Battery monomer, battery device and electric equipment

Abstract

The utility model provides a battery monomer, a battery device and electric equipment. The battery monomer comprises a shell, an electrode assembly and an insulating part, the electrode assembly is arranged in the accommodating cavity of the shell and comprises a plurality of first pole pieces, a plurality of second pole pieces and an electrolyte layer, the electrolyte layer is used for isolating the first pole pieces from the second pole pieces, each first pole piece comprises a first current collector and a first active material layer, and each second pole piece comprises a second current collector and a second active material layer; one part of the first active material layer protrudes out of the peripheral surface of the second active material layer, the first active material layer comprises a base body part and a thinned part, the thinned part is arranged along the periphery of the base body part, and the thickness of the base body part is larger than that of the thinned part; the insulating part is arranged on one side, deviating from the first current collector, of the thinned part along the stacking direction; and the orthographic projection of the insulating part is overlapped with the orthographic projection of the second active material layer. According to the battery monomer provided by the invention, the insulating part inhibits the lap joint of the first pole piece and the second pole piece.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and in particular to battery cells, battery devices and electrical equipment. Background Technology

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and rechargeable alkaline zinc-manganese batteries, among others.

[0003] In the development of batteries, how to ensure the reliability of individual battery cells is a technical problem that urgently needs to be solved. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical appliance, which aims to improve the reliability of the battery cell to a certain extent.

[0005] This application provides a battery cell, which includes a casing, an electrode assembly, and an insulating member. The casing has a receiving cavity. The electrode assembly is disposed within the receiving cavity and includes a plurality of first electrodes, a plurality of second electrodes, and an electrolyte layer. The first electrodes and second electrodes have opposite polarities. The plurality of first electrodes and the plurality of second electrodes are alternately stacked along the stacking direction. The electrolyte layer is used to isolate the first electrodes and the second electrodes. The first electrodes include a first current collector and a first active material layer disposed on the surface of the first current collector. The second electrodes include a second current collector and a second active material layer disposed on the surface of the second current collector. A portion of the first active material layer protrudes from the outer peripheral surface of the second active material layer. The first active material layer includes a base portion and a thinned portion. The thinned portion is disposed along the outer periphery of the base portion, and the thickness of the base portion is greater than the thickness of the thinned portion. The insulating member is disposed on the side of the thinned portion away from the first current collector along the stacking direction. In a plane perpendicular to the stacking direction, the orthographic projection of the insulating member overlaps with the orthographic projection of the second active material layer.

[0006] The battery cell provided in this application has an insulating component disposed in the thinned portion. In a plane perpendicular to the stacking direction, the orthographic projection of the insulating component overlaps with the orthographic projection of the second active material layer, serving to insulate the first and second electrodes. This effectively suppresses edge overlap between the first and second electrodes during the pressurization process of the electrode assembly, reducing the occurrence of internal short circuits and improving the reliability of the battery cell. Furthermore, the insulating component is disposed in the thinned portion, which is thinner than the base portion, reserving a certain thickness space at the edge of the first active material layer. This reduces the additional space occupied by the insulating component within the battery cell, helping to maintain a compact structure. In addition, the thinning design at the edge of the first active material layer not only shortens the ion transport path to accelerate the intercalation / deintercalation reaction rate of active ions and improves the rate performance of the battery, but also helps to release the volume expansion stress generated in the edge region during charging and discharging, reducing the risk of peeling or breakage of the first active material layer and thus improving the cycle stability of the battery cell.

[0007] According to one embodiment of this application, the first electrode is a positive electrode and the second electrode is a negative electrode.

[0008] In these alternative embodiments, the positive electrode active material has high particle hardness and high tap density, exhibiting high resistance to high-pressure compaction. The volume deformation caused by lithium-ion intercalation / deintercalation during the positive electrode reaction is relatively small. The thickness of the positive electrode is greater than the thickness of the electrolyte layer and also greater than the thickness of the negative electrode. Therefore, the thickness that can be reduced in the negative electrode is significantly less than the thickness that can be reduced in the positive electrode. By placing the insulating component in the thinned portion of the positive active material layer of the positive electrode, sufficient thickness space is provided for the insulating component, thereby achieving a more reliable insulation protection effect.

[0009] According to one embodiment of this application, the insulating member and the thinned portion are attached and connected along the stacking direction away from the surface of the first current collector.

[0010] In these alternative embodiments, the insulating element is attached to and connected to the surface of the thinned portion. On the one hand, this can improve the installation stability of the insulating element. On the other hand, the insulating element can better absorb mechanical stress, improve the structural stability of the first active material layer, and reduce the occurrence of warping at the edge of the first electrode.

[0011] According to one embodiment of this application, a portion of the second active material layer protrudes from the outer peripheral surface of the substrate; in the lamination direction, the orthographic projection of the insulating member on the thinned portion covers the orthographic projection of the second active material layer on the thinned portion. During the lamination process, the edge of the second electrode can fall into the thinned portion area of ​​the first electrode and be covered and isolated by the insulating member disposed in that area.

[0012] According to one embodiment of this application, a portion of the insulating element protrudes from the outer peripheral surface of the second active material layer. During the stacking process, if an alignment deviation occurs in the second electrode, its edge can still fall within the thinned portion area, thereby reducing structural interference and improving the insulation reliability inside the battery cell.

[0013] According to one embodiment of this application, in a plane perpendicular to the stacking direction, the orthographic projection of the insulating member overlaps the orthographic projection of the thinned portion. This improves the isolation effect between the first and second electrodes and further reduces the possibility of edge contact.

[0014] According to one embodiment of this application, the outer peripheral surface of the insulating member is flush with the outer peripheral surface of the thinned portion. Since the insulating member is flush with the outer peripheral surface of the thinned portion, the installation of the insulating member causes minimal changes to the overall structure and does not occupy additional space perpendicular to the stacking direction, effectively controlling the overall size of the battery cell and improving space utilization.

[0015] According to one embodiment of this application, the thinned portion is connected to the base portion, and the thinned portion is inclined inward relative to the first current collector, while the insulating member is inclined outward relative to the first current collector.

[0016] In these alternative embodiments, the thickness of the thinned portion near the edge is reduced, while the thickness of the insulating component is increased, which can reduce the phenomenon of the first electrode edge lifting during pressurization. Moreover, by reducing the thickness of the active material layer, the diffusion path of active ions within the active material layer is shortened, reducing ion migration resistance and enabling active ions to quickly complete the intercalation-deintercalation reaction.

[0017] According to one embodiment of this application, in the lamination direction, the surface of the insulating member facing away from the thinned portion is parallel to the surface of the substrate facing away from the first current collector. By utilizing the thinning design of the thinned portion of the first active material layer, the thickness of the insulating member is effectively offset, making the electrode assembly more flat overall, improving the uniformity of contact between the electrode layers, reducing the risk of electrolyte layer damage due to uneven local stress, and improving the reliability of the battery.

[0018] According to one embodiment of this application, the first current collector includes a first current collector body and a first electrode tab arranged along a first direction; the insulating member includes two first insulating portions disposed opposite each other along the first direction and two second insulating portions disposed opposite each other along a second direction, wherein the strength of the first insulating portions is greater than the strength of the second insulating portions, and the first direction, the second direction, and the stacking direction are perpendicular to each other. The insulating member closer to the first electrode tab has higher strength, which can provide better structural support for the root of the first electrode tab and resist the tensile deformation of the first electrode tab, thereby forming a more effective protection for the first electrode tab.

[0019] According to one embodiment of this application, the thickness of the first insulating portion is greater than the thickness of the second insulating portion. This further improves the structural protection of the electrode tabs and enhances the reliability of the battery cell.

[0020] According to one embodiment of this application, the insulating member includes a first insulating portion and a second insulating portion stacked along the lamination direction. The second insulating portion is located between and connects the thinned portion and the first insulating portion. The strength of the first insulating portion is greater than the strength of the second insulating portion. The second insulating portion, as a transition and connection structure, can improve the problem that the high-strength first insulating portion is difficult to directly and tightly adhere to the thinned portion. The second insulating portion achieves better interfacial bonding between the insulating member and the first electrode, while the first insulating portion can improve the overall mechanical strength of the insulating member.

[0021] According to one embodiment of this application, the first insulating portion includes a UV adhesive layer and / or a hot melt adhesive layer. The second insulating portion includes one or more of a ceramic layer, an alumina layer, and a compression-molded polymer layer.

[0022] These optional insulating components, made of insulating materials, allow for precise control of internal charge transfer, reducing the potential risk of short circuits within the battery cells. Furthermore, these specific materials result in high stability of the insulating components, minimizing their involvement in internal chemical reactions that could impact battery performance and extending the lifespan of the battery cells. This dual protection provided by the insulating components also enhances the stability and reliability of the battery.

[0023] According to one embodiment of this application, in the direction from the substrate portion to the thinned portion, the distance L1 between the outer peripheral surface of the substrate portion and the outer peripheral surface of the second active material layer is greater than the distance L2 between the outer peripheral surface of the second active material layer and the outer peripheral surface of the thinned portion. A portion of the insulating member is filled between the thinned portion and the second active material layer, which can absorb part of the stacking stress to disperse the stacking stress on the edge of the first active material layer, that is, to protect the thinned portion.

[0024] According to one embodiment of this application, in the direction from the substrate to the thinned portion, the distance L1 between the outer peripheral surface of the substrate and the outer peripheral surface of the second active material layer satisfies: 0 < L1 ≤ 2 mm. This can better disperse the stacking stress on the edge of the first active material layer and also appropriately reduce the proportion of the thinned portion.

[0025] According to one embodiment of this application, in the direction from the substrate to the thinned portion, the distance L2 between the outer peripheral surface of the second active material layer and the outer peripheral surface of the thinned portion satisfies: 0 < L2 ≤ 1.5 mm. This allows for a certain positional deviation between the first and second electrodes during stacking, effectively suppressing edge overlap between the first and second electrodes. Reducing the proportion of the thinned portion in the overall first active material layer results in a higher energy density for the battery cell.

[0026] According to one embodiment of this application, the size of the thinned portion is 3mm to 6mm in the direction from the substrate portion to the thinned portion. Optimizing the size of the thinned portion reduces its excessive area occupation, thereby ensuring that the substrate portion of the first active material layer has a sufficient proportion, maintaining the overall energy density of the battery cell at a high level.

[0027] According to one embodiment of this application, the maximum thickness C1 of the thinned portion, the maximum thickness C2 of the base portion, and the maximum thickness C3 of the insulating member satisfy: C1≤C3≤C2. The insulating member has a suitable thickness, which enables the insulating member to have a stable insulating effect.

[0028] Secondly, this application provides a battery device including the aforementioned battery cell.

[0029] Thirdly, this application provides an electrical device including a battery cell or a battery device as described above, wherein the battery cell or battery device is used to store or provide electrical energy.

[0030] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0031] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0032] Figure 1 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application;

[0033] Figure 2 This is an exploded view of a battery device provided in an embodiment of this application;

[0034] Figure 3 This is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0035] Figure 4 This is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0036] Figure 5 This is a schematic diagram of a partial cross-sectional structure of a battery cell in the stacking direction according to an embodiment of this application;

[0037] Figure 6 This is a partial cross-sectional structural diagram of the electrode assembly and insulating component of a battery cell provided in an embodiment of this application;

[0038] Figure 7This is a partial cross-sectional structural diagram of the electrode assembly and insulating component of a battery cell provided in another embodiment of this application;

[0039] Figure 8 This is a top view of a portion of the structure of a battery cell provided in an embodiment of this application;

[0040] Figure 9 This is a partial cross-sectional structural diagram of the electrode assembly and insulating component of a battery cell provided in another embodiment of this application;

[0041] Figure 10 This is a partial cross-sectional structural diagram of the first electrode and insulating component of a battery cell provided in an embodiment of this application.

[0042] The accompanying drawings may not be drawn to scale.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1000, Vehicle; 100, Battery Unit; 200, Controller; 300, Motor; 1a, Battery Module; 1b, First Housing; 1c, Second Housing;

[0045] 10. Battery cell; 1. Casing; 11. Receiving cavity; 2. Electrode assembly; 21. First electrode; 211. First current collector; 2111. First current collector body; 2112. First tab; 212. First active material layer; 2121. Substrate; 2122. Thinned portion; 22. Second electrode; 221. Second current collector; 222. Second active material layer; 23. Electrolyte layer; 3. Insulator; 31. First insulating portion; 32. Second insulating portion;

[0046] x, first direction; y, second direction; z, stacking direction. Detailed Implementation

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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 three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0052] 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.

[0053] In this application, "multiple" means two or more (including two).

[0054] Currently, judging from market trends, the application of batteries is becoming increasingly widespread. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace, among other fields.

[0055] A battery device typically refers to a single physical module comprising multiple battery cells to provide higher voltage and capacity. A battery cell can be the smallest unit that makes up a battery device.

[0056] Solid-state batteries, as a novel energy storage device, consist of positive and negative electrodes and a solid electrolyte. Compared to liquid batteries, solid-state batteries have the advantage of not containing a liquid electrolyte, thus offering higher safety and a longer lifespan. However, lithium-ion transport in solid-state battery cells must occur at the solid-solid interface, making densification an essential step in the manufacturing process. Densification helps improve the ionic conductivity of solid-state battery cells, thereby enhancing their electrochemical performance.

[0057] There are three main methods for achieving densification: rolling, flat pressing, and isostatic pressing. However, in the electrode assembly formed by stacking the first electrode, electrolyte layer, and second electrode, the edges of the electrode are prone to warping during the densification process due to high pressure. In the battery cell, the portion of the first electrode extending beyond the second electrode (also known as the overhang region) is difficult to perfectly align due to manufacturing tolerances. This leads to misalignment between different layers of electrodes, creating voids that make the electrodes prone to bending during isostatic pressing. This can cause the edges of the first and second electrodes to overlap, resulting in internal short circuits within the battery cell and reducing its reliability. The above statements are for informational purposes only and do not necessarily constitute prior art.

[0058] The battery cell provided in this application has an insulating component disposed in the thinned portion. In a plane perpendicular to the stacking direction, the orthographic projection of the insulating component overlaps with the orthographic projection of the second active material layer, serving to insulate the first and second electrodes. This effectively suppresses edge overlap between the first and second electrodes during the pressurization process of the electrode assembly, reducing the occurrence of internal short circuits and improving the reliability of the battery cell. Furthermore, the insulating component is disposed in the thinned portion, which is thinner than the base portion, reserving a certain thickness space at the edge of the first active material layer. This reduces the additional space occupied by the insulating component within the battery cell, helping to maintain a compact structure. In addition, the thinning design at the edge of the first active material layer not only shortens the ion transport path to accelerate the intercalation / deintercalation reaction rate of active ions and improves the rate performance of the battery, but also helps to release the volume expansion stress generated in the edge region during charging and discharging, reducing the risk of peeling or breakage of the first active material layer and thus improving the cycle stability of the battery cell.

[0059] The battery apparatus 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 connected in series, parallel, or mixed connections via a busbar.

[0060] 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 together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0061] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0062] 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.

[0063] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0064] 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.

[0065] Battery cells may include, but are not limited to, solid-state batteries, lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-metal hydride battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc.

[0066] 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.

[0067] 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.

[0068] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0069] 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.

[0070] 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.

[0071] See Figure 1 As shown, one embodiment of this application provides a vehicle 1000. The vehicle 1000 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. In one embodiment of this application, the vehicle 1000 may include a motor 300, a controller 200, and a battery device 100. The controller 200 is used to control the battery device 100 to supply power to the motor 300. The motor 300 is connected to the wheels via a transmission mechanism, thereby driving the vehicle 1000. The battery device 100 can serve as the driving power source for the vehicle 1000, replacing or partially replacing gasoline or natural gas to provide driving power to the vehicle 1000. In one example, the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to supply power to the vehicle 1000. In one example, the battery device 100 can serve as the operating power source for the vehicle 1000's electrical system. For example, the battery device 100 can be used to meet the power needs of the vehicle 1000 during startup, navigation and operation.

[0072] Please refer to Figure 2 , Figure 2 Exploded views of battery devices provided in some embodiments of this application.

[0073] In some embodiments, the battery device 100 may include one or more battery cell assemblies for providing voltage and capacity.

[0074] A battery cell assembly may include multiple battery cells ( Figure 2 (Not shown) Multiple battery cells are connected in series, parallel, or mixed connection through a busbar. Mixed connection refers to multiple battery cells being connected in both series and parallel.

[0075] A battery cell can be a rechargeable battery cell, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0076] As an example, a single 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.

[0077] As an example, a battery cell can be a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0078] 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 1a, which is formed by arranging and fixing multiple battery cells to form an independent module. As an example, a battery module 1a can be formed by bundling multiple battery cells together with cable ties.

[0079] In some embodiments, the battery device 100 may be a battery pack, which includes a housing and one or more battery cell assemblies housed within the housing. As an example, the battery cell assembly may be a battery module 1a, which can be housed within the housing by securing the battery module 1a to the housing. Alternatively, the battery cell assembly may be housed within the housing by directly securing multiple battery cells to the housing.

[0080] In some embodiments, the housing is used to house individual battery cells, and the housing can have various structures.

[0081] In some embodiments, the housing may include a first housing 1b and a second housing 1c, which overlap each other, and together define a receiving space for accommodating a single battery cell. The second housing 1c may be a hollow structure with one open end, and the first housing 1b may be a plate-like structure, with the first housing 1b covering the open side of the second housing 1c so that the first housing 1b and the second housing 1c together define the receiving space. Alternatively, both the first housing 1b and the second housing 1c may be hollow structures with one open side, with the open side of the first housing 1b covering the open side of the second housing 1c. Of course, the housing formed by the first housing 1b and the second housing 1c can be of various shapes, such as a cylinder, a cuboid, etc.

[0082] In some embodiments, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, forming an enclosed space inside the enclosure to house the individual battery cells. As an example, the frame may include multiple side beams.

[0083] 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.

[0084] In some embodiments, the battery device 100 may be an energy storage device.

[0085] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, energy storage devices can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours.

[0086] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0087] In a battery, there can be multiple battery cells 10, which can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 10 are connected in both series and parallel connections. Multiple battery cells 10 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 10 is housed within a casing. Alternatively, the battery can be composed of multiple battery cells 10 first connected in series, parallel, or in a mixed configuration to form a battery module, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is also housed within a casing. The battery may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 10.

[0088] Each battery cell 10 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., but the embodiments of this application are not limited to this.

[0089] The battery cell 10 can be cylindrical, flat, cuboid, or other shapes.

[0090] The battery cell 10 is a solid-state battery cell, which typically includes a casing and an electrode assembly. The casing has an inner cavity, and the electrode assembly is disposed within the inner cavity. A solid electrolyte is disposed on the electrode plates.

[0091] In some alternative embodiments, the solid electrolyte includes one or more of sulfide solid electrolytes, oxide solid electrolytes, halide solid electrolytes, and polymer solid electrolytes.

[0092] Sulfide solid electrolytes include sulfide crystalline solid electrolytes, sulfide glass, and glass-ceramic solid electrolytes.

[0093] See Figures 3 to 5 , Figure 3 This is a schematic diagram of the structure of a battery cell provided in an embodiment of this application; Figure 4 This is a partial structural schematic diagram of a battery cell provided in an embodiment of this application; Figure 5 This is a schematic diagram of a partial cross-sectional structure of a battery cell in the stacking direction according to an embodiment of this application.

[0094] like Figures 3 to 5 As shown, this application proposes a battery cell 10, which includes a housing 1 and an electrode assembly 2. The housing 1 has a receiving cavity 11. The electrode assembly 2 is disposed in the receiving cavity 11 and includes a plurality of first electrodes 21, a plurality of second electrodes 22, and an electrolyte layer 23. The first electrodes 21 and the second electrodes 22 have opposite polarities. The plurality of first electrodes 21 and the plurality of second electrodes 22 are alternately stacked along the stacking direction z. The electrolyte layer 23 is used to isolate the first electrodes 21 and the second electrodes 22. The first electrodes 21 include a first current collector. The first electrode 211 includes a body 211 and a first active material layer 212 disposed on the surface of the first current collector 211. The second electrode 22 includes a second current collector 221 and a second active material layer 222 disposed on the surface of the second current collector 221. A portion of the first active material layer 212 protrudes from the outer peripheral surface of the second active material layer 222. The first active material layer 212 includes a base portion 2121 and a thinned portion 2122. The thinned portion 2122 is disposed along the outer periphery of the base portion 2121. The thickness of the base portion 2121 is greater than the thickness of the thinned portion 2122.

[0095] The outer casing 1 has a receiving cavity 11 for accommodating components such as the electrode assembly 2, the insulating layer, and optionally the electrolyte, to form the internal environment of the battery cell.

[0096] In some examples, the housing 1 can be of various shapes and sizes, such as cuboid, cylindrical, or hexagonal prism. Specifically, the shape of the housing 1 can be determined based on the specific shape and size of the electrode assembly 2.

[0097] In some examples, the material of the outer casing 1 can be a variety of materials, such as one or more of copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0098] Optionally, the outer shell 1 is made of a material with a certain hardness and strength, such as aluminum or aluminum alloy, so that the outer shell 1 is not easily deformed when subjected to compression or impact.

[0099] In some examples, the housing 1 includes an end cap and a shell, which can be separate components. An opening can be provided on the shell, and the end cap can be closed at the opening to form the internal environment of the battery cell 10. Alternatively, the end cap and shell can be integrated. Specifically, the end cap and shell can form a common connection surface before other components are inserted into the shell, and the end cap can be closed when it is necessary to encapsulate the interior of the shell.

[0100] Electrode assembly 2 is the component in the battery cell where electrochemical reactions occur.

[0101] In some examples, the housing 1 may contain one or more electrode assemblies 2.

[0102] For example, the electrode assembly 2 includes a plurality of electrode units stacked together. Each electrode unit includes at least one first electrode 21, at least one second electrode 22, and at least three electrolyte layers 23.

[0103] In some examples, the electrode assembly 2 includes a plurality of first electrodes 21, a plurality of second electrodes 22, and a plurality of electrolyte layers 23. The first electrodes 21 and the second electrodes 22 have opposite polarities. The plurality of first electrodes 21 and the plurality of second electrodes 22 are stacked along the stacking direction z. The electrolyte layers 23 are used to isolate the first electrodes 21 and the second electrodes 22. The first electrodes 21 are located at both ends of the stacking direction z. The electrolyte layer 23 is provided on the side of the first electrode 21 located at one end that is away from the second electrode 22.

[0104] In some examples, one of the first electrode 21 and the second electrode 22 is a positive electrode and the other is a negative electrode.

[0105] In some examples, the shape of the outer peripheral surface of the first active material layer 212 is the same as the shape of the outer peripheral surface of the second active material layer 222.

[0106] For example, both the first active material layer 212 and the second active material layer 222 are rectangular, with the two long sides of the first active material layer 212 corresponding to the two long sides of the second active material layer 222, and the two short sides of the first active material layer 212 corresponding to the two short sides of the second active material layer 222.

[0107] In some examples, a portion of the outer peripheral surface of the first active material layer 212 protrudes beyond the outer peripheral surface of the second active material layer 222.

[0108] In other examples, the outer peripheral surface of the first active material layer 212 protrudes beyond the outer peripheral surface of the second active material layer 222.

[0109] For example, the first active material layer 212 and the second active material layer 222 have a rectangular structure, and the four sides of the first active material layer 212 protrude from the four sides of the second active material layer 222.

[0110] The first active material layer 212 includes a substrate 2121 and a thinned portion 2122. The thinned portion 2122 is disposed along the outer periphery of the substrate 2121, and the thickness of the substrate 2121 is greater than the thickness of the thinned portion 2122.

[0111] In some examples, the first active material layer 212 includes a substrate 2121 and a thinned portion 2122, with the substrate 2121 located in the middle region and the thinned portion 2122 located in the edge region. The thinned portion 2122 is located at the edge of the substrate 2121, and the thickness of the thinned portion 2122 is less than the thickness of the substrate 2121.

[0112] In some examples, the thickness of the thinned portion 2122 gradually increases along the direction from the base portion 2121 to the thinned portion 2122; or, the thickness of the thinned portion 2122 first increases and then remains constant; or, the thickness of the thinned portion 2122 first remains constant and then increases; or, the thickness of the thinned portion 2122 remains constant.

[0113] The battery cell 10 includes an insulating member 3, which is disposed on the side of the thinned portion 2122 opposite to the first current collector 211 along the stacking direction z. In a plane perpendicular to the stacking direction z, the orthographic projection of the insulating member 3 overlaps with the orthographic projection of the second active material layer 222. This serves to insulate the first electrode 21 and the second electrode 22, protecting the first active material layer 212 during the pressurization process of the electrode assembly 2. Furthermore, during pressurization, the insulating member 3, disposed on the thinned portion 2122, can absorb the stacking stress on the edge of the first active material layer 212, reducing the likelihood of edge warping of the thinned portion 2122. Therefore, the insulating member 3 effectively suppresses edge overlap between the first electrode 21 and the second electrode 22, reducing the occurrence of internal short circuits in the electrode assembly 2.

[0114] In some examples, the insulating member 3 is disposed along the outer periphery of the base portion 2121, and the insulating member 3 is connected to the outer peripheral surface of the base portion 2121.

[0115] In other examples, the insulating element 3 is spaced apart from the outer peripheral surface of the base portion 2121.

[0116] In some examples, the insulating element 3 is disposed along the outer periphery of the substrate portion 2121, and the insulating element 3 may be disposed on a portion of the outer peripheral surface of the substrate portion 2121 to protect a portion of the first active material layer 212.

[0117] In other examples, the insulating element 3 is disposed around the outer perimeter of the substrate 2121 to provide more effective protection for the first active material layer 212.

[0118] A portion of the first active material layer 212 protrudes beyond the outer peripheral surface of the second active material layer 222. Therefore, there is an overhang region between the stacked first electrode 21 and the second electrode 22, meaning the first active material layer 212 extends beyond the second active material layer 222. In a plane perpendicular to the stacking direction z, the orthographic projection of the insulating member 3 overlaps with the orthographic projection of the second active material layer 222. Therefore, along the direction from the thinned portion 2122 to the substrate portion 2121, the inner end face of the insulating member 3 extending beyond the outer peripheral surface of the second active material layer 222 reduces the probability of edge overlap between the first electrode 21 and the second electrode 22, suppresses the occurrence of internal short circuits in the electrode assembly 2, and effectively improves the problems of edge lithium plating and structural deformation that easily occur during cycling.

[0119] In some examples, the insulating element 3 covers a portion of the thinned portion 2122; alternatively, the insulating element 3 covers the thinned portion 2122.

[0120] The battery cell 10 provided in this application has an insulating member 3 disposed in the thinned portion 2122. In a plane perpendicular to the stacking direction z, the orthographic projection of the insulating member 3 overlaps with the orthographic projection of the second active material layer 222. This serves to insulate the first electrode 21 and the second electrode 22, effectively suppressing edge overlap of the first electrode 21 and the second electrode 22 during the pressurization process of the electrode assembly 2, reducing the occurrence of internal short circuits in the electrode assembly 2, and thus improving the reliability of the battery cell 10. Furthermore, the insulating member 3 is disposed in the thinned portion 2122, the thickness of which is less than that of the base portion 2121. A certain thickness space is reserved at the edge of the first active material layer 212, thereby reducing the additional space occupied by the insulating member 3 within the battery cell 10 and helping to maintain the compact structure of the battery cell 10. In addition, the thinning design at the edge of the first active material layer 212 not only shortens the ion transport path to accelerate the insertion and extraction reaction rate of active ions and improves the rate performance of the battery, but also helps to release the volume expansion stress generated in the edge region during charging and discharging, improves the peeling or breakage of the first active material layer 212, and thus improves the cycle stability of the battery cell 10.

[0121] According to one embodiment of this application, the first electrode 21 is a positive electrode and the second electrode 22 is a negative electrode.

[0122] In some examples, the thickness of the first electrode 21 is greater than the thickness of the second electrode 22.

[0123] For example, the maximum thickness of the first active material layer 212 is greater than the maximum thickness of the second active material layer 222.

[0124] The positive electrode active material has high particle hardness and high tap density, resulting in high resistance to high-pressure compaction. The volume deformation caused by lithium-ion insertion / extraction during the positive electrode reaction is relatively small. The thickness of the positive electrode is greater than that of the electrolyte layer 23 and also greater than that of the negative electrode. Therefore, the thickness that can be reduced in the negative electrode is significantly less than that that of the positive electrode. By placing the insulating component 3 in the thinned portion 2122 of the positive active material layer of the positive electrode, the insulating component 3 has sufficient thickness space, thereby achieving a more reliable insulation protection effect.

[0125] According to one embodiment of this application, such as Figure 5 As shown, the insulating member 3 and the thinned portion 2122 are attached and connected along the stacking direction z away from the surface of the first current collector 211.

[0126] In some examples, a portion of the insulating element 3 is attached to and fixedly connected to the surface of the thinned portion 2122 opposite to the first current collector 211 along the stacking direction z.

[0127] In other examples, a portion of the insulating element 3 is attached to and detachably connected to the surface of the thinned portion 2122 facing away from the first current collector 211 along the stacking direction z.

[0128] In some examples, a portion of the insulating member 3 is attached to and connected to the surface of the thinned portion 2122 away from the first current collector 211 along the stacking direction z, and another portion of the insulating member 3 is connected to the base portion 2121.

[0129] In some examples, the insulating element 3 is coated on the thinned portion 2122.

[0130] In other examples, the insulating element 3 is bonded to the thinned portion 2122 by adhesive.

[0131] The insulating component 3 is attached to and connected to the surface of the thinned portion 2122. On the one hand, this can improve the installation stability of the insulating component 3. On the other hand, the insulating component 3 can better absorb mechanical stress, improve the structural stability of the first active material layer 212, and reduce the occurrence of warping at the edge of the first electrode 21.

[0132] According to one embodiment of this application, such as Figure 5 As shown, a portion of the second active material layer 222 protrudes from the outer peripheral surface of the substrate portion 2121. In the lamination direction z, the orthographic projection of the insulating member 3 onto the thinned portion 2122 covers the orthographic projection of the second active material layer 222 onto the thinned portion 2122.

[0133] In some examples, the size of the substrate 2121 is smaller than the size of the second active material layer 222 along the direction from the substrate 2121 to the thinned portion 2122.

[0134] In some examples, the structure of the second active material layer 222 is the same as that of the substrate 2121.

[0135] For example, the substrate 2121 and the second active material layer 222 have a rectangular structure.

[0136] Optionally, the four sides of the second active material layer 222 protrude from the four sides of the substrate 2121.

[0137] Alternatively, in the direction from the substrate 2121 to the thinned portion 2122, the four sides of the second active material layer 222 protrude from the four sides of the substrate 2121 by equal distances.

[0138] During the lamination process, the edge of the second electrode 22 can fall into the area of ​​the thinned portion 2122 of the first electrode 21, and be covered and isolated by the insulating member 3 provided in this area.

[0139] According to one embodiment of this application, such as Figure 5 As shown, a portion of the insulating element 3 protrudes from the outer peripheral surface of the second active material layer 222.

[0140] In some examples, in a direction parallel to the substrate 2121 pointing towards the thinned portion 2122, one end of the insulating member 3 abuts against the substrate 2121, and the other end protrudes from the outer peripheral surface of the second active material layer 222. This improves the installation stability of the insulating member 3.

[0141] In other examples, in a direction parallel to the substrate 2121 pointing towards the thinned portion 2122, one end of the insulating member 3 is spaced apart from the substrate 2121, and the other end protrudes from the outer peripheral surface of the second active material layer 222. The spaced-apart arrangement of the insulating member 3 with the substrate 2121 provides a buffer space for the expansion of the substrate 2121 during the charging and discharging of the battery cell 10.

[0142] During the stacking process, if the second electrode 22 has an alignment deviation, its edge can still fall within the area of ​​the thinned portion 2122, thereby reducing structural interference and improving the insulation reliability inside the battery cell 10.

[0143] According to one embodiment of this application, in a plane perpendicular to the stacking direction z, the orthographic projection of the insulating member 3 covers the orthographic projection of the thinned portion 2122. This improves the isolation effect of the first electrode 21 and the second electrode 22, further reducing the possibility of edge contact.

[0144] In some examples, a portion of the insulating member 3 protrudes from the outer peripheral surface of the thinned portion 2122 in a plane perpendicular to the stacking direction z; or, along the direction from the base portion 2121 to the thinned portion 2122, the size of the insulating member 3 is equal to the size of the thinned portion 2122.

[0145] According to one embodiment of this application, such as Figure 5 As shown, the outer peripheral surface of the insulating member 3 is flush with the outer peripheral surface of the thinned portion 2122.

[0146] In some examples, the first electrode 21 is provided with insulating elements 3 on both sides along the stacking direction z, and the outer peripheral surface of the insulating element 3 is flush with the outer peripheral surface of the thinned portion 2122.

[0147] The insulating component 3 is flush with the outer peripheral surface of the thinned portion 2122. Therefore, the installation of the insulating component 3 has little impact on the overall structure and does not occupy additional space perpendicular to the stacking direction z, effectively controlling the overall size of the battery cell 10 and improving space utilization.

[0148] See also Figure 6 , Figure 6 This is a partial cross-sectional structural diagram of the electrode assembly and insulating component of a battery cell provided in an embodiment of this application.

[0149] According to one embodiment of this application, the thinned portion 2122 is connected to the base portion 2121, and the thinned portion 2122 is inclined inward relative to the first current collector 211, while the insulating member 3 is inclined outward relative to the first current collector 211.

[0150] In some examples, a portion of the thinned portion 2122 is inclined inward relative to the first current collector 211, that is, the thickness of the thinned portion 2122 remains unchanged and then decreases along the direction from the base portion 2121 to the thinned portion 2122; or, the thickness of the thinned portion 2122 decreases and then remains unchanged.

[0151] In other examples, the thinned portion 2122 is inclined inward relative to the first current collector 211.

[0152] The reduced thickness of the thinned portion 2122 near its edge and the increased thickness of the insulating component 3 reduce the occurrence of edge warping of the first electrode 21 during pressurization. Furthermore, by reducing the thickness of the active material layer, the diffusion path of active ions within the active material layer is shortened, reducing ion migration resistance and enabling active ions to rapidly complete the intercalation / deintercalation reaction.

[0153] According to one embodiment of this application, such as Figure 5 As shown, in the stacking direction z, the surface of the insulating member 3 away from the thinned portion 2122 is parallel to the surface of the base portion 2121 away from the first current collector 211.

[0154] Specifically, an insulating element 3 is coated on the thinned portion 2122. After coating, the surface of the insulating element 3 facing away from the thinned portion 2122 is not parallel to the surface of the substrate portion 2121. After pressure treatment, the substrate portion 2121 is compacted. In the lamination direction z, the surface of the insulating element 3 facing away from the thinned portion 2122 is parallel to the surface of the substrate portion 2121 facing away from the first current collector 211.

[0155] For example, the insulating member 3 has a first surface and a second surface opposite to each other along the stacking direction z. The first surface faces the thinned portion 2122, and the second surface faces away from the thinned portion 2122. The first surface is inclined outward relative to the first current collector 211, and the second surface is parallel to the surface of the substrate portion 2121 that faces away from the first current collector 211.

[0156] Optionally, the base portion 2121 of the insulating member 3 has a third surface and a fourth surface facing each other in the direction of the thinned portion 2122. The third surface faces the base portion 2121, the fourth surface faces away from the base portion 2121, the third surface is attached to the base portion 2121, and the fourth surface is flush with the outer peripheral surface of the thinned portion 2122.

[0157] In some examples, the insulating element 3 is triangular or trapezoidal in a plane parallel to the stacking direction z.

[0158] By utilizing the thinning design of the thinned portion 2122 of the first active material layer 212, the thickness of the insulating component 3 is effectively offset, making the electrode assembly 2 more flat overall, improving the uniformity of contact between the electrode layers, reducing the risk of damage to the electrolyte layer 23 due to uneven local stress, and improving the reliability of the battery.

[0159] See also Figure 7 and Figure 8 , Figure 7 This is a partial cross-sectional structural diagram of the electrode assembly and insulating component of a battery cell provided in another embodiment of this application; Figure 8 This is a top view of a portion of the structure of a battery cell provided in an embodiment of this application.

[0160] According to one embodiment of this application, such as Figure 7 and Figure 8 As shown, the first current collector 211 includes a first current collector body 2111 and a first electrode tab 2112 arranged along the first direction x. The insulating member 3 includes two first insulating parts 31 arranged opposite each other along the first direction x and two second insulating parts 32 arranged opposite each other along the second direction y. The strength of the first insulating part 31 is greater than the strength of the second insulating part 32. The first direction x, the second direction y and the stacking direction z are perpendicular to each other.

[0161] In some examples, the first current collector 211 includes a first current collector body 2111 and a first tab 2112 extending from the outer peripheral surface of the first current collector body 2111. The first current collector body 2111 has a first active material layer 212, while the first tab 2112 does not have the first active material layer 212.

[0162] In some examples, the first current collector 211 includes a first current collector body 2111 and a first tab 2112 extending from the outer peripheral surface of the first current collector body 2111. The first current collector body 2111 has a first active material layer 212, while the first tab 2112 does not have the first active material layer 212.

[0163] In some examples, the first tab 2112 and the second tab may be located together at one end of the electrode assembly 2 or at both ends of the electrode assembly 2 respectively.

[0164] For example, during the charging and discharging process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte layer 23, and the tabs connect the electrode terminals to form a current loop.

[0165] In some examples, the thinning portion 2122 includes two first sub-parts disposed opposite each other along a first direction x and two second sub-parts disposed opposite each other along a second direction y, two first insulating portions 31 are respectively disposed on the two first sub-parts, and two second insulating portions 32 are respectively disposed on the two second sub-parts.

[0166] In some examples, the material strength of the first insulating part 31 is greater than that of the material of the second insulating part 32.

[0167] The first tab 2112 extends from the main body of the first current collector 211. During subsequent casing installation, welding, and battery charging and discharging expansion, the root of the first tab 2112 is a stress concentration area, and the first tab 2112 will be subjected to tensile force. The insulating component 3 near the first tab 2112 has higher strength and can provide better structural support for the root of the first tab 2112, resisting the tensile deformation of the first tab 2112, so as to form more effective protection for the first tab 2112.

[0168] According to one embodiment of this application, the thickness of the first insulating portion 31 is greater than the thickness of the second insulating portion 32. This further improves the structural protection of the electrode tabs and enhances the reliability of the battery cell.

[0169] See also Figure 9 , Figure 9 This is a partial cross-sectional structural diagram of the electrode assembly and insulating component of a battery cell provided in another embodiment of this application.

[0170] According to one embodiment of this application, such as Figure 9As shown, the insulating member 3 includes a first insulating part 31 and a second insulating part 32 stacked along the stacking direction z. The second insulating part 32 is located between the thinned part 2122 and the first insulating part and is connected to the thinned part 2122 and the first insulating part 31. The strength of the first insulating part 31 is greater than the strength of the second insulating part 32.

[0171] In some examples, the second insulating portion 32 is bonded to the thinned portion 2122 and the first insulating portion 31. The thinned portion 2122 and the first insulating portion 31 are bonded together by the second insulating portion 32.

[0172] For example, the second insulating part 32 is made of insulating adhesive.

[0173] In some examples, the thickness of the second insulating portion 32 is greater than the thickness of the first insulating portion 31.

[0174] The second insulating part 32 serves as a transition and connection structure, which can improve the problem that the high-strength first insulating part 31 is difficult to directly and tightly adhere to the thinned part 2122. The second insulating part 32 achieves better interfacial bonding force between the insulating member 3 and the first electrode 21, and the first insulating part 31 can improve the overall mechanical strength of the insulating member 3.

[0175] According to one embodiment of this application, the first insulating portion 31 includes a UV adhesive layer and / or a hot melt adhesive layer. The second insulating portion 32 includes one or more of a ceramic layer, an alumina layer, and a compression-molded polymer layer.

[0176] Optionally, the insulating element 3 is a modified alumina layer. It has high strength and low modulus.

[0177] These optional insulators 3, made of insulating materials, allow for precise control of internal charge transfer, reducing the potential short-circuit risk within the battery cell 10. Furthermore, these specific materials give the insulators 3 high stability, reducing their involvement in internal chemical reactions and their impact on battery performance, thus extending the lifespan of the battery cell 10. This dual protection provided by the insulators 3 also improves the stability and reliability of the battery.

[0178] According to one embodiment of this application, such as Figure 5 As shown, in the direction from the substrate 2121 to the thinned portion 2122, the distance L1 between the outer peripheral surface of the substrate 2121 and the outer peripheral surface of the second active material layer 222 is greater than the distance L2 between the outer peripheral surface of the second active material layer 222 and the outer peripheral surface of the thinned portion 2122.

[0179] During the pressurization process of electrode assembly 2, stress concentration occurs in the edge area of ​​the electrode, which damages the structure of the edge area of ​​the electrode. This not only reduces the bonding force between the active material layer and the current collector, but also causes the active material layer to fall off, and increases the impedance, affecting the performance of the battery cell 10.

[0180] A portion of the insulating element 3 is filled between the thinned portion 2122 and the second active material layer 222, which can absorb part of the stacking stress and disperse the stacking stress on the edge of the first active material layer 212, that is, protect the thinned portion 2122.

[0181] According to one embodiment of this application, such as Figure 5 As shown, in the direction from the substrate 2121 to the thinned portion 2122, the distance L1 between the outer peripheral surface of the substrate 2121 and the outer peripheral surface of the second active material layer 222 satisfies: 0 < L1 ≤ 2 mm. This can better disperse the stacking stress on the edge of the first active material layer 212 and also appropriately reduce the proportion of the thinned portion 2122.

[0182] In some examples, in the direction from the substrate 2121 to the thinned portion 2122, the distance L1 between the outer peripheral surface of the substrate 2121 and the outer peripheral surface of the second active material layer 222 is 0 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, or other ranges formed by any two of the above endpoints.

[0183] Optionally, in the direction from the substrate 2121 to the thinned portion 2122, the distance L1 between the outer peripheral surface of the substrate 2121 and the outer peripheral surface of the second active material layer 222 satisfies: 1mm < L1 ≤ 1.5mm.

[0184] According to one embodiment of this application, such as Figure 5 As shown, in the direction from the substrate 2121 to the thinned portion 2122, the distance L2 between the outer peripheral surface of the second active material layer 222 and the outer peripheral surface of the thinned portion 2122 satisfies: 0 < L2 ≤ 1.5 mm.

[0185] In some examples, in the direction from the substrate 2121 to the thinned portion 2122, the distance L2 between the outer peripheral surface of the second active material layer 222 and the outer peripheral surface of the thinned portion 2122 satisfies 0 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, or other ranges formed by any two of the above endpoints.

[0186] Allowing a certain positional deviation between the first electrode 21 and the second electrode 22 during stacking effectively suppresses edge overlap between the first electrode 21 and the second electrode 22. Reducing the proportion of the thinned portion 2122 in the overall first active material layer 212 results in a higher energy density for the battery cell 10.

[0187] According to one embodiment of this application, in the direction from the base portion 2121 to the thinned portion 2122, the size of the thinned portion 2122 is 3mm to 6mm.

[0188] In some examples, the dimensions of the thinned portion 2122 are 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm, 5.0 mm, 5.1 mm, 5.2 mm, 5.3 mm, 5.4 mm, 5.5 mm, 5.6 mm, 5.7 mm, 5.8 mm, 5.9 mm, 6.0 mm, or other ranges formed by any two of the above endpoints, in the direction from the base portion 2121 to the thinned portion 2122.

[0189] The size of the thinned portion 2122 is optimized to reduce its excessive area occupation, thereby ensuring that the substrate portion 2121 of the first active material layer 212 has a sufficient proportion and maintaining the overall energy density of the battery cell 10 at a high level.

[0190] See also Figure 10 , Figure 10 This is a partial cross-sectional structural diagram of the first electrode and insulating component of a battery cell provided in an embodiment of this application.

[0191] According to one embodiment of this application, such as Figure 10 As shown, the maximum thickness C1 of the thinned portion 2122, the maximum thickness C2 of the base portion 2121, and the maximum thickness C3 of the insulating member 3 satisfy the following condition: C1≤C3≤C2. The insulating member 3 has a suitable thickness, which enables it to have a stable insulating effect.

[0192] Secondly, this application provides a battery device including the aforementioned battery cell 10.

[0193] Thirdly, this application provides an electrical device including the aforementioned battery cell 10 or the aforementioned battery device, wherein the battery cell 10 or the battery device is used to store or provide electrical energy.

[0194] According to some embodiments of this application, see Figures 3 to 5 , Figure 7 and Figure 8The battery cell 10 includes a casing 1, an electrode assembly 2, and an insulating component 3.

[0195] The outer casing 1 has a receiving cavity 11.

[0196] Electrode assembly 2 is disposed within receiving cavity 11. Electrode assembly 2 includes multiple first electrode plates 21, multiple second electrode plates 22, and electrolyte layer 23. The first electrode plates 21 are positive electrode plates, and the second electrode plates 22 are negative electrode plates. The multiple first electrode plates 21 and multiple second electrode plates 22 are alternately stacked along the stacking direction z. Electrolyte layer 23 is used to isolate the first electrode plates 21 and the second electrode plates 22. The first electrode plate 21 includes a first current collector 211 and a first active material layer 212 disposed on the surface of the first current collector 211. The second electrode plate 22 includes a second current collector 221 and a second active material layer 222 disposed on the surface of the second current collector 221. A portion of the first active material layer 212 protrudes from the outer peripheral surface of the second active material layer 222. The first active material layer 212 includes a substrate portion 2121 and a thinned portion 2122. The thinned portion 2122 is disposed along the outer periphery of the substrate portion 2121, and the thickness of the substrate portion 2121 is greater than the thickness of the thinned portion 2122. The first current collector 211 includes a first current collector body 2111 and a first electrode tab 2112 arranged along the first direction x. A portion of the second active material layer 222 protrudes from the outer peripheral surface of the substrate 2121.

[0197] An insulating member 3 is disposed on the side of the thinned portion 2122 facing away from the first current collector 211 along the lamination direction z. The insulating member 3 is attached to and connected to the surface of the thinned portion 2122 facing away from the first current collector 211 along the lamination direction z. In the lamination direction z, the orthographic projection of the insulating member 3 onto the thinned portion 2122 covers the orthographic projection of the second active material layer 222 onto the thinned portion 2122. In a plane perpendicular to the lamination direction z, the orthographic projection of the insulating member 3 covers the orthographic projection of the thinned portion 2122. The outer peripheral surface of the insulating member 3 is flush with the outer peripheral surface of the thinned portion 2122. Along the lamination direction z, the surface of the insulating member 3 facing away from the thinned portion 2122 is parallel to the surface of the substrate portion 2121 facing away from the first current collector 211. In the direction from the substrate 2121 to the thinned portion 2122, the distance L1 between the outer peripheral surface of the substrate 2121 and the outer peripheral surface of the second active material layer 222 is greater than the distance L2 between the outer peripheral surface of the second active material layer 222 and the outer peripheral surface of the thinned portion 2122. In the direction from the substrate 2121 to the thinned portion 2122, the distance L1 between the outer peripheral surface of the substrate 2121 and the outer peripheral surface of the second active material layer 222 satisfies: 0 < L1 ≤ 2 mm. In the direction from the substrate 2121 to the thinned portion 2122, the distance L2 between the outer peripheral surface of the second active material layer 222 and the outer peripheral surface of the thinned portion 2122 satisfies: 0 < L2 ≤ 1.5 mm. In the direction from the substrate 2121 to the thinned portion 2122, the size of the thinned portion 2122 is 3 mm to 6 mm. The maximum thickness C1 of the thinned portion 2122, the maximum thickness C2 of the base portion 2121, and the maximum thickness C3 of the insulating member 3 satisfy: C1 ≤ C3 ≤ C2. The insulating member 3 includes two first insulating portions 31 disposed opposite each other along a first direction x and two second insulating portions 32 disposed opposite each other along a second direction y. The strength of the first insulating portions 31 is greater than the strength of the second insulating portions 32. The thickness of the first insulating portions 31 is greater than the thickness of the second insulating portions 32. The first insulating portions 31 include a UV adhesive layer and / or a hot melt adhesive layer. The second insulating portions 32 include one or more of a ceramic layer, an alumina layer, and a compression-molded polymer layer.

[0198] The first direction x, the second direction y, and the stacking direction z are all perpendicular to each other.

[0199] 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 receiving cavity; An electrode assembly is disposed within the receiving cavity. The electrode assembly includes a plurality of first electrodes, a plurality of second electrodes, and an electrolyte layer. The first electrodes and second electrodes have opposite polarities. The plurality of first electrodes and the plurality of second electrodes are alternately stacked along a stacking direction. The electrolyte layer is used to isolate the first electrodes and the second electrodes. The first electrode includes a first current collector and a first active material layer disposed on the surface of the first current collector. The second electrode includes a second current collector and a second active material layer disposed on the surface of the second current collector. A portion of the first active material layer protrudes from the outer peripheral surface of the second active material layer. The first active material layer includes a base portion and a thinned portion. The thinned portion is disposed along the outer periphery of the base portion, and the thickness of the base portion is greater than the thickness of the thinned portion. An insulating element is disposed on the side of the thinned portion away from the first current collector along the stacking direction. In a plane perpendicular to the stacking direction, the orthographic projection of the insulating element overlaps with the orthographic projection of the second active material layer.

2. The battery cell according to claim 1, characterized in that, The first electrode is the positive electrode, and the second electrode is the negative electrode.

3. The battery cell according to claim 1, characterized in that, The insulating element and the thinned portion are attached and connected along the stacking direction away from the surface of the first current collector.

4. The battery cell according to claim 1, characterized in that, A portion of the second active material layer protrudes from the outer peripheral surface of the substrate. In the stacking direction, the orthogonal projection of the insulating element on the thinned portion overlaps the orthogonal projection of the second active material layer on the thinned portion.

5. The battery cell according to claim 4, characterized in that, A portion of the insulating element protrudes from the outer peripheral surface of the second active material layer.

6. The battery cell according to claim 1, characterized in that, In a plane perpendicular to the stacking direction, the orthographic projection of the insulating element overlaps the orthographic projection of the thinned portion.

7. The battery cell according to claim 1, characterized in that, The outer peripheral surface of the insulating component is flush with the outer peripheral surface of the thinned portion.

8. The battery cell according to claim 1, characterized in that, The thinned portion is connected to the base portion, and the thinned portion is inclined inward relative to the first current collector, while the insulating member is inclined outward relative to the first current collector.

9. The battery cell according to claim 1, characterized in that, In the stacking direction, the surface of the insulating member facing away from the thinned portion is parallel to the surface of the substrate portion facing away from the first current collector.

10. The battery cell according to claim 1, characterized in that, The first current collector includes a first current collector body and a first electrode arranged along a first direction; The insulating component includes two first insulating portions disposed opposite each other along the first direction and two second insulating portions disposed opposite each other along the second direction. The strength of the first insulating portion is greater than the strength of the second insulating portion, and the first direction, the second direction and the stacking direction are perpendicular to each other.

11. The battery cell according to claim 10, characterized in that, The thickness of the first insulating part is greater than the thickness of the second insulating part.

12. The battery cell according to claim 1, characterized in that, The insulating component includes a first insulating portion and a second insulating portion stacked along the stacking direction. The second insulating portion is located between and connected to the thinned portion and the first insulating portion. The strength of the first insulating portion is greater than the strength of the second insulating portion.

13. The battery cell according to claim 10 or 12, characterized in that, The first insulating part includes a UV adhesive layer and / or a hot melt adhesive layer; The second insulating layer includes one or more of a ceramic layer, an alumina layer, and a compression-molded polymer layer.

14. The battery cell according to claim 1, characterized in that, In the direction from the substrate portion to the thinned portion, the distance L1 between the outer peripheral surface of the substrate portion and the outer peripheral surface of the second active material layer is greater than the distance L2 between the outer peripheral surface of the second active material layer and the outer peripheral surface of the thinned portion.

15. The battery cell according to claim 14, characterized in that, In the direction from the substrate portion to the thinned portion, the distance L1 between the outer peripheral surface of the substrate portion and the outer peripheral surface of the second active material layer satisfies: 0 < L1 ≤ 2 mm.

16. The battery cell according to claim 14, characterized in that, In the direction from the substrate to the thinned portion, the distance L2 between the outer peripheral surface of the second active material layer and the outer peripheral surface of the thinned portion satisfies: 0 < L2 ≤ 1.5 mm.

17. The battery cell according to claim 1, characterized in that, In the direction from the base portion to the thinned portion, the size of the thinned portion is 3mm to 6mm.

18. The battery cell according to claim 1, characterized in that, The maximum thickness C1 of the thinned portion, the maximum thickness C2 of the base portion, and the maximum thickness C3 of the insulating component satisfy the following condition: C1≤C3≤C2.

19. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1 to 18.

20. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1 to 18 or a battery device according to claim 19, wherein the battery cell or the battery device is used to store or provide electrical energy.

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