Battery cell, battery apparatus, and electric device

Abstract

The present application discloses a battery cell, a battery apparatus, and an electric device. The battery cell comprises a casing and an electrode assembly; the electrode assembly comprises at least one electrode unit; and the electrode unit comprises a plurality of electrode sheet bodies and separators. The plurality of electrode sheet bodies comprise at least one first electrode sheet body, and a second electrode sheet body and a third electrode sheet body; and the at least one first electrode sheet body is arranged between the second electrode sheet body and the third electrode sheet body. The first electrode sheet body comprises a first current collector body, a first film layer, and a second film layer; the first current collector body comprises a first insulating base layer, a first conductive layer, and a second conductive layer; and the first conductive layer is electrically connected to the second conductive layer. The second electrode sheet body comprises a second current collector body and a third film layer. The third electrode sheet body comprises a third current collector body and a fourth film layer. The polarities of the first film layer and the second film layer are opposite, the polarities of the third film layer and the second film layer are the same, and the polarities of the fourth film layer and the first film layer are the same.

Description

Battery cells, battery devices and electrical equipment

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411611986.6, filed on November 12, 2024, entitled “Battery Cell, Battery Device and Electrical Equipment”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of battery technology, and in particular relates to a battery cell, a battery device, and an electrical device. Background Technology

[0004] With the continuous improvement of people's living standards and environmental awareness, the new energy industry is booming, and batteries, as an important part of the new energy industry, have received widespread attention. In the current era of rapidly evolving battery-containing products such as energy storage base stations, electric vehicles, drones, mobile phones, and power tools, there is a need to design diverse and customized batteries. However, achieving multi-platform compatibility for batteries has become an industry challenge. Summary of the Invention

[0005] This application provides a battery cell, a battery device, and an electrical appliance, which can realize voltage regulation of a single battery cell and expand the capacity regulation range of the battery cell to improve compatibility.

[0006] According to a first aspect of this application, a battery cell is provided, comprising a housing and an electrode assembly housed within the housing. The electrode assembly includes at least one electrode unit, and each electrode unit includes multiple electrode bodies and a separator. The multiple electrode bodies are stacked along the thickness direction of the electrode bodies, and the separator separates adjacent electrode bodies. The multiple electrode bodies include at least one first electrode body, a second electrode body, and a third electrode body, with at least one first electrode body disposed between the second and third electrode bodies. The first electrode body includes a first current collector, a first film layer, and a second film layer. The first current collector includes a first insulating base layer, a first conductive layer, and a second conductive layer. The first conductive layer is disposed on the side of the first insulating base layer facing the second electrode body, and the second conductive layer is disposed on the side of the first insulating base layer facing the third electrode body. The first film layer is disposed on the side of the first conductive layer away from the first insulating base layer, and the second film layer is disposed on the side of the second conductive layer away from the first insulating base layer. The first conductive layer is electrically connected to the second conductive layer. The second electrode body includes a second current collector and a third film layer, with the third film layer disposed on the side of the second current collector facing the first electrode body. The third electrode body includes a third current collector and a fourth film layer, with the fourth film layer disposed on the side of the third current collector facing the first electrode body. The first and second film layers have opposite polarities, the third and second film layers have the same polarity, and the fourth film layer has the same polarity as the first film layer.

[0007] The battery cell provided in this application provides at least one electrode unit, and within each electrode unit, at least one first electrode body, as well as a second electrode body and a third electrode body, to form multiple charge-discharge units. The first conductive layer of the first electrode body is electrically connected to the second conductive layer of the first electrode body, thereby enabling multiple charge-discharge units to be connected in series within the electrode unit. Different numbers of first electrode bodies result in different voltages for individual electrode units, allowing for voltage regulation of a single battery cell by appropriately selecting the number of first electrode bodies included in the electrode unit. Simultaneously, the capacity of a single battery cell can also be adjusted by appropriately selecting the number of electrode units, reducing the dependence on capacity regulation factors, expanding the capacity regulation range of the battery cell, and improving the compatibility of the battery cell.

[0008] In some embodiments, the second current collector includes a second insulating base layer and a third conductive layer. The third conductive layer is disposed on the side of the second insulating base layer facing the first electrode body, and a third film layer is disposed on the side of the third conductive layer away from the second insulating base layer. The third current collector includes a third insulating base layer and a fourth conductive layer. The fourth conductive layer is disposed on the side of the third insulating base layer facing the first electrode body, and a fourth film layer is disposed on the side of the fourth conductive layer away from the second insulating base layer. The second electrode body and the third electrode body are the two outermost electrode bodies of the electrode unit along the thickness direction. Both the second electrode body and the third electrode body have an insulating base layer and a conductive layer. The insulating base layer of both can achieve insulation isolation between the electrode unit and other structures, eliminating the need for other insulation isolation components and simplifying the structure. Furthermore, the insulating base layers of multiple electrode bodies can be made of the same material, which helps to improve material consistency.

[0009] In some embodiments, the electrode unit includes multiple bends, and two adjacent electrode bodies are connected by the bends. The bends connect two adjacent electrode bodies and can at least partially cover the conductive layer and film layer located between the insulating base layers of the two adjacent electrode bodies from the outside, which is beneficial for achieving insulation isolation between the electrode unit and other structures. Furthermore, the bends can also reduce the relative movement of the two adjacent electrode bodies during assembly, shaking, etc., improving structural stability.

[0010] In some embodiments, the first insulating base layer, the second insulating base layer, the third insulating base layer, and the plurality of bent portions are integrally formed. There are no cut edges between any two adjacent elements of the first insulating base layer, the second insulating base layer, the third insulating base layer, and the plurality of bent portions, reducing the number of cut edges and mitigating the risk of burrs on the cut edges puncturing the insulating components covering the electrode assembly, thus improving the reliability of the battery cell. Furthermore, the first insulating base layer, the second insulating base layer, and the third insulating base layer can be formed by repeatedly bending an insulating substrate, simultaneously forming multiple bent portions that provide insulation. This simplifies the insulation design and assembly process of the electrode assembly and improves assembly efficiency.

[0011] In some embodiments, the electrode unit further includes a first tab and a second tab, the first tab being connected to a second current collector and the second tab being connected to a third current collector. The first tab and the second tab are capable of leading the current of the electrode unit to an external circuit.

[0012] In some embodiments, the first tab extends from the end of the second current collector along the first direction, and the second tab extends from the end of the third current collector along the first direction; the insulating member is disposed on the side of the first film layer facing away from the first conductive layer, the two ends of the first film layer along the second direction do not extend beyond the insulating member, and the two ends of the insulating member along the second direction extend beyond the second film layer; the first direction, the second direction, and the thickness direction are perpendicular to each other. The two ends of the insulating member along the second direction extend beyond the second film layer, and the portion of the insulating member extending beyond the second film layer can insulate and isolate the positive and negative film layers, which is beneficial to improving the insulation effect.

[0013] In some embodiments, the separator includes an electrolyte coating. The separator functions both as a barrier membrane and provides the electrolyte required for the electrochemical reaction. The electrolyte coating is a solid electrolyte, which helps reduce the risk of electrolyte leakage or vaporization.

[0014] In some embodiments, the electrode unit includes a conductive connector, and the first conductive layer and the second conductive layer are electrically connected through the conductive connector.

[0015] In some embodiments, there are multiple electrode units, which are stacked along the thickness direction, which is beneficial to increase the capacity of a single battery cell.

[0016] In some embodiments, the electrode unit further includes a first tab and a second tab, the first tab being connected to a second current collector and the second tab being connected to a third current collector; the first tabs of multiple electrode units are stacked and connected along the thickness direction, and the second tabs of multiple electrode units are stacked and connected along the thickness direction. The stacking and connection of the first tabs of multiple electrode units helps to compress the interlayer gap between adjacent first tabs, facilitating the connection of the first electrode lead-out structure, reducing the cracking of the first tabs, lowering the risk of connection failure, and improving the overcurrent capacity and reliability of the battery cell. Similarly, the stacking and connection of the second tabs of multiple electrode units helps to compress the interlayer gap between adjacent second tabs, facilitating the connection of the second electrode lead-out structure, reducing the cracking of the second tabs, lowering the risk of connection failure, and improving the overcurrent capacity and reliability of the battery cell.

[0017] In some embodiments, the electrode assembly includes an insulating connection layer. In two adjacent electrode units, the second current collector of one electrode unit and the third current collector of the other electrode unit are connected by the insulating connection layer. At least a portion of the insulating connection layer is located between the two adjacent electrode units along the thickness direction. The insulating connection layer can insulate and separate the two adjacent electrode units, and also insulate the ends of the second and third current collectors along the second direction from other components, which helps reduce the risk of short circuits. Furthermore, by connecting the second current collector of one electrode unit and the third current collector of the other electrode unit, the insulating connection layer can also reduce the risk of mutual movement between the two adjacent electrode units during battery cell assembly or use, which helps improve structural stability.

[0018] In some embodiments, the second current collector includes a second insulating base layer and a third conductive layer, the third conductive layer being disposed on the side of the second insulating base layer facing the first electrode body; the third current collector includes a third insulating base layer and a fourth conductive layer, the fourth conductive layer being disposed on the side of the third insulating base layer facing the first electrode body; in two adjacent electrode units, the second insulating base layer of one electrode unit, the third insulating base layer of the other electrode unit, and the insulating connecting layer are integrally formed. The second insulating base layer, the insulating connecting layer of one electrode unit, and the third insulating base layer of the other electrode unit can be formed by repeatedly bending an insulating substrate along an S-shaped curve, which helps to simplify the insulation design and assembly process of the electrode assembly and improve assembly efficiency.

[0019] In some embodiments, the electrode assembly includes an outer insulating layer that covers at least a portion of at least one electrode unit from the outside. The outer insulating layer's ability to cover at least a portion of at least one electrode unit provides insulation between the at least one electrode unit and the housing or other components, thereby reducing the risk of short circuits.

[0020] According to a second aspect of this application, this application provides a battery device comprising a plurality of battery cells provided according to any embodiment of the first aspect of this application.

[0021] According to a third aspect of this application, this application provides an electrical device that includes a battery device provided according to any embodiment of the second aspect of this application, the battery device being used to provide electrical energy. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application.

[0024] Figure 2 is an exploded structural diagram of a battery provided in some embodiments of this application.

[0025] Figure 3 is an exploded structural diagram of a battery cell provided in some embodiments of this application.

[0026] Figure 4 is a top view of the electrode assembly of a battery cell provided in some embodiments of this application.

[0027] Figure 5 is a schematic cross-sectional view of Figure 4 taken along the cutting line AA;

[0028] Figure 6 is a cross-sectional view of the electrode assembly of a battery cell provided in some other embodiments of this application;

[0029] Figure 7 is a schematic cross-sectional view of Figure 4 taken along the cutting line BB;

[0030] Figure 8 is a schematic enlarged structural diagram of part C in Figure 5;

[0031] Figure 9 is a schematic enlarged structural diagram of part D in Figure 5;

[0032] Figure 10 is a schematic diagram of the electrode assembly of a battery cell provided in some embodiments of this application in the unfolded state.

[0033] In the attached diagram: Vehicle 1, Battery unit 2, Controller 3, Motor 4, Housing 5, Battery cell 6; Electrode assembly 10, Electrode unit 10a, Insulating connection layer 10b, First main body 10b1, First connecting part 10b2, Outer insulating layer 10c, Second main body 10c1, Second connecting part 10c2, Insulating substrate 10d, First electrode body 11, First current collector body 111, First insulating base layer 1111, First conductive layer 1112, Second conductive layer 1113, First film layer 112, Second film layer 113, Second electrode body 12, Second current collector body 121, Second insulating layer 121, etc. The components are: base layer 1211, third conductive layer 1212, third film layer 122, third electrode body 13, third current collector body 131, third insulating base layer 1311, fourth conductive layer 1312, fourth film layer 132, separator 14, first electrode tab 151, second electrode tab 152, first electrode lead-out structure 161, second electrode lead-out structure 162, conductive connector 17, bending part 18, outer shell 20, housing 21, end cap 22, first box body part 5a, second box body part 5b, accommodating space 5c; thickness direction X, first direction Y, second direction Z. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] 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.

[0036] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0037] 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.

[0038] 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.

[0039] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0040] In this application, "multiple" means two or more (including two).

[0041] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0042] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0043] A battery cell typically includes an electrode assembly and a casing. The electrode assembly, located within the casing, includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. Exemplarily, the electrode assembly also includes a separator, which prevents short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0044] The housing is used to encapsulate electrode components and electrolytes. The housing can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0045] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., but the embodiments of this application are not limited to this.

[0046] As an example, the battery cell can be a cylindrical battery cell, 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. This application does not have any particular limitations.

[0047] The battery cell can be a hard-shell battery cell, a soft-pack battery cell, or other types of battery cells.

[0048] 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.

[0049] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells. A battery device generally includes a housing for encapsulating one or more battery cell assemblies. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0050] As an example, a battery cell assembly can be a battery module, which consists of multiple battery cells arranged and fixed together to form a single module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties. The battery cell assembly can be housed within a housing by securing the battery module within a casing.

[0051] 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.

[0052] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0053] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0054] Electrode assemblies are mainly divided into two categories: wound structures and stacked structures. The electrodes, which form the core of both wound and stacked structures, exhibit a sandwich structure, where the same electrode paste is coated on both sides of a single current collector. Using this electrode structure, an electrode assembly can be formed by assembling a cathode, an insulating separator, an anode, and an insulating separator. The capacity of the electrode assembly can be adjusted by changing the size of the electrode and the number of stacked (or wound) layers. However, the capacity adjustment range of this structure depends on the electrode size and the capabilities of the manufacturing equipment, resulting in a limited actual adjustable range. Furthermore, this structure is difficult to adjust the voltage of individual battery cells, leading to poor compatibility.

[0055] When the capacity and voltage regulation of individual battery cells are limited, in order to meet the requirements of the customer platform, it is necessary to rely on the series and / or parallel connection of battery cells at the module level. This mode will sacrifice module space and reduce the volumetric energy density of the module.

[0056] In view of this, embodiments of this application provide a technical solution that involves setting at least one electrode unit, and within the electrode unit, at least one first electrode body, as well as a second electrode body and a third electrode body. The first conductive layer of the first electrode body is electrically connected to the second conductive layer of the first electrode body, thereby enabling the first, second, and third electrode bodies to be connected in series within the electrode unit. Different numbers of first electrode bodies result in different voltages for individual electrode units, allowing for voltage regulation of a single battery cell by rationally selecting the number of first electrode bodies included in the electrode unit. Simultaneously, the capacity of a single battery cell can also be adjusted by rationally selecting the number of electrode units, reducing the dependence on capacity regulation factors, which is beneficial for expanding the capacity regulation range of the battery cell and improving its compatibility.

[0057] The technical solutions provided in this application are applicable to battery cells, battery devices, and electrical equipment using battery devices.

[0058] The battery device disclosed in this application can be used in electrical devices that use the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. The electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0059] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0060] Figure 1 is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. Referring to Figure 1, vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 2 is installed inside vehicle 1, and the battery device 2 can be located at the bottom, front, or rear of vehicle 1. The battery device 2 can be used to power vehicle 1; for example, the battery device 2 can serve as the operating power source for vehicle 1. Vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, to meet the power needs of vehicle 1 during starting, navigation, and driving.

[0061] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0062] Figure 2 is an exploded structural diagram of a battery device provided in some embodiments of this application. Referring to Figure 2, the battery device 2 includes a housing 5 and a battery cell 6, with the battery cell 6 housed within the housing 5. The housing 5 provides a space for the battery cell 6, and the housing 5 can adopt various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, jointly defining a space 5c for accommodating the battery cell 6. The second housing portion 5b may be a hollow structure with one open end, and the first housing portion 5a may be a plate-like structure, covering the open side of the second housing portion 5b so that the first housing portion 5a and the second housing portion 5b jointly define the space 5c; alternatively, the first housing portion 5a and the second housing portion 5b may both be hollow structures with one open side, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b. Of course, the box 5 formed by the first box part 5a and the second box part 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0063] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0064] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0065] In the battery device 2, there can be multiple battery cells 6, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel configurations. Multiple battery cells 6 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 6 is housed within the housing 5. Alternatively, the battery device 2 can also consist of multiple battery cells 6 first connected in series, parallel, or in a mixed manner to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 5. The battery device 2 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 6.

[0066] For example, the battery cell 6 may be the smallest unit that makes up the battery device 2.

[0067] Figure 3 is an exploded structural diagram of a battery cell provided in some embodiments of this application. Referring to Figure 3, the battery cell 6 includes a housing 20 and an electrode assembly 10, the electrode assembly 10 being housed within the housing 20.

[0068] The outer casing 20 is used to encapsulate the electrode assembly 10 and electrolyte components. The outer casing 20 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0069] In some embodiments, the housing 20 is a hollow structure, with an internal space for accommodating the electrode assembly 10 and the electrolyte. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a cuboid structure, a cuboid housing can be selected.

[0070] The outer casing 20 can be made of various materials, such as metal or plastic. Optionally, the outer casing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. For example, the outer casing 20 can be a steel casing, aluminum casing, plastic casing (such as polypropylene), composite metal casing (such as copper-aluminum composite casing), or aluminum-plastic film, etc.

[0071] As an example, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having an opening and the end cap 22 for closing the opening.

[0072] The housing 21 is a component used to fit the end cap 22 to form the internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte, and other components.

[0073] The housing 21 and the end cap 22 can be separate components. For example, an opening can be provided on the housing 21, and the end cap 22 can be used to close the opening to form an internal cavity for the battery cell 6.

[0074] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21.

[0075] The end cap 22 can be connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0076] The housing 21 may be open at one end or open at both ends. For example, the housing 21 may be open on one side, with one end cap 22 covering the opening of the housing 21. Alternatively, the housing 21 may be open on both sides, with two end caps 22 covering the two openings of the housing 21 respectively.

[0077] Figure 4 is a top view of the electrode assembly of a battery cell provided in some embodiments of this application. Figure 5 is a schematic cross-sectional view taken along the cutting line AA in Figure 4. Figure 6 is a cross-sectional view of the electrode assembly of a battery cell provided in other embodiments of this application. Figure 7 is a schematic cross-sectional view taken along the cutting line BB in Figure 4. Figure 8 is a schematic enlarged view of part C in Figure 5. Figure 9 is a schematic enlarged view of part D in Figure 5.

[0078] Referring to Figures 3 to 9, in some embodiments, the battery cell 6 includes a housing 20 and an electrode assembly 10 housed within the housing 20. The electrode assembly 10 includes at least one electrode unit 10a. The electrode unit 10a includes a plurality of electrode bodies and a separator 14. The plurality of electrode bodies are stacked along the thickness direction X of the electrode bodies, and the separator 14 separates adjacent electrode bodies.

[0079] The plurality of electrode bodies include at least one first electrode body 11, a second electrode body 12 and a third electrode body 13, wherein at least one first electrode body 11 is disposed between the second electrode body 12 and the third electrode body 13.

[0080] The first electrode body 11 includes a first current collector 111, a first film layer 112, and a second film layer 113. The first current collector 111 includes a first insulating base layer 1111, a first conductive layer 1112, and a second conductive layer 1113. The first conductive layer 1112 is disposed on the side of the first insulating base layer 1111 facing the second electrode body 12, and the second conductive layer 1113 is disposed on the side of the first insulating base layer 1111 facing the third electrode body 13. The first film layer 112 is disposed on the side of the first conductive layer 1112 facing away from the first insulating base layer 1111, and the second film layer 113 is disposed on the side of the second conductive layer 1113 facing away from the first insulating base layer 1111. The first conductive layer 1112 is electrically connected to the second conductive layer 1113.

[0081] The second electrode body 12 includes a second current collector 121 and a third film layer 122, wherein the third film layer 122 is disposed on the side of the second current collector 121 facing the first electrode body 11.

[0082] The third electrode body 13 includes a third current collector 131 and a fourth film layer 132, with the fourth film layer 132 disposed on the side of the third current collector 131 facing the first electrode body 11.

[0083] The first film layer 112 and the second film layer 113 have opposite polarities, the third film layer 122 and the second film layer 113 have the same polarity, and the fourth film layer 132 has the same polarity as the first film layer 112.

[0084] One of the first film layer 112 and the second film layer 113 is a positive electrode film layer, and the other is a negative electrode film layer. One of the third film layer 122 and the fourth film layer 132 is a positive electrode film layer, and the other is a negative electrode film layer.

[0085] As an example, the positive electrode film layer may include a positive electrode active material. 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 material layers in batteries may also be used. These positive electrode active material layers may be used alone or in combination of two or more.

[0086] As an example, the negative electrode film may include a negative electrode active material. The negative electrode active material may be a negative electrode active material known in the art for use in battery cells.

[0087] The first film layer 112 can be coated on the surface of the first conductive layer 1112 that is opposite to the first insulating base layer 1111. The second film layer 113 can be coated on the surface of the second conductive layer 1113 that is opposite to the first insulating base layer 1111.

[0088] The first conductive layer 1112 can be attached to the surface of the first insulating base layer 1111 along the thickness direction X facing the second electrode body 12 by vapor deposition, bonding or other suitable means. The second conductive layer 1113 can be attached to the surface of the first insulating base layer 1111 along the thickness direction X facing the third electrode body 13 by vapor deposition, bonding or other suitable means.

[0089] The materials of the first conductive layer 1112 and the second conductive layer 1113 can be the same or different. Optionally, of the first conductive layer 1112 and the second conductive layer 1113, the one connected to the positive electrode film layer can be an aluminum layer or an aluminum alloy layer, and the one connected to the negative electrode film layer can be a copper layer or a copper alloy layer.

[0090] The first conductive layer 1112 can be directly electrically connected to the second conductive layer 1113, or it can be indirectly electrically connected to the second conductive layer 1113 through a conductive component, so that electrons can flow between the first conductive layer 1112 and the second conductive layer 1113.

[0091] The first membrane layer 112, the second membrane layer 113, the third membrane layer 122, and the fourth membrane layer 132 are used to undergo an electrochemical reaction with the electrolyte, thereby generating an electric current. The first current collector 111, the second current collector 121, and the third current collector 131 are used to collect the current.

[0092] In some examples, the second current collector 121 may be an integral metal conductive layer. A third film layer 122 may also be provided on the side of the second current collector 121 facing away from the first electrode body 11 along the thickness direction X.

[0093] In other examples, the second current collector 121 may also be a composite layer structure having an insulating substrate and a metallic conductive layer.

[0094] In some examples, the third current collector 131 may be an integral metal conductive layer. A fourth film layer 132 may also be provided on the side of the third current collector 131 facing away from the first electrode body 11 along the thickness direction X.

[0095] In other examples, the third current collector 131 may also be a composite layer structure having an insulating substrate and a metallic conductive layer.

[0096] For example, the second current collector 121 can be copper foil or aluminum foil. The third current collector 131 can be aluminum foil or copper foil.

[0097] The spacer 14 can be a single component and is disposed between two adjacent electrode bodies. The spacer 14 can also be attached to the surface of the electrode body.

[0098] In some examples, the separator 14 may include a separator membrane. The separator membrane may be a single-layer film or a multi-layer composite film, without particular limitation. When the separator membrane is a multi-layer composite film, the materials of each layer may be the same or different, without particular limitation.

[0099] In other examples, the separator 14 can also be 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.

[0100] Along the thickness direction X, two adjacent electrode bodies can be connected together or set separately.

[0101] In electrode unit 10a, a charge-discharge unit is formed between the second electrode body 12 and an adjacent first electrode body 11, and a charge-discharge unit is formed between the third electrode body 13 and an adjacent first electrode body 11. When there are multiple first electrode bodies 11, a charge-discharge unit is also formed between two adjacent first electrode bodies 11. In a charge-discharge unit, active ions can migrate back and forth between the positive electrode film layer and the negative electrode film layer.

[0102] Two adjacent charging and discharging units are connected in series through an electrical connection between the first conductive layer 1112 and the second conductive layer 1113 of a corresponding first electrode body 11.

[0103] For example, if the voltage of each charging and discharging unit is the same and is V0, the total voltage of the electrode unit 10a is Vtotal, Vtotal = (n+1)V0, where n is the number of first electrode bodies 11 of the electrode unit 10a.

[0104] The battery cell 6 provided in this application embodiment forms multiple charge / discharge units by providing at least one electrode unit 10a, and within the electrode unit 10a, at least one first electrode body 11, a second electrode body 12, and a third electrode body 13. The first conductive layer 1112 of the first electrode body 11 is electrically connected to the second conductive layer 1113 of the first electrode body 11, thereby enabling the series connection of multiple charge / discharge units within the electrode unit 10a. Different numbers of first electrode bodies 11 result in different voltages for individual electrode units 10a, allowing for voltage regulation of a single battery cell 6 by appropriately selecting the number of first electrode bodies 11 included in the electrode unit 10a. Simultaneously, the capacity of a single battery cell 6 can also be adjusted by appropriately selecting the number of electrode units 10a, reducing the dependence on capacity regulation factors, expanding the capacity regulation range of the battery cell 6, and improving the compatibility of the battery cell 6.

[0105] In some embodiments, the second current collector 121 includes a second insulating base layer 1211 and a third conductive layer 1212. The third conductive layer 1212 is disposed on the side of the second insulating base layer 1211 facing the first electrode body 11, and a third film layer 122 is disposed on the side of the third conductive layer 1212 away from the second insulating base layer 1211. The third current collector 131 includes a third insulating base layer 1311 and a fourth conductive layer 1312. The fourth conductive layer 1312 is disposed on the side of the third insulating base layer 1311 facing the first electrode body 11, and a fourth film layer 132 is disposed on the side of the fourth conductive layer 1312 away from the second insulating base layer 1211.

[0106] The third conductive layer 1212 may be attached to the surface of the second insulating base layer 1211 along the thickness direction X towards the first electrode body 11 by vapor deposition, bonding, coating or other suitable means.

[0107] The fourth conductive layer 1312 can be attached to the surface of the third insulating base layer 1311 along the thickness direction X facing the first electrode body 11 by vapor deposition, bonding, coating or other suitable means.

[0108] The third film layer 122 can be coated on the surface of the third conductive layer 1212 that is away from the second insulating base layer 1211 along the thickness direction X. The fourth film layer 132 can be coated on the surface of the fourth conductive layer 1312 that is away from the third insulating base layer 1311 along the thickness direction X.

[0109] The materials of the first insulating base layer 1111, the second insulating base layer 1211, and the third insulating base layer 1311 can be the same or different.

[0110] The first insulating base layer 1111 and the second insulating base layer 1211 can be connected to each other (see Figure 5) or they can be set separately (see Figure 6). The first insulating base layer 1111 and the third insulating base layer 1311 can be connected to each other (see Figure 5) or they can be set separately (see Figure 6).

[0111] When there are multiple first electrode bodies 11, the first insulating base layers 1111 of two adjacent first electrode bodies 11 can be connected to each other or set separately.

[0112] The second electrode body 12 and the third electrode body 13 are the two outermost electrode bodies of the electrode unit 10a along the thickness direction X. Both the second electrode body 12 and the third electrode body 13 have an insulating base layer and a conductive layer. The insulating base layer of both can achieve insulation isolation between the electrode unit 10a and other structures, eliminating the need for other insulating isolation components and simplifying the structure. Furthermore, the insulating base layers of multiple electrode bodies can be made of the same material, which helps to improve material consistency.

[0113] In some embodiments, referring to FIG5, the electrode unit 10a includes a plurality of bends 18, and two adjacent electrode bodies are connected through the bends 18.

[0114] The connection between two adjacent electrode bodies via the bending portion 18 means that the insulating base layers of two adjacent electrode bodies are connected via the bending portion 18. The bending portion 18 can connect the ends of the insulating base layers of two adjacent electrode bodies on the same side in the same direction.

[0115] The second insulating base layer 1211 is connected to the first insulating base layer 1111 of an adjacent first electrode body 11 via a bending portion 18. The third insulating base layer 1311 is connected to the first insulating base layer 1111 of an adjacent first electrode body 11 via a bending portion 18. When there are multiple first electrode bodies 11, the first insulating base layers 1111 of two adjacent first electrode bodies 11 are connected via a bending portion 18.

[0116] The bending portion 18 can be bent from the insulating base layer of one electrode body toward the insulating base layer of the other electrode body. Optionally, the bending portion 18 can be arc-shaped.

[0117] The bending portion 18 is made of insulating material. The materials of the bending portion 18, the first insulating base layer 1111, the second insulating base layer 1211, and the third insulating base layer 1311 can be the same or different.

[0118] During the preparation of the battery cell 6, the bending portion 18 and multiple electrode bodies can be pre-connected to form an electrode, and then the electrode is repeatedly bent along an S-shaped curve to form multiple electrode bodies and multiple bending portions 18 stacked together; alternatively, multiple electrode bodies can be stacked first and then the bending portion 18 can be connected between two adjacent electrode bodies.

[0119] The bending portion 18 connects two adjacent electrode bodies. The bending portion 18 can at least partially cover the conductive layer and film layer located between the insulating base layer of the two adjacent electrode bodies from the outside, which is beneficial to achieve insulation isolation between the electrode unit 10a and other structures. In addition, the bending portion 18 can also reduce the relative movement of the two adjacent electrode bodies during assembly, shaking, etc., and improve structural stability.

[0120] In some embodiments, referring to FIG5, the first insulating base layer 1111, the second insulating base layer 1211, the third insulating base layer 1311, and the plurality of bending portions 18 are integrally formed structures.

[0121] The first insulating base layer 1111, the second insulating base layer 1211, the third insulating base layer 1311, and the bending portion 18 can be formed by repeatedly bending an insulating base material along an S-shaped curve.

[0122] The first conductive layer 1112, the second conductive layer 1113, the third conductive layer 1212, and the fourth conductive layer 1312 may be disposed at corresponding positions on the surface of the insulating substrate before bending the insulating substrate. The first film layer 112, the second film layer 113, the third film layer 122, and the fourth film layer 132 may be disposed on the surfaces of the first conductive layer 1112, the second conductive layer 1113, the third conductive layer 1212, and the fourth conductive layer 1312, respectively, before bending the insulating substrate.

[0123] In the first insulating base layer 1111, the second insulating base layer 1211, the third insulating base layer 1311, and the plurality of bending portions 18, there are no cut edges between any two adjacent parts, reducing the number of cut edges and thus reducing the risk of burrs on the cut edges puncturing the insulating components covering the electrode assembly 10, thereby improving the reliability of the battery cell 6. Furthermore, the first insulating base layer 1111, the second insulating base layer 1211, and the third insulating base layer 1311 can be formed by repeatedly bending an insulating substrate, while simultaneously forming the plurality of bending portions 18 that provide insulation. This simplifies the insulation design and assembly process of the electrode assembly 10 and improves assembly efficiency.

[0124] In some embodiments, referring to FIG7, the electrode unit 10a further includes a first tab 151 and a second tab 152, the first tab 151 being connected to the second current collector 121 and the second tab 152 being connected to the third current collector 131. The first tab 151 and the second tab 152 are capable of leading the current of the electrode unit 10a to the external circuit.

[0125] In some examples, the second current collector 121 is a metal conductive layer, and the first tab 151 can be integrally formed with the second current collector 121. Optionally, the first tab 151 can be formed by a cutting process.

[0126] In other examples, the second current collector 121 includes a second insulating base layer 1211 and a third conductive layer 1212, and the first tab 151 can be soldered to the third conductive layer 1212.

[0127] In some examples, the third current collector 131 is a metal conductive layer, and the second tab 152 can be integrally formed with the third current collector 131. Optionally, the second tab 152 can be formed by a cutting process.

[0128] In other examples, the third current collector 131 includes a third insulating base layer 1311 and a fourth conductive layer 1312, and the second tab 152 can be soldered to the fourth conductive layer 1312.

[0129] In some embodiments, the battery cell 6 further includes a first electrode lead-out structure 161 and a second electrode lead-out structure 162. The first electrode lead-out structure 161 and the second electrode lead-out structure 162 are disposed on the housing 20, with the first electrode lead-out structure 161 connected to a first tab 151 and the second electrode lead-out structure 162 connected to a second tab 152. The first electrode lead-out structure 161 and the second electrode lead-out structure 162 are used to connect to an external circuit to conduct the current generated by the electrode assembly 10.

[0130] In some embodiments, the first tab 151 extends from the end of the second current collector 121 along the first direction Y, and the second tab 152 extends from the end of the third current collector 131 along the first direction Y. The insulating member 14 is disposed on the side of the first film layer 112 facing away from the first conductive layer 1112. The two ends of the first film layer 112 along the second direction Z do not extend beyond the insulating member 14, while the two ends of the insulating member 14 along the second direction Z extend beyond the second film layer 113. The first direction Y, the second direction Z, and the thickness direction X are all perpendicular to each other.

[0131] The first electrode 151 and the second electrode 152 can extend from the same side end of the second current collector 121 and the third current collector 131 along the first direction Y, respectively. Alternatively, the first electrode 151 and the second electrode 152 can extend from different side ends of the second current collector 121 and the third current collector 131 along the first direction Y, respectively.

[0132] The separator 14 can be coated on the surface of the first film layer 112 facing away from the first conductive layer 1112, which helps to simplify the molding process of the electrode assembly 10.

[0133] The end of the separator 14 along the second direction Z can be flush with the end of the first membrane layer 112 along the second direction Z, and the end of the separator 14 along the second direction Z can also extend beyond the first membrane layer 112 along the second direction Z.

[0134] The end of the first membrane layer 112 along the second direction Z can extend beyond the second membrane layer 113, so that the first membrane layer 112 can provide a larger surface area for the isolation member 14, which is beneficial for the two ends of the isolation member 14 along the second direction Z to extend beyond the second membrane layer 113.

[0135] The ends of the first membrane layer 112 and the fourth membrane layer 132 in the second direction Z are flush with the thickness direction X. The ends of the second membrane layer 113 and the third membrane layer 122 in the second direction Z are flush with the thickness direction X. The spacer 14 extends beyond the third membrane layer 122 at both ends in the second direction Z.

[0136] The two ends of the insulating member 14 extend beyond the second membrane layer 113 along the second direction Z. The portion of the insulating member 14 that extends beyond the second membrane layer 113 can insulate and isolate the positive and negative membrane layers, which is beneficial to improving the insulation effect.

[0137] In some embodiments, the separator 14 includes an electrolyte coating. Thus, the separator 14 serves both as a barrier membrane and provides the electrolyte required for the electrochemical reaction. The electrolyte coating is a solid electrolyte, which helps reduce the risk of electrolyte leakage or vaporization.

[0138] Optionally, the separator 14 may include an inorganic solid electrolyte, an organic solid electrolyte, or a composite solid electrolyte.

[0139] In some embodiments, the ends of the first insulating base layer 1111, the second insulating base layer 1211 and the third insulating base layer 1311 in the second direction Z are flush with the thickness direction X, which is beneficial to reduce the size of the electrode unit 10a in the second direction Z and facilitates the arrangement of each conductive layer and each film layer.

[0140] In some embodiments, the two ends of the first conductive layer 1112 along the second direction Z do not extend beyond the insulating base layer of each electrode body, and the two ends of the second conductive layer 1113 along the second direction Z do not extend beyond the insulating base layer of each electrode body.

[0141] In some embodiments, both ends of the first conductive layer 1112 extend beyond the first film layer 112 along the second direction Z. A portion of the surface of the first conductive layer 1112 facing away from the first insulating base layer 1111 is covered by the first film layer 112, while another portion is not covered by the first film layer 112.

[0142] In some embodiments, both ends of the second conductive layer 1113 extend beyond the second film layer 113 along the second direction Z. A portion of the surface of the second conductive layer 1113 facing away from the first insulating base layer 1111 is covered by the second film layer 113, while another portion is not covered by the second film layer 113.

[0143] In some embodiments, the portion of the first conductive layer 1112 not covered by the first film layer 112 is electrically connected to the portion of the second conductive layer 1113 not covered by the second film layer 113.

[0144] In some embodiments, referring to FIG7, the electrode unit 10a includes a conductive connector 17, and the first conductive layer 1112 and the second conductive layer 1113 are electrically connected through the conductive connector 17.

[0145] The conductive connector 17 can be connected to the first conductive layer 1112 and the second conductive layer 1113 by welding or other suitable means.

[0146] In some examples, the conductive connector 17 may include three integrally formed parts, two of which are located on opposite sides of the first current collector 111 along the thickness direction X and are electrically connected to the first conductive layer 1112 and the second conductive layer 1113, respectively, and the third part is connected between the two parts and located on one side of the first current collector 111 along the first direction Y. The conductive connector 17 is generally U-shaped.

[0147] In other examples, the first conductive layer 1112 and the second conductive layer 1113 are both formed on the two surfaces of the first insulating base layer 1111 by vapor deposition. The conductive connector 17 can be formed on the end face of the first insulating base layer 1111 along the first direction Y by vapor deposition. The two ends of the conductive connector 17 along the thickness direction X are respectively connected to the first conductive layer 1112 and the second conductive layer 1113.

[0148] In some other examples, the conductive connector 17 may include two components, one of which is electrically connected to the first conductive layer 1112 and extends beyond the first current collector 111 in the first direction Y; the other component is electrically connected to the second conductive layer 1113 and extends beyond the first current collector 111 in the first direction Y. The portions of the two components extending beyond the first current collector 111 are electrically connected.

[0149] The material of the conductive connector 17 can be the same as or different from the material of the first conductive layer 1112.

[0150] The material of the conductive connector 17 can be the same as or different from the material of the second conductive layer 1113.

[0151] The conductive connector 17 enables electrical connection between the first conductive layer 1112 and the second conductive layer 1113, facilitating flexible selection of the formation process of the first conductive layer 1112 and the second conductive layer 1113, and helping to improve the stability and reliability of the electrical connection between the first conductive layer 1112 and the second conductive layer 1113.

[0152] In some embodiments, the first tab 151 and the second tab 152 may extend from the same side end of the second current collector 121 and the third current collector 131 along the first direction Y, respectively. The conductive connector 17 is disposed on the side of the first current collector 111 along the first direction Y near the first tab 151. The conductive connector 17, the first tab 151 and the second tab 152 can share the space in the first direction Y, which is beneficial to improving space utilization and increasing energy density.

[0153] In some embodiments, there are multiple electrode units 10a, and the multiple electrode units 10a are stacked along the thickness direction X, which is beneficial to increasing the capacity of a single battery cell 6.

[0154] Two adjacent electrode units 10a can be connected insulated from each other or set up independently.

[0155] Optionally, the second insulating base layer 1211 and the third insulating base layer 1311 of two adjacent electrode units 10a can be connected to each other.

[0156] In some embodiments, the electrode unit 10a further includes a first tab 151 and a second tab 152, the first tab 151 being connected to the second current collector 121 and the second tab 152 being connected to the third current collector 131. The first tabs 151 of the plurality of electrode units 10a are stacked and connected along the thickness direction X, and the second tabs 152 of the plurality of electrode units 10a are stacked and connected along the thickness direction X.

[0157] The first tabs 151 of the multiple electrode units 10a can be welded (e.g., ultrasonically welded) to form a first welded portion. The first welded portion can be connected to the first electrode lead-out structure 161 by welding, attachment or other means.

[0158] The second tabs 152 of the multiple electrode units 10a can be welded (e.g., ultrasonically welded) to form a second welded portion. The second welded portion can be connected to the second electrode lead-out structure 162 by welding, attachment or other means.

[0159] The stacking and connection of first tabs 151 of multiple electrode units 10a helps to compress the interlayer gaps between adjacent first tabs 151, facilitates the connection of the first electrode lead structure 161, reduces the cracking of the first tabs, lowers the risk of connection failure, and improves the overcurrent capacity and reliability of the battery cell 6. Similarly, the stacking and connection of second tabs 152 of multiple electrode units 10a helps to compress the interlayer gaps between adjacent second tabs 152, facilitates the connection of the second electrode lead structure 162, reduces the cracking of the second tabs, lowers the risk of connection failure, and improves the overcurrent capacity and reliability of the battery cell 6.

[0160] In some embodiments, the electrode assembly 10 includes an insulating connection layer 10b. In two adjacent electrode units 10a, the second current collector 121 of one electrode unit 10a and the third current collector 131 of the other electrode unit 10a are connected by the insulating connection layer 10b. Along the thickness direction X, at least a portion of the insulating connection layer 10b is located between two adjacent electrode units 10a.

[0161] The insulating connection layer 10b is connected to the second current collector 121 and the third current collector 131 at both ends along the second direction Z.

[0162] The second current collector 121 includes a second insulating base layer 1211, and the third current collector 131 includes a third insulating base layer 1311. The insulating connecting layer 10b is connected to the second insulating base layer 1211 and the third insulating base layer 1311 at both ends along the second direction Z.

[0163] The materials of the insulating connecting layer 10b, the second insulating base layer 1211, and the third insulating base layer 1311 can be the same or different.

[0164] The insulating connecting layer 10b and the second insulating base layer 1211 can be connected by welding, bonding or other suitable methods, or they can be integrally formed.

[0165] The insulating connecting layer 10b and the third insulating base layer 1311 can be connected by welding, bonding or other suitable methods, or they can be integrally formed.

[0166] Referring to Figure 8, the insulating connection layer 10b may include a first main body portion 10b1 and two first connecting portions 10b2. Along the thickness direction X, the first main body portion 10b1 is located between two adjacent electrode units 10a, and the two first connecting portions 10b2 are respectively located on both sides of the first main body portion 10b1 along the second direction Z.

[0167] Optionally, in two adjacent electrode units 10a, the second current collector 121 of one electrode unit 10a and the third current collector 131 of the other electrode unit 10a can be respectively attached to two surfaces of the first main body 10b1 along the thickness direction X.

[0168] The first connecting part 10b2 can be bent relative to the first main body 10b1. The two first connecting parts 10b2 are respectively connected to the second current collector 121 of one electrode unit 10a and the third current collector 131 of another electrode unit 10a. The first connecting part 10b2 can insulate the ends of the second current collector 121 and the third current collector 131 along the second direction Z from other components, which helps to reduce the risk of short circuit.

[0169] The insulating connection layer 10b can insulate and separate two adjacent electrode units 10a, and can also insulate and separate the ends of the second current collector 121 and the third current collector 131 along the second direction Z from other components, which helps to reduce the risk of short circuit. Furthermore, the insulating connection layer 10b connects the second current collector 121 of one electrode unit 10a and the third current collector 131 of another electrode unit 10a, which can also reduce the risk of mutual movement between two adjacent electrode units 10a during the assembly or use of the battery cell 6, which helps to improve structural stability.

[0170] In some embodiments, the second current collector 121 includes a second insulating base layer 1211 and a third conductive layer 1212, the third conductive layer 1212 being disposed on the side of the second insulating base layer 1211 facing the first electrode body 11. The third current collector 131 includes a third insulating base layer 1311 and a fourth conductive layer 1312, the fourth conductive layer 1312 being disposed on the side of the third insulating base layer 1311 facing the first electrode body 11. In two adjacent electrode units 10a, the second insulating base layer 1211 of one electrode unit 10a, the third insulating base layer 1311 of the other electrode unit 10a, and the insulating connection layer 10b are integrally formed.

[0171] The second insulating base layer 1211 of one electrode unit 10a, the insulating connecting layer 10b, and the third insulating base layer 1311 of another electrode unit 10a can be formed by repeatedly bending an insulating substrate along an S-shaped curve, which helps to simplify the insulation design and assembly process of the electrode assembly 10 and improve assembly efficiency.

[0172] In some embodiments, the electrode assembly 10 includes an outer insulating layer 10c that covers at least a portion of at least one electrode unit 10a from the outside.

[0173] The outer insulating layer 10c can be connected to the outermost electrode unit 10a along the thickness direction X.

[0174] Referring to FIG9, the outer insulating layer 10c includes a second main body portion 10c1 and a second connecting portion 10c2. The second main body portion 10c1 is disposed on one side of at least one electrode unit 10a along the thickness direction X, and covers an adjacent electrode unit 10a along the thickness direction X. The second connecting portion 10c2 is bent from the end of the second main body portion 10c1 along the second direction Z toward the direction close to at least one electrode unit 10a, and is connected to an electrode unit 10a adjacent to the outer insulating layer 10c.

[0175] Optionally, the outer insulating layer 10c may be bonded, fused or otherwise connected to the second insulating base layer 1211 or the third insulating base layer 1311 of the outermost electrode unit 10a, or may be integrally formed with the second insulating base layer 1211 or the third insulating base layer 1311 of the outermost electrode unit 10a.

[0176] There may be two external insulating layers 10c, and the two external insulating layers 10c respectively cover at least a portion of at least one electrode unit 10a on both sides along the thickness direction X.

[0177] The outer insulating layer 10c can cover at least a portion of at least one electrode unit 10a, which can insulate at least one electrode unit 10a from the housing 20 or other components, thereby reducing the risk of short circuit.

[0178] In some embodiments, the external insulating layer 10c, the insulating connection layer 10b, and the first insulating base layer 1111, the second insulating base layer 1211, and the third insulating base layer 1311 of each electrode unit 10a are integrally formed structures.

[0179] The external insulating layer 10c, the insulating connecting layer 10b, and the first insulating base layer 1111, the second insulating base layer 1211, and the third insulating base layer 1311 of each electrode unit 10a can be formed by repeatedly bending an insulating substrate 10d along an S-shaped curve, which helps to simplify the insulation design and assembly process of the electrode assembly 10 and improve assembly efficiency.

[0180] In some embodiments, the electrode assembly 10 may be formed by repeatedly bending an electrode sheet. Figure 10 is a schematic structural diagram of the electrode sheet of a battery cell electrode assembly provided in some embodiments of this application in its unfolded state. The electrode sheet includes an insulating substrate 10d, a first conductive layer 1112, a second conductive layer 1113, a third conductive layer 1212, a fourth conductive layer 1312, a first film layer 112, a second film layer 113, a third film layer 122, and a fourth film layer 132.

[0181] The insulating substrate 10d has a continuous extending structure. When the insulating substrate 10d is in a flattened state, the two external insulating layers 10c form the two ends of the insulating substrate 10d along its own extending direction.

[0182] The insulating substrate 10d also includes at least one insulating unit located between two outer insulating layers 10c, with adjacent insulating units connected by an insulating connecting layer 10b.

[0183] The insulation unit includes at least one first insulating base layer 1111, one second insulating base layer 1211, one third insulating base layer 1311, and a plurality of bends 18. Along the extension direction of the insulating substrate 10d, at least one first insulating base layer 1111 is located between the second insulating base layer 1211 and the third insulating base layer 1311, and adjacent first insulating base layers 1111, the first insulating base layer 1111 and the second insulating base layer 1211, and the first insulating base layer 1111 and the third insulating base layer 1311 are all connected by bends 18.

[0184] The third conductive layer 1212 is disposed on one surface of the second insulating base layer 1211 along the thickness direction of the insulating substrate 10d, and the fourth conductive layer 1312 is disposed on one surface of the third insulating base layer 1311 along the thickness direction of the insulating substrate 10d. The third conductive layer 1212 and the fourth conductive layer 1312 are respectively located on both sides of the insulating substrate 10d along its own thickness direction.

[0185] The first conductive layer 1112 and the second conductive layer 1113 are disposed one-to-one on both sides of the first insulating base layer 1111 along the thickness direction of the insulating substrate 10d.

[0186] Along the extension direction of the insulating substrate 10d, positive electrode film and negative electrode film are alternately arranged on the same side of the thickness direction of the insulating substrate 10d.

[0187] In some embodiments, when the insulating substrate 10d is in a flattened state, the first insulating base layer 1111, the second insulating base layer 1211 and the third insulating base layer 1311 have the same size and are all W1 along the extension direction of the insulating substrate 10d; the size of the insulating connecting layer 10b is X1, where X1 > W1.

[0188] In some embodiments, when the insulating substrate 10d is in a flattened state, the dimension of the bending portion 18 along the extending direction of the insulating substrate 10d is X2. Along the thickness direction of the insulating substrate 10d, the thicknesses of the first conductive layer 1112 and the fourth conductive layer 1312 are the same and are both T1; the thicknesses of the second conductive layer 1113 and the third conductive layer 1212 are the same and are both T2; the thicknesses of the first film layer 112 and the fourth film layer 132 are the same and are both T3; the thicknesses of the second film layer 113 and the third film layer 122 are the same and are both T4; the thickness of the insulating member 14 is T5, and X2 > T1 + T2 + T3 + T4 + T5.

[0189] In some embodiments, when the insulating substrate 10d is in a flattened state, the outer insulating layer 10c has a size of X3 along the extending direction of the insulating substrate 10d, and the first insulating base layer 1111, the second insulating base layer 1211 and the third insulating base layer 1311 have the same size and are all W1, where X3 > W1.

[0190] According to some embodiments of this application, this application also provides a battery device 2, which includes a plurality of battery cells 6 provided in any of the above embodiments.

[0191] The battery cell 6 of the battery device 2 provided in this application embodiment can adjust the voltage and capacity within a large range, reducing the dependence of the overall voltage and capacity regulation of the battery device 2 on the series and parallel assembly of the battery cells 6, which is beneficial to improving the space utilization of the battery device 2 and increasing the energy density of the battery device 2.

[0192] According to some embodiments of this application, this application also provides an electrical device, which includes a battery device 2 of any of the above embodiments, the battery device 2 being used to provide electrical energy.

[0193] This application provides a battery cell 6, including a housing 20 and an electrode assembly 10 housed within the housing 20. The electrode assembly 10 includes at least one electrode unit 10a, which includes multiple electrode bodies, a separator 14, and multiple bends 18. The multiple electrode bodies are stacked along the thickness direction X of the electrode bodies, and the separator 14 separates adjacent electrode bodies. The multiple electrode bodies include at least one first electrode body 11, a second electrode body 12, and a third electrode body 13, with at least one first electrode body 11 disposed between the second electrode body 12 and the third electrode body 13. The first electrode body 11 includes a first current collector 111, a first film layer 112, and a second film layer 113. The first current collector 111 includes a first insulating base layer 1111, a first conductive layer 1112, and a second conductive layer 1113. A first conductive layer 1112 is disposed on the side of the first insulating base layer 1111 facing the second electrode body 12, and a second conductive layer 1113 is disposed on the side of the first insulating base layer 1111 facing the third electrode body 13. A first film layer 112 is disposed on the side of the first conductive layer 1112 facing away from the first insulating base layer 1111, and a second film layer 113 is disposed on the side of the second conductive layer 1113 facing away from the first insulating base layer 1111. The first conductive layer 1112 is electrically connected to the second conductive layer 1113. The second electrode body 12 includes a second current collector 121 and a third film layer 122. The second current collector 121 includes a second insulating base layer 1211 and a third conductive layer 1212. The third conductive layer 1212 is disposed on the side of the second insulating base layer 1211 facing the first electrode body 11, and the third film layer 122 is disposed on the side of the third conductive layer 1212 facing away from the second insulating base layer 1211. The third electrode body 13 includes a third current collector 131 and a fourth film layer 132. The third current collector 131 includes a third insulating base layer 1311 and a fourth conductive layer 1312. The fourth conductive layer 1312 is disposed on the side of the third insulating base layer 1311 facing the first electrode body 11, and the fourth film layer 132 is disposed on the side of the fourth conductive layer 1312 facing away from the second insulating base layer 1211. The first film layer 112 and the second film layer 113 have opposite polarities, the third film layer 122 and the second film layer 113 have the same polarity, and the fourth film layer 132 and the first film layer 112 have the same polarity. The second insulating base layer 1211 is connected to the first insulating base layer 1111 of an adjacent first electrode body 11 through a bending portion 18. The third insulating base layer 1311 is connected to the first insulating base layer 1111 of an adjacent first electrode body 11 through a bending portion 18. When there are multiple first electrode bodies 11, the first insulating base layers 1111 of two adjacent first electrode bodies 11 are connected by a bending portion 18.

[0194] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. 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, comprising a housing and an electrode assembly housed within the housing, the electrode assembly comprising at least one electrode unit, the electrode unit comprising a plurality of electrode bodies and a separator, the plurality of electrode bodies being stacked along the thickness direction of the electrode bodies, and the separator separating adjacent electrode bodies; The plurality of electrode bodies include at least one first electrode body, as well as a second electrode body and a third electrode body, wherein the at least one first electrode body is disposed between the second electrode body and the third electrode body; The first electrode body includes a first current collector, a first film layer, and a second film layer. The first current collector includes a first insulating base layer, a first conductive layer, and a second conductive layer. The first conductive layer is disposed on the side of the first insulating base layer facing the second electrode body, and the second conductive layer is disposed on the side of the first insulating base layer facing the third electrode body. The first film layer is disposed on the side of the first conductive layer away from the first insulating base layer, and the second film layer is disposed on the side of the second conductive layer away from the first insulating base layer. The first conductive layer is electrically connected to the second conductive layer. The second electrode body includes a second current collector and a third film layer, wherein the third film layer is disposed on the side of the second current collector facing the first electrode body; The third electrode body includes a third current collector and a fourth film layer, wherein the fourth film layer is disposed on the side of the third current collector facing the first electrode body; The first film layer and the second film layer have opposite polarities, the third film layer and the second film layer have the same polarity, and the fourth film layer and the first film layer have the same polarity.

2. The battery cell according to claim 1, wherein, The second current collector includes a second insulating base layer and a third conductive layer. The third conductive layer is disposed on the side of the second insulating base layer facing the first electrode body, and the third film layer is disposed on the side of the third conductive layer away from the second insulating base layer. The third current collector includes a third insulating base layer and a fourth conductive layer. The fourth conductive layer is disposed on the side of the third insulating base layer facing the first electrode body, and the fourth film layer is disposed on the side of the fourth conductive layer away from the second insulating base layer.

3. The battery cell according to claim 2, wherein, The electrode unit includes multiple bends, and two adjacent electrode bodies are connected through the bends.

4. The battery cell according to claim 3, wherein, The first insulating base layer, the second insulating base layer, the third insulating base layer, and the plurality of bent portions are integrally formed structures.

5. The battery cell according to any one of claims 1-4, wherein, The electrode unit further includes a first electrode tab and a second electrode tab, wherein the first electrode tab is connected to the second current collector body and the second electrode tab is connected to the third current collector body.

6. The battery cell according to claim 5, wherein, The first electrode extends from the end of the second current collector body along the first direction, and the second electrode extends from the end of the third current collector body along the first direction; The insulating member is disposed on the side of the first film layer facing away from the first conductive layer. The two ends of the first film layer along the second direction do not extend beyond the insulating member, and the two ends of the insulating member along the second direction extend beyond the second film layer. The first direction, the second direction, and the thickness direction are perpendicular to each other.

7. The battery cell according to claim 6, wherein, The isolation element includes an electrolyte coating.

8. The battery cell according to any one of claims 1-7, wherein, The electrode unit includes a conductive connector, and the first conductive layer and the second conductive layer are electrically connected through the conductive connector.

9. The battery cell according to any one of claims 1-8, wherein, The electrode units are multiple, and the multiple electrode units are stacked along the thickness direction.

10. The battery cell according to claim 9, wherein, The electrode unit further includes a first electrode tab and a second electrode tab, wherein the first electrode tab is connected to the second current collector and the second electrode tab is connected to the third current collector; The first tabs of the plurality of electrode units are stacked and connected along the thickness direction, and the second tabs of the plurality of electrode units are stacked and connected along the thickness direction.

11. The battery cell according to claim 9 or 10, wherein, The electrode assembly includes an insulating connection layer. In two adjacent electrode units, the second current collector of one electrode unit and the third current collector of the other electrode unit are connected through the insulating connection layer. Along the thickness direction, at least a portion of the insulating connection layer is located between two adjacent electrode units.

12. The battery cell according to claim 11, wherein, The second current collector includes a second insulating base layer and a third conductive layer, wherein the third conductive layer is disposed on the side of the second insulating base layer facing the first electrode body; The third current collector includes a third insulating base layer and a fourth conductive layer, wherein the fourth conductive layer is disposed on the side of the third insulating base layer facing the first electrode body; In two adjacent electrode units, the second insulating base layer of one electrode unit, the third insulating base layer of the other electrode unit, and the insulating connecting layer are integrally formed.

13. The battery cell according to any one of claims 1-12, wherein, The electrode assembly includes an outer insulating layer that covers at least a portion of the at least one electrode unit from the outside.

14. A battery device comprising a plurality of battery cells according to any one of claims 1-13.

15. An electrical device comprising a battery device according to claim 14, the battery device being used to provide electrical energy.

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