Battery cell, battery, battery pack and electric equipment

Abstract

The embodiment of the utility model provides a battery cell, a battery, a battery pack and electric equipment, and relates to the technical field of battery cells. The battery cell comprises a first packaging film layer, a second packaging film layer and a pole core, at least one of the first packaging film layer and the second packaging film layer comprises a metal layer and a bonding layer. The metal layer comprises a first area and a second area, the bonding layer covers the second area and does not cover the first area, or the thickness of the bonding layer covering the first area is smaller than that of the bonding layer covering the second area. At least part of the bonding layer in the second area is used for edge sealing, so that the first packaging film layer and the second packaging film layer are enclosed to form a sealing cavity, and the pole core is arranged in the sealing cavity. Therefore, the battery cell has relatively high volume energy density.

Description

[0001] This application claims priority to the Chinese Patent Application No. 202422334935.5, filed on September 24, 2024, entitled "Battery Cell, Battery, Battery Pack and Electrical Equipment", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the technical field of battery cells, and in particular to a battery cell, a battery, a battery pack and an electrical equipment. BACKGROUND

[0003] A battery cell is a power storage component of a battery or a battery pack, and is widely used in devices such as mobile phones, tablet computers, vehicles, unmanned aerial vehicles, robots, and power storage base stations.

[0004] In the related art, a battery cell has a packaging structure and a pole core disposed in the packaging structure. The packaging structure can be formed by edge bonding of two layers of packaging films. In the related art, the volumetric energy density of the battery cell needs to be improved. UTILITY MODEL CONTENT

[0005] Embodiments of the present application provide a battery cell, a battery, a battery pack and an electrical equipment, which can make the battery cell have a higher volumetric energy density.

[0006] In a first aspect, the present application provides a battery cell. The battery cell includes a first packaging film layer, a second packaging film layer, and a pole core. At least one of the first packaging film layer and the second packaging film layer includes a metal layer and a bonding layer. The metal layer includes a first region and a second region, and the bonding layer covers the second region and does not cover the first region, or the thickness of the bonding layer covering the first region is less than the thickness of the bonding layer covering the second region. At least part of the bonding layer located in the second region is used for edge sealing, so that the first packaging film layer and the second packaging film layer form a sealed cavity, and the pole core is disposed in the sealed cavity. Here, the metal layer refers to the metal layer including the first region and the second region.

[0007] The battery cell provided by the embodiments of the present application can realize edge sealing by using the bonding layer, and by thinning or removing the bonding layer of the first region, a capacity expansion space can be formed at the first region. On the basis of the unchanged size of the battery cell, the capacity expansion space increases the capacity of the sealed cavity, which is beneficial to increase the arrangement amount of the electrode material in the sealed cavity, and further beneficial to improve the volumetric energy density of the battery cell.

[0008] In a possible implementation, the first region is located on a large face of the battery cell. Here, the large face of the battery cell refers to the face with the largest area on the packaging structure of the battery cell.

[0009] In this way, the recessed portion for forming the encapsulation structure can be formed by stamping the first encapsulation film layer and the second encapsulation film layer. The bottom wall of the recessed portion is used to form the large surface of the battery cell. The first region is located on the bottom wall of the recessed portion. It is relatively easy to process the original bonding layer on the bottom wall of the recessed portion (e.g., laser cleaning), making it easier to form the expansion space.

[0010] In one possible implementation, the second region includes a first sub-region and a second sub-region, the bonding layer located in the first sub-region is used for edge sealing, the bonding layer located in the second sub-region is not used for edge sealing, and the second sub-region is located between the first region and the first sub-region.

[0011] In this way, the second sub-region, which is not used for edge sealing, has a bonding layer, which can serve as insulation and protection in the second sub-region. In addition, the bonding layer in the second sub-region can also improve the strength of the second sub-region, making it less susceptible to damage due to tension or other reasons.

[0012] In one possible implementation, when the thickness of the bonding layer covering the first region is less than the thickness of the bonding layer covering the second region, the thickness of the bonding layer covering the first region is less than the thickness of the bonding layer covering the second sub-region.

[0013] Thus, the thicker bonding layer covering the second sub-region can effectively improve the strength and provide insulation protection in the second sub-region. Conversely, the thinner bonding layer in the first region can also contribute to improving strength and providing insulation protection to some extent.

[0014] In one possible implementation, a portion of the second region is located on the large surface of the battery cell.

[0015] This reduces the precision requirements for the edge positioning of the expanded space, making its formation easier. Furthermore, the second region extends to the large surface of the cell, with the bonding layer covering the corner where the large surface of the cell connects to the sealing edge. This corner offers good strength and is less prone to damage from tensile deformation. Additionally, the corner where the large surface of the cell connects to the sealing edge also provides good insulation.

[0016] In one possible implementation, the second region surrounds the outer edge of the first region, and the bonding layer in the second region is used for edge sealing. This facilitates the formation of a larger expansion space.

[0017] In one possible implementation, when the bonding layer covers the second region but not the first region: the thickness of the metal layer in the first region is less than the thickness of the metal layer in the second region.

[0018] In this way, the portion of the metal layer that is left empty in the first region can be used to arrange electrode materials, which is beneficial to further increase the amount of electrode materials arranged inside the packaging structure.

[0019] In one possible implementation, when the bonding layer covers the second region but not the first region: the surface of the first region near the electrode core is covered with an oxide layer.

[0020] In this way, the formed oxide layer can improve the strength of the encapsulation structure in the first region, making the encapsulation structure less prone to damage.

[0021] In one possible implementation, the battery cell further includes a first electrode plate. The first electrode plate is disposed within a sealed cavity, between the battery core and the first region.

[0022] In this way, the amount of electrode material arranged in the packaging structure can be increased by adding a first electrode sheet between the electrode core and the first region, thereby increasing the volumetric energy density of the battery cell. Increasing the amount of electrode material arranged in the packaging structure is relatively easy.

[0023] In one possible implementation, the first electrode sheet includes a first current collector and a first electrode material, the first electrode material being disposed on the side of the first current collector close to the electrode core.

[0024] In this way, the utilization rate of the electrode material coated on the first electrode sheet is relatively high, which makes it easier to increase the amount of electrode material that can be used on the first electrode sheet.

[0025] In one possible implementation, when the bonding layer covers the second region but not the first region, the surface of the first region near the electrode core is provided with the second electrode material.

[0026] In this way, the amount of electrode material arranged in the packaging structure can be increased by setting electrode material on the surface of the first region, thereby improving the volumetric energy density of the battery cell. In addition, by using a metal layer including the first and second regions as a current collector to carry the electrode material, the space utilization rate of the battery cell is high, and a larger amount of electrode material can be arranged in the expanded space, which is beneficial to improving the volumetric energy density of the battery cell.

[0027] In one possible implementation, the battery cell further includes a tab, and the metal layer includes a connecting portion protruding from the outer edge of the second region, the connecting portion being located outside the sealed cavity and connected to the tab.

[0028] In this way, the metal layer can be connected to the tab outside the package structure via the connector, making it easier to connect the metal layer, including the first and second regions, to the tab. Furthermore, the connection between the metal layer and the tab is less likely to damage the package structure.

[0029] In one possible implementation, the metal layer is an aluminum layer, and the second electrode material is a cathode electrode material.

[0030] This facilitates the galvanic cell reaction and electrolysis reaction of the second electrode material disposed on the surface of the aluminum metal layer, thereby improving the volumetric energy density of the aluminum metal layer battery cell.

[0031] In one possible implementation, the metal layer is a steel layer, and the second electrode material is an anode electrode material.

[0032] This facilitates the galvanic cell reaction and electrolysis reaction of the second electrode material disposed on the surface of the metal layer being steel, thereby improving the volumetric energy density of the battery cell with the metal layer being steel.

[0033] A second aspect of this application provides a battery comprising the cells described in any of the above embodiments.

[0034] A third aspect of this application provides a battery pack, which includes a battery management system and battery cells as described in any of the above embodiments, wherein the battery cells are electrically connected to the battery management system.

[0035] A fourth aspect of this application provides an electrical device that includes a battery or a battery pack as described in any of the above embodiments. Attached Figure Description

[0036] Figure 1 A schematic diagram of a battery cell provided in an embodiment of this application;

[0037] Figure 2 This is a cross-sectional schematic diagram of a battery cell provided in an embodiment of this application;

[0038] Figure 3 This is a schematic diagram of the stacking of a first encapsulation film layer provided in an embodiment of this application;

[0039] Figure 4 A schematic diagram of the unfolded first and second encapsulation film layers provided in the embodiments of this application;

[0040] Figure 5 A schematic cross-sectional view of the electrode core of a battery cell in a first region, provided as an embodiment of this application;

[0041] Figure 6 A schematic cross-sectional view of the electrode core of a battery cell at the first electrode sheet, provided as an embodiment of this application;

[0042] Figure 7 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0043] Figure 8This application provides a schematic diagram of the stacking of a first encapsulation film layer with a second electrode material, as shown in an embodiment of the present application.

[0044] Figure 9 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0045] Figure 10 A schematic cross-sectional view of the electrode core of a battery cell at the second electrode material, provided as an embodiment of this application;

[0046] Figure 11 A schematic diagram of the unfolded first and second encapsulation film layers provided in the embodiments of this application;

[0047] Figure 12 A schematic diagram of yet another type of battery cell provided in an embodiment of this application;

[0048] Figure 13 This is a schematic diagram of the stacking of a second encapsulation film layer provided in an embodiment of this application;

[0049] Figure 14 A schematic diagram of the unfolded first and second encapsulation film layers provided in the embodiments of this application;

[0050] Figure 15 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0051] Figure 16 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0052] Figure 17 This application provides a schematic diagram of the stacking of a second encapsulation film layer with a second electrode material, as shown in the embodiments of the present application.

[0053] Figure 18 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0054] Figure 19 A schematic diagram of the unfolded first and second encapsulation film layers provided in the embodiments of this application;

[0055] Figure 20 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0056] Figure 21 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0057] Figure 22 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0058] Figure 23A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0059] Figure 24 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0060] Figure 25 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0061] Figure 26 A cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application;

[0062] Figure 27 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0063] Explanation of reference numerals in the attached figures:

[0064] 10. Encapsulation structure; 11. Sealed cavity; 12. First encapsulation film layer; 13. Second encapsulation film layer; 20. First tab; 21. First bonding material; 30. Second tab; 31. Second bonding material; 40. Connecting segment; 50. Insulating material;

[0065] 110, Metal layer; 110a, First metal layer; 110b, Second metal layer; 111, Connecting portion; 120, Bonding layer; 120a, First bonding layer; 120b, Second bonding layer; 130, Adhesive layer; 130a, First adhesive layer; 130b, Second adhesive layer; 130c, Third adhesive layer; 130d, Fourth adhesive layer; 140a, First protective layer; 140b, Second protective layer; 150, Oxide layer; 150a, First oxide layer;

[0066] 200, Electrode core; 210, Second electrode sheet; 211, Second current collector; 212, Third electrode material; 220, First separator; 230, Third electrode sheet; 231, Third current collector; 232, Fourth electrode material;

[0067] 300. First electrode sheet; 310. First current collector; 320. First electrode material;

[0068] 400. Second electrode material;

[0069] S1, First Region; S2, Second Region; S21, First Sub-region; S22, Second Sub-region. Detailed Implementation

[0070] The terminology used in the implementation section of this application is only for explaining specific embodiments of this application and is not intended to limit this application. The implementation of the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0071] This application provides an electrical device, which may include, but is not limited to, devices with energy storage capabilities such as mobile phones, tablets, laptops, e-readers, wearable devices, vehicles, drones, robots, energy storage base stations, and power banks. The electrical device includes a battery or battery pack.

[0072] In some possible implementations, the electrical device includes a battery, which includes cells for storing electricity.

[0073] For example, the battery may also include a battery protection board, which is electrically connected to the battery cell. The battery protection board can protect the battery cell from charging and discharging. For example, the battery protection board can provide functions such as overcharge protection, over-discharge protection, overcurrent protection, short circuit protection, over-temperature protection, and equalization protection for the battery cell.

[0074] In some possible implementations, the electrical device includes a battery pack, which may include a battery management system (BMS) and multiple battery cells. The multiple battery cells may be connected in series or in parallel. The battery cells are electrically connected to the battery management system and are used for energy storage. The battery management system can manage all the electrically connected battery cells.

[0075] For example, a battery pack may include multiple batteries, which may be connected in series or in parallel, and the battery cells may be electrically connected to a battery management system via a battery protection board.

[0076] In some examples, the electrical equipment may also include a load, with the battery cell electrically connected to the load, and the battery cell can supply power to the load.

[0077] When the electrical equipment includes a battery protection board, the battery cell can be electrically connected to the load through the battery protection board.

[0078] When the electrical equipment includes a battery management system, the battery cell can be electrically connected to the load through the battery management system.

[0079] For example, the load may include, but is not limited to, a processor, a display screen, etc.

[0080] In some examples, the electrical device may also include a power conversion device, with the battery cell electrically connected to the power conversion device, which can be used to convert current from the outside into the current required by the battery cell and then deliver it to the battery cell.

[0081] When the electrical equipment includes a battery protection board, the battery cell can be electrically connected to the power conversion device through the battery protection board.

[0082] When the electrical equipment includes a battery management system, the battery cell can be electrically connected to the power conversion device through the battery management system.

[0083] Figure 1 This is a schematic diagram of a battery cell provided in an embodiment of this application.

[0084] like Figure 1 As shown in the embodiment of this application, the battery cell includes a packaging structure 10 and a core 200. The core 200 can also be called a bare battery cell. The packaging structure 10 encloses and forms a sealed cavity 11. The core 200 is disposed in the sealed cavity 11. That is to say, the core 200 is disposed in the packaging structure 10.

[0085] In some examples, the pole core 200 can be a wound structure, that is, the pole core 200 can be a wound pole core.

[0086] In other examples, the pole core 200 can be a stacked structure, that is, the pole core 200 can be a stacked pole core.

[0087] In this embodiment of the application, the battery cell also includes a plurality of tabs. Part of the tabs are located inside the sealed cavity 11 and are electrically connected to the battery core 200. Part of the tabs extend outside the packaging structure 10 and are electrically connected to devices outside the packaging structure 10, so that the battery core 200 is electrically connected to devices outside the packaging structure 10 through the tabs.

[0088] For example, one of the plurality of tabs is a first tab 20, and the other of the plurality of tabs is a second tab 30. Parts of the first tab 20 and the second tab 30 are located inside the sealed cavity 11 and are electrically connected to the electrode core 200. Parts of the first tab 20 and the second tab 30 extend out of the package structure 10 and are electrically connected to the device outside the package structure 10, so that the electrode core 200 is electrically connected to the device outside the package structure 10 through the first tab 20 and the second tab 30.

[0089] In an example where the battery cell is electrically connected to the load, the first tab 20 and the second tab 30 are electrically connected to the load located outside the package structure 10. For example, the first tab 20 and the second tab 30 can be electrically connected to a battery protection board located outside the package structure 10, and the first tab 20 and the second tab 30 are electrically connected to the load through the battery protection board. As another example, the first tab 20 and the second tab 30 can be electrically connected to a battery management system located outside the package structure 10, and the first tab 20 and the second tab 30 are electrically connected to the load through the battery management system.

[0090] In an example of the electrical connection between the battery cell and the power conversion device, the first tab 20 and the second tab 30 are electrically connected to the power conversion device located outside the package structure 10. For example, the first tab 20 and the second tab 30 can be electrically connected to a battery protection board located outside the package structure 10, and the first tab 20 and the second tab 30 are electrically connected to the power conversion device through the battery protection board. As another example, the first tab 20 and the second tab 30 can be electrically connected to a battery management system located outside the package structure 10, and the first tab 20 and the second tab 30 are electrically connected to the power conversion device through the battery management system.

[0091] For example, the electrode core 200 includes multiple electrode plates and a separator. Some of the electrode plates are cathode electrode plates, and some are anode electrode plates. That is, the electrode core 200 includes cathode electrode plates, anode electrode plates, and a separator. The cathode electrode plates and anode electrode plates are arranged alternately, and a separator is disposed between adjacent cathode electrode plates and anode electrode plates, separating them through the separator. The cathode electrode plate is electrically connected to one of the first tab 20 and the second tab 30, and the anode electrode plate is electrically connected to the other of the first tab 20 and the second tab 30.

[0092] The cathode electrode sheet includes a cathode current collector and a cathode electrode material, the cathode electrode material being disposed on the surface of the cathode current collector, and the cathode current collector being electrically connected to one of the first tab 20 and the second tab 30. The anode electrode sheet includes an anode current collector and an anode electrode material, the anode electrode material being disposed on the surface of the anode current collector, and the anode current collector being electrically connected to the other of the first tab 20 and the second tab 30.

[0093] The cathode electrode and the anode electrode are electrode plates with opposite polarities, the cathode current collector and the anode current collector are current collectors with opposite polarities, and the cathode electrode material and the anode electrode material are electrode materials with opposite polarities.

[0094] For example, the cathode electrode material may include, but is not limited to, lithium cobalt oxide, lithium iron phosphate, etc.

[0095] For example, the cathode current collector can be made of aluminum.

[0096] For example, the anode electrode material may include, but is not limited to, graphite, silicon-based materials, etc.

[0097] For example, the anode current collector can be made of copper.

[0098] Figure 2 This is a cross-sectional schematic diagram of a battery cell provided in an embodiment of this application.

[0099] like Figure 2 As shown, and see Figure 1The encapsulation structure 10 includes a first encapsulation film layer 12 and a second encapsulation film layer 13. At least one of the first encapsulation film layer 12 and the second encapsulation film layer 13 includes a metal layer 110 and a bonding layer 120. The first encapsulation film layer 12 and the second encapsulation film layer 13 are bonded together through the bonding layer 120 to form the encapsulation structure 10, thereby enclosing and forming a sealed cavity 11.

[0100] For example, the first encapsulation film layer 12 includes a metal layer 110 and a bonding layer 120. The metal layer 110 of the first encapsulation film layer 12 is a first metal layer 110a, and the bonding layer 120 of the first encapsulation film layer 12 is a first bonding layer 120a. The first bonding layer 120a is disposed on one side of the thickness direction of the first metal layer 110a. That is, the first metal layer 110a includes a first surface, which is located on one side of the thickness direction of the first metal layer 110a, and the first bonding layer 120a is stacked on the first surface. Here, the first surface refers to the surface located on one side of the thickness direction of the first metal layer 110a. The first surface can be a continuous surface or it can include multiple surfaces with discontinuities.

[0101] The first metal layer 110a can give the first encapsulation film layer 12 better structural strength and better sealing performance.

[0102] For example, the second encapsulation film layer 13 includes a metal layer 110 and a bonding layer 120. The metal layer 110 of the second encapsulation film layer 13 is a second metal layer 110b, and the bonding layer 120 of the second encapsulation film layer 13 is a second bonding layer 120b. The second bonding layer 120b is disposed on one side of the thickness direction of the second metal layer 110b. That is, the second metal layer 110b includes a second surface located on one side of the thickness direction of the second metal layer 110b, and the second bonding layer 120b is stacked on the second surface. Here, the second surface refers to the surface located on one side of the thickness direction of the second metal layer 110b. The second surface can be a continuous surface or it can include multiple surfaces with discontinuities.

[0103] The second metal layer 110b can give the second encapsulation film layer 13 better structural strength and better sealing performance.

[0104] The first surface and the second surface are disposed opposite to each other, that is, the first bonding layer 120a and the second bonding layer 120b are disposed opposite to each other, and at least a portion of the first bonding layer 120a and at least a portion of the second bonding layer 120b are bonded together, so that the first encapsulation film layer 12 and the second encapsulation film layer 13 form an encapsulation structure 10 to enclose and form a sealed cavity 11. The first electrode tab 20 and the second electrode tab 30 are sandwiched between the first encapsulation film layer 12 and the second encapsulation film layer 13. Part of the first electrode tab 20 is located outside the encapsulation structure 10, part is located inside the sealed cavity 11, and part is wrapped by the first encapsulation film layer 12 and the second encapsulation film layer 13. Part of the second electrode tab 30 is located outside the encapsulation structure 10, part is located inside the sealed cavity 11, and part is wrapped by the first encapsulation film layer 12 and the second encapsulation film layer 13.

[0105] After at least a portion of the first bonding layer 120a is bonded to at least a portion of the second bonding layer 120b, the bonded portions of the first bonding layer 120a and the second bonding layer 120b form an integral structure.

[0106] For example, at least a portion of the first bonding layer 120a can be bonded to at least a portion of the second bonding layer 120b by hot pressing. After hot pressing, the bonded portions of the first bonding layer 120a and the second bonding layer 120b can be fused into one.

[0107] For example, the first tab 20 is bonded to the first bonding layer 120a and the second bonding layer 120b. For instance, the outer periphery of the portion of the first tab 20 that is wrapped by the first encapsulation film layer 12 and the second encapsulation film layer 13 is covered with a first bonding material 21. The first tab 20 is bonded to the first bonding layer 120a and the second bonding layer 120b through the first bonding material 21, making it easy and relatively stable to bond and fix the first tab 20 to the encapsulation structure 10.

[0108] The first bonding material 21 is a material with properties similar to those of the first bonding layer 120a and the second bonding layer 120b, so as to facilitate bonding with the first bonding layer 120a and the second bonding layer 120b.

[0109] For example, the first bonding material 21 is bonded to the first bonding layer 120a and the second bonding layer 120b as a whole. That is, after the first bonding material 21 is bonded to the first bonding layer 120a and the second bonding layer 120b, the first bonding material 21 forms an integral structure with the first bonding layer 120a and the second bonding layer 120b.

[0110] For example, the second tab 30 is bonded to the first bonding layer 120a and the second bonding layer 120b. For instance, the outer periphery of the portion of the second tab 30 that is wrapped by the first encapsulation film layer 12 and the second encapsulation film layer 13 is covered with a second bonding material 31. The second tab 30 is bonded to the first bonding layer 120a and the second bonding layer 120b through the second bonding material 31, making it easy and relatively stable to bond and fix the second tab 30 to the encapsulation structure 10.

[0111] The second bonding material 31 is a material with properties similar to those of the first bonding layer 120a and the second bonding layer 120b, so as to facilitate bonding with the first bonding layer 120a and the second bonding layer 120b.

[0112] For example, the second bonding material 31 is bonded to the first bonding layer 120a and the second bonding layer 120b as a whole. That is, after the second bonding material 31 is bonded to the first bonding layer 120a and the second bonding layer 120b, the second bonding material 31 forms an integral structure with the first bonding layer 120a and the second bonding layer 120b.

[0113] For example, the materials forming the first bonding layer 120a and the second bonding layer 120b may include, but are not limited to, polyolefins, acid-modified polyolefins and mixtures thereof.

[0114] For example, the first bonding layer 120a and the second bonding layer 120b are formed of the same material, making it easy and stable to bond the first bonding layer 120a and the second bonding layer 120b together. For example, the first bonding layer 120a and the second bonding layer 120b can be polypropylene (PP) layers, and the first bonding layer 120a and the second bonding layer 120b can be bonded by hot pressing.

[0115] In some examples, the first encapsulation film layer 12 can be an aluminum-plastic film layer, in which case the first metal layer 110a is an aluminum layer.

[0116] In other examples, the first encapsulation film layer 12 can be a steel-plastic film layer, in which case the first metal layer 110a is a steel layer.

[0117] In some examples, the second encapsulation film layer 13 can be an aluminum-plastic film layer, in which case the second metal layer 110b is an aluminum layer.

[0118] In other examples, the second encapsulation film layer 13 can be a steel-plastic film layer, in which case the second metal layer 110b is a steel layer.

[0119] For example, the first encapsulation film layer 12 and the second encapsulation film layer 13 can be an integral structure or a separate structure.

[0120] When the first encapsulation film layer 12 and the second encapsulation film layer 13 are an integral structure, the first encapsulation film layer 12 and the second encapsulation film layer 13 are two parts formed by folding the same encapsulation film. The first metal layer 110a and the second metal layer 110b are an integral structure, and the first bonding layer 120a and the second bonding layer 120b are an integral structure.

[0121] When the first encapsulation film layer 12 and the second encapsulation film layer 13 are an integral structure, the first metal layer 110a and the second metal layer 110b are made of the same material, and the first bonding layer 120a and the second bonding layer 120b are made of the same material.

[0122] In some examples, the first encapsulation film layer 12 and the second encapsulation film layer 13 can both be aluminum-plastic film layers or both be steel-plastic film layers. In this case, the first encapsulation film layer 12 and the second encapsulation film layer 13 can be an integral structure or a separate structure.

[0123] In other examples, one of the first encapsulation film layer 12 and the second encapsulation film layer 13 can be an aluminum-plastic film layer, and the other of the first encapsulation film layer 12 and the second encapsulation film layer 13 can be a steel-plastic film layer. In this case, the first encapsulation film layer 12 and the second encapsulation film layer 13 are separate structures.

[0124] In related technologies, the inner surface of the first encapsulation film layer is covered by a first bonding layer of uniform thickness, and the inner surface of the second encapsulation film layer is covered by a second bonding layer of uniform thickness. That is, the first surface of the first metal layer is covered by the first bonding layer of uniform thickness, and the second surface of the second metal layer is covered by the second bonding layer of uniform thickness. The first bonding layer includes a first sealing edge portion and a first sidewall portion, with the first sealing edge portion surrounding the outer side of the first sidewall portion. The second bonding layer includes a second sealing edge portion and a second sidewall portion, with the second sealing edge portion surrounding the outer side of the second sidewall portion. The first sealing edge portion and the second sealing edge portion are opposite each other and are used for sealing edges. In other words, the first sealing edge portion and the second sealing edge portion are combined to form an encapsulation structure between the first encapsulation film layer and the second encapsulation film layer. The first sidewall portion and the second sidewall portion are used to form the inner wall of the encapsulation cavity.

[0125] In related technologies, the first and second sidewall portions not used for sealing have a relatively thick thickness, which occupies the space of the battery cell, making the internal space of the packaging structure smaller. Consequently, there is less electrode material that can be arranged inside the packaging structure, resulting in a lower volumetric energy density of the battery cell.

[0126] Figure 3 This is a schematic diagram of the stacking of a first encapsulation film layer provided in an embodiment of this application. Figure 4 This is a schematic diagram of the unfolded first and second encapsulation film layers provided in an embodiment of this application.

[0127] likeFigure 3 , Figure 4 As shown, and see Figure 2 As shown, based on this, in the embodiments of this application, at least one of the first metal layer 110a and the second metal layer 110b includes a first region S1 and a second region S2, the bonding layer 120 covers the second region S2, and at least a portion of the bonding layer 120 located in the second region S2 is used for sealing, so that the first encapsulation film layer 12 and the second encapsulation film layer 13 form an encapsulation structure 10 to enclose and form a sealed cavity 11.

[0128] In some possible implementations, the bonding layer 120 does not cover the first region S1, so as to form an expansion space at the first region S1. The expansion space is the space within the encapsulation structure 10, that is, the expansion space is a part of the space within the sealed cavity 11.

[0129] In this way, while the bonding layer 120 can be used to seal the edge, by not covering the first region S1 with the bonding layer 120, space can be left in the first region S1 to form an expansion space. With the size of the battery cell remaining unchanged, the expansion space increases the capacity of the sealing cavity 11, which is conducive to increasing the amount of electrode material arranged in the sealing cavity 11, and thus conducive to increasing the volumetric energy density of the battery cell.

[0130] In some examples, the first metal layer 110a includes a first region S1 and a second region S2. The first bonding layer 120a covers the second region S2 of the first metal layer 110a but does not cover the first region S1 of the first metal layer 110a, thereby forming an expansion space at the first region S1 of the first metal layer 110a. At least a portion of the first bonding layer 120a located in the second region S2 is used for edge sealing, that is, the first bonding layer 120a located in the second region S2 is bonded to the second encapsulation film layer 13. For example, at least a portion of the first bonding layer 120a located in the second region S2 is bonded integrally with the second bonding layer 120b.

[0131] In this way, while the first bonding layer 120a can be used to seal the edge, by ensuring that the first bonding layer 120a does not cover the first region S1 of the first metal layer 110a, space can be left in the first region S1 of the first metal layer 110a to form an expansion space. On the basis of keeping the size of the battery cell unchanged, the capacity of the sealing cavity 11 can be increased, which is conducive to increasing the amount of electrode material arranged in the sealing cavity 11, and thus conducive to increasing the volumetric energy density of the battery cell.

[0132] For example, the first surface includes a first edge sealing region and a first sidewall region. The first surface located in the first region S1 is the first sidewall region, and at least a portion of the first surface located in the second region S2 is the first edge sealing region. The first bonding layer 120a disposed in the first edge sealing region is used for edge sealing, that is, the first bonding layer 120a disposed in the first edge sealing region is bonded to the second bonding layer 120b.

[0133] For example, the second region S2 surrounds the outer edge of the first region S1, that is, the first sealing region surrounds the outer edge of the first sidewall region.

[0134] For example, the inner edge of the second region S2 coincides with the outer edge of the first region S1.

[0135] In some examples, the bonding layer 120 located in the second region S2 is used for edge sealing. That is, the first region S1 extends to the position where the bonding layer 120 is used for edge sealing. This facilitates the formation of a larger expansion space.

[0136] In some examples, the first bonding layer 120a located in the second region S2 is used for edge sealing, that is, the first region S1 of the first metal layer 110a extends to the position where the first bonding layer 120a is used for edge sealing. At this time, the first surface located in the second region S2 is the first edge sealing region, the first bonding layer 120a is disposed in the first edge sealing region, and the orthographic projection of the first bonding layer 120a on the first surface is located outside the first sidewall region, that is, the first bonding layer 120a covers the first edge sealing region but does not cover the first sidewall region.

[0137] Thus, the first bonding layer 120a is disposed in the first sealing region, while the surface of the first sidewall region is not provided with the first bonding layer 120a. In the thickness direction of the first encapsulation film layer 12, the first bonding layer 120a leaves a portion of the space opposite the first sidewall region unused, increasing the internal space of the encapsulation structure 10. This unused space opposite the first sidewall region can be used to arrange electrode materials, which is beneficial for increasing the amount of electrode material arranged inside the encapsulation structure 10, thereby improving the volumetric energy density of the battery cell. For example, the first bonding layer 120a, originally covering the first region S1 of the first metal layer 110a, can be removed by laser cleaning of the inner surface of the first encapsulation film layer 12, thereby forming an expanded space at the first region S1 of the first metal layer 110a.

[0138] For example, the first edge sealing area may be covered by the first bonding layer 120a.

[0139] For example, the second region S2 can surround the outer edge of the first region S1, or it can surround only a portion of the outer edge of the first region S1. That is, when the first metal layer 110a includes the first region S1 and the second region S2, the first sealing region can surround the outer edge of the first sidewall region, or it can only surround a portion of the outer edge of the first sidewall region. As long as the first bonding layer 120a and the second bonding layer 120b are combined in the first sealing region, a sealed cavity 11 can be formed inside the encapsulation structure 10. For example, when the first encapsulation film layer 12 and the second encapsulation film layer 13 are an integral structure, the outer edge of the first sidewall region includes a first side that is integrally connected to the second encapsulation film layer 13, and the first sealing region surrounds the portion of the outer edge of the first sidewall region excluding the first side.

[0140] For example, the distance between the outer edge of the first bonding layer 120a and the inner edge of the first bonding layer 120a is greater than or equal to 1 mm and less than or equal to 8 mm, that is, the width of the first bonding layer 120a is greater than or equal to 1 mm and less than or equal to 8 mm.

[0141] This allows for a more stable bond between the first encapsulation layer 12 and the second encapsulation layer 13. Furthermore, it allows for a larger space enclosed by the inner edge of the first bonding layer 120a, resulting in a larger space within the encapsulation structure 10, which facilitates the arrangement of more electrode materials.

[0142] For example, the first sealing area is located at the outer edge of the first surface, that is, the first bonding layer 120a is disposed at the outer edge of the first surface.

[0143] In some possible implementations, the first bonding layer 120a is bonded and fixed to the first metal layer 110a via an adhesive layer 130. Specifically, the first bonding layer 120a is bonded and fixed to the first surface via an adhesive layer 130. The adhesive layer 130 that bonds and fixes the first bonding layer 120a to the first metal layer 110a is the first adhesive layer 130a.

[0144] This makes it easier to place the first bonding layer 120a on the first surface, and the first bonding layer 120a is more firmly fixed to the first surface.

[0145] In some examples where the first bonding layer 120a covers the second region S2 of the first metal layer 110a but does not cover the first region S1 of the first metal layer 110a, the first adhesive layer 130a covers the second region S2 of the first metal layer 110a but does not cover the first region S1 of the first metal layer 110a.

[0146] In this way, the portion of the first adhesive layer 130a that is empty at the first region S1 can be used to arrange electrode material, which is beneficial to increasing the amount of electrode material arranged inside the packaging structure 10. In addition, it is beneficial to expose the first region S1 of the first metal layer 110a on the inner surface of the first packaging film layer 12, so that electrode material can be placed on the surface of the first region S1 of the first metal layer 110a. This facilitates the use of the first metal layer 110a as a current collector to supply power to the electrode material placed on the surface of the first region S1 of the first metal layer 110a, which can further improve the space utilization of the packaging structure 10.

[0147] For example, after removing the first bonding layer 120a of the first region S1 of the first metal layer 110a, the first adhesive layer 130a of the first region S1 of the first metal layer 110a can be removed by laser cleaning.

[0148] In some examples, the first adhesive layer 130a is disposed in the first edge sealing region, and the orthographic projection of the first adhesive layer 130a on the first surface is located outside the first sidewall region. That is, the first adhesive layer 130a covers the first edge sealing region but does not cover the first sidewall region.

[0149] Thus, the first adhesive layer 130a is disposed in the first sealing region, while the surface of the first sidewall region is not provided with the first adhesive layer 130a. In the thickness direction of the first encapsulation film layer 12, the first adhesive layer 130a leaves a portion of the space opposite the first sidewall region unused, which can be used to arrange electrode materials, thus increasing the amount of electrode material arranged inside the encapsulation structure 10. Furthermore, it facilitates the use of the first metal layer 110a as a current collector to supply power to the electrode materials disposed on the surface of the first sidewall region, further improving the space utilization of the encapsulation structure 10.

[0150] In some possible implementations, the second bonding layer 120b is bonded and fixed to the second metal layer 110b via an adhesive layer 130. Specifically, the second bonding layer 120b is bonded and fixed to the second surface via an adhesive layer 130. The adhesive layer 130 that bonds and fixes the second bonding layer 120b to the second metal layer 110b is the second adhesive layer 130b.

[0151] This facilitates the placement of the second bonding layer 120b on the second surface, ensuring a more stable fixation between the second bonding layer 120b and the second surface, and thus a more stable bond between the first encapsulation film layer 12 and the second encapsulation film layer 13. When the first encapsulation film layer 12 and the second encapsulation film layer 13 are an integral structure, the first adhesive layer 130a and the second adhesive layer 130b are also an integral structure.

[0152] In some possible implementations, the first encapsulation film layer 12 further includes a first protective layer 140a, which is stacked on the side of the first metal layer 110a opposite to the first bonding layer 110. Exemplarily, the first metal layer 110a further includes a third surface, with the first and third surfaces located on opposite sides of the thickness direction of the first metal layer 110a, and the first protective layer 140a stacked on the third surface. The second encapsulation film layer 13 further includes a second protective layer 140b, which is stacked on the side of the second metal layer 110b opposite to the second bonding layer 120b. Exemplarily, the second metal layer 110b further includes a fourth surface, with the second and fourth surfaces located on opposite sides of the thickness direction of the second metal layer 110b, and the second protective layer 140b stacked on the fourth surface.

[0153] In this way, the first protective layer 140a and the second protective layer 140b can play a protective role, making the encapsulation structure 10 less prone to damage.

[0154] The first protective layer 140a covers the third surface, and the second protective layer 140b covers the fourth surface.

[0155] For example, both the first protective layer 140a and the second protective layer 140b are made of insulating material, so that the first protective layer 140a and the second protective layer 140b can also serve as insulation.

[0156] For example, the material forming the first protective layer 140a may include, but is not limited to, polyester, polyamide, epoxy resin, acrylic resin, fluoropolymer, polyurethane, and mixtures thereof. For instance, the first protective layer 140a may be a nylon layer.

[0157] For example, the material forming the second protective layer 140b may include, but is not limited to, polyester, polyamide, epoxy resin, acrylic resin, fluoropolymer, polyurethane, and mixtures thereof. For instance, the second protective layer 140b may be a nylon layer.

[0158] For example, the first protective layer 140a is bonded and fixed to the first metal layer 110a through the adhesive layer 130. Specifically, the first protective layer 140a is bonded and fixed to the third surface through the adhesive layer 130, so that the adhesive layer 130 for bonding and fixing the first protective layer 140a to the first metal layer 110a is the third adhesive layer 130c.

[0159] This makes it easier to place the first protective layer 140a on the third surface.

[0160] For example, the second protective layer 140b is bonded and fixed to the second metal layer 110b through the adhesive layer 130. Specifically, the second protective layer 140b is bonded and fixed to the fourth surface through the adhesive layer 130, so that the adhesive layer 130 for bonding and fixing the second protective layer 140b to the second metal layer 110b is the fourth adhesive layer 130d.

[0161] This makes it easier to place the second protective layer 140b on the fourth surface.

[0162] When the first encapsulation film layer 12 and the second encapsulation film layer 13 are an integral structure, the first protective layer 140a and the second protective layer 140b are an integral structure, and the third adhesive layer 130c and the fourth adhesive layer 130d are an integral structure.

[0163] In some possible implementations, a portion of the core 200 is located within the expansion space.

[0164] In this way, the amount of electrode material in the electrode core 200 can be increased by increasing the size of the electrode core 200, thereby increasing the amount of electrode material in the packaging structure 10, which in turn can increase the volumetric energy density of the battery cell. Increasing the amount of electrode material in the packaging structure 10 is relatively easy.

[0165] For example, the size of the electrode core 200 can be increased while the amount of electrode material arranged in the electrode core 200 can be increased by increasing the thickness of the electrode material inside the electrode core 200.

[0166] In some examples where the electrode core 200 is a wound electrode core, the size of the electrode core 200 can be increased while the amount of electrode material arranged in the electrode core 200 can be increased by increasing the length of the electrode sheet of the electrode core 200.

[0167] In some examples where the electrode core 200 is a stacked electrode core, the size of the electrode core 200 can be increased while the amount of electrode material in the electrode core 200 can be increased by increasing the number of electrode sheets in the electrode core 200.

[0168] In some examples, a portion of the electrode core 200 is located within the expanded space formed at the first region S1 of the first metal layer 110a. In other words, the distance between the outer surface of the electrode core 200 and the first sidewall region is less than the distance between the side of the first bonding layer 120a facing away from the first sealing edge region and the first sealing edge region. That is, the distance between the outer surface of the electrode core 200 facing the first encapsulation film layer 12 and the outer surface of the first encapsulation film layer 12 at the first region S1 is less than the thickness of the first encapsulation film layer 12 at the second region S2.

[0169] The outer surface of the core 200 refers to the surface of the core 200 near the outside of the packaging structure 10, and the outer surface of the first packaging film layer 12 refers to the surface located on the outside of the packaging structure 10.

[0170] In this way, the size of the electrode core 200 can be increased in the direction closer to the first sidewall region. By increasing the size of the electrode core 200, the amount of electrode material arranged in the electrode core 200 can be increased, thereby increasing the amount of electrode material arranged in the packaging structure 10, which in turn can increase the volumetric energy density of the battery cell. Increasing the amount of electrode material arranged in the packaging structure 10 is relatively easy.

[0171] Figure 5 This is a cross-sectional schematic diagram of the electrode core of a battery cell in a first region, provided as an embodiment of this application.

[0172] like Figure 5 As shown, in some examples where a portion of the electrode core 200 is located within the expansion space, the electrode core 200 includes a second electrode sheet 210, at least a portion of which is located on the outer surface of the electrode core 200 and on the side of the electrode core 200 closest to the first region S1. The second electrode sheet 210 includes a second current collector 211 and a third electrode material 212, the third electrode material 212 being disposed on the inner surface of the second current collector 211.

[0173] In this way, there is no separator on the outermost side of the electrode core 200, the number of separators in the electrode core 200 is small, and the amount of electrode material in the electrode core 200 is relatively large, which is conducive to improving the volumetric energy density of the cell.

[0174] For example, at least a portion of the second electrode sheet 210 may be located within the expansion space.

[0175] The second electrode 210 is one of the anode electrode pieces of the electrode core 200, or the second electrode 210 is one of the cathode electrode pieces of the electrode core 200. The second current collector 211 is electrically connected to one of the first tab 20 and the second tab 30.

[0176] The inner surface of the second current collector 211 refers to the surface of the second current collector 211 facing the center of the pole core 200.

[0177] In some examples, when the electrode core 200 is a stacked electrode core, a second electrode sheet 210 may be provided on the outer surface of the electrode core 200 facing the first sidewall region, and a second electrode sheet 210 may also be provided on the outer surface of the electrode core 200 away from the first sidewall region.

[0178] Figure 6 This is a cross-sectional schematic diagram of the electrode core of a battery cell at the first electrode sheet, provided as an embodiment of this application.

[0179] like Figure 6As shown, in some possible embodiments, the electrode core 200 includes a first isolation film 220 and a third electrode sheet 230. The first isolation film 220 is located on the outer surface of the electrode core 200, and at least a portion of the first isolation film 220 is located on the side of the electrode core 200 near the first region S1. The third electrode sheet 230 is disposed adjacent to the first isolation film 220.

[0180] The third electrode 230 is one of the anode electrode pieces of the electrode core 200, or the third electrode 230 is one of the cathode electrode pieces of the electrode core 200, and the first isolation film 220 is one of the isolation films of the electrode core 200.

[0181] The third electrode sheet 230 includes a third current collector 231 and a fourth electrode material 232. The fourth electrode material 232 is provided on both sides of the third current collector 231 in the thickness direction.

[0182] In some examples, at least a portion of the first isolation membrane 220 is located on the outer surface of the pole core 200 facing the first sidewall region.

[0183] In some examples where the electrode core 200 is a stacked electrode core, the outer surface of the electrode core 200 facing the first sidewall region is provided with a first isolation film 220. That is, the outer surface of the electrode core 200 facing the first region S1 of the first metal layer 110a is provided with a first isolation film 220, and the electrode sheet of the electrode core 200 near the first sidewall region is a third electrode sheet 230.

[0184] Figure 7 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0185] like Figure 7 As shown, and see Figure 6 In some examples, the battery cell also includes a first electrode plate 300. The first electrode plate 300 is disposed within the sealed cavity 11 and is located between the electrode core 200 and the first region S1.

[0186] In this way, the amount of electrode material arranged in the packaging structure 10 can be increased by adding a first electrode sheet 300 between the electrode core 200 and the first region S1, thereby increasing the volumetric energy density of the battery cell. Increasing the amount of electrode material arranged in the packaging structure 10 is relatively easy.

[0187] One of the first electrode plate 300 and the third electrode plate 230 is a cathode electrode plate, and the other of the first electrode plate 300 and the third electrode plate 230 is an anode electrode plate. That is, the first electrode plate 300 and the third electrode plate 230 are electrode plates with opposite polarities. The first electrode plate 300 is electrically connected to one of the first tab 20 and the second tab 30, and the third electrode plate 230 is electrically connected to the other of the first tab 20 and the second tab 30.

[0188] The first electrode plate 300 is an electrode plate independent of the electrode core 200. The connection between the first electrode plate 300 and one of the first electrode tabs 20 and the second electrode tab 30 can be referred to the connection between the electrode plate of the electrode core 200 and the first electrode tab 20 and the second electrode tab 30.

[0189] For example, at least a portion of the first electrode sheet 300 is located within the expansion space.

[0190] In some examples where the first metal layer 110a includes a first region S1 and a second region S2, a first electrode sheet 300 is provided between the electrode core 200 and the first region S1 of the first metal layer 110a, that is, a first electrode sheet 300 is provided between the electrode core 200 and the first sidewall region.

[0191] For example, the first electrode sheet 300 includes a first current collector 310 and a first electrode material 320. The first electrode material 320 is disposed on the side of the first current collector 310 near the electrode core 200. The first current collector 310 is electrically connected to one of the first tab 20 and the second tab 30, and the third current collector 231 is electrically connected to the other of the first tab 20 and the second tab 30.

[0192] In this way, the utilization rate of the electrode material coated on the first electrode sheet 300 is relatively high, which makes it easier to increase the amount of electrode material that can be used on the first electrode sheet 300.

[0193] In some examples where a first electrode sheet 300 is provided between the electrode core 200 and the first sidewall region, for the first electrode sheet 300 between the electrode core 200 and the first sidewall region, the first electrode material 320 is provided on the side of the first current collector 310 away from the first sidewall region along the thickness direction of the first current collector 310.

[0194] For example, the first current collector 310 can be electrically connected to the first tab 20, and the third current collector 231 can be electrically connected to the second tab 30.

[0195] When the first electrode plate 300 is a cathode electrode plate, the first current collector 310 is a cathode current collector, the first electrode material 320 is a cathode electrode material, the first tab 20 can be electrically connected to the cathode electrode plate of the electrode core 200, the third electrode plate 230 is an anode electrode plate, the third current collector 231 is an anode current collector, the fourth electrode material 232 is an anode electrode material, and the second tab 30 can be electrically connected to the anode electrode plate of the electrode core 200.

[0196] When the first electrode plate 300 is the anode electrode plate, the first current collector 310 is the anode current collector, the first electrode material 320 is the anode electrode material, the first tab 20 can be electrically connected to the anode electrode plate of the electrode core 200, the third electrode plate 230 is the cathode electrode plate, the third current collector 231 is the cathode current collector, the fourth electrode material 232 is the cathode electrode material, and the second tab 30 can be electrically connected to the cathode electrode plate of the electrode core 200.

[0197] For example, the first current collector 310 may have a tab connection portion, which may be welded to the first tab 20 or the second tab 30.

[0198] Figure 8 This is a schematic diagram of a first encapsulation film layer with a second electrode material provided in an embodiment of this application. Figure 9 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application. Figure 10 This is a schematic cross-sectional view of the electrode core of a battery cell at the second electrode material, provided as an embodiment of this application.

[0199] like Figure 8-10 As shown, in some examples where the bonding layer 120 covers the second region S2 but does not cover the first region S1, the surface of the first region S1 near the electrode core 200 is provided with the second electrode material 400.

[0200] In this way, the amount of electrode material arranged in the packaging structure 10 can be increased by setting electrode material on the surface of the first region S1, thereby increasing the volumetric energy density of the battery cell. In addition, by using the metal layer 110 including the first region S1 and the second region S2 as the current collector to carry the electrode material, the space utilization rate of the battery cell is high, and a large amount of electrode material can be arranged in the expanded space, which is beneficial to improving the volumetric energy density of the battery cell.

[0201] The third electrode plate 230 is a cathode electrode plate and the second electrode material 400 is an anode electrode material, or the third electrode plate 230 is an anode electrode plate and the second electrode material 400 is a cathode electrode material. The metal layer 110 including the first region S1 and the second region S2 is electrically connected to one of the first tab 20 and the second tab 30, and the third electrode plate 230 is electrically connected to the other of the first tab 20 and the second tab 30.

[0202] One of the fourth electrode material 232 and the second electrode material 400 is a cathode electrode material, and the other of the fourth electrode material 232 and the second electrode material 400 is an anode electrode material. That is, the fourth electrode material 232 and the second electrode material 400 are electrode materials with opposite polarities. The metal layer 110 including the first region S1 and the second region S2 is electrically connected to one of the first tab 20 and the second tab 30, and the third current collector 331 is electrically connected to the other of the first tab 20 and the second tab 30.

[0203] In the example where the second electrode material 400 is provided on the surface of the first region S1, the fourth electrode material 232 is provided on both sides of the third current collector 231 in the thickness direction, which can also result in a larger coating amount of electrode material. Furthermore, the utilization rate of the coated electrode material is high.

[0204] In some examples where the first metal layer 110a includes a first region S1 and a second region S2, a second electrode material 400 is disposed in the first sidewall region. That is, the second electrode material 400 is disposed on the surface of the first region S1 of the first metal layer 110a near the electrode core 200. The first metal layer 110a is electrically connected to one of the first tabs 20 and the second tab 30, and the third electrode sheet 230 is electrically connected to the other of the first tabs 20 and the second tab 30.

[0205] In this way, the amount of electrode material arranged in the packaging structure 10 can be increased by setting electrode material in the first sidewall region, thereby improving the volumetric energy density of the battery cell. In addition, by using the first metal layer 110a as a current collector to carry the electrode material, the space utilization rate of the battery cell is high. The portion of the first bonding layer 120a that is empty in the corresponding position in the first sidewall region can accommodate a large amount of electrode material, which is beneficial to improving the volumetric energy density of the battery cell.

[0206] When the fourth electrode material 232 is the cathode electrode material and the second electrode material 400 located in the first sidewall region is the anode electrode material, the first metal layer 110a can serve as the anode current collector, the first tab 20 can be electrically connected to the anode electrode sheet of the electrode core 200, the third electrode sheet 230 is the cathode electrode sheet, the third current collector 231 is the cathode current collector, and the second tab 30 can be electrically connected to the cathode electrode sheet of the battery core.

[0207] When the fourth electrode material 232 is the anode electrode material and the second electrode material 400 located in the first sidewall region is the cathode electrode material, the first metal layer 110a can serve as the cathode current collector, the first tab 20 can be electrically connected to the cathode electrode sheet of the electrode core 200, the third electrode sheet 230 is the anode electrode sheet, the third current collector 231 is the anode current collector, and the second tab 30 can be electrically connected to the anode electrode sheet of the electrode core 200.

[0208] Figure 11 This is a schematic diagram showing the unfolded first and second encapsulation film layers provided in an embodiment of this application. Figure 12 This is a schematic diagram of another type of battery cell provided in an embodiment of this application.

[0209] like Figure 11 , Figure 12 As shown, in some possible embodiments, the metal layer 110 including the first region S1 and the second region S2 further includes a connecting portion 111 protruding from the outer edge of the second region S2. The connecting portion 111 is located outside the sealing cavity 11, that is, outside the packaging structure 10. The connecting portion 111 is connected to the first tab 20 or the second tab 30 to electrically connect the metal layer 110 including the first region S1 and the second region S2 to the first tab 20 or the second tab 30.

[0210] In this way, the metal layer 110, including the first region S1 and the second region S2, can be connected to the first tab 20 or the second tab 30 outside the packaging structure 10 via the connecting portion 111, making it easier to connect the metal layer 110, including the first region S1 and the second region S2, to the first tab 20 or the second tab 30. Furthermore, the connection between the metal layer 110, including the first region S1 and the second region S2, and the first tab 20 or the second tab 30 is less likely to damage the packaging structure 10.

[0211] For example, the first metal layer 110a includes a connecting portion 111 protruding from the outer edge of the first sealing region. That is, the first metal layer 110a includes a connecting portion 111 protruding from the outer edge of the second region S2. The connecting portion 111 is located outside the packaging structure 10. The connecting portion 111 of the first metal layer 110a is connected to the first tab 20 so that the first metal layer 110a is electrically connected to the first tab 20.

[0212] In this way, the first metal layer 110a is connected to the first tab 20 outside the packaging structure 10 through the connecting portion 111, making it easier to connect the first metal layer 110a to the first tab 20. In addition, the connection between the first metal layer 110a and the first tab 20 is less likely to damage the first packaging film layer 12.

[0213] For example, the connection portion 111 of the first metal layer 110a is welded to the first tab 20.

[0214] In some possible implementations, the first metal layer 110a is an aluminum layer, in which case the first encapsulation film layer 12 can be an aluminum-plastic film. The third electrode sheet 230 located on the side of the electrode core 200 near the first sidewall region is an anode electrode sheet, the fourth electrode material 232 of the third electrode sheet 230 located on the side of the electrode core 200 near the first sidewall region is an anode electrode material, the second electrode material 400 located in the first sidewall region is a cathode electrode material, the first metal layer 110a can serve as a cathode current collector, and the third current collector 231 of the third electrode sheet 230 located on the side of the electrode core 200 near the first sidewall region is an anode current collector.

[0215] This facilitates the second electrode material 400, which is disposed on the surface of the first metal layer 110a being an aluminum layer, to undergo galvanic cell reaction and electrolytic reaction, thereby improving the volumetric energy density of the battery cell with the first metal layer 110a being an aluminum layer.

[0216] In some possible implementations, the first metal layer 110a is a steel layer, in which case the first encapsulation film layer 12 is a steel-plastic film. The third electrode sheet 230 located on the side of the electrode core 200 near the first sidewall region is a cathode electrode sheet, the fourth electrode material 232 of the third electrode sheet 230 located on the side of the electrode core 200 near the first sidewall region is a cathode electrode material, the second electrode material 400 located in the first sidewall region is an anode electrode material, the first metal layer 110a can serve as an anode current collector, and the third current collector 231 of the third electrode sheet 230 located on the side of the electrode core 200 near the first sidewall region is a cathode current collector.

[0217] This facilitates the second electrode material 400, which is disposed on the surface of the first metal layer 110a being a steel layer, to undergo galvanic cell reaction and electrolytic reaction, thereby improving the volumetric energy density of the battery cell with the first metal layer 110a being a steel layer.

[0218] In some examples, the second tab 30 is connected to the first metal layer 110a via an insulating medium (e.g., at least one of the first bonding layer 120a and the second bonding material 31), and the second tab 30 is not in direct electrical contact with the first metal layer 110a.

[0219] In some possible implementations, at least one of the first tab 20 and the second tab 30 includes a connecting segment 40, that is, at least one tab includes a connecting segment 40 located between the electrode core 200 and the cavity wall of the sealing cavity 11, and the outer peripheral surface of the connecting segment 40 is covered by an insulating material 50.

[0220] This makes it less likely that a short circuit will occur between the first tab 20 and the second tab 30 due to electrical contact between the connecting segment 40 and the first metal layer 110a or the second metal layer 110b.

[0221] For example, the second tab 30 of the battery cell includes a connecting section 40 located between the electrode core 200 and the cavity wall of the sealed cavity 11, and the second tab 30 is electrically connected to the electrode sheet of the first region S1 of the battery cell near the first metal layer 110a.

[0222] This makes it less likely that a short circuit will occur between the first tab 20 and the second tab 30 due to electrical contact between the connecting section 40 of the second tab 30 and the first metal layer 110a.

[0223] For example, the insulating material 50 covering the outer periphery of the connecting section 40 of the second tab 30 extends to the surface of the second bonding material 31 and covers a portion of the second bonding material 31.

[0224] In some examples, the first tab 20 includes a connecting section 40 located between the pole core 200 and the cavity wall of the sealed cavity 11, and the insulating material 50 covering the outer periphery of the connecting section 40 of the first tab 20 extends to the surface of the first bonding material 21 and covers a portion of the first bonding material 21.

[0225] In some examples where the electrode core 200 includes a second electrode sheet 210, both the first electrode tab 20 and the second electrode tab 30 are connected to the first metal layer 110a through an insulating medium (e.g., a first bonding layer 120a), and neither the first electrode tab 20 nor the second electrode tab 30 are in direct electrical contact with the first metal layer 110a.

[0226] In some examples where the battery cell also includes a first electrode sheet 300, both the first tab 20 and the second tab 30 are connected to the first metal layer 110a through an insulating medium (e.g., the first bonding layer 120a), and neither the first tab 20 nor the second tab 30 is in direct electrical contact with the first metal layer 110a.

[0227] In some examples where the first metal layer 110a includes a first region S1 and a second region S2, the second surface is covered by a second bonding layer 120b, that is, the second metal layer 110b does not include the first region S1 and the second region S2, and the second metal layer 110b is covered by the second bonding layer 120b.

[0228] Figure 13 This is a schematic diagram of the stacking of a second encapsulation film layer provided in an embodiment of this application. Figure 14 This is a schematic diagram showing the unfolded first and second encapsulation film layers provided in an embodiment of this application. Figure 15 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0229] like Figure 13-15As shown, in some other possible embodiments, the second metal layer 110b includes a first region S1 and a second region S2. The second bonding layer 120b covers the second region S2 of the second metal layer 110b but does not cover the first region S1 of the second metal layer 110b, thereby forming an expansion space at the first region S1 of the second metal layer 110b. At least a portion of the second bonding layer 120b located in the second region S2 is used for edge sealing, that is, the second bonding layer 120b located in the second region S2 is bonded to the first encapsulation film layer 12. For example, at least a portion of the second bonding layer 120b located in the second region S2 is bonded integrally with the first bonding layer 120a.

[0230] In this way, while the second bonding layer 120b can be used to seal the edge, by ensuring that the second bonding layer 120b does not cover the first region S1 of the second metal layer 110b, space can be left in the first region S1 of the second metal layer 110b to form an expansion space. On the basis of keeping the size of the battery cell unchanged, the capacity of the sealing cavity 11 can be increased, which is conducive to increasing the amount of electrode material arranged in the sealing cavity 11, and thus conducive to increasing the volumetric energy density of the battery cell.

[0231] For example, the second surface includes a second edge sealing region and a second sidewall region. The second surface located in the first region S1 is the second sidewall region, and at least a portion of the second surface located in the second region S2 is the second edge sealing region. The second bonding layer 120b disposed in the second edge sealing region is used for edge sealing, that is, the second bonding layer 120b disposed in the second edge sealing region is bonded to the first bonding layer 120a.

[0232] For example, the second sealing area surrounds the outer edge of the second sidewall area, and the second sealing area is disposed opposite to the first sealing area.

[0233] In some examples, the second bonding layer 120b located in the second region S2 is used for edge sealing, that is, the first region S1 of the second metal layer 110b extends to the position where the second bonding layer 120b is used for edge sealing. At this time, the second surface located in the second region S2 is the second edge sealing region, the second bonding layer 120b is disposed in the second edge sealing region, and the orthographic projection of the second bonding layer 120b on the second surface is located outside the second sidewall region, that is, the second bonding layer 120b covers the second edge sealing region but does not cover the second sidewall region.

[0234] Thus, the second bonding layer 120b is disposed in the second sealing region, while the surface of the second sidewall region is not provided with the second bonding layer 120b. In the thickness direction of the second encapsulation film layer 13, the second bonding layer 120b leaves a portion of the space opposite to the second sidewall region empty, increasing the internal space of the encapsulation structure 10. The empty space opposite to the second sidewall region can be used to arrange electrode materials, which is beneficial to increasing the amount of electrode materials arranged inside the encapsulation structure 10, thereby improving the volumetric energy density of the battery cell.

[0235] For example, the second bonding layer 120b that originally covered the first region S1 of the second metal layer 110b can be removed by laser cleaning of the inner surface of the second encapsulation film layer 13, so as to form an expansion space at the first region S1 of the second metal layer 110b.

[0236] The insulating material 50 covering the surface of the connecting section 40 makes it difficult for the connecting section 40 to make electrical contact with the second metal layer 110b.

[0237] For example, the second edge sealing area can be covered by the second bonding layer 120b.

[0238] For example, when the second metal layer 110b includes a first region S1 and a second region S2, the second sealing region can surround the outer edge of the second sidewall region, or it can only surround a portion of the outer edge of the second sidewall region. As long as the second bonding layer 120b disposed in the second sealing region is bonded to the first bonding layer 120a, a sealed cavity 11 can be formed inside the encapsulation structure 10. For example, when the first encapsulation film layer 12 and the second encapsulation film layer 13 are an integral structure, the outer edge of the second sidewall region includes a second side integrally connected to the first encapsulation film layer 12, and the second sealing region surrounds the portion of the outer edge of the second sidewall region excluding the second side.

[0239] For example, the distance between the outer edge of the second bonding layer 120b and the inner edge of the second bonding layer 120b is greater than or equal to 1 mm and less than or equal to 8 mm, that is, the width of the second bonding layer 120b is greater than or equal to 1 mm and less than or equal to 8 mm.

[0240] This allows for a more stable bond between the first encapsulation layer 12 and the second encapsulation layer 13. Furthermore, it allows for a larger space enclosed by the inner edge of the second bonding layer 120b, resulting in a larger space within the encapsulation structure 10, which facilitates the placement of more electrode materials.

[0241] For example, the second sealing area is located at the outer edge of the second surface, that is, the second bonding layer 120b is disposed at the outer edge of the second surface.

[0242] In some examples where the second bonding layer 120b covers the second region S2 of the second metal layer 110b but does not cover the first region S1 of the second metal layer 110b, the second adhesive layer 130b covers the second region S2 of the second metal layer 110b but does not cover the first region S1 of the second metal layer 110b.

[0243] In this way, the portion of the second adhesive layer 130b that is empty at the first region S1 can be used to arrange electrode material, which is beneficial to increasing the amount of electrode material arranged inside the packaging structure 10. In addition, it is beneficial to expose the first region S1 of the second metal layer 110b to the inner surface of the second packaging film layer 13, so that electrode material can be placed on the surface of the first region S1 of the second metal layer 110b. This facilitates the use of the second metal layer 110b as a current collector to supply power to the electrode material placed on the surface of the first region S1 of the second metal layer 110b, which can further improve the space utilization of the packaging structure 10.

[0244] For example, after removing the second bonding layer 120b of the first region S1 of the second metal layer 110a, the second adhesive layer 130b of the first region S1 of the second metal layer 110b can be removed by laser cleaning.

[0245] In some possible implementations, the second adhesive layer 130b is disposed in the second edge sealing region, and the orthographic projection of the second adhesive layer 130b on the second surface is located outside the second sidewall region. That is, the second adhesive layer 130b covers the second edge sealing region but does not cover the second sidewall region.

[0246] Thus, the second adhesive layer 130b is disposed in the second sealing region, while the surface of the second sidewall region is not provided with the second adhesive layer 130b. In the thickness direction of the second encapsulation film layer 13, the second adhesive layer 130b leaves a portion of the space opposite the second sidewall region unused, which can be used to arrange electrode material, thus increasing the amount of electrode material arranged inside the encapsulation structure 10. Furthermore, it facilitates the use of the second metal layer 110b as a current collector to supply power to the electrode material disposed on the surface of the second sidewall region, further improving the space utilization of the encapsulation structure 10.

[0247] In some examples, a portion of the electrode core 200 is located within the expanded space formed at the first region S1 of the second metal layer 110b. In other words, the distance between the outer surface of the electrode core 200 and the second sidewall region is less than the distance between the side of the second bonding layer 120b facing away from the second sealing edge region and the second sealing edge region. That is, the distance between the outer surface of the electrode core 200 and the outer surface of the second encapsulation film layer 13 at the first region S1 is less than the thickness of the second encapsulation film layer 13 at the second region S2.

[0248] In this way, the size of the electrode core 200 can be increased in the direction closer to the second sidewall region. By increasing the size of the electrode core 200, the amount of electrode material arranged in the electrode core 200 can be increased, thereby increasing the amount of electrode material arranged in the packaging structure 10, which in turn can increase the volumetric energy density of the battery cell. Increasing the amount of electrode material arranged in the packaging structure 10 is relatively easy.

[0249] When the outer surface of the electrode core 200 facing the first sidewall region and the outer surface away from the first sidewall region are both provided with second electrode sheets 210, and the first encapsulation film layer 12 and the second encapsulation film layer 13 are integral structures, the second electrode sheets 210 provided on the outer surface of the electrode core 200 facing the first sidewall region and the second electrode sheets 210 provided on the outer surface of the electrode core 200 away from the first sidewall region can be electrode sheets with the same polarity. That is to say, the second electrode sheets 210 provided on the outer surface of the electrode core 200 facing the first sidewall region and the second electrode sheets 210 provided on the outer surface of the electrode core 200 away from the first sidewall region are both anode electrode sheets or both are cathode electrode sheets, so as to avoid the second electrode sheets 210 provided on the outer surface of the electrode core 200 facing the first sidewall region and the second electrode sheets 210 provided on the outer surface of the electrode core 200 away from the first sidewall region from contacting the first metal layer 110a and the second metal layer 110b respectively and causing a short circuit.

[0250] When the outer surface of the electrode core 200 facing the first sidewall region and the outer surface away from the first sidewall region are both provided with second electrode sheets 210, and the first encapsulation film layer 12 and the second encapsulation film layer 13 are separate structures connected by an insulating medium, the second electrode sheet 210 provided on the outer surface of the electrode core 200 facing the first sidewall region and the second electrode sheet 210 provided on the outer surface of the electrode core 200 away from the first sidewall region can be electrode sheets with the same polarity, or the second electrode sheet 210 provided on the outer surface of the electrode core 200 facing the first sidewall region and the second electrode sheet 210 provided on the outer surface of the electrode core 200 away from the first sidewall region can be electrode sheets with opposite polarities.

[0251] When the second electrode sheet 210 on the outer surface of the electrode core 200 facing the first sidewall region and the second electrode sheet 210 on the outer surface of the electrode core 200 away from the first sidewall region are electrode sheets with the same polarity, the second electrode sheet 210 on the outer surface of the electrode core 200 facing the first sidewall region and the second electrode sheet 210 on the outer surface of the electrode core 200 away from the first sidewall region can both be electrically connected to the first electrode tab 20.

[0252] When the second electrode sheet 210 on the outer surface of the electrode core 200 facing the first sidewall region and the second electrode sheet 210 on the outer surface of the electrode core 200 away from the first sidewall region are electrode sheets with opposite polarities, the second electrode sheet 210 on the outer surface of the electrode core 200 facing the first sidewall region can be electrically connected to the first electrode tab 20, and the second electrode sheet 210 on the outer surface of the electrode core 200 away from the first sidewall region can be electrically connected to the second electrode tab 30.

[0253] Figure 16 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0254] like Figure 16 As shown, in some examples, a first electrode sheet 300 is provided between the electrode core 200 and the first region S1 of the second metal layer 110b.

[0255] In this way, the amount of electrode material arranged in the packaging structure 10 can be increased by adding a first electrode sheet 300 between the electrode core 200 and the second sidewall region, thereby increasing the volumetric energy density of the battery cell. Increasing the amount of electrode material arranged in the packaging structure 10 is relatively easy.

[0256] For example, a first electrode sheet 300 is provided between the electrode core 200 and the first region S1 of the first metal layer 110a, and between the electrode core 200 and the first region S1 of the second metal layer 110b.

[0257] In some examples, the electrode core 200 is a wound electrode core, which includes a first insulating film 220 and a third electrode sheet 230. Part of the first insulating film 220 is located on the outer surface of the electrode core 200 facing the first sidewall region, and part of it is located on the outer surface of the electrode core 200 facing the second sidewall region. The first electrode sheet 300 is provided between the electrode core 200 and the first region S1 of the second metal layer 110b. That is, the first electrode sheet 300 is provided between the electrode core 200 and the second sidewall region.

[0258] Thus, when the electrode core 200 is a wound electrode core, the amount of electrode material arranged in the packaging structure 10 can be increased by adding a first electrode sheet 300 between the electrode core 200 and the second sidewall region, thereby increasing the volumetric energy density of the battery cell. Increasing the amount of electrode material arranged in the packaging structure 10 is relatively easy.

[0259] In some examples, the electrode core 200 is a stacked electrode core, and the second metal layer 110b includes a first region S1 and a second region S2. A first insulating film 220 is provided on the outer surface of the electrode core 200 facing the second sidewall region. That is, a first insulating film 220 is provided on the outer surface of the electrode core 200 facing the first region S1 of the second metal layer 110b. The electrode sheet of the electrode core 200 near the second sidewall region is a third electrode sheet 230. A first electrode sheet 300 is provided between the electrode core 200 and the first region S1 of the second metal layer 110b. That is, a first electrode sheet 300 is provided between the electrode core 200 and the second sidewall region.

[0260] Thus, when the electrode core 200 is a stacked electrode core, the amount of electrode material arranged in the packaging structure 10 can be increased by adding electrode sheets between the electrode core 200 and the second sidewall region, thereby increasing the volumetric energy density of the cell. Increasing the amount of electrode material arranged in the packaging structure 10 is relatively easy.

[0261] In some examples, the third electrode sheet 230 located on the side of the electrode core 200 near the first sidewall region and the third electrode sheet 230 located on the side of the electrode core 200 near the second sidewall region are electrode sheets with the same polarity. That is, the third electrode sheet 230 located on the side of the electrode core 200 near the first sidewall region and the third electrode sheet 230 located on the side of the electrode core 200 near the second sidewall region are both anode electrode sheets or cathode electrode sheets. In this case, the first electrode sheet 30 located between the electrode core 200 and the first sidewall region... 0. The first electrode sheet 300 disposed between the electrode core 200 and the second sidewall region is an electrode sheet with the same polarity. The first electrode sheet 300 disposed between the electrode core 200 and the first sidewall region and the first electrode sheet 300 disposed between the electrode core 200 and the second sidewall region can be electrically connected to the first electrode tab 20. The third electrode sheet 230 disposed on the side of the electrode core 200 near the first sidewall region and the third electrode sheet 230 disposed on the side of the electrode core 200 near the second sidewall region can be electrically connected to the second electrode tab 30.

[0262] In other examples, the third electrode plate 230 located on the side of the electrode core 200 near the first sidewall region and the third electrode plate 230 located on the side of the electrode core 200 near the second sidewall region are electrode plates with opposite polarities. That is, one of the third electrode plates 230 located on the side of the electrode core 200 near the first sidewall region and the third electrode plate 230 located on the side of the electrode core 200 near the second sidewall region is an anode electrode plate, and the third electrode plate 230 located on the side of the electrode core 200 near the first sidewall region... The first electrode 300 located between the electrode core 200 and the first sidewall region, and the third electrode 230 located near the second sidewall region of the electrode core 200, are both cathode electrodes. In this case, the first electrode 300 located between the electrode core 200 and the first sidewall region, and the third electrode 230 located near the second sidewall region of the electrode core 200 are electrically connected to the second electrode tab 30. The first electrode 300 located between the electrode core 200 and the second sidewall region, and the third electrode 230 located near the first sidewall region of the electrode core 200 are electrically connected to the first electrode tab 20.

[0263] When the first electrode sheet 300 disposed between the electrode core 200 and the first sidewall region and the first electrode sheet 300 disposed between the electrode core 200 and the second sidewall region are electrode sheets with opposite polarities, the first encapsulation film layer 12 and the second encapsulation film layer 13 can be a separate structure connected by an insulating medium, so as to avoid the first electrode sheet 300 disposed between the electrode core 200 and the first sidewall region and the first electrode sheet 300 disposed between the electrode core 200 and the second sidewall region from contacting the first metal layer 110a and the second metal layer 110b respectively and causing a short circuit.

[0264] Figure 17 This is a schematic diagram of a stacked second encapsulation film layer with a second electrode material provided in an embodiment of this application. Figure 18 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0265] like Figure 17 , Figure 18 As shown, in some examples, the second sidewall region is provided with the second electrode material 400, that is, the surface of the first region S1 of the second metal layer 110b near the electrode core 200 is provided with the second electrode material 400, and the second metal layer 110b is electrically connected to one of the first tab 20 and the second tab 30.

[0266] In this way, the amount of electrode material in the packaging structure 10 can be increased by setting electrode material in the second sidewall region, thereby improving the volumetric energy density of the battery cell. In addition, by using the second metal layer 110b as a current collector to carry the electrode material, the space utilization rate of the battery cell is high. The portion of the second bonding layer 120b that is empty in the relative position of the second sidewall region can accommodate a large amount of electrode material, which is beneficial to improving the volumetric energy density of the battery cell.

[0267] When the second electrode material 400 located in the second sidewall region is an anode electrode material, the second metal layer 110b can serve as an anode current collector.

[0268] When the second electrode material 400 located in the second sidewall region is a cathode electrode material, the second metal layer 110b can serve as a cathode current collector.

[0269] For example, both the first sidewall region and the second sidewall region are provided with the second electrode material 400.

[0270] When the electrode core 200 is a wound electrode core, the second electrode material 400 provided in the first sidewall region and the second electrode material 400 provided in the second sidewall region are electrode materials with the same polarity.

[0271] In some examples where the electrode core 200 is a stacked electrode core, the second metal layer 110b includes a first region S1 and a second region S2. The outer surface of the electrode core 200 facing the second sidewall region is provided with a first isolation film 220. The electrode sheet of the electrode core 200 near the second sidewall region is a third electrode sheet 230. The second sidewall region is provided with a second electrode material 400.

[0272] This allows for increased electrode material arrangement in the packaging structure 10 when the electrode core 200 is a stacked electrode core, thereby improving the volumetric energy density of the battery cell. Furthermore, the use of the second metal layer 110b as a current collector to carry the electrode material results in high space utilization of the battery cell. The portion of the second bonding layer 120b in the corresponding position in the second sidewall region allows for a larger amount of electrode material to be arranged, further contributing to increased volumetric energy density of the battery cell.

[0273] When the first encapsulation film layer 12 and the second encapsulation film layer 13 are an integral structure, the second electrode material 400 provided in the first sidewall region and the second electrode material 400 provided in the second sidewall region are electrode materials with the same polarity. That is to say, the second electrode material 400 provided in the first sidewall region and the second electrode material 400 provided in the second sidewall region are both cathode electrode materials or both anode electrode materials.

[0274] When the first encapsulation film layer 12 and the second encapsulation film layer 13 are separate structures connected by an insulating medium, the second electrode material 400 provided in the first sidewall region and the second electrode material 400 provided in the second sidewall region can be electrode materials with the same polarity, or the second electrode material 400 provided in the first sidewall region and the second electrode material 400 provided in the second sidewall region can be electrode materials with opposite polarities.

[0275] When the second electrode material 400 in the first sidewall region and the second electrode material 400 in the second sidewall region are electrode materials with the same polarity, the first metal layer 110a and the second metal layer 110b can be electrically connected to the first tab 20.

[0276] When the second electrode material 400 in the first sidewall region and the second electrode material 400 in the second sidewall region are electrode materials with opposite polarities, the first metal layer 110a can be electrically connected to the first tab 20, and the second metal layer 110b can be electrically connected to the second tab 30.

[0277] Figure 19 This is a schematic diagram of the unfolded first and second encapsulation film layers provided in an embodiment of this application.

[0278] like Figure 19 As shown, when the first encapsulation film layer 12 and the second encapsulation film layer 13 are integral structures, the second metal layer 110b can be electrically connected to the first tab 20 or the second tab 30 through the connecting portion 111 of the first metal layer 110a.

[0279] When the first encapsulation film layer 12 and the second encapsulation film layer 13 are separate structures, and the second metal layer 110b is electrically connected to the first electrode 20, the second metal layer 110b includes a connecting portion 111 protruding from the outer edge of the second sealing region. That is, the second metal layer 110b includes a connecting portion 111 protruding from the outer edge of the second region S2. The connecting portion 111 of the second metal layer 110b is connected to the first electrode 20 so that the second metal layer 110b is electrically connected to the first electrode 20.

[0280] For example, the connection portion 111 of the second metal layer 110b can be welded to the first tab 20.

[0281] When the first encapsulation film layer 12 and the second encapsulation film layer 13 are separate structures, and the second metal layer 110b is electrically connected to the second tab 30, the second metal layer 110b includes a connecting portion 111 protruding from the outer edge of the second sealing region. That is, the second metal layer 110b includes a connecting portion 111 protruding from the outer edge of the second region S2. The connecting portion 111 of the second metal layer 110b is connected to the second tab 30 so that the second metal layer 110b is electrically connected to the second tab 30.

[0282] For example, the connection portion 111 of the second metal layer 110b can be welded to the second tab 30.

[0283] In some possible implementations, the second metal layer 110b is an aluminum layer, in which case the second encapsulation film layer 13 can be an aluminum-plastic film. The second electrode material 400 disposed in the second sidewall region is a cathode electrode material, the second metal layer 110b can serve as a cathode current collector, and the third electrode sheet 230 disposed on the side of the electrode core 200 near the second sidewall region is an anode electrode sheet.

[0284] This facilitates the second electrode material 400, which is disposed on the surface of the second metal layer 110b being an aluminum layer, to undergo galvanic cell reaction and electrolysis reaction, thereby improving the volumetric energy density of the battery cell with the second metal layer 110b being an aluminum layer.

[0285] In some possible implementations, the second metal layer 110b is a steel layer, in which case the second encapsulation film layer 13 is a steel-plastic film. The second electrode material 400 disposed in the second sidewall region is an anode electrode material, the second metal layer 110b can serve as an anode current collector, and the third electrode sheet 230 disposed on the side of the electrode core 200 near the second sidewall region is a cathode electrode sheet.

[0286] This facilitates the second electrode material 400, which is disposed on the surface of the second metal layer 110b being a steel layer, to undergo galvanic cell reaction and electrolysis reaction, thereby improving the volumetric energy density of the battery cell with the second metal layer 110b being a steel layer.

[0287] When the second metal layer 110b is electrically connected to the second tab 30, the first tab 20 is connected to the second metal layer 110b through an insulating medium (e.g., at least one of the first bonding layer 120a and the first bonding material 21), and the first tab 20 is not in direct electrical contact with the second metal layer 110b.

[0288] In some examples where the electrode core 200 includes a second electrode sheet 210, both the first electrode tab 20 and the second electrode tab 30 are connected to the second metal layer 110b through an insulating medium (e.g., a second bonding layer 120b), and neither the first electrode tab 20 nor the second electrode tab 30 are in direct electrical contact with the second metal layer 110b.

[0289] In some examples where the battery cell also includes a first electrode sheet 300, both the first tab 20 and the second tab 30 are connected to the second metal layer 110b through an insulating medium (e.g., the second bonding layer 120b), and neither the first tab 20 nor the second tab 30 is in direct electrical contact with the second metal layer 110b.

[0290] In some examples, both the first metal layer 110a and the second metal layer 110b include a first region S1 and a second region S2.

[0291] In some other examples where the second metal layer 110b includes the first region S1 and the second region S2, the first surface is covered by the first bonding layer 120a, that is, the first metal layer 110a does not include the first region S1 and the second region S2, and the first metal layer 110a is covered by the first bonding layer 120a.

[0292] Figure 20 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0293] like Figure 20 As shown, in some possible implementations, the first region S1 is located on the large surface of the battery cell. Here, the large surface of the battery cell refers to the surface with the largest area on the battery cell's packaging structure 10.

[0294] In this way, the recessed portion for forming the encapsulation structure 10 can be formed by stamping the first encapsulation film layer 12 and the second encapsulation film layer 13. The bottom wall of the recessed portion is used to form the large surface of the battery cell. The first region S1 is located on the bottom wall of the recessed portion. It is easier to process the original bonding layer 120 on the bottom wall of the recessed portion (e.g., laser cleaning), making it easier to form the expansion space.

[0295] For example, the battery cell may have two large surfaces, which are located on both sides of the thickness direction of the encapsulation structure 10. The first region S1 is located on one side of the sealing cavity 11 in the thickness direction of the battery cell. That is, the first region S1 is used to form the cavity wall of the sealing cavity 11 on the side of the thickness direction of the battery cell.

[0296] For example, the first region S1 of the first metal layer 110a is located on the large surface of the cell.

[0297] In some examples, the second region S2 includes a first sub-region S21 and a second sub-region S22. The bonding layer 120 located in the first sub-region S21 is used for edge sealing, while the bonding layer 120 located in the second sub-region S22 is not used for edge sealing. The second sub-region S22 is located between the first region S1 and the first sub-region S21, and the first region S1 is connected to the first sub-region S21 through the second sub-region S22.

[0298] Thus, the second sub-region S22, which is not used for edge sealing, is provided with a bonding layer. The bonding layer 120 located in the second sub-region S22 can play a role in insulation and protection in the second sub-region S22. In addition, the bonding layer 120 located in the second sub-region S22 can also improve the strength of the second sub-region S22, making the second sub-region S22 less prone to damage due to tension or other reasons.

[0299] The two ends of the second sub-region S22 are spaced apart in the thickness direction of the battery cell. At least a portion of the second sub-region S22 is located on the peripheral wall of the recess formed by stamping. The second sub-region S22 is used to form the cavity wall of the sealing cavity 11.

[0300] For example, the second region S2 of the first metal layer 110a includes a first sub-region S21 and a second sub-region S22, and the first surface located in the first sub-region S21 is the first edge sealing region.

[0301] In some possible implementations, a portion of the second region S2 is located on the large surface of the battery cell.

[0302] This reduces the precision requirements for the edge position of the expanded space, making its formation easier. Furthermore, the second region extends to the large surface of the battery cell, with the bonding layer 120 covering the corner where the large surface of the battery cell connects to the sealing edge. This corner offers good strength and is less prone to damage from tensile deformation. Additionally, the corner where the large surface of the battery cell connects to the sealing edge also provides good insulation.

[0303] For example, the second region S2 of the first metal layer 110a is located on the large surface of the cell.

[0304] For example, the edge of the separator protrudes beyond the edge of the cathode electrode plate and the edge of the anode electrode plate of the electrode core 200, so that the separator can effectively separate the cathode electrode plate and the anode electrode plate of the electrode core 200.

[0305] For example, the portion of the separator projected along the thickness direction of the battery cell can be located outside the projection of the first region S1 along the thickness direction of the battery cell, so as to improve the space utilization within the sealing cavity 11.

[0306] In some examples where the electrode core 200 is a wound electrode core, the electrode core 200 has a main body and a corner part. The corner part is connected to both sides of the main body. The projection of the main body along the thickness direction of the battery cell is located within the projection of the first region S1 along the thickness direction of the battery cell. The projection of the corner part along the thickness direction of the battery cell is located outside the projection of the first region S1 along the thickness direction of the battery cell. This is to improve the space utilization rate within the sealed cavity 11 while increasing the volumetric energy density of the battery cell.

[0307] In some examples where the electrode core 200 is a stacked electrode core, cathode electrode material is provided within the expansion space. The projection of the cathode electrode sheet of the electrode core 200 along the thickness direction of the cell lies within the projection of the first region S1 along the thickness direction of the cell. In this case, the projection of the anode electrode sheet of the electrode core 200 along the thickness direction of the cell can lie within the projection of the first region S1 along the thickness direction of the cell, or a portion of the projection of the anode electrode sheet of the electrode core 200 along the thickness direction of the cell can lie outside the projection of the first region S1 along the thickness direction of the cell. Thus, by providing cathode electrode material within the expansion space to increase the amount of cathode electrode material, it is beneficial to fully utilize the cathode electrode material provided within the expansion space.

[0308] In some examples where the electrode core 200 is a stacked electrode core, the anode electrode material is provided within the expansion space. The projection of the anode electrode sheet of the electrode core 200 along the thickness direction of the cell lies within the projection of the first region S1 along the thickness direction of the cell. In this case, the projection of the cathode electrode sheet of the electrode core 200 along the thickness direction of the cell can lie within the projection of the first region S1 along the thickness direction of the cell, and a portion of the projection of the cathode electrode sheet of the electrode core 200 along the thickness direction of the cell can also lie outside the projection of the first region S1 along the thickness direction of the cell. Thus, by providing anode electrode material within the expansion space to increase the amount of anode electrode material, it is beneficial to fully utilize the anode electrode material provided within the expansion space.

[0309] In some examples where the second region S2 includes the first sub-region S21 and the second sub-region S22, the amount of electrode material arranged within the packaging structure 10 can be increased by placing a portion of the electrode core 200 within the expansion space.

[0310] Figure 21 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0311] like Figure 21 As shown, in some examples where the second region S2 includes a first sub-region S21 and a second sub-region S22, the amount of electrode material arranged within the packaging structure 10 can be increased by setting a first electrode sheet 300 between the electrode core 200 and the first region S1.

[0312] Figure 22 A cross-sectional schematic diagram of another type of battery cell provided in this application embodiment.

[0313] like Figure 22 As shown, in some examples where the second region S2 includes a first sub-region S21 and a second sub-region S22, the amount of electrode material arranged within the packaging structure 10 can be increased by setting a second electrode material 400 on the surface of the first region S1 near the electrode core 200.

[0314] Figure 23This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0315] like Figure 23 As shown, in some examples where the bonding layer 120 covers the second region S2 but does not cover the first region S1, the thickness of the metal layer 110 located in the first region S1 is less than the thickness of the metal layer 110 located in the second region S2.

[0316] In this way, the portion of the metal layer 110 that is empty in the first region S1 can be used to arrange electrode materials, which is beneficial to further increase the amount of electrode materials arranged inside the packaging structure 10.

[0317] For example, after removing the bonding layer 120 of the first region S1, the metal layer 110 of the first region S1 can be thinned by laser cleaning.

[0318] In some examples where the first metal layer 110a includes a first region S1 and a second region S2, the thickness of the first metal layer 110a located in the first region S1 is less than the thickness of the first metal layer 110a located in the second region S2.

[0319] In some examples where the thickness of the metal layer 110 in the first region S1 is less than the thickness of the metal layer 110 in the second region S2, a second electrode material 400 may be disposed on the surface of the first region S1 near the electrode core 200 to increase the amount of electrode material arranged in the cell.

[0320] For example, in order to facilitate the placement of the second electrode material 400 on the surface of the first region S1 near the electrode core 200, when the first region S1 of the metal layer 110 is laser cleaned, the metal layer 110 can be placed in an inert gas environment, so that the surface of the first region S1 near the electrode core 200 is not easily oxidized by laser cleaning, thereby facilitating the placement of the second electrode material 400 on the surface of the first region S1 near the electrode core 200 after laser cleaning.

[0321] Figure 24 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0322] like Figure 24 As shown, in some examples where the thickness of the metal layer 110 in the first region S1 is less than the thickness of the metal layer 110 in the second region S2, the amount of electrode material arranged in the package structure 10 can be increased by placing a portion of the electrode core 200 within the expansion space.

[0323] In some examples where the bonding layer 120 covers the second region S2 but not the first region S1, the surface of the first region S1 near the electrode core 200 is covered with an oxide layer 150. That is, the oxide layer 150 and the bonding layer 120 are located on the same side of the metal layer 110.

[0324] In this way, the oxide layer 150 formed can improve the strength of the encapsulation structure 10 in the first region S1, making the encapsulation structure 10 less prone to damage.

[0325] For example, oxide layer 150 may be formed on the surface of metal layer 110 during laser cleaning of metal layer 110.

[0326] For example, the surface of the first region S1 of the first metal layer 110a near the electrode core 200 is covered with an oxide layer 150, and the oxide layer 150 covering the surface of the first region S1 of the first metal layer 110a near the electrode core 200 is the first oxide layer 150a.

[0327] For example, the first encapsulation film layer 12 is an aluminum-plastic film, the first metal layer 110a is an aluminum layer, and the first oxide layer 150a is an aluminum oxide layer.

[0328] In some examples where the surface of the first region S1 is covered with an oxide layer 150, the amount of electrode material arranged within the package structure 10 can be increased by placing a portion of the electrode core 200 within the expansion space.

[0329] Figure 25 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0330] like Figure 25 As shown, in some examples where the thickness of the metal layer 110 in the first region S1 is less than the thickness of the metal layer 110 in the second region S2, the amount of electrode material arranged in the packaging structure 10 can be increased by setting the first electrode sheet 300 between the electrode core 200 and the first region S1.

[0331] In some examples where the surface of the first region S1 is covered with an oxide layer 150, the amount of electrode material arranged within the packaging structure 10 can be increased by placing a first electrode sheet 300 between the electrode core 200 and the first region S1.

[0332] Figure 26 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0333] like Figure 26 As shown, in some examples, the first region S1 of the second metal layer 110b is located on the large surface of the cell.

[0334] In some examples where the second region S2 of the first metal layer 110a includes a first sub-region S21 and a second sub-region S22, the second region S2 of the second metal layer 110b includes a first sub-region S21 and a second sub-region S22, and the second surface located in the first sub-region S21 is the second edge sealing region.

[0335] When the second region S2 of the second metal layer 110b includes the first sub-region S21 and the second sub-region S22, the structure at the expansion space between the electrode core 200 and the second encapsulation film layer 13 can be set with reference to the structure at the expansion space between the electrode core 200 and the first encapsulation film layer 12.

[0336] In some other examples where the second region S2 of the first metal layer 110a includes the first sub-region S21 and the second sub-region S22, the second region S2 of the second metal layer 110b may also not include the first sub-region S21 and the second sub-region S22. The second bonding layer 120b located in the second region S2 is used for edge sealing. In this case, the second surface located in the second region S2 is the second edge sealing region.

[0337] Figure 27 This is a cross-sectional schematic diagram of another type of battery cell provided in an embodiment of this application.

[0338] like Figure 27 As shown, in some possible implementations, the bonding layer 120 covers the first region S1 and the second region S2, and the thickness of the bonding layer 120 covering the first region S1 is less than the thickness of the bonding layer 120 covering the second region S2, so as to form an expansion space at the first region S1.

[0339] In this way, while sealing the edge can be achieved using the bonding layer 120, thinning the bonding layer 120 in the first region S1 creates space in the first region S1, forming an expanded capacity space. With the cell size remaining unchanged, this expanded capacity increases the capacity of the sealing cavity 11, facilitating the arrangement of electrode material within the sealing cavity 11 and thus improving the volumetric energy density of the cell. Furthermore, the bonding layer 120 in the first region S1 also provides some strength enhancement and insulation protection.

[0340] For example, the thickness of the first bonding layer 120a covering the first region S1 of the first metal layer 110a is less than the thickness of the first bonding layer 120a covering the second region S2 of the first metal layer 110a, so as to form an expansion space in the first region S1 of the first metal layer 110a. In this way, while the first bonding layer 120a can be used to achieve edge sealing, by thinning the bonding layer 120 in the first region S1, space can be freed up in the first region S1 of the first metal layer 110a to form an expansion space. Without changing the size of the battery cell, the capacity of the sealing cavity 11 can be increased, which is beneficial for increasing the amount of electrode material arranged in the sealing cavity 11, and thus for increasing the volumetric energy density of the battery cell. The bonding layer 120 located in the first region S1 of the first metal layer 110a can play a certain role in improving strength and providing insulation protection.

[0341] For example, the first bonding layer 120a, which originally covered the first region S1 of the first metal layer 110a, can be thinned by laser cleaning of the inner surface of the first encapsulation film layer 12, so as to form an expansion space at the first region S1 of the first metal layer 110a.

[0342] In the example where the thickness of the bonding layer 120 covering the first region S1 is less than the thickness of the bonding layer 120 covering the second region S2, and the second region S2 includes the second sub-region S22, the thickness of the bonding layer 120 covering the first region S1 is less than the thickness of the bonding layer 120 covering the second sub-region S22, so that the bonding layer 120 located in the second sub-region S22 can play a better role in improving strength and providing insulation protection.

[0343] In some examples where the thickness of the bonding layer 120 covering the first region S1 is less than the thickness of the bonding layer 120 covering the second region S2, the amount of electrode material arranged within the encapsulation structure 10 can be increased by setting the first electrode sheet 300 between the electrode core 200 and the first region S1.

[0344] In some examples where the thickness of the bonding layer 120 covering the first region S1 is less than the thickness of the bonding layer 120 covering the second region S2, the amount of electrode material arranged within the packaging structure 10 can be increased by placing a portion of the electrode core 200 within the expansion space.

[0345] In some examples where the thickness of the first region S1 of the first bonding layer 120a covering the first metal layer 110a is less than the thickness of the second region S2 of the first metal layer 110a covered by the first bonding layer 120a, the first adhesive layer 130a covers the first region S1 and the second region S2 of the first metal layer 110a.

[0346] In some examples where the thickness of the first region S1 covered by the first bonding layer 120a is less than the thickness of the second region S2 covered by the first bonding layer 120a, the second bonding layer 120b can be a structure of equal thickness covering the second metal layer 110b.

[0347] In some other examples, where the thickness of the first region S1 covered by the first bonding layer 120a is less than the thickness of the second region S2 covered by the first bonding layer 120a, the thickness of the first region S1 covered by the second bonding layer 120b is less than the thickness of the second region S2 covered by the second bonding layer 120b. In this case, the structure at the expansion space between the electrode core 200 and the second encapsulation film layer 13 can be configured with reference to the structure at the expansion space between the electrode core 200 and the first encapsulation film layer 12.

[0348] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0349] The devices or elements referred to in the embodiments of this application or implied herein must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of this application. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise precisely specified.

[0350] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the present application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0351] The term "multiple" in this article refers to two or more. The term "and / or" in this article 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 alone, A and B simultaneously, or B alone. Furthermore, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects; in formulas, the character " / " indicates a "division" relationship between the preceding and following related objects.

[0352] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application.

[0353] It is understood that, in the embodiments of this application, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

Claims

1. A battery cell, characterized in that, It includes a first encapsulation film layer (12), a second encapsulation film layer (13), and an electrode core (200); At least one of the first encapsulation film layer (12) and the second encapsulation film layer (13) includes a metal layer and a bonding layer; The metal layer includes a first region (S1) and a second region (S2), the bonding layer covers the second region (S2) but does not cover the first region (S1), or the thickness of the bonding layer covering the first region (S1) is less than the thickness of the bonding layer covering the second region (S2). At least a portion of the bonding layer located in the second region (S2) is used for sealing so that the first encapsulation film layer (12) and the second encapsulation film layer (13) enclose to form a sealed cavity (11), and the electrode core (200) is disposed in the sealed cavity (11).

2. The battery cell according to claim 1, characterized in that, The first region (S1) is located on the large surface of the battery cell.

3. The battery cell according to claim 1 or 2, characterized in that, The second region (S2) is located on the large surface of the battery cell.

4. The battery cell according to any one of claims 1-3, characterized in that, When the bonding layer covers the second region (S2) but does not cover the first region (S1): the thickness of the metal layer located in the first region (S1) is less than the thickness of the metal layer located in the second region (S2).

5. The battery cell according to claim 1 or 2, characterized in that, The second region (S2) surrounds the outer edge of the first region (S1), and the bonding layer in the second region (S2) is used for edge sealing.

6. The battery cell according to any one of claims 1-4, characterized in that, The second region (S2) includes a first sub-region (S21) and a second sub-region (S22). The bonding layer located in the first sub-region (S21) is used for edge sealing, and the bonding layer located in the second sub-region (S22) is not used for edge sealing. The second sub-region (S22) is located between the first region (S1) and the first sub-region (S21).

7. The battery cell according to claim 6, characterized in that, When the thickness of the bonding layer covering the first region (S1) is less than the thickness of the bonding layer covering the second region (S2), the thickness of the bonding layer covering the first region (S1) is less than the thickness of the bonding layer covering the second sub-region (S22).

8. The battery cell according to any one of claims 1-6, characterized in that, When the bonding layer covers the second region (S2) but does not cover the first region (S1): the surface of the first region (S1) near the pole core (200) is covered with an oxide layer (150).

9. The battery cell according to any one of claims 1-8, characterized in that, It also includes a first electrode sheet (300); The first electrode plate (300) is disposed in the sealed cavity (11) and is located between the electrode core (200) and the first region (S1).

10. The battery cell according to claim 9, characterized in that, The first electrode sheet (300) includes a first current collector (310) and a first electrode material (320), wherein the first electrode material (320) is disposed on the side of the first current collector (310) near the electrode core (200).

11. The battery cell according to any one of claims 1-6, characterized in that, When the bonding layer covers the second region (S2) but does not cover the first region (S1), the surface of the first region (S1) near the electrode core (200) is provided with a second electrode material (400).

12. The battery cell according to claim 11, characterized in that, It also includes the electrode ear; The metal layer includes a connecting portion (111) protruding from the outer edge of the second region (S2), the connecting portion (111) being located outside the sealing cavity (11), and the connecting portion (111) being connected to the electrode tab.

13. The battery cell according to claim 11 or 12, characterized in that, The metal layer is an aluminum layer, and the second electrode material (400) is a cathode electrode material.

14. The battery cell according to claim 11 or 12, characterized in that, The metal layer is a steel layer, and the second electrode material (400) is an anode electrode material.

15. A battery, characterized in that, Includes the battery cell as described in any one of claims 1-14.

16. A battery pack, characterized in that, Includes a battery management system and a battery cell as described in any one of claims 1-14; The battery cell is electrically connected to the battery management system.

17. An electrical appliance, characterized in that, This includes the battery as described in claim 15 or the battery pack as described in claim 16.

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