Battery cell, battery, and electric device

Abstract

A battery cell, a battery, and an electric device. The battery cell comprises a casing, a pressure relief structure and an electrode assembly, wherein the casing is provided with a first wall; the pressure relief structure is arranged on the first wall; and the electrode assembly is arranged in the casing and comprises a plurality of electrode sheet layers stacked in a first direction, the plurality of electrode sheet layers including cathode electrode sheet layers and anode electrode sheet layers, each electrode sheet layer comprising an electrode sheet body, a first active material layer and a second active material layer, the first active material layer and the second active material layer being respectively arranged on two sides of the thickness of the electrode sheet body, at least one electrode sheet layer being constructed as a first preset electrode sheet layer, the distance between the first active material layer of the first preset electrode sheet layer and the first wall being greater than the distance between the second active material layer of the first preset electrode sheet layer and the first wall, and the first direction being parallel to a plane where the first wall is located.

Description

Battery cells, batteries and electrical devices Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] In recent years, new energy vehicles have experienced rapid development. In the electric vehicle sector, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. Typically, batteries consist of multiple cells, which generate significant heat during constant charging and discharging. Pressure relief structures are typically incorporated into these cells to relieve pressure in the event of thermal runaway. However, typical pressure relief structures often lack reliability, impacting the reliability of the cells.

[0003] Summary of the Invention

[0004] The present application provides a battery cell, a battery, and an electrical device, which can improve the reliability of the battery cell.

[0005] In the first aspect, an embodiment of the present application provides a battery cell, which includes: a shell having a first wall; a pressure relief structure, which is arranged on the first wall; an electrode assembly, which is arranged in the shell and includes a plurality of electrode layers stacked along a first direction, the plurality of electrode layers including a cathode electrode layer and an anode electrode layer, each electrode layer including a electrode body, a first active material layer and a second active material layer, the first active material layer and the second active material layer are respectively arranged on both sides of the thickness of the electrode body, at least one electrode layer is constructed as a first preset electrode layer, the distance x1 between the first active material layer of the first preset electrode layer and the first wall is greater than the distance x2 between its second active material layer and the first wall, and the first direction is parallel to the plane where the first wall is located.

[0006] In the above technical solution, at least one electrode layer is provided to form a first preset electrode layer, and the distance x1 between the first active material layer of the first preset electrode layer and the first wall is greater than the distance x2 between the second active material layer of the first preset electrode layer and the first wall, and the pressure relief structure is provided on the first wall, so that the amount of active material of the battery cell close to the first wall is relatively small. When the battery cell expands and deforms, it is beneficial to weaken the effect of the part of the shell close to the first wall on the first wall, and weaken the pulling effect of other walls of the shell on the pressure relief structure through the first wall, which can reduce the probability of damage such as cracking of the pressure relief structure on the first wall, and at the same time, to a certain extent, it can also reduce the probability of leakage due to cracking of the pressure relief structure, thereby improving the reliability of the battery cell.

[0007] In some embodiments, at least one cathode electrode layer is configured as a first preset electrode layer; or, at least one anode electrode layer is configured as a first preset electrode layer, and the cathode electrode layer at least partially adjacent to the anode electrode layer configured as the first preset electrode layer is also configured as a first preset electrode layer.

[0008] In the above technical solution, at least one cathode electrode layer is configured to form a first preset electrode layer, so that the amount of active material of the battery cell close to the first wall is reduced on at least one cathode electrode layer, so as to reduce the risk of the pressure relief structure being pulled and damaged on the first wall, and at the same time, when the battery cell is a lithium battery, it is convenient to better take into account the capacity of the electrode assembly for lithium ions, which is conducive to achieving the design requirement that the coverage range of the active material layer of the anode electrode layer in the battery cell is larger than the coverage range of the corresponding active material layer of the cathode electrode layer, so as to maintain good electrochemical performance of the battery cell; by configuring at least one anode electrode layer to form a first preset electrode layer, the anode electrode layer configured to form the first preset electrode layer is At least part of the adjacent cathode electrode layer is also constructed as a first preset electrode layer, so that when the amount of active material close to the first wall of the battery cell is reduced on at least one anode electrode layer, the cathode electrode layer at least part of the adjacent anode electrode layer constructed as the first preset electrode layer is also set to reduce the amount of active material accordingly, so as to reduce the risk of the pressure relief structure being pulled and damaged on the first wall, while facilitating better consideration of the electrode assembly's capacity to accommodate lithium ions when the battery cell is a lithium battery, and is conducive to achieving the design requirement that the coverage range of the active material layer of the anode electrode layer in the battery cell is larger than the coverage range of the corresponding active material layer of the cathode electrode layer, so as to maintain good electrochemical properties of the battery cell.

[0009] In some embodiments, all cathode electrode layers in the multi-layer electrode layer are configured as a first preset electrode layer; or, all electrode layers are configured as a first preset electrode layer.

[0010] In the above technical solution, by setting all cathode electrode layers in the multi-layer electrode layer to be constructed as the first preset electrode layer, the amount of active material of the battery cell close to the first wall can be further reduced, which is beneficial to further reduce the pulling effect on the pressure relief structure on the first wall and further improve the reliability of the battery cell; by setting all electrode layers to be constructed as the first preset electrode layer, the amount of active material of the battery cell close to the first wall can be further reduced, which is beneficial to further reduce the pulling effect on the pressure relief structure on the first wall and further improve the reliability of the battery cell.

[0011] In some embodiments, adjacent cathode electrode layers and anode electrode layers are respectively constructed into first preset electrode layers, and in adjacent cathode electrode layers and anode electrode layers, the first active material layer of the cathode electrode layer and the first active material layer of the anode electrode layer are arranged opposite to each other or back to back.

[0012] In the above technical solution, in the cathode electrode layer and the anode electrode layer that are adjacently arranged and both are constructed as the first preset electrode layer, the first active material layer of the cathode electrode layer and the first active material layer of the anode electrode layer are arranged relative to each other or back to back, so as to facilitate the matching of the coverage of the active material layers on the opposite sides of the adjacent cathode electrode layer and the anode electrode layer, so as to reduce the risk of the pressure relief structure being pulled and damaged on the first wall, while facilitating the design requirement that the coverage of the active material layer of the anode electrode layer in the battery cell is larger than the coverage of the corresponding active material layer of the cathode electrode layer, so as to maintain the good electrochemical performance of the battery cell.

[0013] In some embodiments, at least one anode electrode layer and two adjacent cathode electrode layers are respectively constructed as first preset electrode layers, the first active material layer of at least one anode electrode layer is arranged opposite to the first active material layer of one of the adjacent cathode electrode layers, and the second active material layer of at least one anode electrode layer is arranged opposite to the second active material layer of another adjacent cathode electrode layer.

[0014] In the above technical solution, by arranging the first active material layer and the second active material layer of the anode electrode layer configured as the first preset electrode layer to correspond to the first active material layer and the second active material layer of the adjacent cathode electrode layer, respectively, it is convenient to match the coverage of the active material layers on the opposite sides of the adjacent cathode electrode layer and the anode electrode layer, so as to reduce the risk of the pressure relief structure being pulled and damaged on the first wall, while facilitating the design requirement that the coverage of the active material layer of the anode electrode layer in the battery cell is larger than the coverage of the corresponding active material layer of the cathode electrode layer, so as to maintain good electrochemical properties of the battery cell.

[0015] In some embodiments, x1-x2≥2 mm.

[0016] In the above technical solution, by setting x1-x2≥2mm, the amount of active material close to the first wall of the battery cell can be appropriately reduced to reduce the pulling effect on the pressure relief structure, while at the same time, the energy density of the battery cell will not be excessively reduced to a certain extent, thereby achieving a balance between the reliability and capacity of the battery cell, and facilitating the processing of the first preset electrode layer.

[0017] In some embodiments, x1-x2≤12 mm.

[0018] In the above technical solution, by setting x1-x2≤12mm, the reliability and capacity of the battery cell can be further taken into consideration at the same time.

[0019] In some embodiments, at least one cathode electrode layer is configured as a first preset electrode layer, and a distance x11 between the first active material layer of the at least one cathode electrode layer and the first wall is ≥3 mm.

[0020] In the above technical solution, by setting x11≥3mm, the amount of active material can be effectively reduced, the pulling effect on the pressure relief structure can be effectively weakened, and the processing of the cathode electrode layer into the first preset electrode layer can be facilitated.

[0021] In some embodiments, x11≤17 mm.

[0022] In the above technical solution, by setting x11≤17mm, the amount of active material close to the first wall of the battery cell can be appropriately reduced to reduce the pulling effect on the pressure relief structure, while not causing excessive waste of the cathode electrode body and not causing excessive reduction in the energy density of the battery cell, so as to achieve a balance between battery cell capacity and cost.

[0023] In some embodiments, at least one anode electrode layer is configured as a first preset electrode layer, and a distance x12 between the first active material layer of the at least one anode electrode layer and the first wall is ≥2 mm.

[0024] In the above technical solution, by setting x12≥2mm, the amount of active material can be effectively reduced, the pulling effect on the pressure relief structure can be effectively weakened, and the processing of the anode electrode layer into the first preset electrode layer can be facilitated.

[0025] In some embodiments, x12≤15 mm.

[0026] In the above technical solution, by setting x12≤15mm, the amount of active material close to the first wall of the battery cell can be appropriately reduced to reduce the pulling effect on the pressure relief structure, while not causing excessive waste of the anode electrode body or excessive reduction in the energy density of the battery cell, so as to achieve a balance between the battery cell capacity and cost.

[0027] In some embodiments, the number of the first predetermined pole piece layers accounts for at least 16% of the total number of pole piece layers.

[0028] In the above technical solution, by setting the number of first preset electrode layers to account for at least 16% of the total number of electrode layers, the amount of active material close to the first wall of the battery cell can be appropriately reduced, which is conducive to effectively reducing the pulling effect on the pressure relief structure.

[0029] In some embodiments, the number of the first preset pole piece layers accounts for no more than 50% of the total number of pole piece layers.

[0030] In the above technical solution, the number of the first preset electrode layer is set to no more than 50% of the total number of electrode layers, so as to reduce the pulling effect on the pressure relief structure while not excessively reducing the energy density of the battery cell to a certain extent, thereby achieving a balance between the reliability and capacity of the battery cell.

[0031] In some embodiments, the number of the first preset pole piece layers accounts for no more than 24% of the total number of pole piece layers.

[0032] In the above technical solution, the number of the first preset electrode layer is set to no more than 24% of the total number of electrode layers, so as to reduce the pulling effect on the pressure relief structure while further facilitating not excessively reducing the energy density of the battery cell, thereby achieving a balance between reliability of use and battery cell capacity.

[0033] In some embodiments, at least one electrode layer is configured as a second preset electrode layer, and the distance between the first active material layer of the second preset electrode layer and the first wall is equal to the distance between the second active material layer of the second preset electrode layer and the first wall.

[0034] In the above technical solution, a multi-layer electrode layer is provided including at least one first preset electrode layer and at least one second preset electrode layer, so that the amount of active material close to the first wall of the battery cell can be appropriately reduced to reduce the pulling effect on the pressure relief structure, while the energy density of the battery cell will not be excessively reduced to a certain extent, thereby achieving a balance between the reliability and capacity of the battery cell.

[0035] In some embodiments, multiple layers of first preset pole piece layers and multiple layers of second preset pole piece layers are alternately stacked one by one.

[0036] In the above technical solution, by arranging multiple layers of first preset electrode layers and multiple layers of second preset electrode layers alternately, the distribution of active materials close to the first wall of the battery cell is more balanced, which is beneficial to improving the overall expansion and deformation of the electrode assembly.

[0037] In some embodiments, all cathode electrode layers are configured as a first predetermined electrode layer, and all anode electrode layers are configured as a second predetermined electrode layer.

[0038] In the above technical solution, all cathode electrode layers are configured as first preset electrode layers, and all anode electrode layers are configured as second preset electrode layers, so that the amount of active material close to the first wall of the battery cell can be appropriately reduced to reduce the pulling effect on the pressure relief structure, while at the same time, it is beneficial to achieve the design requirement that the coverage range of the active material layer of the anode electrode layer in the battery cell is larger than the coverage range of the corresponding active material layer of the cathode electrode layer, so as to maintain good electrochemical properties of the battery cell.

[0039] In some embodiments, the electrode assembly is a laminated electrode assembly, and the stacking direction of the anode electrode layer and the cathode electrode layer in the electrode assembly is a first direction; or, the electrode assembly is a wound electrode assembly, and the axial direction of the electrode assembly is perpendicular to the first direction.

[0040] In the above technical solution, by setting the electrode assembly to a laminated structure or a wound structure, the battery cell can be provided with electrode assemblies of different structures according to actual needs, which is beneficial to improving the applicability of the battery cell.

[0041] In some embodiments, the shell has two second walls arranged opposite to each other along a first direction, the first wall connects the two second walls, and the second wall is the wall with the largest area in the shell.

[0042] In the above technical solution, by arranging the pressure relief structure on the first wall, which is not the wall with the largest area of ​​the shell, the pressure relief structure can be arranged on the smaller stress surface of the shell. Compared with arranging the pressure relief structure on the second wall, when the electrode assembly expands and deforms, the stress on the pressure relief structure can be reduced, which is conducive to further reducing the risk of the pressure relief structure being pulled, damaged or failed.

[0043] In some embodiments, the pressure relief structure and the poles of the battery cells are disposed on walls on different sides of the housing.

[0044] In the above technical solution, the pole is connected to the pole ear of the electrode assembly, and there is a certain gap between the wall where the pole is located and the main body of the electrode assembly. By placing the pressure relief structure and the pole on the walls on different sides of the shell, the distance between the pressure relief structure and the main body of the electrode assembly can be appropriately shortened to a certain extent, so that the distance between the pressure relief structure and the main body of the electrode assembly is not easily restricted by the pole. When the battery cell thermally runs away, most of the emission medium in the shell can flow directly from the edge of the main body of the electrode assembly to the pressure relief structure, thereby shortening the path of the emission medium flowing to the pressure relief structure, allowing the emission medium to flow quickly to the pressure relief structure, shortening the time for the emission medium to reach the pressure relief structure, and improving the timeliness of the pressure relief of the battery cell.

[0045] In some embodiments, the shell includes a shell body and a shell cover, at least one of the two ends of the shell body in the second direction is open, the shell cover is arranged at the open end of the shell body, the first wall is formed on the shell body, and the second direction is perpendicular to the first direction.

[0046] In the above technical solution, the first wall is formed on the shell body, which can simplify the structure of the shell cover and facilitate shortening the distance between the pressure relief structure and the main body of the electrode assembly. This can shorten the path of the discharge medium flowing to the pressure relief structure during pressure relief, shorten the time for the discharge medium to reach the pressure relief structure, and improve the timeliness of pressure relief of the battery cell.

[0047] In some embodiments, the pressure relief structure is integrally formed with the first wall; or, the pressure relief structure and the first wall are provided separately, and the pressure relief structure is installed on the first wall.

[0048] In the above technical solution, by forming the pressure relief structure and the first wall into one piece, the molding method of the pressure relief structure is simple, which can reduce the number of components that make up the battery cell, simplify the structure of the battery cell and reduce costs; by constructing the pressure relief structure and the first wall as separate parts, it is convenient to set the pressure relief structure on the shell, the generation difficulty is low and the efficiency is high, which can improve the production efficiency of the battery cell.

[0049] In a second aspect, an embodiment of the present application provides a battery comprising the above-mentioned battery cell.

[0050] In the above technical solution, since the battery adopts the above-mentioned battery monomer and the battery monomer has good reliability in use, it is beneficial to improve the reliability of the battery.

[0051] In a third aspect, an embodiment of the present application provides an electrical device, comprising the above-mentioned battery, which is used to provide electrical energy.

[0052] In the above technical solution, since the electrical device adopts the above battery and the battery has good reliability, it is beneficial to improve the reliability of the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0054] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0055] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0056] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application, wherein the motor assembly is a wound electrode assembly;

[0057] FIG4 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0058] FIG5 is a schematic diagram of a battery cell provided in some embodiments of the present application, wherein the electrode assembly is a laminated electrode assembly;

[0059] FIG6 is a partial cross-sectional view of a battery cell provided in some embodiments of the present application;

[0060] FIG7 is a cross-sectional view of a battery cell provided in some embodiments of the present application;

[0061] FIG8 is a cross-sectional view of a battery cell provided in some embodiments of the present application.

[0062] Figure numerals: electrical device 1000, controller 300, motor 400, battery 200, battery cell 100, box 101, first box 101a, second box 101b, shell 1, first wall 11, notch groove 11b, second wall 12, third wall 13, shell body 1a, shell cover 1b, pressure relief structure 2, electrode assembly 3, pole piece layer 30, pole piece body 301, first active material layer 302, second active material layer 303, first preset pole piece layer 30a, second preset pole piece layer 30b, straight area 30c, cathode pole piece layer 31, anode pole piece layer 32, isolation membrane 33, pole post 4. DETAILED DESCRIPTION

[0063] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0064] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0065] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0066] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0067] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the dimensions and other sizes of the various components in the embodiments of the present application shown in the drawings are for illustrative purposes only and should not constitute any limitation on the present application.

[0068] The term "plurality" used in this application refers to two or more (including two).

[0069] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, or lead-acid batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0070] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may be a battery module or battery pack. A battery module generally includes multiple battery cells. A battery generally includes a casing for enclosing multiple battery cells or multiple battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells. Of course, the battery may also not include a casing.

[0071] For example, a battery cell may generally include a housing, a cell assembly, and an electrolyte. The housing is used to accommodate the cell assembly and the electrolyte, and is provided with at least one positive electrode post and at least one negative electrode post. The cell assembly includes one or more electrode assemblies, which are formed by stacking or winding a positive electrode sheet, a negative electrode sheet, and a separator. The housing may be a steel shell, an aluminum shell, a plastic shell (such as a polypropylene shell), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film.

[0072] Among them, the positive electrode sheet generally includes a positive electrode sheet body and a positive electrode active material layer. The positive electrode active material layer is directly or indirectly coated on the positive electrode sheet body. The positive electrode sheet body not coated with the positive electrode active material layer serves as a positive electrode tab. Multiple positive electrode tabs are stacked together and electrically connected to the positive electrode column. For example, the multiple stacked positive electrode tabs can be directly welded to the positive electrode column to form an electrical connection; alternatively, the battery cell assembly may further include a positive electrode adapter. The multiple stacked positive electrode tabs are welded to one end of the positive electrode adapter, and the other end of the positive electrode adapter is welded to the positive electrode column to form an electrical connection between the positive electrode tab and the positive electrode column.

[0073] The negative electrode sheet can generally include a negative electrode sheet body and a negative electrode active material layer. The negative electrode active material layer is directly or indirectly coated on the negative electrode sheet body. The negative electrode sheet body not coated with the negative electrode active material layer serves as a negative electrode tab sheet. Multiple negative electrode tab sheets are stacked together and electrically connected to the negative electrode column. For example, the multiple stacked negative electrode tab sheets can be directly welded to the negative electrode column to form an electrical connection; alternatively, the battery cell assembly can further include a negative electrode adapter sheet. The multiple stacked negative electrode tab sheets are welded to one end of the negative electrode adapter sheet, and the other end of the negative electrode adapter sheet is welded to the negative electrode column to form an electrical connection between the negative electrode tab sheet and the negative electrode column. The material of the separator is not limited, for example, it can be polypropylene or polyethylene.

[0074] The pressure relief structure on the battery cell mentioned in this application is used to release gas from the battery cell when the internal pressure of the battery cell is excessive (for example, due to overcharging), thereby reducing the internal pressure of the battery cell and preventing the battery cell from exploding due to excessive internal pressure. For example, the pressure relief structure can be an explosion-proof valve, explosion-proof disk, etc.

[0075] In recent years, new energy vehicles have experienced rapid development. In the electric vehicle sector, batteries, as the power source of electric vehicles, play an irreplaceable and important role. As core components of new energy vehicles, batteries have high requirements in terms of both energy density and reliability.

[0076] In related technologies, a battery includes multiple battery cells. A battery cell generates a large amount of heat during continuous charging and discharging. Generally, a pressure relief structure is provided in the battery cell to relieve pressure when the battery cell experiences thermal runaway.

[0077] When designing a battery cell, considering the battery's energy density, the battery cell's electrode assembly occupies as much space within the casing as possible. Therefore, the distance between the electrode assembly and the casing wall where the pressure relief structure is located is relatively close to the distance between the electrode assembly and the casing wall opposite the pressure relief structure. However, when the battery cell's electrode assembly expands and deforms, the battery cell casing also deforms, causing the casing to bulge. The pressure relief structure is usually located on the casing, which subjects the casing wall where the pressure relief structure is located to tension. When the tension reaches a certain level, it can easily cause the pressure relief structure to crack, resulting in damage and failure, and reduced battery cell reliability. Therefore, developing more reliable, heat-resistant battery systems has become a goal pursued by battery manufacturers and automakers.

[0078] Based on the above considerations, in order to improve the reliability of battery cells, a battery cell is proposed, including a shell, a pressure relief structure and an electrode assembly, the shell having a first wall, the pressure relief structure being arranged on the first wall, the electrode assembly being arranged in the shell, and including a plurality of electrode layers stacked along a first direction, the plurality of electrode layers including a cathode electrode layer and an anode electrode layer, each electrode layer including a electrode body, a first active material layer and a second active material layer, the first active material layer and the second active material layer being respectively arranged on both sides of the thickness of the electrode body, at least one electrode layer being constructed as a first preset electrode layer, the distance x1 between the first active material layer of the first preset electrode layer and the first wall being greater than the distance x2 between its second active material layer and the first wall, and the first direction being parallel to the plane where the first wall is located.

[0079] In the above technical solution, at least one electrode layer is provided to form a first preset electrode layer, and the distance x1 between the first active material layer of the first preset electrode layer and the first wall is greater than the distance x2 between the second active material layer of the first preset electrode layer and the first wall, and the pressure relief structure is provided on the first wall, so that the amount of active material of the battery cell close to the first wall is relatively small. When the battery cell expands and deforms, it is beneficial to weaken the effect of the part of the shell close to the first wall on the first wall, and weaken the pulling effect of other walls of the shell on the pressure relief structure through the first wall, which can reduce the probability of damage such as cracking of the pressure relief structure on the first wall, and at the same time, to a certain extent, it can also reduce the probability of leakage due to cracking of the pressure relief structure, thereby improving the reliability of the battery cell.

[0080] The present application provides an electrical device using the battery of the present disclosure as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, and the like. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0081] For the convenience of description, the following embodiments take the electric device 1000 as a vehicle as an example, and describe in detail the structures of the electric device 1000, the battery 200 and the battery cell 100 of the present application.

[0082] Please refer to Figure 1, which is a schematic structural diagram of a vehicle in which the power-consuming device 1000 provided in some embodiments of the present application is a vehicle. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The vehicle is provided with a battery 200, and the battery 200 can be arranged at the bottom, head or tail of the vehicle. The battery 200 can be used to power the vehicle, for example, the battery 200 can be used as an operating power source for the vehicle. The vehicle may also include a controller 300 and a motor 400, and the controller 300 is used to control the battery 200 to power the motor 400, for example, for the starting, navigation and working power requirements of the vehicle during driving. In some embodiments of the present application, the battery 200 can not only serve as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0083] Please refer to Figure 2, which is an exploded view of the structure of a battery 200 provided in some embodiments of the present application. The battery 200 includes a housing 101 and a plurality of battery cells 100, and the battery cells 100 are accommodated in the housing 101. The housing 101 is used to provide an assembly space for the battery cells 100, and the housing 101 can adopt a variety of structures. In some embodiments, the housing 101 can include a first housing 101a and a second housing 101b, and the first housing 101a and the second housing 101b cover each other, and the first housing 101a and the second housing 101b jointly define a housing cavity for accommodating the battery cells. The second box 101b can be a hollow structure with one end open, and the first box 101a can be a plate-like structure. The first box 101a covers the open side of the second box 101b, so that the first box 101a and the second box 101b together define a storage cavity; alternatively, the first box 101a and the second box 101b can both be hollow structures with one end open (for example, as shown in FIG. 2 ), with the open side of the first box 101a covering the open side of the second box 101b. Of course, the box 101 formed by the first box 101a and the second box 101b can be of various shapes, such as a cylinder or a rectangular parallelepiped.

[0084] In the battery 200, multiple battery cells 100 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 100. Multiple battery cells 100 can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 100 can be housed within the housing 101. Alternatively, the battery 200 can be constructed by first connecting multiple battery cells 100 in series, in parallel, or in a hybrid connection to form a battery module. The multiple battery modules are then connected in series, in parallel, or in a hybrid connection to form a single unit, which is then housed within the housing 101. The battery 200 may also include other structures. For example, the battery 200 may also include a busbar to electrically connect the multiple battery cells 100.

[0085] In some embodiments, the box 101 may serve as part of a chassis structure of a vehicle. For example, the box 101 may serve as at least a portion of a floor of the vehicle, or the box 101 may serve as at least a portion of a cross member and a longitudinal member of the vehicle.

[0086] Please refer to Figures 3 and 4. Figure 3 is a schematic diagram of the structure of a battery cell provided in some embodiments of the present application, and Figure 4 is a schematic diagram of the structure of a battery cell provided in some embodiments of the present application. The battery cell is a rectangular parallelepiped, with the height direction of the battery cell being the third direction Z, the length direction of the battery cell being the second direction Y, and the thickness direction of the battery cell being the first direction X. The first direction X, the second direction Y, and the third direction Z are mutually perpendicular; however, this is not limiting. In other embodiments of the present application, the battery cell may also be a polygonal prism, a flat body, or other shapes.

[0087] Please refer to Figures 3 to 5. In an embodiment of the present application, the battery cell 100 includes a shell 1 and a pressure relief structure 2. The shell 1 has a first wall 11. The pressure relief structure 2 is provided on the first wall 11. The pressure relief structure 2 is configured to release the pressure inside the battery cell 100.

[0088] The battery cell 100 also includes an electrode assembly 3, which is disposed within the housing 1. The electrode assembly 3 includes multiple electrode layers 30 stacked along a first direction. The multiple electrode layers 30 include at least one cathode electrode layer 31 and at least one anode electrode layer 32. Each electrode layer 30 includes an electrode body 301, a first active material layer 302, and a second active material layer 303. The first active material layer 302 and the second active material layer 303 are respectively disposed on opposite sides of the thickness of the electrode body 301. The first direction is parallel to the plane of the first wall 11.

[0089] It is understandable that one or more electrode assemblies 3 may be provided in the housing 1, and each electrode assembly 3 includes multiple electrode sheets 30 stacked along a first direction. It can be seen that the cathode electrode sheet 31 includes a cathode electrode body, a first cathode active material layer, and a second cathode active material layer, and the first cathode active material layer and the second cathode active material layer are respectively provided on both sides of the thickness of the cathode electrode body; similarly, the anode electrode sheet 32 ​​includes an anode electrode body, a first anode active material layer, and a second anode active material layer, and the first anode active material layer and the second anode active material layer are respectively provided on both sides of the thickness of the anode electrode body.

[0090] Exemplarily, the electrode assembly 3 can be a laminated structure, that is, the multi-layer electrode layer 30 of the electrode assembly 3 is stacked, and the multi-layer electrode layer 30 is stacked to form a straight area 30c. In the straight area 30c, at least a portion of the cathode electrode layer 31 and the anode electrode layer 32 are stacked along the first direction, or at least a portion of the anode electrode layer 32 and the cathode electrode layer 31 are stacked along the first direction. At this time, the expansion deformation of the electrode assembly 3 is particularly obvious in the first direction; the electrode assembly 3 can also be a wound structure, that is, the multi-layer electrode layer 30 of the electrode assembly 3 is stacked and wound into shape, and a straight area 30c is formed. In the straight area 30c, a portion of the anode electrode layer (i.e., the anode electrode layer 32) and a portion of the cathode electrode layer (i.e., the cathode electrode layer 31) are stacked along the first direction. For example, after winding, the cathode electrode layer 31 and the anode electrode layer 32 can both be pierced by an axis extending along the first direction. At this time, the expansion deformation of the electrode assembly 3 is particularly obvious in the first direction.

[0091] Obviously, when the electrode assembly 3 expands, most of the expansion of the electrode assembly 3 will act on the other walls of the shell 1 that are relatively arranged along the first direction. The first direction is parallel to the plane where the first wall 11 is located. The impact of the expansion of the electrode assembly 3 on the first wall 11 is smaller than that on the other walls mentioned above. Therefore, the pressure relief structure 2 is arranged on the first wall 11, which is beneficial to reducing the risk of blocking or damaging the pressure relief structure 2 due to the expansion of the electrode assembly 3.

[0092] Please refer to Figures 6 to 8. At least one electrode layer 30 is constructed as a first preset electrode layer 30a. The number of electrode layers 30 of the electrode assembly 3 is greater than or equal to the number of the first preset electrode layers 30a. The distance x1 between the first active material layer 302 of the first preset electrode layer 30a and the first wall 11 is greater than the distance x2 between the second active material layer 303 of the first preset electrode layer 30a and the first wall 11. The pressure relief structure 2 is provided on the first wall 11. Then, in a direction perpendicular to the first wall 11, the distance x1 between the first active material layer 302 of the first preset electrode layer 30a and the pressure relief structure 2 is greater than the distance x2 between the second active material layer 303 of the first preset electrode layer 30a and the pressure relief structure 2, so that in the subsequent cycle of the battery cell 100 Due to the obvious deformation of the electrode layer 30 due to rebound, the electrode assembly 3 exerts a force on the other walls of the shell 1 except the first wall 11, causing the above-mentioned other walls of the shell 1 to deform. Since x1>x2, the amount of active material of the battery cell 100 close to the first wall 11 is relatively small, which is beneficial to reducing the force on the parts of the above-mentioned other walls close to the first wall 11 and reducing the deformation of the parts of the above-mentioned other walls close to the first wall 11, thereby weakening the effect of the parts of the above-mentioned other walls close to the first wall 11 on the first wall 11, and weakening the pulling effect of the parts of the above-mentioned other walls close to the first wall 11 on the pressure relief structure 2 through the first wall 11, thereby reducing the probability of damage to the pressure relief structure 2 such as cracking on the first wall 11, and improving the reliability of the battery cell 100.

[0093] In addition, the above-mentioned arrangement of the embodiment of the present application can reduce the probability of the pressure relief structure 2 being pulled and damaged, thereby reducing the probability of leakage to a certain extent, and also improving the reliability of the battery cell 100.

[0094] Exemplarily, the height direction of the battery cell 100 is the third direction Z, the length direction of the battery cell 100 is the second direction Y, and the thickness direction of the battery cell 100 is the first direction X. In the third direction Z, the distance x1 between the first active material layer 302 of the first preset electrode layer 30a and the first wall 11 is greater than the distance x2 between the second active material layer 303 of the first preset electrode layer 30a and the first wall 11. Taking the third direction Z as the up-down direction as an example, the first wall 11 is the bottom wall of the shell 1. By differentially setting the sizes of the first active material layer 302 and the second active material layer 303 in the up-down direction on both sides of the thickness of the first preset electrode layer 30a, so that the distances between the first active material layer 302 and the second active material layer 303 and the first wall 11 are not equal, it is beneficial to reduce the force on the lower part of the shell 1 due to the expansion and deformation of the electrode assembly 3, thereby reducing the pulling effect on the pressure relief structure 2 on the bottom wall of the shell 1 and reducing the risk of the pressure relief structure 2 being pulled and cracked; in addition, the pressure relief structure 2 is arranged on the bottom wall of the shell 1, so that the battery cell 100 realizes a bottom spray design. It is beneficial to improve the heat spread of the battery 200. For example, the battery 200 is generally placed at the bottom of the electrical device, with electrical components or personnel above it. When the battery 200 has thermal runaway, the battery cell 100 can exhaust and release pressure downward, which can reduce the fire in the area above the battery 200, especially when there are a large number of battery cells 100, that is, reducing the loss of electrical components and reducing personal injury. The use of this structure can reduce the impact of the battery 200 on the electrical device under thermal runaway and improve the reliability of the battery 200.

[0095] It is understood that at least one electrode layer 30 configured as the first predetermined electrode layer 30a may include: at least one cathode electrode layer 31 configured as the first predetermined electrode layer 30a; and / or at least one anode electrode layer 32 configured as the first predetermined electrode layer 30a. For other electrode layers 30 not configured as the first predetermined electrode layer 30a, they may be configured as the second predetermined electrode layer 30b described below.

[0096] In the above technical solution, at least one electrode layer 30 is provided to form a first preset electrode layer 30a, and the distance x1 between the first active material layer 302 of the first preset electrode layer 30a and the first wall 11 is greater than the distance x2 between the second active material layer 303 of the first preset electrode layer 30a and the first wall 11, and the pressure relief structure 2 is provided on the first wall 11, so that the amount of active material close to the first wall 11 of the battery cell 100 is relatively small. When the battery cell 100 expands and deforms, it is beneficial to weaken the effect of the part of the shell 1 close to the first wall 11 on the first wall 11, and weaken the pulling effect of other walls of the shell 1 on the pressure relief structure 2 through the first wall 11, which can reduce the probability of damage such as cracking of the pressure relief structure 2 on the first wall 11, and at the same time, to a certain extent, it can also reduce the probability of leakage due to cracking of the pressure relief structure 2, thereby improving the reliability of the battery cell 100.

[0097] Please refer to Figures 6 to 8. In some embodiments, at least one layer of cathode electrode layer 31 is configured as the first preset electrode layer 30a, then the number of cathode electrode layers 31 of the electrode assembly 3 is greater than or equal to the number of cathode electrode layers 31 configured as the first preset electrode layer 30a; for a single-layer cathode electrode layer 31 configured as the first preset electrode layer 30a, it includes a cathode electrode body, and a first active material layer 302 and a second active material layer 303 arranged on both sides of the thickness of the cathode electrode body, and the distance x11 between the above-mentioned first active material layer 302 and the first wall 11 is greater than the distance x21 between the above-mentioned second active material layer 303 and the first wall 11.

[0098] In the above technical solution, at least one cathode electrode layer 31 is provided to form a first preset electrode layer 30a, so that the amount of active material of the battery cell 100 close to the first wall 11 is reduced on at least one cathode electrode layer 31, so as to reduce the risk of the pressure relief structure 2 being pulled and damaged on the first wall 11, while facilitating better consideration of the lithium ion accommodation capacity of the electrode assembly 3 when the battery cell 100 is a lithium battery, and is conducive to achieving the design requirement that the coverage range of the active material layer of the anode electrode layer 32 in the battery cell 100 is larger than the coverage range of the corresponding active material layer of the cathode electrode layer 31, so as to maintain the good electrochemical performance of the battery cell 100.

[0099] It is understood that in the above embodiment, when at least one cathode electrode layer 31 is configured as the first predetermined electrode layer 30a, the arrangement of the anode electrode layer 32 may include the following multiple embodiments: 1. All anode electrode layers 32 in the multiple electrode layers 30 are not configured as the first predetermined electrode layer 30a; 2. At least one anode electrode layer 32 is configured as the first predetermined electrode layer 30a. In the first embodiment, the anode electrode layer 32 configured as the first predetermined electrode layer 30a and the cathode electrode layer 31 configured as the first predetermined electrode layer 30a may be arranged adjacent to each other, or at least one other electrode layer 30 may be provided between the anode electrode layer 32 configured as the first predetermined electrode layer 30a and the cathode electrode layer 31 configured as the first predetermined electrode layer 30a.

[0100] In a further embodiment of the present application, all cathode electrode layers 31 in the multi-layer electrode layer 30 are constructed as a first preset electrode layer 30a.

[0101] In the above technical solution, by setting all the cathode electrode layers 31 in the multi-layer electrode layer 30 to be constructed as the first preset electrode layer 30a, the amount of active material close to the first wall 11 of the battery cell 100 can be further reduced, which is beneficial to further reduce the pulling effect of the pressure relief structure 2 on the first wall 11 and further improve the reliability of the battery cell 100.

[0102] Referring to Figures 6 and 7 , in some embodiments, at least one anode electrode layer 32 is configured as a first predetermined electrode layer 30a, and the cathode electrode layer 31 at least partially adjacent to the anode electrode layer 32 configured as the first predetermined electrode layer 30a is also configured as the first predetermined electrode layer 30a. Thus, the number of anode electrode layers 32 in the electrode assembly 3 is greater than or equal to the number of anode electrode layers 32 configured as the first predetermined electrode layer 30a. For a single anode electrode layer 32 configured as the first predetermined electrode layer 30a, it includes an anode electrode body, and a first active material layer 302 and a second active material layer 303 disposed on both sides of the thickness of the anode electrode body. Furthermore, the distance x12 between the first active material layer 302 and the first wall 11 is greater than the distance x22 between the second active material layer 303 and the first wall 11.

[0103] Exemplarily, the anode electrode layer 32 of the electrode assembly 3 is n layers, and along the first direction are respectively the first anode electrode layer 32, the second anode electrode layer 32, ..., the nth anode electrode layer 32, n is a positive integer. If the first anode electrode layer 32 to the nmth anode electrode layer 32 are respectively constructed as the first preset electrode layer 30a, the cathode electrode layer 31 adjacent to at least one anode electrode layer 32 from the first anode electrode layer 32 to the nmth anode electrode layer 32 is also constructed as the first preset electrode layer 30a, m is an integer and 0≤m<n. Of course, in other examples, when the anode electrode layer 32 configured as the first preset electrode layer 30a is multi-layer, a cathode electrode layer 31 is respectively provided between any two adjacent anode electrode layers 32 in the multi-layer anode electrode layer 32 configured as the first preset electrode layer 30a; or, at least two adjacent anode electrode layers 32 in the multi-layer anode electrode layer 32 configured as the first preset electrode layer 30a are respectively provided with at least one other anode electrode layer 32 not configured as the first preset electrode layer 30a and a multi-layer cathode electrode layer 31, and at least the two outermost cathode electrode layers 31 in the first direction in the multi-layer cathode electrode layer 31 are also configured as the first preset electrode layer 30a.

[0104] It can be understood that for a single-layer anode electrode layer 32 configured as the first preset electrode layer 30a, the cathode electrode layer 31 adjacent to the anode electrode layer 32 can be one layer or two layers. As long as the cathode electrode layer 31 is adjacent to the above-mentioned anode electrode layer 32, the cathode electrode layer 31 is configured as the first preset electrode layer 30a.

[0105] In the above technical solution, at least one anode electrode layer 32 is set to form a first preset electrode layer 30a, and the cathode electrode layer 31 adjacent to at least part of the anode electrode layer 32 configured as the first preset electrode layer 30a is also configured as the first preset electrode layer 30a. When the amount of active material of the battery cell 100 close to the first wall 11 is reduced on at least one anode electrode layer 32, the cathode electrode layer 31 adjacent to at least part of the anode electrode layer 32 configured as the first preset electrode layer 30a is also set to reduce the amount of active material accordingly. This is to reduce the risk of the pressure relief structure 2 being pulled and damaged on the first wall 11, while facilitating better consideration of the lithium ion accommodation capacity of the electrode assembly 3 when the battery cell 100 is a lithium battery 200, and is conducive to achieving the design requirement that the coverage range of the active material layer of the anode electrode layer 32 in the battery cell 100 is larger than the coverage range of the corresponding active material layer of the cathode electrode layer 31, so as to maintain the good electrochemical performance of the battery cell 100.

[0106] For example, in the example of the figure, for the adjacent anode electrode layer 32 and cathode electrode layer 31, if the two layers are respectively constructed as the first preset electrode layer 30a, the first active material layer 302 of the anode electrode layer 32 is arranged on the side of the anode electrode body facing the cathode electrode layer 31, and the first active material layer 302 of the cathode electrode layer 31 is arranged on the side of the cathode electrode body facing the anode electrode layer 32, or, the second active material layer 303 of the anode electrode layer 32 is arranged on the side of the anode electrode body facing the cathode electrode layer 31, and the second active material layer 303 of the cathode electrode layer 31 is arranged on the side of the cathode electrode body facing the anode electrode layer 32.

[0107] In a further embodiment of the present application, all pole piece layers 30 are constructed as a first preset pole piece layer 30a.

[0108] In the above technical solution, by setting all the electrode layers 30 to be constructed as the first preset electrode layer 30a, the amount of active material of the battery cell 100 close to the first wall 11 can be further reduced, which is beneficial to further reduce the pulling effect of the pressure relief structure 2 on the first wall 11 and further improve the reliability of the battery cell 100.

[0109] Please refer to Figures 6 and 7. In some embodiments, the adjacent cathode electrode layer 31 and the anode electrode layer 32 are respectively constructed into a first preset electrode layer 30a, and in the adjacent cathode electrode layer 31 and the anode electrode layer 32, the first active material layer 302 of the cathode electrode layer 31 and the first active material layer 302 of the anode electrode layer 32 are arranged relative to each other or back to back.

[0110] It can be seen that in the above scheme, for the anode electrode layer 32 and the cathode electrode layer 31 that are adjacently arranged and both are constructed into the first preset electrode layer 30a, the arrangement methods include the following: 1. The first active material layer 302 of the anode electrode layer 32 is arranged on the side of the anode electrode layer body facing the cathode electrode layer 31, and the first active material layer 302 of the cathode electrode layer 31 is arranged on the side of the cathode electrode layer body facing the anode electrode layer 32. At this time, the first active material layer 302 of the cathode electrode layer 31 and the first active material layer 302 of the anode electrode layer 32 are arranged opposite to each other; 2. The first active material layer 302 of the anode electrode layer 32 is arranged on the side of the anode electrode layer body facing away from the cathode electrode layer 31, and the first active material layer 302 of the cathode electrode layer 31 is arranged on the side of the cathode electrode layer body facing away from the anode electrode layer 32. At this time, the first active material layer 302 of the cathode electrode layer 31 and the first active material layer 302 of the anode electrode layer 32 are arranged back to back.

[0111] In the above technical solution, in the cathode electrode layer 31 and the anode electrode layer 32 that are adjacently arranged and both are constructed as the first preset electrode layer 30a, the first active material layer 302 of the cathode electrode layer 31 and the first active material layer 302 of the anode electrode layer 32 are arranged opposite to each other or back to back, so as to facilitate the matching of the coverage of the active material layers on the opposite sides of the adjacent cathode electrode layer 31 and the anode electrode layer 32, so as to reduce the risk of the pressure relief structure 2 being pulled and damaged on the first wall 11, while facilitating the design requirement that the coverage of the active material layer of the anode electrode layer 32 in the battery cell 100 is larger than the coverage of the corresponding active material layer of the cathode electrode layer 31, so as to maintain the good electrochemical performance of the battery cell 100.

[0112] Please refer to Figures 6 and 7. In some embodiments, at least one anode electrode layer 32 and two adjacent cathode electrode layers 31 are respectively constructed as first preset electrode layers 30a, and the first active material layer 302 of at least one anode electrode layer 32 is arranged opposite to the first active material layer 302 of one of the adjacent cathode electrode layers 31, and the second active material layer 303 of at least one anode electrode layer 32 is arranged opposite to the second active material layer 303 of another adjacent cathode electrode layer 31.

[0113] It can be seen that in the above scheme, for the single-layer anode electrode layer 32 constructed as the first preset electrode layer 30a, the first active material layer 302 of the anode electrode layer 32 is arranged on the side of the anode electrode body facing one of the two cathode electrode layers 31 adjacent to it, and the second active material layer 303 of the anode electrode layer 32 is arranged on the side of the anode electrode body facing the other of the two cathode electrode layers 31 adjacent to it, then the first active material layer 302 of the above one of the two cathode electrode layers 31 adjacent to the anode electrode layer 32 is arranged on the side of the cathode electrode body facing the anode electrode layer 32, and the second active material layer 303 of the above other of the two cathode electrode layers 31 adjacent to the anode electrode layer 32 is arranged on the side of the cathode electrode body facing the anode electrode layer 32.

[0114] For example, taking the first direction as the left-right direction, for a single-layer anode electrode layer 32 configured as a first preset electrode layer 30a, adjacent cathode electrode layers 31 are respectively provided on its left and right sides. If the first active material layer 302 of the anode electrode layer 32 is provided on the left side of the anode electrode body and the second active material layer 303 is provided on the right side of the anode electrode body, then the first active material layer 302 of the left cathode electrode layer 31 is provided on the right side of its cathode electrode body, and the second active material layer 303 of the right cathode electrode layer 31 is provided on the left side of its cathode electrode body.

[0115] In the above technical solution, by setting the first active material layer 302 and the second active material layer 303 of the anode electrode layer 32 configured as the first preset electrode layer 30a to correspond to the first active material layer 302 and the second active material layer 303 of the adjacent cathode electrode layer 31, respectively, it is convenient to match the coverage of the active material layers on the opposite sides of the adjacent cathode electrode layer 31 and the anode electrode layer 32, so as to reduce the risk of the pressure relief structure 2 being pulled and damaged on the first wall 11, while facilitating the design requirement that the coverage of the active material layer of the anode electrode layer 32 in the battery cell 100 is larger than the coverage of the corresponding active material layer of the cathode electrode layer 31, so as to maintain the good electrochemical performance of the battery cell 100.

[0116] It can be understood that in the embodiment of the present application, the distance between the active material layer on the side of the anode electrode layer 32 facing the cathode electrode layer 31 and the first wall 11 is smaller than the distance between the active material layer on the side of the cathode electrode layer 31 facing the anode electrode layer 32 and the first wall 11. Exemplarily, taking the first direction as the left-right direction as an example, for a single-layer anode electrode layer 32 constructed as a first preset electrode layer 30a, adjacent cathode electrode layers 31 are respectively provided on its left and right sides. If the first active material layer 302 of the anode electrode layer 32 is arranged on the right side of the anode electrode body and the second active material layer 303 is arranged on the left side of the anode electrode body, then the second active material layer 303 of the left cathode electrode layer 31 is arranged on the right side of its cathode electrode body, and the first active material layer 302 of the right cathode electrode layer 31 is arranged on the left side of its cathode electrode body, and the distance between the second active material layer 303 of the left cathode electrode layer 31 and the first wall 11 is greater than the distance between the second active material layer 303 of the anode electrode layer 32 and the first wall 11, and the distance between the first active material layer 302 of the right cathode electrode layer 31 and the first wall 11 is greater than the distance between the first active material layer 302 of the anode electrode layer 32 and the first wall 11.

[0117] Please refer to FIG. 6 to FIG. 8 . In some embodiments, x1-x2≥2 mm.

[0118] For example, for the cathode electrode layer 31 configured as the first predetermined electrode layer 30a, the distance x11 between the first active material layer 302 of the cathode electrode layer 31 and the first wall 11 is greater than the distance x21 between the second active material layer 303 of the cathode electrode layer 31 and the first wall 11, and x11-x21 ≥ 2 mm. For the anode electrode layer 32 configured as the first predetermined electrode layer 30a, the distance x12 between the first active material layer 302 of the anode electrode layer 32 and the first wall 11 is greater than the distance x22 between the second active material layer 303 of the cathode electrode layer 31 and the first wall 11, and x12-x22 ≥ 2 mm.

[0119] Optionally, x1-x2 can be 2mm, 3mm, 5mm, 6mm, 8mm, 9mm, 11mm, 12mm, or 13mm, etc.

[0120] In the above technical solution, by setting x1-x2≥2mm, the amount of active material close to the first wall 11 of the battery cell 100 can be appropriately reduced to reduce the pulling effect on the pressure relief structure 2, while the energy density of the battery cell 100 will not be excessively reduced to a certain extent, thereby achieving a balance between the reliability and capacity of the battery cell 100 and facilitating the processing of the first preset electrode layer 30a.

[0121] Furthermore, x1-x2≤12 mm. For example, x1-x2 may be 4 mm, 4.5 mm, 7 mm, 10 mm, 10.5 mm, or 11.5 mm.

[0122] In the above technical solution, by setting x1-x2≤12mm, the reliability and capacity of the battery cell 100 can be taken into consideration at the same time.

[0123] For example, for the cathode electrode layer 31 configured as the first predetermined electrode layer 30a, the distance x11 between the first active material layer 302 of the cathode electrode layer 31 and the first wall 11 is greater than the distance x21 between the second active material layer 303 of the cathode electrode layer 31 and the first wall 11, and x11-x21≤12 mm. For the anode electrode layer 32 configured as the first predetermined electrode layer 30a, the distance x12 between the first active material layer 302 of the anode electrode layer 32 and the first wall 11 is greater than the distance x22 between the second active material layer 303 of the cathode electrode layer 31 and the first wall 11, and x12-x22≤12 mm.

[0124] Please refer to Figures 6 to 8. In some embodiments, at least one cathode electrode layer 31 is configured as a first preset electrode layer 30a, and the distance x11 between the first active material layer 302 of the at least one cathode electrode layer 31 and the first wall 11 is ≥3mm. That is, the distance x11 between the first active material layer 302 of the cathode electrode layer 31 configured as the first preset electrode layer 30a and the first wall 11 is ≥3mm.

[0125] Optionally, x11 can be 3mm, 5mm, 6mm, 8mm, 11mm, 12mm, 15mm, 16mm or 18mm, etc.

[0126] In the above technical solution, by setting x11≥3mm, the amount of active material can be effectively reduced, the pulling effect on the pressure relief structure 2 can be effectively weakened, and the processing of the cathode electrode layer 31 into the first preset electrode layer 30a can be facilitated.

[0127] Furthermore, x11≤17 mm. For example, x11 may be 3.5 mm, 4 mm, 7 mm, 9 mm, 10 mm, 13 mm, 14 mm, or 17 mm.

[0128] In the above technical solution, by setting x11≤17mm, the amount of active material close to the first wall 11 of the battery cell 100 can be appropriately reduced to reduce the pulling effect on the pressure relief structure 2, while not causing excessive waste of the cathode electrode body and not causing excessive reduction in the energy density of the battery cell 100, so as to achieve a balance between the capacity and cost of the battery cell 100.

[0129] Please refer to Figures 6 and 7. In some embodiments, at least one anode electrode layer 32 is configured as a first preset electrode layer 30a, and the distance x12 between the first active material layer 302 of at least one anode electrode layer 32 and the first wall 11 is ≥2mm. That is, the distance x12 between the first active material layer 302 of the anode electrode layer 32 configured as the first preset electrode layer 30a and the first wall 11 is ≥2mm.

[0130] Optionally, x12 is 2mm, 4mm, 5mm, 7mm, 9mm, 10mm, 12mm, 13mm, 15mm, or 16mm, etc.

[0131] In the above technical solution, by setting x12≥2mm, the amount of active material can be effectively reduced, the pulling effect on the pressure relief structure 2 can be effectively weakened, and the processing of the anode electrode layer 32 into the first preset electrode layer 30a can be facilitated.

[0132] Furthermore, x12≤15 mm. For example, x12 is 2.5 mm, 3 mm, 6 mm, 8 mm, 11 mm, or 14 mm.

[0133] In the above technical solution, by setting x12≤15mm, the amount of active material close to the first wall 11 of the battery cell 100 can be appropriately reduced to reduce the pulling effect on the pressure relief structure 2, while not causing excessive waste of the anode electrode body and not causing excessive reduction in the energy density of the battery cell 100, so as to achieve a balance between the capacity and cost of the battery cell 100.

[0134] Please refer to Figures 6 to 8. In some embodiments, the number of layers of the first preset electrode layer 30a accounts for at least 16% of the total number of layers of the electrode layer 30, that is, the ratio of the number of layers of the first preset electrode layer 30a to the total number of layers of the electrode layer 30 of the electrode assembly 3 is greater than or equal to 16%.

[0135] In the above technical solution, the number of the first preset electrode layer 30a is set to account for at least 16% of the total number of electrode layers 30, so that the amount of active material close to the first wall 11 of the battery cell 100 is appropriately reduced, which is conducive to effectively reducing the pulling effect on the pressure relief structure 2.

[0136] Exemplarily, the ratio of the number of first preset pole piece layers 30a to the total number of pole piece layers 30 is 16%, 20%, 23%, 25%, 28%, 30%, 35%, 40%, 45%, 50%, or 55%, etc.

[0137] In some embodiments, the number of layers of the first preset electrode layer 30a accounts for no more than 50% of the total number of electrode layers 30, that is, the ratio of the number of layers of the first preset electrode layer 30a to the total number of electrode layers 30 of the electrode assembly 3 is less than or equal to 50%.

[0138] In the above technical solution, by setting the number of first predetermined electrode sheet layers 30a to no more than 50% of the total number of electrode sheet layers 30, the tension on the pressure relief structure 2 is reduced while the energy density of the battery cell 100 is not excessively reduced to a certain extent, thereby achieving a balance between the reliability and capacity of the battery cell 100. For example, the ratio of the number of first predetermined electrode sheet layers 30a to the total number of electrode sheet layers 30 is 17%, 22%, 26%, 29%, 33%, 37%, 42%, 48%, etc.

[0139] Furthermore, the number of the first preset electrode layer 30a accounts for no more than 24% of the total number of electrode layers 30, that is, the ratio of the number of the first preset electrode layer 30a to the total number of electrode layers 30 of the electrode assembly 3 is less than or equal to 24%.

[0140] In the above technical solution, by setting the number of first predetermined electrode sheet layers 30a to no more than 24% of the total number of electrode sheet layers 30, the tension on the pressure relief structure 2 is reduced while further preventing an excessive reduction in the energy density of the battery cell 100, thereby achieving a balance between reliability and capacity of the battery cell 100. For example, the ratio of the number of first predetermined electrode sheet layers 30a to the total number of electrode sheet layers 30 is 18%, 19%, 21%, 24%, and so on.

[0141] Please refer to Figure 8. In some embodiments, at least one electrode layer 30 is constructed as a second preset electrode layer 30b, then the number of electrode layers 30 of the electrode assembly 3 is greater than or equal to the sum of the number of layers of the first preset electrode layer 30a and the second preset electrode layer 30b; the distance between the first active material layer 302 of the second preset electrode layer 30b and the first wall 11 is equal to the distance between the second active material layer 303 of the second preset electrode layer 30b and the first wall 11.

[0142] In the above technical solution, a multi-layer electrode layer 30 is provided including at least one first preset electrode layer 30a and at least one second preset electrode layer 30b, so that the amount of active material close to the first wall 11 of the battery cell 100 can be appropriately reduced to reduce the pulling effect on the pressure relief structure 2, while the energy density of the battery cell 100 will not be excessively reduced to a certain extent, thereby achieving a balance between the reliability and capacity of the battery cell 100.

[0143] It can be understood that at least one electrode layer 30 is configured as the second preset electrode layer 30b, which may include: at least one cathode electrode layer 31 is configured as the second preset electrode layer 30b; and / or, at least one anode electrode layer 32 is configured as the second preset electrode layer 30b.

[0144] Please refer to Figure 8. In some embodiments, multiple layers of first preset pole sheet layers 30a and multiple layers of second preset pole sheet layers 30b are alternately stacked one by one, and a layer of second preset pole sheet layer 30b is provided between two adjacent layers of first preset pole sheet layers 30a, and a layer of first preset pole sheet layer 30a is provided between two adjacent layers of second preset pole sheet layers 30b.

[0145] In the above technical solution, by arranging multiple layers of first preset electrode layer 30a and multiple layers of second preset electrode layer 30b alternately, the distribution of active material near the first wall 11 of the battery cell 100 is more balanced, which is beneficial to improving the overall expansion deformation of the electrode assembly 3.

[0146] Referring to FIG. 8 , in some embodiments, all cathode electrode layers 31 are configured as a first predetermined electrode layer 30 a , and all anode electrode layers 32 are configured as a second predetermined electrode layer 30 b .

[0147] In the above technical solution, all cathode electrode layers 31 are configured as the first preset electrode layer 30a, and all anode electrode layers 32 are configured as the second preset electrode layer 30b, so that the amount of active material close to the first wall 11 of the battery cell 100 is appropriately reduced to reduce the pulling effect on the pressure relief structure 2, while at the same time, it is beneficial to achieve the design requirement that the coverage range of the active material layer of the anode electrode layer 32 in the battery cell 100 is larger than the coverage range of the corresponding active material layer of the cathode electrode layer 31, so as to maintain the good electrochemical performance of the battery cell 100.

[0148] In some embodiments, the electrode assembly 3 is a laminated electrode assembly, in which the anode electrode layer 32 and the cathode electrode layer 31 are stacked in the first direction; alternatively, the electrode assembly 3 is a wound electrode assembly, in which the axial direction of the electrode assembly 3 is perpendicular to the first direction. In the above technical solution, by configuring the electrode assembly 3 as a laminated structure or a wound structure, the battery cell 100 can be configured with electrode assemblies 3 of different structures according to actual needs, which is beneficial to improving the applicability of the battery cell 100.

[0149] As an example, the anode electrode layer 32 and the cathode electrode layer 31 are respectively multi-layered, and the multi-layer anode electrode layer 32 and the multi-layer cathode electrode layer 31 are alternately stacked. As an example, the cathode electrode layer 31 is multi-layered, and the anode electrode sheet is folded to form a plurality of stacked anode electrode layers 32, and a cathode electrode layer 31 is sandwiched between adjacent anode electrode layers 32. As an example, the anode electrode sheet is folded to form a plurality of stacked anode electrode layers 32, and the cathode electrode sheet is folded to form a plurality of stacked cathode electrode layers 31. As an example, a plurality of isolation membranes can be provided, and each isolation membrane is respectively provided between any adjacent anode electrode layer 32 and cathode electrode layer 31. As an example, the isolation membrane can be provided continuously, and can be provided between any adjacent anode electrode layer 32 and cathode electrode layer 31 by folding or winding. For example, for a laminated electrode assembly, the isolation membrane can extend roughly in a serpentine shape.

[0150] Please refer to Figures 3 and 4. In some embodiments, the shell 1 has two second walls 12 arranged opposite to each other along the first direction. The first wall 11 connects the two second walls 12. The second wall 12 is the wall with the largest area in the shell 1. The second wall 12 can be understood as the "large surface" of the shell 1.

[0151] It can be seen that the first wall 11 is a narrow shell wall connected between the two second walls 12. After the electrode assembly 3 is installed in the shell 1, the second wall 12 is opposite to the straight area 30c of the electrode assembly 3. When the internal pressure of the shell 1 reaches a certain value, the pressure relief structure 2 realizes pressure relief.

[0152] When the electrode assembly 3 expands, the electrode assembly 3 pushes against the second wall 12 and pushes the shell 1 outward in the first direction, causing the shell 1 to deform. The second wall 12 is the main stress-bearing surface and deforms greatly, and the force on the first wall 11 is smaller than that on the second wall 12. Therefore, by arranging the pressure relief structure 2 on the first wall 11, the pressure relief structure 2 is arranged on the less stress-bearing surface of the shell 1. Compared with arranging the pressure relief structure 2 on the second wall 12, the force on the pressure relief structure 2 can be reduced, thereby further reducing the risk of the pressure relief structure 2 being damaged or failing due to pulling.

[0153] In the above technical solution, by arranging the pressure relief structure 2 on the first wall 11, the first wall 11 is not the wall with the largest area of ​​the shell 1, and the pressure relief structure 2 can be arranged on the smaller stress surface of the shell 1. Compared with arranging the pressure relief structure 2 on the second wall 12, when the electrode assembly 3 expands and deforms, the stress on the pressure relief structure 2 can be reduced, which is conducive to further reducing the risk of the pressure relief structure 2 being pulled, damaged or failed.

[0154] 3 and 4 , in some embodiments, the pressure relief structure 2 and the pole 4 of the battery cell 100 are disposed on walls on different sides of the housing 1 , that is, the pole 4 is disposed on walls of the housing 1 other than the first wall 11 .

[0155] In the above technical solution, the pole 4 is connected to the pole ear of the electrode assembly 3, and there is a certain gap between the wall where the pole 4 is located and the main body of the electrode assembly 3. By placing the pressure relief structure 2 and the pole 4 on the walls on different sides of the shell 1, the distance between the pressure relief structure 2 and the main body of the electrode assembly 3 can be appropriately shortened to a certain extent, so that the distance between the pressure relief structure 2 and the main body of the electrode assembly 3 is not easily restricted by the pole 4. When the battery cell 100 thermally runs away, most of the emission medium in the shell 1 can flow directly from the edge of the main body of the electrode assembly 3 to the pressure relief structure 2, thereby shortening the path of the emission medium flowing to the pressure relief structure 2, so that the emission medium can flow quickly to the pressure relief structure 2, shortening the time for the emission medium to reach the pressure relief structure 2, and improving the timeliness of the pressure relief of the battery cell 100.

[0156] In some embodiments, the housing 1 further comprises a second wall 12 and a third wall 13. The second wall 12 is disposed adjacent to and connected to the first wall 11, and the pole 4 is disposed on the third wall 13. The third wall 13 is disposed adjacent to and connected to the first wall 11 and the second wall 12, respectively; alternatively, the third wall 13 is disposed adjacent to and connected to the second wall 12, and the third wall 13 is disposed opposite to the first wall 11.

[0157] Exemplarily, the shell 1 includes a shell body 1a and a shell cover 1b, the shell body 1a is open at both ends in the second direction, the shell cover 1b is arranged at the open end of the shell body 1a, the first wall 11 and the second wall 12 are both formed on the shell body 1a, and at least one of the two shell covers 1b is formed as a third wall 13. At this time, the third wall 13 is adjacent to and connected to the first wall 11 and the second wall 12 respectively; one of the two ends of the shell body 1a in the second direction is open, the shell cover 1b is arranged at the open end of the shell body 1a, the shell cover 1b is formed as the third wall 13, and the shell cover 1b is opposite to the first wall 11 along the second direction.

[0158] In some embodiments, the shell 1 includes a shell body 1a and a shell cover 1b, at least one of the two ends of the shell body 1a in the second direction is open, the shell cover 1b is arranged at the open end of the shell body 1a, the first wall 11 is formed on the shell body 1a, and the second direction is perpendicular to the first direction.

[0159] Exemplarily, the shell body 1a can be a hollow structure with an opening formed at one end, or the shell body 1a can be a hollow structure with openings formed at two opposite ends. The shell body 1a can be of various shapes, such as a prismatic shape. The shell cover 1b is a component that closes the opening of the shell body 1a to isolate the internal environment of the battery cell 100 from the external environment. The shell cover 1b and the shell body 1a together define a mounting cavity for accommodating the electrode assembly 3, electrolyte, and other components. The shape of the shell cover 1b can be compatible with the shape of the shell body 1a. For example, if the shell body 1a is a rectangular parallelepiped structure, the shell cover 1b can be a rectangular plate structure that is compatible with the shell body 1a. For another example, if the shell body 1a is a cylindrical structure, the shell cover 1b can be a circular plate structure that is compatible with the shell body 1a. The material of the shell cover 1b can also be various, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc. The material of the shell cover 1b and the shell body 1a can be the same or different.

[0160] In an embodiment where the shell body 1a is opened at one end, one shell cover 1b may be provided. In an embodiment where the shell body 1a is opened at opposite ends, two shell covers 1b may be provided. The two shell covers 1b respectively close the two openings of the shell body 1a, and the two shell covers 1b and the shell body 1a together define an installation cavity. The shell body 1a has a first wall 11. The pressure relief structure 2 may be integrally formed with the first wall 11 or may be provided separately from the first wall 11. By providing the pressure relief structure 2 on the shell body 1a, the structure of the shell cover 1b may be simplified, and the distance between the pressure relief structure 2 and the main body of the electrode assembly 3 may be shortened. This may shorten the path for the discharge medium to flow to the pressure relief structure 2 during pressure relief, shorten the time for the discharge medium to reach the pressure relief structure 2, and improve the timeliness of pressure relief of the battery cell 100, thereby further improving the reliability of the battery cell 100.

[0161] In the above technical solution, the first wall 11 is formed on the shell body 1a, which can simplify the structure of the shell cover 1b and facilitate shortening the distance between the pressure relief structure 2 and the main body of the electrode assembly 3. This can shorten the path of the discharge medium flowing to the pressure relief structure 2 during pressure relief, shorten the time for the discharge medium to reach the pressure relief structure 2, and improve the timeliness of pressure relief of the battery cell 100.

[0162] For example, one end of the shell body 1a in the second direction is open, and the first wall 11 is arranged at the end of the shell body 1a away from the open end; or, both ends of the shell body 1a in the second direction are open, and the first wall 11 extends to the open ends on both sides, and the opposite ends of the first wall 11 are respectively connected to the two end covers.

[0163] Please refer to FIG. 4 . In some embodiments, the pressure relief structure 2 and the first wall 11 are integrally formed. Alternatively, as shown in FIG. 3 , the pressure relief structure 2 and the first wall 11 are separately provided, and the pressure relief structure 2 is installed on the first wall 11 .

[0164] When the pressure relief structure 2 is integrally formed with the first wall 11, a notched groove 11b can be provided on the first wall 11. The area of ​​the first wall 11 corresponding to the notched groove 11b forms a weak area of ​​the pressure relief structure 2. The weak area is configured to crack when the battery cell 100 is depressurized. The molding method of the pressure relief structure 2 is simple and the production cost is low. It can be understood that the notched groove 11b is formed on the inner surface of the first wall 11 and / or the outer surface of the first wall 11.

[0165] It can be seen that in the above technical solution, by integrally forming the pressure relief structure 2 and the first wall 11, the pressure relief structure 2 is formed in a simple manner, which can reduce the number of components constituting the battery cell 100, simplify the structure of the battery cell 100, and reduce costs.

[0166] In the embodiment of the present application, there is no specific restriction on the shape of the notched groove 11b; for example, the notched groove 11b includes a first straight groove segment and four second straight groove segments, and the two ends of the first straight groove segment are respectively connected to two second straight groove segments set at a preset angle, so that the two ends of the notched groove 41 can roughly form a Y shape.

[0167] When the pressure relief structure 2 is separately provided from the first wall 11, the pressure relief structure 2 and the shell 1 are two separate components, which are separately formed and then installed together; the pressure relief structure 2 can be a component such as an explosion-proof plate, an explosion-proof valve, a safety valve, etc., and the pressure relief structure 2 can be installed on the first wall 11 by bonding, welding, etc. The first wall 11 is provided with a through hole, and the pressure relief structure 2 is installed in the through hole. When the internal pressure of the battery cell 100 reaches a threshold value or the temperature reaches a threshold value, the pressure relief structure 2 opens at least part of the through hole, and the emission medium inside the battery cell 100 is discharged through the through hole to release the pressure inside the battery cell 100.

[0168] It can be seen that in the above technical solution, the pressure relief structure 2 and the first wall 11 are constructed as separate parts, which facilitates the arrangement of the pressure relief structure 2 on the shell 1 , has low production difficulty and high efficiency, and can improve the production efficiency of the battery cell 100 .

[0169] For example, if the pressure relief structure 2 is a bursting disc, the disc is a sheet with at least some areas having less strength than the first wall 11. The disc covers the through-hole and is welded to the first wall 11. When the internal pressure or temperature of the battery cell 100 reaches a threshold, the disc is at least partially destroyed, thereby opening at least some of the through-holes to release the pressure within the battery cell 100.

[0170] In a second aspect, an embodiment of the present application provides a battery 200 including the above-mentioned battery cell 100 .

[0171] In the above technical solution, since the battery 200 adopts the above-mentioned battery cell 100 and the battery cell 100 has good reliability in use, it is beneficial to improve the reliability of the battery 200.

[0172] In a third aspect, an embodiment of the present application provides an electrical device 1000 , comprising the above-mentioned battery 200 , wherein the battery 200 is used to provide electrical energy.

[0173] In the above technical solution, since the power-consuming device 1000 adopts the above-mentioned battery 200 and the battery 200 has good reliability, it is beneficial to improve the reliability of the power-consuming device 1000.

[0174] Please refer to FIG. 3 to FIG. 8 again to describe the battery cell 100 according to a specific embodiment of the present application.

[0175] In the embodiment of the present application, a battery cell 100 includes a housing 1, a pressure relief structure 2, and an electrode assembly 3. The housing 1 has a first wall 11, and the pressure relief structure 2 is disposed on the first wall 11. The electrode assembly 3 is disposed within the housing 1 and includes multiple electrode layers 30 stacked along a first direction. The multiple electrode layers 30 include a cathode electrode layer 31 and an anode electrode layer 32. Each electrode layer 30 includes an electrode body 301, a first active material layer 302, and a second active material layer 303. The first active material layer 302 and the second active material layer 303 are respectively disposed on both sides of the thickness of the electrode body 301.

[0176] As shown in Figures 6 and 7, all electrode layers 30 are configured as a first preset electrode layer 30a, wherein the distance x1 between the first active material layer 302 of the first preset electrode layer 30a and the first wall 11 is greater than the distance x2 between the second active material layer 303 of the first preset electrode layer 30a and the first wall 11, and the first direction is parallel to the plane of the first wall 11. As shown in Figure 8, all cathode electrode layers 31 are configured as the first preset electrode layer 30a, and all anode electrode layers 32 are configured as the second preset electrode layer 30b, wherein the distance x1 between the first active material layer 302 of the first preset electrode layer 30a and the first wall 11 is greater than the distance x2 between the second active material layer 303 of the first preset electrode layer 30b and the first wall 11, and the distance between the first active material layer 302 of the second preset electrode layer 30b and the first wall 11 is equal to the distance between the second active material layer 303 of the second preset electrode layer 30b and the first wall 11.

[0177] In the above technical solution, the amount of active material near the first wall 11 of the battery cell 100 is relatively small, and the pressure relief structure 2 is arranged on the first wall 11. When the battery cell 100 expands and deforms, the probability of damage such as cracking of the pressure relief structure 2 on the first wall 11 can be reduced. At the same time, to a certain extent, the probability of leakage due to cracking of the pressure relief structure 2 can also be reduced, thereby improving the reliability of the battery cell 100.

[0178] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0179] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, wherein, comprising: a housing having a first wall; a pressure relief structure provided on the first wall; an electrode assembly provided within the housing and including multiple layers of electrode sheet layers stacked along a first direction, the multiple layers of electrode sheet layers including a cathode electrode sheet layer and an anode electrode sheet layer, each layer of electrode sheet layer including an electrode sheet body, a first active material layer, and a second active material layer, the first active material layer and the second active material layer being respectively provided on two thickness sides of the electrode sheet body, at least one layer of the electrode sheet layer is configured as a first preset electrode sheet layer, a distance x1 between the first active material layer of the first preset electrode sheet layer and the first wall is greater than a distance x2 between the second active material layer thereof and the first wall, and the first direction is parallel to a plane where the first wall is located.

2. The battery cell according to claim 1, wherein, at least one layer of the cathode electrode sheet layer is configured as the first preset electrode sheet layer; or, at least one layer of the anode electrode sheet layer is configured as the first preset electrode sheet layer, and at least part of the cathode electrode sheet layer adjacent to the anode electrode sheet layer configured as the first preset electrode sheet layer is also configured as the first preset electrode sheet layer.

3. The battery cell according to claim 2, wherein, all of the cathode electrode sheet layers in the multiple layers of electrode sheet layers are configured as the first preset electrode sheet layer; or, all of the electrode sheet layers are configured as the first preset electrode sheet layer.

4. The battery cell according to claim 2 or 3, wherein, adjacent cathode electrode sheet layer and anode electrode sheet layer are respectively configured as the first preset electrode sheet layer, and in the adjacent cathode electrode sheet layer and anode electrode sheet layer, the first active material layer of the cathode electrode sheet layer and the first active material layer of the anode electrode sheet layer are disposed opposite to or back to back with each other.

5. The battery cell according to any one of claims 2-4, wherein, at least one layer of the anode electrode sheet layer and two adjacent cathode electrode sheet layers thereto are respectively configured as the first preset electrode sheet layer, the first active material layer of the at least one layer of the anode electrode sheet layer is disposed opposite to the first active material layer of one of the adjacent cathode electrode sheet layers, and the second active material layer of the at least one layer of the anode electrode sheet layer is disposed opposite to the second active material layer of the other adjacent cathode electrode sheet layer.

6. The battery cell according to any one of claims 1-5, wherein, x1 - x2 ≥ 2 mm.

7. The battery cell according to claim 6, wherein, x1 - x2 ≤ 12 mm.

8. The battery cell according to any one of claims 1-7, wherein, at least one layer of the cathode electrode sheet layer is configured as the first preset electrode sheet layer, and a distance x11 between the first active material layer of the at least one layer of the cathode electrode sheet layer and the first wall is ≥ 3 mm.

9. The battery cell according to claim 8, wherein, x11 ≤ 17 mm.

10. The battery cell according to any one of claims 1-7, wherein, At least one of the anode electrode sheet layers is configured as the first preset electrode sheet layer, and the distance x12 between the first active material layer of the at least one anode electrode sheet layer and the first wall is x12≥2 mm.

11. The battery cell according to claim 10, wherein, x12≤15 mm.

12. The battery cell according to any one of claims 1-11, wherein, The number of layers of the first preset electrode sheet layer accounts for at least 16% of the total number of layers of the electrode sheet layers.

13. The battery cell according to claim 12, wherein, The proportion of the number of layers of the first preset electrode sheet layer in the total number of layers of the electrode sheet layers does not exceed 50%.

14. The battery cell according to claim 13, wherein, The proportion of the number of layers of the first preset electrode sheet layer in the total number of layers of the electrode sheet layers does not exceed 24%.

15. The battery cell according to any one of claims 1-14, wherein, At least one of the electrode sheet layers is configured as a second preset electrode sheet layer, and the distance between the first active material layer of the second preset electrode sheet layer and the first wall is equal to the distance between the second active material layer and the first wall.

16. The battery cell according to claim 15, wherein, Multiple layers of the first preset electrode sheet layer and multiple layers of the second preset electrode sheet layer are stacked alternately one by one.

17. The battery cell according to claim 15 or 16, wherein, All the cathode electrode sheet layers are configured as the first preset electrode sheet layer, and all the anode electrode sheet layers are configured as the second preset electrode sheet layer.

18. The battery cell according to any one of claims 1-17, wherein, The electrode assembly is a stacked electrode assembly, and the stacking direction of the anode electrode sheet layer and the cathode electrode sheet layer in the electrode assembly is the first direction; or, The electrode assembly is a wound electrode assembly, and the axial direction of the electrode assembly is perpendicular to the first direction.

19. The battery cell according to any one of claims 1-18, wherein, The housing has two second walls oppositely arranged along the first direction, the first wall connects the two second walls, and the second wall is the wall with the largest area in the housing.

20. The battery cell according to any one of claims 1-19, wherein, The pressure relief structure and the pole column of the battery cell are disposed on different side walls of the housing.

21. The battery cell according to any one of claims 1-20, wherein, The housing includes a housing body and a housing cover, at least one end of the two ends of the housing body in the second direction is open, the housing cover is disposed at the open end of the housing body, and the first wall is formed on the housing body, and the second direction is perpendicular to the first direction.

22. The battery cell according to any one of claims 1-21, wherein, The pressure relief structure is integrally formed with the first wall; or, The pressure relief structure is separately provided from the first wall, and the pressure relief structure is installed on the first wall.

23. A battery, wherein, It includes the battery cell according to any one of claims 1-22.

24. An electrical device, wherein, It includes the battery according to claim 23, and the battery is used to provide electric energy.

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