, which includes a housing 21, a first electrode terminal 23a, an electrode assembly 22, and a first adapter 24. The housing 21 has a first wall 211; the first electrode terminal 23a is disposed on the first wall 211; the electrode assembly 22 is disposed inside the housing 21, and the electrode assembly 22 has a first tab 22a; the first adapter 24 includes a first connecting portion 241, a second connecting portion 242, and a bending portion 243. The first connecting portion 241 is electrically connected to the first electrode terminal 23a, the second connecting portion 242 is electrically connected to the first tab 22a, and the bending portion 243 connects the first connecting portion 241 and the second connecting portion 242. On the same projection plane perpendicular to the thickness direction z of the first wall, the orthographic projection of the first connecting portion 241 and the orthographic projection of the second connecting portion 242 at least partially overlap. The bent portion 243 includes at least two first conductive layers 2431 stacked together.

[0151] The outer casing 21 can be made of metal, such as steel or aluminum.

[0152] In some embodiments, the first wall 211 may be an end cap 21b.

[0153] The first electrode terminal 23a can be either a positive terminal or a negative terminal.

[0154] The first electrode terminal 23a can be insulated from the first wall 211. For example, an insulating structure is provided between the first electrode terminal 23a and the first wall 211. Alternatively, the first electrode terminal 23a can also be electrically connected to the first wall 211.

[0155] The polarity of the first electrode tab 22a is the same as that of the first electrode terminal 23a. The first electrode tab 22a can be a positive electrode tab or a negative electrode tab.

[0156] The first connecting portion 241 is used to electrically connect with the first electrode terminal 23a. For example, the first connecting portion 241 is welded to the first electrode terminal 23a so that the first connecting portion 241 is firmly connected to the first electrode terminal 23a.

[0157] The second connecting part 242 is used to electrically connect with the first electrode tab 22a. For example, the second connecting part 242 is welded to the first electrode tab 22a so that the second connecting part 242 is firmly connected to the first electrode tab 22a.

[0158] The bent portion 243 is a bent structure formed after the first connecting portion 241 and the second connecting portion 242 are bent. For example, the first adapter 24 is bent so that the first connecting portion 241 and the second connecting portion 242 at least partially overlap in the thickness direction z of the first wall, and the bent portion 243 connects the first connecting portion 241 and the second connecting portion 242.

[0159] In some embodiments, the first connecting portion 241, the bending portion 243, and the second connecting portion 242 may be distributed sequentially along the length direction L of the first adapter 24.

[0160] With the thickness direction z of the first wall as the projection direction, the orthographic projection of the first connecting part 241 and the orthographic projection of the second connecting part 242 at least partially overlap, and the first electrode terminal 23a and the first electrode tab 22a at least partially overlap in the thickness direction z of the first wall; relative to the first electrode terminal 23a and the first electrode tab 22a being staggered in the thickness direction z of the first wall, the length of the first connecting part 241 can be designed to be shorter so that current can flow between the first electrode tab 22a and the first electrode terminal 23a.

[0161] The bending portion 243 has a multi-layer structure. Multiple layers of first conductive layers 2431 are stacked to form the bending portion 243. These multiple layers of first conductive layers 2431 are electrically connected to the first connecting portion 241 and the second connecting portion 242, respectively, so that the first adapter 24 has a high current-carrying capacity. For example, at least one layer of the multiple layers of first conductive layers 2431 can be integrally formed with the first connecting portion 241, and at least one layer of the multiple layers of first conductive layers 2431 can be integrally formed with the second connecting portion 242. Alternatively, the multiple layers of first conductive layers 2431 can be welded to the first connecting portion 241, and the multiple layers of first conductive layers 2431 can be welded to the second connecting portion 242.

[0162] Compared to the single-layer structure of the bending section 243, the multi-layer structure of the bending section 243 can improve the flexibility of the bending section 243 and facilitate stress absorption.

[0163] In some embodiments, the first conductive layer 2431 can be a metal sheet, for example, the material of the first conductive layer 2431 can be copper or aluminum, which has good conductivity.

[0164] According to the battery cell 20 of this application embodiment, the first adapter 24 has a bent structure. The first connecting part 241 and the second connecting part 242 are connected by a bent part 243, and the orthographic projection of the first connecting part 241 and the orthographic projection of the second connecting part 242 at least partially overlap. When the battery cell 20 is subjected to vibration, the first adapter 24 can absorb the force generated by the movement of the electrode assembly 22. Furthermore, the bent part 243 includes at least two stacked first conductive layers 2431, which can form a buffer structure between the first electrode terminal 23a and the first tab 22a. This facilitates the bending of the first adapter 24 and also helps the first adapter 24 absorb the force generated by the movement of the electrode assembly 22. It can disperse the stress at the bent part of the first tab 22a, reduce the risk of fatigue cracking of the first tab 22a, and make the battery cell 20 have high reliability.

[0165] According to some embodiments of this application, the battery cell 20 further includes a second insulating member 26, which is disposed on the side of the first wall 211 facing the interior of the battery cell 20. The second insulating member 26 is used to separate the electrode assembly 22 from the first wall 211 to reduce the risk of short circuit between the electrode assembly 22 and the first wall 211.

[0166] Please refer to Figure 5, which is a schematic diagram of a bent portion provided in some embodiments of this application. According to some embodiments of this application, at least one first conductive layer 2431 is provided with a weakening portion 244.

[0167] The weakened portion 244 refers to the area of ​​the first conductive layer 2431 where the strength is relatively weak. For example, the weakened portion 244 can be a through hole, groove, or groove.

[0168] In some embodiments, the weakening portion 244 can be disposed on any one layer of the first conductive layer 2431, or it can be disposed on any multiple layers of the first conductive layer 2431. Correspondingly, along the stacking direction of the multiple layers of the first conductive layer 2431, the weakening portion 244 can be disposed on the first conductive layer 2431 at the end of the multiple layers of the first conductive layer 2431, or it can be disposed on the first conductive layer 2431 in the middle of the multiple layers of the first conductive layer 2431, or it can be disposed on both the first conductive layer 2431 at the end of the multiple layers of the first conductive layer 2431 and the first conductive layer 2431 in the middle of the multiple layers of the first conductive layer 2431.

[0169] In some embodiments, the weakening portion 244 is disposed on all first conductive layers 2431 to facilitate mass production.

[0170] In some embodiments, the weakened portions 244 of the multilayer first conductive layer 2431 overlap at least partially along the thickness direction of the bent portion 243. For example, the multilayer first conductive layer 2431 can be mass-produced. When the multilayer first conductive layer 2431 is stacked, the weakened portions 244 of the multilayer first conductive layer 2431 overlap. After the multilayer first conductive layer 2431 is bent to form the bent portion 243, the weakened portions 244 of the multilayer first conductive layer 2431 can overlap at least partially.

[0171] In some embodiments, the weakening portion 244 may be circular, square, or irregular in shape.

[0172] In the above scheme, the weakening part 244 is disposed on at least one first conductive layer 2431, which can reduce the overall strength of the bending part 243. The bending difficulty of the first adapter 24 is low, which makes it easier for the bending part 243 to bend relative to the first connecting part 241 and the second connecting part 242, and the processing and manufacturing difficulty is low.

[0173] According to some embodiments of this application, the weakened portion 244 includes at least one of a through hole, a groove, and a notch.

[0174] In some embodiments, the weakening portion 244 may be a through hole that penetrates the first conductive layer 2431 along the thickness direction of the first conductive layer 2431.

[0175] In some embodiments, the weakening portion 244 may be a groove provided in the first conductive layer 2431. For example, a portion of the material is removed from the surface of the first conductive layer 2431 to form the weakening portion 244 on the first conductive layer 2431.

[0176] In some embodiments, the weakening portion 244 can be a groove provided on the first conductive layer 2431, for example, a groove is formed on the surface of the first conductive layer 2431 by means of laser etching, mechanical cutting with a cutting tool, etc.

[0177] In some embodiments, the weakening portion 244 may include two or three of the following: through-hole, groove, and groove.

[0178] In the above scheme, through holes, grooves and engravings are all relatively easy to process, making them convenient to manufacture and reducing manufacturing costs.

[0179] According to some embodiments of this application, the weakening portion 244 is disposed inside the bending portion 243.

[0180] The bending portion 243, the first connecting portion 241, and the second connecting portion 242 form a first space. The inner side of the bending portion 243 refers to the side of the bending portion 243 facing the first space. It can also be understood as the inner side of the bending portion 243 referring to the concave side of the bending portion 243.

[0181] The weakening portion 244 may be located in a first conductive layer 2431 inside the bending portion 243, or the weakening portion 244 may be located in at least two first conductive layers 2431 inside the bending portion 243.

[0182] In the above scheme, the weakened part 244 is located inside the bending part 243, which facilitates the bending of the first adapter 24.

[0183] Please refer to Figure 6, which is a schematic diagram of the unfolded state of the first adapter 24 according to some embodiments of this application. According to some embodiments of this application, in the unfolded state of the first adapter 24, the first connecting portion 241, the bending portion 243, and the second connecting portion 242 are sequentially distributed along the length direction L of the first adapter 24; the length direction of the weakening portion 244 is parallel to the width direction K of the first adapter 24.

[0184] Please refer to Figure 9. The dashed line in the figure can represent the boundary line between the bent portion 243 and the first connecting portion 241 and the second connecting portion 242.

[0185] Before the first adapter 24 is assembled with the first electrode terminal 23a and the first tab 22a, the first adapter 24 is in an unfolded state. In the length direction L of the first adapter 24, the first connecting portion 241, the bending portion 243 and the second connecting portion 242 are sequentially distributed to facilitate the assembly of the first adapter 24 with the first electrode terminal 23a and the first tab 22a. After the first connecting portion 241 is connected to the first electrode terminal 23a and the second connecting portion 242 is connected to the first tab 22a, the first adapter 24 is bent so that the first connecting portion 241 and the second connecting portion 242 at least partially overlap in the thickness direction z of the first wall.

[0186] In some embodiments, the weakening portion 244 may be elongated and extends along the width direction K of the first adapter 24, thereby reducing the strength of the bent portion 243 in the width direction K of the first adapter 24.

[0187] In the above scheme, the length direction of the weakened part 244 is parallel to the width direction K of the first adapter 24. The weakened part 244 has a large size in the width direction K of the first adapter 24, which further reduces the strength of the bent part 243 and facilitates the bending of the bent part 243 relative to the first connecting part 241 and the second connecting part 242.

[0188] Please refer to Figures 5 and 6, and further to Figure 7, which is a schematic diagram of a bent portion provided in some embodiments of this application. According to some embodiments of this application, there are multiple weakening portions 244, which are spaced apart along the width direction K of the first adapter 24.

[0189] Multiple weakening parts 244 can be arranged at equal intervals along the width direction K of the first adapter 24, or multiple weakening parts 244 can be arranged at unequal intervals along the width direction K of the first adapter 24.

[0190] Optionally, multiple weakened portions 244 are equally spaced along the width direction K of the first adapter 24 to facilitate processing and manufacturing.

[0191] The number of weakening sections 244 can be selected according to actual conditions. For example, the total length of multiple weakening sections 244 can meet the current carrying requirements of the bending section 243, so that the bending section 243 has high current carrying energy. In addition, the setting of multiple weakening sections 244 can increase the heat dissipation surface area of ​​the bending section 243, which is beneficial to the heat dissipation of the bending section 243.

[0192] In the above scheme, multiple weakening parts 244 are arranged at intervals along the width direction K of the first adapter 24. On the one hand, this can reduce the strength of the bending part 243 in the width direction K of the first adapter 24, making it easier to reduce the bending difficulty of the first adapter 24. On the other hand, it can increase the heat dissipation area of ​​the bending part 243, so that the bending part 243 has a better heat dissipation effect.

[0193] Referring to Figure 7, according to some embodiments of this application, the bending portion 243 has a first end face 243a and a second end face 243b disposed opposite to each other along the width direction K of the first adapter 24, and a plurality of weakening portions 244 including a first weakening portion 244a and a second weakening portion 244b, one end of the first weakening portion 244a extending to the first end face 243a, and one end of the second weakening portion 244b extending to the second end face 243b.

[0194] The first end face 243a and the second end face 243b are the end faces of the bent portion 243 at both ends in the width direction K of the first adapter 24, respectively, and the first end face 243a and the second end face 243b are parallel to each other.

[0195] The first weakening portion 244a and the second weakening portion 244b are provided at intervals along the width direction K of the first adapter 24, and the first weakening portion 244a and the second weakening portion 244b are respectively located at the two ends of the bending portion 243 located in the width direction K of the first adapter 24.

[0196] In some embodiments, the first weakening portion 244a may be a notch formed on the first end face 243a, and the second weakening portion 244b may be a notch formed on the second end face 243b.

[0197] In some embodiments, along the width direction K of the first adapter 24, the length of the first weakened portion 244a can be equal to the length of the second weakened portion 244b to facilitate manufacturing.

[0198] In some embodiments, the plurality of weakening portions 244 may further include at least one third weakening portion, located between the first weakening portion 244a and the second weakening portion 244b along the width direction K of the first adapter 24. For example, the number of third weakening portions may be one, which may be located at the middle of the bent portion 243 in the width direction K of the first adapter 24.

[0199] In the above scheme, one end of the first weakening part 244a extends to the first end face 243a, and one end of the second weakening part 244b extends to the second end face 243b, so that the first weakening part 244a and the second weakening part 244b can be manufactured from the end of the first adapter 24 in the width direction K of the first adapter 24, and the manufacturing difficulty is low.

[0200] Please refer to Figure 8, which is a schematic diagram of the assembly of the first adapter and the first tab provided in some embodiments of this application. According to some embodiments of this application, the second connection portion 242 includes multiple layers of second conductive layers 2421 stacked together, and the first tab 22a is sandwiched between the multiple layers of second conductive layers 2421.

[0201] The second conductive layer 2421 can be a metal sheet, for example, the material of the second conductive layer 2421 can be copper or aluminum, which has good conductivity.

[0202] In some embodiments, the second conductive layer 2421 may be integrally formed with the first conductive layer 2431, for example, by bending a metal sheet to form the second conductive layer 2421 and the first conductive layer 2431; or, the second conductive layer 2421 may be welded to the first conductive layer 2431 so that the second conductive layer 2421 and the first conductive layer 2431 are firmly connected.

[0203] The first tab 22a is held between multiple layers of second conductive layers 2421, facilitating connection between the multiple layers of second conductive layers 2421 and the first tab 22a, and promoting current flow between the first tab 22a and the second connection portion 242. The first tab 22a is sandwiched between the multiple layers of second conductive layers 2421, and can be welded to the multiple layers of second conductive layers 2421 to ensure a firm connection.

[0204] In the above scheme, the multilayer second conductive layer 2421 clamps the first electrode tab 22a to facilitate the welding connection between the multilayer second conductive layer 2421 and the first electrode tab 22a, and facilitate the assembly of the first adapter 24 and the first electrode tab 22a.

[0205] Please refer to Figure 9, which is a structural schematic diagram of the first adapter provided in some embodiments of this application, and Figure 10 is a partial enlarged view of point A in Figure 9. According to some embodiments of this application, the number of layers of the first conductive layer 2431 is less than or equal to the number of layers of the second conductive layer 2421.

[0206] In some embodiments, the number of layers of the first conductive layer 2431 may be equal to the number of layers of the second conductive layer 2421, and the second conductive layer 2421 may be integrally formed with the first conductive layer 2431. For example, the first adapter 24 is formed by stacking multiple conductive sheets 24a and bending them to give the first adapter 24 a higher current carrying capacity.

[0207] In some embodiments, referring to Figures 9 and 10, the number of layers in the first conductive layer 2431 may be less than the number of layers in the second conductive layer 2421. For example, after the first adapter 24 is made of multiple conductive sheets 24a, a portion of the conductive sheets 24a is cut off in the area where the bending portion 243 is located and bent, so that the number of layers in the first conductive layer 2431 is less than the number of layers in the second conductive layer 2421.

[0208] In the above scheme, when the number of layers of the first conductive layer 2431 is less than the number of layers of the second conductive layer 2421, the bending part 243 has lower strength, which is conducive to bending the bending part 243; when the number of layers of the first conductive layer 2431 is equal to the number of layers of the second conductive layer 2421, the bending part 243 can have higher current carrying capacity, which is conducive to the flow of current on the first adapter 24.

[0209] According to some embodiments of this application, each first conductive layer 2431 is integrally formed with a second conductive layer 2421.

[0210] The bent portion 243 and the second connecting portion 242 can be formed by bending multiple metal sheets so that each first conductive layer 2431 can be integrally formed with a second conductive layer 2421.

[0211] In the above scheme, the first conductive layer 2431 and the second conductive layer 2421 are integrally formed, the first conductive layer 2431 and the second conductive layer 2421 are firmly connected, and it is easy to process and manufacture.

[0212] According to some embodiments of this application, the thickness of the second conductive layer 2421 is equal to the thickness of the first conductive layer 2431.

[0213] When the second conductive layer 2421 and the first conductive layer 2431 are integrally formed, the second conductive layer 2421 and the first conductive layer 2431 can be formed by bending the same metal sheet so that the thickness of the second conductive layer 2421 is equal to the thickness of the first conductive layer 2431.

[0214] The fact that the thickness of the second conductive layer 2421 is equal to the thickness of the first conductive layer 2431 means that the second conductive layer 2421 and the first conductive layer 2431 can be formed from metal sheets of the same thickness, and there can be processing errors between the thickness of the second conductive layer 2421 and the thickness of the first conductive layer 2431.

[0215] In the above scheme, the thickness of the second conductive layer 2421 is equal to the thickness of the first conductive layer 2431, which facilitates processing and manufacturing.

[0216] Please refer to Figures 8 and 10. According to some embodiments of this application, the first electrode 22a includes a plurality of first sub-electrodes 221 stacked together, with the plurality of first sub-electrodes 221 sandwiched between two adjacent second conductive layers 2421.

[0217] Multiple first sub-tabs 221 are stacked to facilitate electrical connection of the multiple first sub-tabs 221. The multiple first sub-tabs 221 are connected to the second connecting part 242 to realize the electrical connection between the first sub-tab 22a and the first adapter 24.

[0218] Multiple first sub-tabs 221 are sandwiched between two adjacent second conductive layers 2421. The multiple first sub-tabs 221 are sandwiched between the two adjacent second conductive layers 2421, which can increase the connection area between the second connection portion 242 and the first tab 22a. This facilitates welding the first tab 22a and the second connection portion 242 from both sides of the thickness direction of the first tab 22a, thereby improving the connection reliability between the first tab 22a and the second connection portion 242.

[0219] In the above scheme, multiple first sub-tabs 221 are stacked to enable the first tab 22a to have a high current carrying capacity; multiple first sub-tabs 221 are sandwiched between two adjacent second conductive layers 2421 to facilitate the connection between the first tab 22a and the second connection part 242, thereby improving the connection reliability between the first tab 22a and the first adapter 24.

[0220] According to some embodiments of this application, the number of second conductive layers 2421 on both sides of the first tab 22a of the second connection portion 242 is equal.

[0221] The multilayer second conductive layer 2421 is symmetrically distributed on both sides of the first electrode tab 22a in the thickness direction, which facilitates the welding of the multilayer second conductive layer 2421 and the first electrode tab 22a on both sides of the thickness direction of the first electrode tab 22a, resulting in a high welding quality between the second connection part 242 and the first electrode tab 22a.

[0222] In the above scheme, the number of second conductive layers 2421 on both sides of the first tab 22a of the second connecting part 242 is equal, which can improve the welding quality of the multi-layer second conductive layers 2421 and the first tab 22a, so that the second connecting part 242 and the first tab 22a are firmly connected.

[0223] Please refer to Figure 11, which is a schematic diagram of the assembly of the first adapter and the first electrode according to some embodiments of this application. According to some embodiments of this application, the first connecting portion 241 includes at least two stacked third conductive layers 2411.

[0224] The third conductive layer 2411 can be a metal sheet, for example, the material of the third conductive layer 2411 can be copper or aluminum, which has high conductivity.

[0225] In some embodiments, the third conductive layer 2411 may be integrally formed with the first conductive layer 2431, for example, by bending a metal sheet to form the third conductive layer 2411 and the first conductive layer 2431; or, the third conductive layer 2411 may be welded to the first conductive layer 2431 so that the third conductive layer 2411 and the first conductive layer 2431 are firmly connected.

[0226] In the above scheme, the third conductive layer 2411 has a multi-layer structure, and each first conductive layer 2431 can be connected to a third conductive layer 2411, which facilitates the connection between the first connecting part 241 and the bending part 243.

[0227] According to some embodiments of this application, the number of layers of the first conductive layer 2431 is less than or equal to the number of layers of the third conductive layer 2411.

[0228] In some embodiments, the number of layers of the first conductive layer 2431 may be equal to the number of layers of the third conductive layer 2411, and the third conductive layer 2411 may be integrally formed with the first conductive layer 2431. For example, the first adapter 24 is formed by stacking multiple conductive sheets 24a and bending them to give the first adapter 24 a higher current carrying capacity.

[0229] In some embodiments, the number of layers of the first conductive layer 2431 may be less than the number of layers of the third conductive layer 2411. For example, after the first adapter 24 is made of multiple conductive sheets 24a, a portion of the conductive sheets 24a is cut off in the area where the bending portion 243 is located and bent, so that the number of layers of the first conductive layer 2431 is less than the number of layers of the third conductive layer 2411.

[0230] In the above scheme, when the number of layers of the first conductive layer 2431 is less than the number of layers of the third conductive layer 2411, the bending part 243 has lower strength, which is beneficial for bending the bending part 243; when the number of layers of the first conductive layer 2431 is equal to the number of layers of the third conductive layer 2411, the bending part 243 can have higher current carrying capacity, which is convenient for current to flow on the first adapter 24.

[0231] According to some embodiments of this application, each first conductive layer 2431 and a third conductive layer 2411 are integrally formed.

[0232] The bent portion 243 and the first connecting portion 241 can be formed by bending multiple metal sheets so that each first conductive layer 2431 can be integrally formed with a third conductive layer 2411.

[0233] In the above scheme, the first conductive layer 2431 and the third conductive layer 2411 are integrally formed, the first conductive layer 2431 and the third conductive layer 2411 are firmly connected, and it is easy to process and manufacture.

[0234] According to some embodiments of this application, the thickness of the third conductive layer 2411 is equal to the thickness of the first conductive layer 2431.

[0235] When the third conductive layer 2411 and the first conductive layer 2431 are integrally formed, the third conductive layer 2411 and the first conductive layer 2431 can be formed by bending the same metal sheet so that the thickness of the third conductive layer 2411 is equal to the thickness of the first conductive layer 2431.

[0236] The fact that the thickness of the third conductive layer 2411 is equal to the thickness of the first conductive layer 2431 means that the third conductive layer 2411 and the first conductive layer 2431 can be formed from metal sheets of the same thickness, and there can be processing errors between the thickness of the third conductive layer 2411 and the thickness of the first conductive layer 2431.

[0237] In the above scheme, the thickness of the third conductive layer 2411 is equal to the thickness of the first conductive layer 2431, which facilitates processing and manufacturing.

[0238] According to some embodiments of this application, the first connecting portion 241 is a single-layer structure.

[0239] The first connecting part 241 can be a sheet structure, and the thickness of the first connecting part 241 can be greater than or equal to the maximum thickness of the multilayer first conductive layer 2431, so that the first connecting part 241 can have a large current-carrying area, which facilitates the first adapter 24 to have a high current-carrying capacity.

[0240] In the above scheme, the first connecting part 241 is a single-layer structure, which is simple and facilitates the flow of current.

[0241] According to some embodiments of this application, the thickness of each first conductive layer 2431 is greater than or equal to 0.05 mm and less than or equal to 0.25 mm.

[0242] In some embodiments, the thickness of each first conductive layer 2431 is greater than or equal to 0.05 mm and less than or equal to 0.15 mm.

[0243] In some embodiments, the thickness of each first conductive layer 2431 is any one or a range between any two of 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, or 0.25 mm.

[0244] The first conductive layer 2431 can be formed by stacking metal sheets. The thinner the first conductive layer 2431, the more difficult it is to process and manufacture.

[0245] In the above scheme, the thickness of each first conductive layer 2431 satisfies the above relationship (greater than or equal to 0.05mm and less than or equal to 0.25mm). On the one hand, the processing and manufacturing difficulty is low and it is easy to process and manufacture. On the other hand, the bending difficulty of the bending part 243 is low and it is easy to bend the first adapter 24.

[0246] According to some embodiments of this application, the thickness of each first conductive layer 2431 is greater than or equal to 0.1 mm and less than or equal to 0.2 mm.

[0247] In some embodiments, the thickness of each first conductive layer 2431 is greater than or equal to 0.12 mm and less than or equal to 0.18 mm.

[0248] In the above scheme, when the thickness of each first conductive layer 2431 is greater than or equal to 0.1 mm, the first conductive layer 2431 has a relatively thick thickness, which further reduces the difficulty of processing and manufacturing; when the thickness of each first conductive layer 2431 is less than or equal to 0.2 mm, the first conductive layer 2431 has a lower strength, which further reduces the bending difficulty of the bending part 243.

[0249] According to some embodiments of this application, the first adapter 24 is made of copper, and the maximum thickness of the bent portion 243 is greater than or equal to 0.4 mm and less than or equal to 1.5 mm.

[0250] The first adapter 24 is made of copper, and the first tab 22a can also be made of copper, so that the first adapter 24 and the first tab 22a can be welded together.

[0251] When the material of the first adapter 24 is copper, the maximum thickness of the bent portion 243 can be any one or any two of 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm or 1.5mm.

[0252] The maximum thickness of the bending portion 243 can be the thickness of the area of ​​the bending portion 243 where the weakening portion 244 is not provided.

[0253] In this application, the maximum thickness of the bent portion 243 can be the sum of the thicknesses of all the first conductive layers 2431.

[0254] In the above scheme, the first adapter 24 is made of copper, which has good conductivity. The maximum thickness of the bent portion 243 satisfies the above relationship (greater than or equal to 0.4 mm and less than or equal to 1.5 mm). On the one hand, the bent portion 243 has a large current-carrying area, and the first adapter 24 has a high current-carrying capacity. On the other hand, it is convenient to realize the connection between the first adapter 24 and the first electrode terminal 23a and the first electrode tab 22a.

[0255] According to some embodiments of this application, the maximum thickness of the bent portion 243 is greater than or equal to 0.6 mm and less than or equal to 1.2 mm.

[0256] In some embodiments, the maximum thickness of the bend 243 is greater than or equal to 0.7 mm and less than or equal to 1.1 mm.

[0257] In the above scheme, when the maximum thickness of the bending part 243 is greater than or equal to 0.6 mm, the bending part 243 has a large flow area, which further improves the flow capacity of the first adapter 24; when the maximum thickness of the bending part 243 is less than or equal to 1.2 mm, the strength of the bending part 243 is low, which further reduces the bending difficulty of the bending part 243.

[0258] According to some embodiments of this application, the first adapter 24 is made of aluminum, and the maximum thickness of the bent portion 243 is greater than or equal to 0.4 mm and less than or equal to 1.8 mm.

[0259] The first adapter 24 is made of aluminum, and the first tab 22a can also be made of aluminum, so that the first adapter 24 and the first tab 22a can be welded together.

[0260] When the first adapter 24 is made of aluminum, the maximum thickness of the bent portion 243 can be any one or any two of the following: 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, or 1.8mm.

[0261] In the above scheme, the first adapter 24 is made of aluminum, which has low cost and low density, and aluminum has good processing performance; the maximum thickness of the bending part 243 satisfies the above relationship (greater than or equal to 0.4 mm and less than or equal to 1.8 mm). On the one hand, the bending part 243 has a large flow area, and the first adapter 24 can have a high flow capacity. On the other hand, the bending part 243 has low strength, which makes it easy to bend the bending part 243.

[0262] According to some embodiments of this application, the maximum thickness of the bent portion 243 is greater than or equal to 0.7 mm and less than or equal to 1.5 mm.

[0263] In some embodiments, the maximum thickness of the bend 243 is greater than or equal to 0.9 mm and less than or equal to 1.3 mm.

[0264] In the above scheme, when the maximum thickness of the bending part 243 is greater than or equal to 0.7 mm, the bending part 243 has a large flow area, which further improves the flow capacity of the first adapter 24; when the maximum thickness of the bending part 243 is less than or equal to 1.5 mm, the strength of the bending part 243 is low, which further reduces the bending difficulty of the bending part 243.

[0265] According to some embodiments of this application, the number of first conductive layers 2431 is greater than or equal to 10 and less than or equal to 12; the thickness of each first conductive layer 2431 is greater than or equal to 0.05 mm and less than or equal to 0.15 mm.

[0266] When the number of first conductive layers 2431 is greater than or equal to 10 and less than or equal to 12, the number of each first conductive layer 2431 can be any one of 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm or 0.15mm or any range between two of these.

[0267] In the above scheme, the number of first conductive layers 2431 and the thickness of each first conductive layer 2431 satisfy the above relationship. On the one hand, when the thickness of each first conductive layer 2431 is greater than or equal to 0.05mm, it is convenient to process and manufacture the first conductive layer 2431. On the other hand, when the thickness of each first conductive layer 2431 is less than or equal to 0.15mm, the overall thickness of the bending part 243 is thinner, the bending difficulty of the bending part 243 is lower, and it is convenient to bend the first adapter 24.

[0268] According to some embodiments of this application, the minimum cross-sectional area of ​​the bending portion 243 is H1, and the minimum cross-sectional area of ​​the first connecting portion 241 is H2, satisfying 0.1*H2≤H1≤0.5*H2.

[0269] The cross-sectional area of ​​the bent portion 243 can be the area of ​​the cross-section obtained by the bent portion 243 from a plane parallel to the width direction K of the first adapter 24. In some embodiments, the cross-sectional area of ​​the bent portion 243 can be the flow area of ​​the bent portion 243. For example, the cross-sectional area of ​​the bent portion 243 is the thickness of the bent portion 243 multiplied by the dimension of the bent portion 243 in the width direction K of the first adapter 24. When the first conductive layer 2431 is provided with a through hole, the dimension of the bent portion 243 in the width direction K of the first adapter 24 needs to be subtracted from the dimension of the through hole in the width direction K of the first adapter 24.

[0270] The cross-sectional area of ​​the first connecting portion 241 can be the area of ​​the cross section of the first connecting portion 241 obtained by a plane parallel to the width direction K of the first adapter 24. In some embodiments, the cross-sectional area of ​​the first connecting portion 241 can be the flow area of ​​the bending portion 243.

[0271] In some embodiments, the ratio H1 / H2 can be any one of 0.1, 0.2, 0.3, 0.4 or 0.5, or a range between any two.

[0272] In the above scheme, the minimum cross-sectional area of ​​the bending part 243 and the minimum cross-sectional area of ​​the first connecting part 241 satisfy the above relationship (0.1*H2≤H1≤0.5*H2). On the one hand, it can reduce the bending difficulty of the first adapter 24, and on the other hand, the bending part 243 has a high flow capacity.

[0273] According to some embodiments of this application, 0.2*H2≤H1≤0.4*H2.

[0274] In some embodiments, 0.25*H2≤H1≤0.35*H2.

[0275] In the above scheme, when H1≥0.2*H2, the cross-sectional area of ​​the bending part 243 is larger, which further improves the flow capacity of the bending part 243; when H1≤0.4*H2, the strength of the bending part 243 is lower, which further reduces the bending difficulty of the bending part 243.

[0276] Referring to Figure 11, according to some embodiments of this application, the first adapter 24 includes a plurality of conductive sheets 24a stacked together. Each conductive sheet 24a includes an integrally formed first conductive layer 2431, a second conductive layer 2421 and a third conductive layer 2411. The multiple layers of the first conductive layer 2431 form a bending portion 243, the multiple layers of the second conductive layer 2421 form a second connecting portion 242, and the multiple layers of the third conductive layer 2411 form a first connecting portion 241.

[0277] The conductive sheet 24a is a conductive metal sheet with good conductivity.

[0278] The third conductive layer 2411, the first conductive layer 2431, and the second conductive layer 2421 are three regions of the conductive sheet 24a. The third conductive layer 2411, the first conductive layer 2431, and the second conductive layer 2421 can be distributed sequentially along the length of the conductive sheet 24a. After multiple conductive sheets 24a are stacked and bent, multiple layers of the third conductive layer 2411 form the first connecting part 241, multiple layers of the first conductive layer 2431 form the bending part 243, and multiple layers of the second conductive layer 2421 form the second connecting part 242.

[0279] The third conductive layer 2411, the first conductive layer 2431, and the second conductive layer 2421 are integrally formed. The thicknesses of the third conductive layer 2411, the first conductive layer 2431, and the second conductive layer 2421 can be equal. However, processing errors are allowed in the thicknesses of the third conductive layer 2411, the first conductive layer 2431, and the second conductive layer 2421.

[0280] In the above scheme, the first adapter 24 has a multi-layer structure, with the first conductive layer 2431, the second conductive layer 2421 and the third conductive layer 2411 integrally formed, which is convenient for processing and manufacturing, and the first conductive layer 2431 is firmly connected to the second conductive layer 2421 and the third conductive layer 2411.

[0281] According to some embodiments of this application, the thickness of each of the plurality of conductive sheets 24a is equal.

[0282] During the manufacturing process, multiple conductive sheets 24a can be manufactured in batches. For example, a continuous strip of conductive metal sheet can be cut into multiple conductive sheets 24a, and the multiple conductive sheets 24a can be stacked to form a first adapter 24, so that the thickness of each conductive sheet 24a is equal. It should be noted that the equal thickness of each conductive sheet 24a means approximately equal, and processing errors are allowed.

[0283] In the above scheme, the thickness of each conductive sheet 24a is equal, which facilitates mass production and reduces processing costs.

[0284] According to some embodiments of this application, two adjacent conductive sheets 24a of a plurality of conductive sheets 24a are welded or connected by conductive adhesive.

[0285] After multiple conductive sheets 24a are stacked, they can be fixedly connected, for example, by welding or connecting two adjacent conductive sheets 24a with conductive adhesive.

[0286] When welding or connecting two adjacent conductive sheets 24a with conductive adhesive, the two ends of the bent portion 243 that are connected to the first connecting portion 241 and the second connecting portion 242 can be connected to make the bent portion 243 more flexible and easier to bend.

[0287] In the above scheme, two adjacent conductive sheets 24a are welded or connected by conductive adhesive to facilitate electrical connection between the multiple conductive sheets 24a, so that the first adapter 24 has a high current carrying capacity.

[0288] According to some embodiments of this application, the battery cell 20 further includes a first insulating member 25, which covers at least a portion of the surface of the electrode assembly 22 to separate the electrode assembly 22 from the housing 21.

[0289] For example, the first insulating element 25 can be an insulating film, such as a Mylar film, wrapped around the outer surface of the electrode assembly 22.

[0290] Optionally, the housing 21 includes a housing 21a and an end cap 21b, and the first insulating member 25 may be disposed between the electrode assembly 22 and the housing 21a.

[0291] Please refer to Figures 12 and 13. Figure 12 is an exploded view of the structure of a battery cell provided in some other embodiments of this application, and Figure 13 is an exploded view of the structure of a battery cell provided in yet another embodiment of this application. According to some embodiments of this application, the outer casing 21 includes a housing 21a and an end cap 21b. The housing 21a has an opening, and the end cap 21b covers the opening. The end cap 21b is a first wall 211. The electrode assembly 22 also has a second tab 22b, the polarity of which is opposite to that of the first tab 22a. The battery cell 20 also includes a second electrode terminal 23b, which is disposed on the end cap 21b or the housing 21a, and is electrically connected to the second tab 22b.

[0292] The housing 21a and end cap 21b are separate parts, which facilitates processing and manufacturing.

[0293] The first electrode tab 22a can be a positive electrode tab, and the second electrode tab 22b can be a negative electrode tab; or, the first electrode tab 22a can be a negative electrode tab, and the second electrode tab 22b can be a positive electrode tab.

[0294] The polarity of the second tab 22b is opposite to that of the first tab 22a. Referring to Figure 10, the second tab 22b may be located on the same side of the electrode assembly 22 as the first tab 22a; or, referring to Figure 11, the second tab 22b may be located on opposite sides of the electrode assembly 22 as the first tab 22a. For example, the second tab 22b may be located on adjacent sides or opposite sides of the electrode assembly 22 as the first tab 22a.

[0295] In some embodiments, when the second electrode tab 22b and the first electrode tab 22a are located on the same side of the electrode assembly 22, the second electrode terminal 23b may be disposed on the end cap 21b.

[0296] In some embodiments, when the second electrode tab 22b and the first electrode tab 22a are located on opposite sides of the electrode assembly 22, the second electrode terminal 23b may be disposed on the housing 21a.

[0297] In some embodiments, the second electrode terminal 23b can be directly soldered to the second electrode tab 22b, or the second electrode terminal 23b can be electrically connected to the second electrode tab 22b through the second adapter 27.

[0298] In the above scheme, the end cap 21b is the first wall 211, which facilitates the assembly of the first electrode terminal 23a with the first wall 211, facilitates the connection of the first adapter 24 with the first electrode terminal 23a, and facilitates the assembly of the battery cell 20. When the second electrode terminal 23b is disposed on the end cap 21b, the second tab 22b and the first tab 22a can be located on the same side of the electrode assembly 22, which facilitates the connection of the second electrode terminal 23b and the first electrode terminal 23a with the electrode assembly 22; when the second electrode terminal 23b is disposed on the housing 21a, the second electrode terminal 23b and the first electrode terminal 23a are flexibly positioned, which facilitates the connection of the battery cell 20 with other components.

[0299] Please refer to Figures 14 and 15. Figure 14 is an exploded view of the structure of a battery cell provided in some embodiments of this application from one perspective, and Figure 15 is an exploded view of the structure of a battery cell provided in some embodiments of this application from another perspective. According to some embodiments of this application, the outer casing 21 includes a first end cap 21c, a housing 21a, and a second end cap 21d. The housing 21a has two openings disposed opposite to each other. The first end cap 21c and the second end cap 21d cover the two openings respectively. The first end cap 21c is a first wall 211. The electrode assembly 22 also has a second tab 22b, the polarity of which is opposite to that of the first tab 22a. The battery cell 20 also includes a second electrode terminal 23b, which is disposed on the second end cap 21d and electrically connected to the second tab 22b.

[0300] The first end cap 21c and the second end cap 21d respectively cover the two openings of the housing 21a, and the first end cap 21c and the second end cap 21d are respectively connected to the housing 21a to separate the interior and exterior of the battery cell 20.

[0301] The electrode assembly 22 includes a main body 220, a first electrode tab 22a, and a second electrode tab 22b. The main body 220 has a first edge 220a and a second edge 220b disposed opposite to each other along the thickness direction z of the first wall. The first edge 220a is closer to the first end cap 21c than the second edge 220b, and the second edge 220b is closer to the second end cap 21d than the first edge 220a. The first electrode tab 22a extends from the first edge 220a, and the second electrode tab 22b extends from the second edge 220b.

[0302] The second tab 22b and the first tab 22a are distributed at opposite ends of the electrode assembly 22 in the thickness direction z of the first wall, so as to output or input current from opposite ends of the electrode assembly 22 in the thickness direction Z of the first wall.

[0303] During the assembly of the battery cell 20, the first tab 22a is connected to the first electrode terminal 23a disposed on the first end cover 21c via the first adapter 24, and the second tab 22b is connected to the second electrode terminal 23b disposed on the second end cover 21d. The first electrode terminal 23a and the second electrode terminal 23b are arranged opposite to each other in the thickness direction z of the first wall, which can reduce the risk of short circuit between the positive and negative electrodes.

[0304] In some embodiments, the second electrode terminal 23b can be directly soldered to the second electrode tab 22b, or the second electrode terminal 23b can be electrically connected to the second electrode tab 22b through the second adapter 27.

[0305] In the above scheme, the second electrode terminal 23b is disposed on the second end cover 21d, the first end cover 21c and the second end cover 21d are disposed opposite to each other, and the first end cover 21c and the second end cover 21d can be assembled with the housing 21a from both ends of the housing 21a respectively, which facilitates the assembly flexibility of the battery cell 20 and facilitates the assembly of the battery cell 20.

[0306] According to some embodiments of this application, the structure of the second adapter 27 is the same as that of the first adapter 24, and the second adapter 27 can also be a bent structure. The assembly method of the second adapter 27 with the second electrode terminal 23b and the second tab 22b can refer to the assembly method of the first adapter 24 with the first electrode terminal 23a and the first tab 22a.

[0307] In some embodiments, the second adapter 27 is also composed of a multilayer conductive sheet 24a.

[0308] According to some embodiments of this application, the battery cell 20 further includes a third insulating member 29, which is disposed on the side of the second end cover 21d facing the inside of the battery cell 20. The third insulating member 29 is used to separate the electrode assembly 22 from the second end cover 21d to reduce the risk of short circuit between the electrode assembly 22 and the second end cover 21d.

[0309] Please refer to Figure 16, which is a schematic diagram of the assembly of an electrode assembly and a first adapter according to some embodiments of this application. According to some embodiments of this application, the electrode assembly 22 has two first tabs 22a; the first adapter 24 includes two second connecting portions 242 and two bending portions 243. The two second connecting portions 242 are spaced apart along the thickness direction Y of the electrode assembly. Each second connecting portion 242 is connected to a first connecting portion 241 through a bending portion 243, and each first tab 22a is connected to a second connecting portion 242.

[0310] When the electrode assembly 22 has a wound structure, the electrode assembly 22 includes a flat region, and the electrode sheets in the flat region are stacked along the thickness direction Y of the electrode assembly. When the electrode assembly 22 has a stacked structure, the electrode sheets of the electrode assembly 22 are stacked along the thickness direction Y of the electrode assembly.

[0311] In some embodiments, when the number of electrode components 22 is one, all the first sub-tabs 221 of the electrode component 22 are divided into two first tabs 22a in the stacking direction. When the number of electrode components 22 is an even number (e.g., two, four, etc.), half of the electrode components 22 have their first sub-tabs 221 forming one first tab 22a, and the other half of the electrode components 22 have their first sub-tabs 221 forming another first tab 22a.

[0312] The electrode assembly 22 may be provided with a number of first sub-tabs 221. All the first sub-tabs 221 are divided into two first tabs 22a. Two second connecting parts 242 are arranged at intervals along the thickness direction Y of the electrode assembly, so as to realize the connection between the first tabs 22a and the second connecting parts 242 at both ends of the thickness direction Y of the electrode assembly, which is conducive to improving the energy density of the battery cell 20.

[0313] In the above scheme, when the electrode assembly 22 is provided with a plurality of first sub-tabs 221, the battery cell 20 can have a high energy density. The plurality of first sub-tabs 221 can be divided into two first tabs 22a. The two first tabs 22a can be spaced apart along the thickness direction Y of the electrode assembly to facilitate the convergence of the plurality of first sub-tabs 221. The first adapter 24 includes two second connecting parts 242. Each second connecting part 242 is connected to the first connecting part 241 through a bending part 243, which facilitates the connection between the first tabs 22a and the first adapter 24. At the same time, the provision of the two second connecting parts 242 and the two bending parts 243 facilitates the dispersion of stress on the two first tabs 22a and reduces the risk of cracking of the first tabs 22a.

[0314] According to some embodiments of this application, the outer casing 21 is rectangular.

[0315] In the above scheme, the outer shell 21 is cuboid, has high strength, and facilitates the stacking of multiple battery cells 20 to improve the energy density of the battery device 100 composed of the battery cells 20.

[0316] In some embodiments, the outer casing 21 may be a steel casing or an aluminum casing, and the battery cell 20 may be a rigid-cased battery cell.

[0317] According to some embodiments of this application, the battery cell 20 further includes a pressure relief mechanism 28 disposed in the housing 21a, and the pressure relief mechanism 28 can be actuated to release the internal pressure of the battery cell 20.

[0318] The pressure relief mechanism 28 can be a groove provided on the housing 21a, or the pressure relief mechanism 28 can also be an explosion-proof valve provided on the housing 21a.

[0319] In some embodiments, when the battery cell 20 experiences thermal runaway, the pressure relief mechanism 28 can be actuated to release the internal pressure of the battery cell 20. Actuation of the pressure relief mechanism 28 may include, but is not limited to, at least partial structural damage to the pressure relief mechanism 28, or opening of the valve core of the pressure relief mechanism 28.

[0320] In some embodiments, the housing 21a includes two first sidewalls 212 disposed opposite to each other along a first direction X and two second sidewalls 213 disposed opposite to each other along a second direction. The opposite ends of the first sidewalls 212 in the second direction are respectively connected to the two second sidewalls 213. The two first sidewalls 212 and the two second sidewalls 213 form a space for accommodating the electrode assembly 22. The second direction is parallel to the thickness direction Y of the electrode assembly.

[0321] Optionally, the surface area of ​​the first sidewall 212 is smaller than the surface area of ​​the second sidewall 213, and the pressure relief mechanism 28 is disposed on the first sidewall 212.

[0322] In some embodiments, the thickness direction z of the first wall may be parallel to the length direction of the battery cell 20.

[0323] According to some embodiments of this application, this application also provides a battery device 100, which includes a battery cell 20 provided according to any of the above embodiments.

[0324] According to some embodiments of this application, this application also provides an electrical device, which includes a battery cell 20 or a battery device 100 provided according to any of the above embodiments, wherein the battery cell 20 or the battery device 100 is used to provide electrical energy.

[0325] The electrical device can be any of the above-mentioned devices or systems that use battery cell 20 or battery device 100 as power source.

[0326] According to some embodiments of this application, please refer to Figures 3 to 11, 14 and 15. This application provides a battery cell 20, which includes a housing 21, a first electrode terminal 23a, an electrode assembly 22, a first adapter 24, a second electrode terminal 23b and a second adapter 27.

[0327] The outer shell 21 is rectangular and includes a shell 21a, a first end cap 21c and a second end cap 21d. The shell 21a has two openings that are arranged opposite to each other. The first end cap 21c and the second end cap 21d respectively close the two openings. The first end cap 21c is the first wall 211.

[0328] The first electrode terminal 23a is disposed on the first wall 211, and the second electrode terminal 23b is disposed on the second end cap 21d.

[0329] Electrode assembly 22 is disposed inside housing 21. Electrode assembly 22 includes main body 220, first electrode tab 22a and second electrode tab 22b. Main body 220 has a first edge 220a and a second edge 220b disposed opposite to each other along the thickness direction z of the first wall. The first edge 220a is closer to the first wall 211 than the second edge 220b, and the second edge 220b is closer to the second end cap 21d than the first edge 220a. The first electrode tab 22a extends from the first edge 220a and the second electrode tab 22b extends from the second edge 220b to facilitate the output or input of electrical energy at both ends in the thickness direction z of the first wall.

[0330] The first adapter 24 has a bent structure and includes a first connecting portion 241, a second connecting portion 242, and a bent portion 243. The first connecting portion 241 is welded to the first electrode terminal 23a, the second connecting portion 242 is welded to the first electrode tab 22a, and the bent portion 243 connects the first connecting portion 241 and the second connecting portion 242. In the unfolded state, the first connecting portion 241, the bent portion 243, and the second connecting portion 242 are sequentially distributed along the length direction L of the first adapter 24. On the same projection plane perpendicular to the thickness direction z of the first wall, the orthographic projection of the first connecting portion 241 and the orthographic projection of the second connecting portion 242 at least partially overlap. The first adapter 24 includes a plurality of conductive sheets 24a stacked together, and a first tab 22a is sandwiched between the plurality of conductive sheets 24a; each conductive sheet 24a includes an integrally formed first conductive layer 2431, a second conductive layer 2421 and a third conductive layer 2411, the multiple layers of the first conductive layer 2431 form a bending portion 243, the multiple layers of the second conductive layer 2421 form a second connecting portion 242, and the multiple layers of the third conductive layer 2411 form a first connecting portion 241.

[0331] According to the battery cell 20 of the present application embodiment, the first adapter 24 includes a plurality of conductive sheets 24a, and the first adapter 24 has a bent structure, so that the first adapter 24 connecting the first electrode terminal 23a and the first tab 22a is a buffer structure, which can buffer the force generated by the movement of the electrode assembly 22 caused by the vibration of the battery cell 20, can disperse the stress of the first tab 22a, and can reduce the risk of fatigue cracking of the first tab 22a.

[0332] In some embodiments, the number of layers in the first conductive layer 2431 is less than the number of layers in the third conductive layer 2411; the number of layers in the first conductive layer 2431 is less than the number of layers in the second conductive layer 2421. The fewer layers in the first conductive layer 2431 make bending the bending portion 243 easier, thus facilitating the bending of the first adapter 24.

[0333] In some embodiments, at least one first conductive layer 2431 is provided with weakening portions 244, and the number of weakening portions 244 is multiple. These weakening portions 244 are spaced apart along the width direction K of the first adapter 24. The bending portion 243 has a first end face 243a and a second end face 243b disposed opposite to each other along the width direction K of the first adapter 24. The multiple weakening portions 244 include a first weakening portion 244a and a second weakening portion 244b. One end of the first weakening portion 244a extends to the first end face 243a, and one end of the second weakening portion 244b extends to the second end face 243b. The provision of the first weakening portions 244a and the second weakening portions 244b reduces the strength of the first adapter 24 at the bending portion 243, facilitating bending of the first adapter 24. Furthermore, it reduces manufacturing difficulty and facilitates processing, while also increasing the heat dissipation area, thus improving heat dissipation of the first adapter 24.

[0334] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer shell has a first wall; The first electrode terminal is disposed on the first wall; An electrode assembly is disposed within the housing, the electrode assembly having a first tab; The first adapter includes a first connecting part, a second connecting part, and a bending part. The first connecting part is electrically connected to the first electrode terminal, the second connecting part is electrically connected to the first electrode tab, and the bending part connects the first connecting part and the second connecting part. On the same projection plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first connecting part and the orthographic projection of the second connecting part at least partially overlap. The bent portion includes at least two stacked first conductive layers.

2. The battery cell according to claim 1, characterized in that, At least one of the first conductive layers has a weakening portion.

3. The battery cell according to claim 2, characterized in that, The weakened portion includes at least one of a through hole, a groove, and a groove.

4. The battery cell according to any one of claims 2-3, characterized in that, The weakened portion is located on the inside of the bent portion.

5. The battery cell according to any one of claims 2-4, characterized in that, In the unfolded state of the first adapter, the first connecting part, the bent part, and the second connecting part are distributed sequentially along the length direction of the first adapter; The length direction of the weakened part is parallel to the width direction of the first adapter.

6. The battery cell according to claim 5, characterized in that, The number of weakened parts is multiple, and the multiple weakened parts are spaced apart along the width direction of the first adapter.

7. The battery cell according to claim 6, characterized in that, The bending portion has a first end face and a second end face disposed opposite to each other along the width direction of the first adapter. The plurality of weakening portions include a first weakening portion and a second weakening portion, one end of the first weakening portion extending to the first end face and one end of the second weakening portion extending to the second end face.

8. The battery cell according to any one of claims 1-7, characterized in that, The second connection portion includes multiple layers of second conductive layers stacked together, with the first electrode tab sandwiched between the multiple layers of second conductive layers.

9. The battery cell according to claim 8, characterized in that, The number of layers in the first conductive layer is less than or equal to the number of layers in the second conductive layer.

10. The battery cell according to claim 9, characterized in that, Each layer of the first conductive layer and each layer of the second conductive layer are integrally formed.

11. The battery cell according to claim 10, characterized in that, The thickness of the second conductive layer is equal to the thickness of the first conductive layer.

12. The battery cell according to any one of claims 8-11, characterized in that, The first electrode includes a plurality of first sub-electrodes stacked together, with the plurality of first sub-electrodes sandwiched between two adjacent layers of the second conductive layer.

13. The battery cell according to any one of claims 8-12, characterized in that, The number of layers of the second conductive layer on both sides of the first electrode tab of the second connection portion is equal.

14. The battery cell according to any one of claims 1-13, characterized in that, The first connection portion includes at least two stacked third conductive layers.

15. The battery cell according to claim 14, characterized in that, The number of layers in the first conductive layer is less than or equal to the number of layers in the third conductive layer.

16. The battery cell according to claim 15, characterized in that, The first conductive layer and the third conductive layer are integrally formed in each layer.

17. The battery cell according to claim 16, characterized in that, The thickness of the third conductive layer is equal to the thickness of the first conductive layer.

18. The battery cell according to any one of claims 1-13, characterized in that, The first connecting part is a single-layer structure.

19. The battery cell according to any one of claims 1-18, characterized in that, The thickness of the first conductive layer in each layer is greater than or equal to 0.05 mm and less than or equal to 0.25 mm.

20. The battery cell according to claim 19, characterized in that, The thickness of the first conductive layer in each layer is greater than or equal to 0.1 mm and less than or equal to 0.2 mm.

21. The battery cell according to any one of claims 1-20, characterized in that, The first adapter is made of copper, and the maximum thickness of the bent portion is greater than or equal to 0.4 mm and less than or equal to 1.5 mm.

22. The battery cell according to claim 21, characterized in that, The maximum thickness of the bent portion is greater than or equal to 0.6 mm and less than or equal to 1.2 mm.

23. The battery cell according to any one of claims 1-20, characterized in that, The first adapter is made of aluminum, and the maximum thickness of the bent portion is greater than or equal to 0.4 mm and less than or equal to 1.8 mm.

24. The battery cell according to claim 23, characterized in that, The maximum thickness of the bent portion is greater than or equal to 0.7 mm and less than or equal to 1.5 mm.

25. The battery cell according to any one of claims 1-18, characterized in that, The number of layers in the first conductive layer is greater than or equal to 10 and less than or equal to 12; The thickness of the first conductive layer in each layer is greater than or equal to 0.05 mm and less than or equal to 0.15 mm.

26. The battery cell according to any one of claims 1-25, characterized in that, The minimum cross-sectional area of ​​the bent portion is H1, and the minimum cross-sectional area of ​​the first connecting portion is H2, satisfying 0.1*H2≤H1≤0.5*H2.

27. The battery cell according to claim 26, characterized in that, 0.2*H2≤H1≤0.4*H2.

28. The battery cell according to claim 1, characterized in that, The first adapter includes multiple conductive sheets stacked together. Each conductive sheet includes an integrally formed first conductive layer, a second conductive layer, and a third conductive layer. Multiple layers of the first conductive layer form the bending portion, multiple layers of the second conductive layer form the second connecting portion, and multiple layers of the third conductive layer form the first connecting portion.

29. The battery cell according to claim 28, characterized in that, The thickness of each of the plurality of conductive sheets is equal.

30. The battery cell according to claim 28 or 29, characterized in that, Adjacent conductive sheets among the plurality of conductive sheets are welded together or connected by conductive adhesive.

31. The battery cell according to any one of claims 1-30, characterized in that, The outer casing includes a housing and an end cap, the housing having an opening, the end cap covering the opening, and the end cap being the first wall; The electrode assembly also has a second tab, the polarity of which is opposite to that of the first tab; The battery cell also includes a second electrode terminal, which is disposed on the end cap or the housing and is electrically connected to the second tab.

32. The battery cell according to any one of claims 1-30, characterized in that, The outer casing includes a first end cap, a housing, and a second end cap. The housing has two openings that are disposed opposite to each other. The first end cap and the second end cap respectively cover the two openings. The first end cap is the first wall. The electrode assembly also has a second tab, the polarity of which is opposite to that of the first tab; The battery cell also includes a second electrode terminal, which is disposed on the second end cap and electrically connected to the second tab.

33. The battery cell according to any one of claims 1-32, characterized in that, The electrode assembly has two first electrode tabs; The first adapter includes two second connecting portions and two bending portions. The two second connecting portions are spaced apart along the thickness direction of the electrode assembly. Each second connecting portion is connected to the first connecting portion through one of the bending portions. Each first tab is connected to one of the second connecting portions.

34. The battery cell according to any one of claims 1-33, characterized in that, The outer shell is rectangular.

35. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-34.

36. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-34 or a battery device as described in claim 35, wherein the battery cell or battery device is used to provide electrical energy.

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