Battery monomer, battery and electric equipment

Abstract

The embodiment of the utility model provides a battery monomer, a battery and electric equipment. The battery cell includes: a housing; and the at least one electrode assembly is accommodated in the shell, the at least one electrode assembly comprises a first electrode assembly, and the value range of the length of the first electrode assembly is [300mm, 800mm]. According to the battery monomer, the battery and the electric equipment provided by the embodiment of the invention, the space utilization rate of the battery can be improved.

Description

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] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. In this case, electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] With the rapid development of battery technology, how to improve the processing and production efficiency of batteries is a technical problem that needs to be solved urgently. Utility Model Content

[0004] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can improve the space utilization of the battery.

[0005] In a first aspect, a battery cell is provided, comprising: a housing; and at least one electrode assembly housed in the housing, wherein the at least one electrode assembly comprises a first electrode assembly, and a length of the first electrode assembly ranges from [300 mm to 800 mm].

[0006] Therefore, the battery cell of the embodiment of the present application achieves optimal space utilization of the battery cell including the first electrode assembly by setting the length of the first electrode assembly to a value range of [300mm, 800mm], that is, the space occupied by the mechanical structure inside the battery cell except the electrode assembly can be minimized.

[0007] Specifically, in order to ensure that the output power of the battery meets the demand, there are certain requirements for the number of battery cells inside the battery. For each battery cell, if the height of the battery cell is constant, the length of the electrode assembly is too small, which will lead to a thicker thickness of the electrode assembly, and the space occupied by the tab will be too large, resulting in low space utilization of the battery cell, which will also lead to low space utilization of the battery.

[0008] On the contrary, if the length of the electrode assembly is set too large, the thickness of the electrode assembly will be too thin. In order to ensure the overcurrent requirements, the connecting component electrically connected to the pole ear needs to be thickened, which will increase the space occupied by the connecting component. It will also reduce the space utilization of the battery cell, which will cause the space utilization of the battery to be too low.

[0009] In some embodiments, the first electrode assembly includes: a first pole piece and a second pole piece with opposite polarities, the first pole piece and the second pole piece are wound around a winding axis, and the length direction of the first electrode assembly is perpendicular to the winding axis. A wound electrode assembly is adopted, and the first pole piece and the second pole piece of the electrode assembly are continuous and do not need to be cut multiple times, which is convenient for processing and the wound electrode assembly is also conducive to wetting.

[0010] In some embodiments, the at least one electrode assembly satisfies at least one of the following conditions: the value range of H / T is [0.5, 20]; the value range of H / T is [1, 18]; the value range of L / T is [6, 80]; the value range of L / T is [8, 40]; the value range of H / L is [0.062, 0.4]; the value range of H / L is [0.08, 0.28]; the value range of V / T is [28000mm 2 , 96000mm 2 ]; the value range of V / T is [32000mm 2 , 72000mm 2 ]; the value range of V / H is [4000mm 2 , 56000mm 2 ]; the value range of V / H is [6000mm 2 , 28000mm 2 ]; the value range of V / L is [600mm 2 , 8400mm 2 ]; the value range of V / L is [1050mm 2 , 4400mm 2 ]; wherein, L is the length of the first electrode assembly; T is the total thickness of the at least one electrode assembly; H is the local height of the first electrode assembly, and the local height is the height of the portion of the positive electrode plate of the first electrode assembly coated with the positive electrode active material; V=L*T*H.

[0011] In this way, the space utilization rate of the battery cell including the electrode assembly is better, and the space utilization rate of the battery including the battery cell can also be optimized, that is, the space occupied by the mechanical structure inside the battery except the electrode assembly can be minimized.

[0012] In some embodiments, a local height H of the first electrode assembly and a height H1 of the housing satisfy: H / H1≥80%, wherein the local height is the height of a portion of the positive electrode sheet of the first electrode assembly coated with a positive active material.

[0013] Setting H / H1≥80%, that is, making the first electrode assembly occupy as much internal space of the battery cell as possible, other mechanical components in the battery cell except the electrode assembly occupy less space, thereby improving the space utilization and energy density of the battery cell.

[0014] In some embodiments, the thickness of the first electrode assembly ranges from [7mm, 40mm]. If the total thickness is set too small, on the one hand, it will increase the difficulty of processing. On the other hand, the battery cell is thin. In order to ensure the overcurrent requirement, the connecting member electrically connected to the tab needs to be thickened, which will increase the space occupied by the connecting member. It will also affect the proportion of the space occupied by the electrode assembly in the battery cell, resulting in low space utilization of the battery cell. On the contrary, if the total thickness is set too large, when the length of the battery cell is constant, this will cause the tab to occupy a larger space, which in turn leads to low space utilization of the battery cell.

[0015] In some embodiments, the at least one electrode assembly includes a plurality of electrode assemblies arranged along the thickness direction of the first electrode assembly, and the total thickness of the plurality of electrode assemblies is in the range of [25 mm, 80 mm]. This will not make the thickness of each electrode assembly too small to increase the difficulty of processing, but will also improve the space utilization and energy density of the battery cell.

[0016] In some embodiments, the first electrode assembly includes a corner area, and the length L1 of the corner area satisfies the length L of the first electrode assembly: 0.025≤L1 / L≤0.25, preferably satisfies: [0.05, 0.2]. The ratio of the length L1 of the corner area to the length L of the first electrode assembly should not be too small. When the length L of the first electrode assembly is constant, the length L1 of the corner area of ​​the first electrode assembly will be too small, which will increase the difficulty of processing the electrode assembly. In addition, too small L1 may cause excessive local extrusion pressure of the electrode assembly, which will affect the performance of the battery cell. On the contrary, if L1 / L is too large, then when the length L of the first electrode assembly is constant, the length L1 of the corner area of ​​the first electrode assembly will be too large, and the arc area of ​​the electrode assembly will be too large, which will cause the gap between the first electrode assembly and the shell to be too large, reducing the space utilization of the battery cell.

[0017] In some embodiments, the housing includes a first wall and a second wall intersecting each other, the first wall is provided with an electrode terminal, the first end surface of the first electrode assembly faces the second wall, the first end surface is provided with a pole ear, and the pole ear is electrically connected to the electrode terminal.

[0018] The electrode terminal and the electrode tab are arranged to correspond to two intersecting walls of the outer shell. On the one hand, the area of ​​the connecting component used to electrically connect the electrode terminal and the electrode tab can be increased, thereby ensuring the flow area. On the other hand, the space occupied by the connecting component can be reduced, thereby increasing the proportion of the electrode assembly occupying the internal space of the outer shell to improve the energy density of the battery cell.

[0019] In some embodiments, the first wall includes an electrode lead-out hole, the electrode terminal covers the electrode lead-out hole, and the distance H2 between the axis of the electrode lead-out hole and the second wall and the height H1 of the shell satisfy: 5%≤H2 / H1≤50%, preferably satisfying: 10%≤H2 / H1≤40%.

[0020] If H2 / H1 is set too small, the size of H will be too small, which will also cause the size of the electrode terminal to be too small, which will cause the connection between the connecting member and the electrode terminal to be unstable, and will also cause the connection between the current collector used to connect different battery cells and the electrode terminal to be unstable. On the contrary, if H2 / H1 is set too large, the size of the connecting member connected to the electrode terminal will be too large, which will increase the space occupied by the connecting member, thereby reducing the space utilization and energy density of the battery cell; and the over-large size of the connecting member may cause the over-current path to be too long, and the temperature of the battery cell may be too high during use, thereby affecting the safety performance of the battery cell.

[0021] In some embodiments, the housing includes: a housing having two openings arranged opposite to each other; and two cover plates, covering the two openings of the housing respectively. By arranging the housing to have two openings arranged opposite to each other, it is convenient to insert the internal electrode assembly into the housing. For example, the electrode assembly can be inserted into the housing through any opening, and the installation is more flexible. In particular, when the battery cell includes multiple electrode assemblies, different electrode assemblies can enter the hollow part of the housing through the same or different openings to speed up the installation.

[0022] In some embodiments, the wall thickness of the shell has a value range of [0.05mm, 2mm], preferably a value range of [0.15mm, 1.1mm]. If the wall thickness of the shell is set too small, the strength requirement of the shell cannot be guaranteed, resulting in insufficient strength of the battery cell, thereby affecting the safety of the battery cell. On the contrary, if the wall thickness of the shell is set too large, when the external dimensions of the battery cell are constant, the larger the wall thickness of the shell, the smaller its internal space, which will reduce the space utilization of the battery cell.

[0023] In some embodiments, the two cover plates include the smallest wall of the housing, so as to minimize the area required to connect the housing and the cover plates, facilitate the connection between the two, and improve the strength and processing efficiency of the battery cell.

[0024] In some embodiments, the shell includes the second wall, and the two cover plates include the first wall. In this way, when assembling the battery cell, it is convenient for the connecting components inside the shell to connect to the electrode terminals located on the cover plates, and it is also convenient for the connecting components to pass through the two openings of the shell to connect to the pole ears inside the shell to speed up assembly.

[0025] In some embodiments, the second wall is the wall with the smallest area of ​​the shell, that is, the first end face where the pole ear is located faces the wall with the smallest area of ​​the shell, so that the pole ear or the first end face where the pole ear is located occupies less space, avoiding space waste and improving the space utilization and energy density of the battery cell.

[0026] In some embodiments, the battery cell includes two electrode terminals, which are respectively located on the two cover plates, so that the connecting components inside the battery cell can be installed respectively through the two openings of the shell, thereby improving the processing and assembly efficiency of the battery cell; and, the electrode terminals are respectively arranged on the two cover plates, which can also reduce the probability of short circuit between the two pole ears electrically connected to the two electrode terminals.

[0027] In some embodiments, the first electrode assembly includes two pole tabs, wherein the two pole tabs are both located on the first end surface, or the first electrode assembly includes two opposite first end surfaces, and the two pole tabs are respectively located on the two first end surfaces.

[0028] Arranging the two tabs on the same first end surface can reduce the space occupied by the tabs in the height direction Z, and improve the space utilization of the main body of the electrode assembly inside the battery cell. Arranging the two tabs on two oppositely arranged first end surfaces can realize electrical connection between the tabs and the connecting member from both sides at the same time, which can improve the processing efficiency of the battery cell.

[0029] In some embodiments, the battery cell further includes: a connecting member, the connecting member including a first portion and a second portion connected to each other, the first portion being used to electrically connect to the electrode terminal, and the second portion being used to electrically connect to the tab. The two portions are electrically connected to the tab and the electrode terminal respectively, so that the structure of the connecting member is more flexible, and a suitable connecting member can be selected according to the positions of the tab and the electrode terminal.

[0030] In some embodiments, the first part and the second part are an integrally formed structure; or, the first part and the second part are separate structures and are connected by welding.

[0031] The first part and the second part are an integrally formed structure, which can ensure the strength of the connecting member and facilitate the assembly of the battery cell. Alternatively, the first part and the second part are separate structures and are connected by welding, making the structure of the connecting member more flexible. For example, the electrical connection between the first part and the electrode terminal and the electrical connection between the second part and the pole ear can be performed separately or simultaneously, making the processing and assembly process of the battery cell more flexible.

[0032] In a second aspect, a battery is provided, comprising the battery cell described in the first aspect.

[0033] In a third aspect, an electrical device is provided, comprising: the battery cell described in the first aspect, wherein the battery cell is used to provide electrical energy to the electrical device.

[0034] In some embodiments, the electrical equipment is a vehicle, a ship or a spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a structural schematic diagram of a vehicle disclosed in an embodiment of the present application;

[0036] Figure 2 is a schematic diagram of the exploded structure of a battery disclosed in one embodiment of the present application;

[0037] Figure 3 is a schematic structural diagram of a battery cell disclosed in one embodiment of the present application;

[0038] Figure 4 is a schematic diagram of the exploded structure of a battery cell disclosed in one embodiment of the present application;

[0039] Figure 5 is a cross-sectional schematic diagram of a first electrode assembly disclosed in an embodiment of the present application;

[0040] Figure 6 It is a structural schematic diagram of a main body of at least one electrode assembly disclosed in one embodiment of the present application;

[0041] Figure 7 is a front view of a main body of at least one electrode assembly disclosed in one embodiment of the present application;

[0042] Figure 8 is a partial schematic diagram of a second pole piece of a first electrode assembly disclosed in one embodiment of the present application;

[0043] Fig. 9 is a schematic diagram of a surface perpendicular to the height direction of a main body of at least one electrode assembly disclosed in an embodiment of the present application;

[0044] Fig.10is a cross-sectional schematic diagram of a battery cell disclosed in one embodiment of the present application;

[0045] Fig.11 is a partial cross-sectional schematic diagram of a battery cell disclosed in one embodiment of the present application;

[0046] Fig.12 It is a structural schematic diagram of a cover plate and a connecting component disclosed in one embodiment of the present application.

[0047] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0048] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0049] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0050] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0051] 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 thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0052] 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 thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0053] In the present application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries or magnesium-ion batteries, etc., and the embodiments of the present application do not limit this. Battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0054] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0055] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. The negative electrode collector not coated with the negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc. In order to ensure that a large current can be passed without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the isolation film may be polypropylene (PP) or polyethylene (PE), etc. In addition, the electrode assembly may be a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto.

[0056] The development of battery technology must consider many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters, among which energy density is particularly important. In order to ensure that the output power of the battery meets the demand, there are certain requirements for the number of battery cells inside the battery; and the size of each battery cell is mainly determined by the electrode assembly inside it. Therefore, how to reasonably set the size of the electrode assembly to make the size of the battery cell better, thereby making the distribution of the battery cells inside the battery more reasonable, and improving the space utilization of the battery is a problem that needs to be solved urgently.

[0057] The embodiments of the present application provide a battery cell, a battery and an electrical device that can solve the above problems. The battery cell of the embodiments of the present application includes a shell and at least one electrode assembly contained in the shell, wherein the first electrode assembly is any one of the at least one electrode assembly, and the length of the first electrode assembly is in the range of [300mm, 800mm], so that the space utilization of the battery cell including the electrode assembly is optimal, that is, the space occupied by the mechanical structure inside the battery cell except the electrode assembly can be minimized. Specifically, in order to ensure that the output power of the battery meets the demand, there are certain requirements for the number of battery cells inside the battery. For each battery cell, if the height of the battery cell is certain, the length of the electrode assembly is too small, which will cause the thickness of the electrode assembly to be too thick, then the space occupied by the tab will be too large, resulting in low space utilization of the battery cell, which will also cause the space utilization of the battery to be too low. On the contrary, if the length of the electrode assembly is too large, the thickness of the electrode assembly will be too thin. In order to ensure the overcurrent requirements, the connecting component electrically connected to the tab needs to be thickened, which will increase the space occupied by the connecting component. It will also lead to low space utilization of the battery cell, which will also lead to too low space utilization of the battery.

[0058] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using batteries.

[0059] Electrical equipment may be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, electric tools, and the like. Vehicles may be fuel vehicles, gas vehicles, or new energy vehicles, and new energy vehicles may be pure electric vehicles, hybrid vehicles, or extended-range vehicles, and the like; spacecraft include airplanes, rockets, space shuttles, and spacecraft, and the like; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.

[0060] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0061] For example, Figure 1 As shown, it is a structural schematic diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A motor 40, a controller 30 and a battery 10 may be arranged inside the vehicle 1. The controller 30 is used to control the battery 10 to supply power to the motor 40. For example, a battery 10 may be arranged at the bottom, front or rear of the vehicle 1. The battery 10 may be used to supply power to the vehicle 1. For example, the battery 10 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, for example, for the working power requirements during the start-up, navigation and operation of the vehicle 1. In another embodiment of the present application, the battery 10 may not only be used as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0062] In order to meet different power requirements, a battery may include multiple battery cells, wherein multiple battery cells may be connected in series, in parallel, or in hybrid connection, where hybrid connection refers to a mixture of series and parallel connection. A battery may also be referred to as a battery pack. For example, multiple battery cells may be connected in series, in parallel, or in hybrid connection to form a battery module, and multiple battery modules may be connected in series, in parallel, or in hybrid connection to form a battery. In other words, multiple battery cells may be directly connected to form a battery, or they may be connected to form a battery module first, and then the battery module may be connected to form a battery.

[0063] For example, Figure 2 The schematic diagram of the structure of a battery 10 according to an embodiment of the present application is shown. The battery 10 may include a plurality of battery cells 20. The battery 10 may also include a box body 11. The box body 11 is a hollow structure, and the plurality of battery cells 20 are accommodated in the box body 11. Figure 2 A possible implementation of the box 11 of the embodiment of the present application is shown, such as Figure 2 As shown, the box body 11 may include two parts, which are respectively referred to as a first box body part 111 and a second box body part 112, and the first box body part 111 and the second box body part 112 are buckled together. The shapes of the first box body part 111 and the second box body part 112 may be determined according to the shapes of the battery cells 20 after being combined, and at least one of the first box body part 111 and the second box body part 112 has an opening. For example, Figure 2 As shown, the first box body part 111 and the second box body part 112 can both be hollow rectangular parallelepipeds and each has only one open face, the opening of the first box body part 111 and the opening of the second box body part 112 are arranged opposite to each other, and the first box body part 111 and the second box body part 112 are interlocked to form a box body 11 with a closed chamber.

[0064] For example, unlike Figure 2 As shown, only one of the first box body 111 and the second box body 112 may be a hollow cuboid with an opening, and the other may be a plate-shaped to cover the opening. For example, here, the second box body 112 is a hollow cuboid with only one face as an opening face, and the first box body 111 is a plate-shaped example, then the first box body 111 covers the opening of the second box body 112 to form a box body 11 with a closed chamber, which can be used to accommodate multiple battery cells 20. Multiple battery cells 20 are connected in parallel, in series, or in a mixed combination and placed in the box body 11 formed by the first box body 111 and the second box body 112 being buckled.

[0065] In some embodiments, the battery 10 may also include other structures, which are not described one by one here. For example, the battery 10 may also include a busbar, which is used to realize the electrical connection between multiple battery cells 20, such as parallel connection, series connection or mixed connection. Specifically, the busbar can realize the electrical connection between the battery cells 20 by connecting the electrode terminals of the battery cells 20. Further, the busbar can be fixed to the electrode terminals of the battery cells 20 by welding. The electrical energy of multiple battery cells 20 can be further led out through the box 11 through the conductive mechanism.

[0066] The number of battery cells 20 in the battery 10 can be set to any value according to different power requirements. Multiple battery cells 20 can be connected in series, parallel or mixed to achieve a larger capacity or power. Since the number of battery cells 20 included in each battery 10 may be large, for ease of installation, the battery cells 20 can be grouped, and each group of battery cells 20 constitutes a battery module. The number of battery cells 20 included in the battery module is not limited and can be set according to demand.

[0067] Figure 3 A schematic diagram of a battery cell 20 according to an embodiment of the present application is shown. Figure 4 A possible at least partially exploded structural diagram of a battery cell 20 according to an embodiment of the present application is shown. Figure 4 The battery cell 20 shown may be Figure 3 The schematic diagram of the exploded structure of the battery cell 20 is shown in FIG. Figure 3 and Figure 4 As shown, the battery cell 20 of the embodiment of the present application includes: a shell 21; at least one electrode assembly 22, which is accommodated in the shell 21, and the at least one electrode assembly 22 includes a first electrode assembly 220, and the length of the first electrode assembly 220 ranges from [300mm, 800mm].

[0068] It should be understood that the battery cell 20 of the embodiment of the present application has a shell 21, and the shell 21 has a receiving cavity inside, so that the battery cell 20 is a hollow polyhedron structure. The shell 21 can be a polyhedron structure of any shape, for example, the shell 21 can be as follows: Figure 3 and Figure 4 The outer shell 21 is a rectangular parallelepiped, or a cylindrical shell, or other shapes, and the present application is not limited thereto. For ease of description, the present application takes the outer shell 21 of a rectangular parallelepiped as an example, that is, the battery cell 20 is a rectangular parallelepiped.

[0069] The housing cavity of the housing 21 of the embodiment of the present application can be used to accommodate at least one electrode assembly 22, for example, Figure 4 The first electrode assembly 220 is any one of the at least one electrode assembly 22. For example, if the battery cell 20 is as shown in FIG. Figure 4 As shown, only one electrode assembly 22 is included, and the first electrode assembly 220 is the only electrode assembly 22 ; for another example, if the battery cell 20 includes multiple electrode assemblies 22 , the first electrode assembly 220 is any electrode assembly 22 at any position among the multiple electrode assemblies 22 .

[0070] When the battery cell 20 includes multiple electrode assemblies 22, the dimensions of the multiple electrode assemblies 22 in various directions may be the same or different. For example, for ease of description, the embodiment of the present application takes the multiple electrode assemblies 22 included in the battery cell 20 as an example of having the same dimensions, so as to facilitate the processing and installation of the battery cell 20.

[0071] For the sake of convenience, the present embodiment defines three directions of the battery cell 20 to illustrate the relevant dimensions in the three directions. Figure 3 and Figure 4 As shown, the battery cell 20 includes a length direction X, a thickness direction Y and a height direction Z, and the length direction X, the thickness direction Y and the height direction Z are perpendicular to each other. Therefore, the length of the first electrode assembly 220 of the embodiment of the present application can represent the length of the first electrode assembly 220 along the length direction X, wherein, Figure 3 to Figure 4 The length of the first electrode assembly 220 is not marked in FIG. The length of the first electrode assembly 220 can be found in FIG. Figure 7 or Fig. 9 For example, in the embodiment of the present application, the height direction Z is taken as an example as a direction perpendicular to the first end surface 224 where the electrode ear 222 of the electrode assembly 22 is located, and the thickness direction Y and the length direction X are perpendicular to the height direction Z, and perpendicular to or parallel to the corresponding sides of the electrode assembly 22.

[0072] Therefore, the battery cell 20 of the embodiment of the present application achieves optimal space utilization of the battery cell 20 including the first electrode assembly 220 by setting the length of the first electrode assembly 220 to a value range of [300mm, 800mm], that is, the space occupied by the mechanical structure inside the battery cell 20 except the electrode assembly 22 can be minimized.

[0073] Specifically, in order to ensure that the output power of the battery 10 meets the demand, there are certain requirements for the number of battery cells 20 inside the battery 10. For each battery cell 20, if the height of the battery cell 20 is certain, the length of the electrode assembly 22 is too small, which will cause the thickness of the electrode assembly 22 to be too thick. Then, the space occupied by the tab 222 will be too large, which will lead to low space utilization of the battery cell 20, and also lead to too low space utilization of the battery 10. Therefore, the length of the first electrode assembly 220 of the embodiment of the present application should not be too small. For example, the length of the first electrode assembly 220 is usually set to be greater than or equal to 300 mm, or, set to be greater than or equal to 400 mm, or, set to be greater than or equal to 500 mm.

[0074] On the contrary, if the length of the electrode assembly 22 is set too large, the thickness of the electrode assembly 22 will be too thin. In order to ensure the overcurrent requirement, the connecting member 23 electrically connected to the tab 222 needs to be thickened, which will increase the space occupied by the connecting member 23, and also lead to low space utilization of the battery cell 20, which will also lead to too low space utilization of the battery 10. Therefore, the length of the first electrode assembly 220 of the embodiment of the present application should not be too large. For example, the length of the first electrode assembly 220 is usually set to be less than or equal to 800 mm, or less than or equal to 750 mm, or less than or equal to 700 mm.

[0075] Therefore, the length of the first electrode assembly 220 may be set to a value range of [300 mm, 800 mm], or [400 mm, 750 mm], or [500 mm, 700 mm] to improve the space utilization of the battery 10. For example, the length of the first electrode assembly 220 may be equal to 300 mm, 350 mm, 400 mm, 450 mm, 500 mm, 550 mm, 600 mm, 650 mm, 700 mm, 750 mm, or 800 mm.

[0076] The electrode assembly 22 of the embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0077] like Figure 3 and Figure 4As shown, the electrode assembly 22 of the embodiment of the present application may include a main body 221 and a tab 222. For example, taking the first electrode assembly 220 as an example, the tab 222 of the first electrode assembly 220 may include a positive tab 222a and a negative tab 222b, the positive tab 222a may be formed by stacking a portion of the positive electrode sheet that is not coated with the positive electrode active material layer, and the negative tab 222b may be formed by stacking a portion of the negative electrode sheet that is not coated with the negative electrode active material layer. The main body 221 of the first electrode assembly 220 may be formed by stacking or winding a portion of the positive electrode sheet coated with the positive electrode active material layer and a portion of the negative electrode sheet coated with the negative electrode active material layer.

[0078] For the sake of convenience, the present application embodiment mainly takes the wound electrode assembly 22 as an example. For example, Figure 5 The schematic cross-sectional view of the first electrode assembly 220 of the embodiment of the present application is shown. The cross-sectional view may be a cross-sectional view perpendicular to the height direction Z. The cross-sectional view is used to show the structure of the first electrode assembly. Figure 4 The figure is drawn to scale. Figure 5 As shown, the first electrode assembly 220 of the embodiment of the present application includes: a first electrode piece 2211 and a second electrode piece 2212 with opposite polarities, the first electrode piece 2211 and the second electrode piece 2212 are wound around a winding axis, and the length direction X of the first electrode assembly 220 is perpendicular to the winding axis. The winding axis of the first electrode assembly 220 can be parallel to the height direction Z. The polarities of the first electrode piece 2211 and the second electrode piece 2212 are opposite, for example, Figure 5 As shown, the first electrode 2211 may be a negative electrode, and the second electrode 2212 may be a positive electrode to avoid lithium deposition. Figure 5 As shown, the first electrode assembly 220 is wound in other ways, but the embodiments of the present application are not limited thereto. With a wound electrode assembly 22, each first pole piece 2211 and second pole piece 2212 of the electrode assembly 22 is continuous and does not need to be cut multiple times, which is convenient for processing and can also improve the energy density of the battery cell where the electrode assembly 22 is located. In addition, the wound electrode assembly 22 is also conducive to wetting.

[0079] like Figure 5As shown, the first electrode assembly 220 also includes a first isolation film 2213 and a second isolation film 2214 disposed between the first pole piece 2211 and the second pole piece 2212. The first isolation film 2213 and the second isolation film 2214 are used to insulate and isolate the first pole piece 2211 from the second pole piece 2212. In some embodiments, the first pole piece 2211, the second pole piece 2212, the first isolation film 2213 and the second isolation film 2214 are all strip structures. The first pole piece 2211, the second pole piece 2212, the first isolation film 2213 and the second isolation film 2214 are stacked and wound at least two times along the winding axis to form the first electrode assembly 220. The material of the first isolation film 2213 and the second isolation film 2214 can be set according to the actual application, for example, it can be polypropylene or polyethylene, and the embodiments of the present application are not limited thereto.

[0080] like Figure 5 As shown, the first electrode assembly 220 may further include other components. For example, the first electrode assembly 220 may further include a finishing glue 2215 to fix the winding end of the first electrode assembly 220 and protect the first electrode assembly 220 .

[0081] It should be understood that the shape of the first electrode assembly 220 in the embodiment of the present application can also be flexibly set according to the actual application. For example, the embodiment of the present application takes the main body 221 of the first electrode assembly 220 as a column as an example for explanation, and as Figure 5 As shown, the cross-section of the first electrode assembly 220 is approximately oval, but the present invention is not limited thereto. In addition, if the battery cell 20 includes a plurality of electrode assemblies 22, the shapes of the plurality of electrode assemblies 22 can also be set to be the same for ease of processing and installation.

[0082] For a wound electrode assembly 22, the tabs 222 of the electrode assembly 22 may be located at a first end surface 224 perpendicular to the height direction Z of the electrode assembly 22, that is, the first end surface 224 perpendicular to the winding axis of the electrode assembly 22. In addition, the two tabs 222 of each electrode assembly 22 may be as follows: Figure 4 As shown, they are located on the same end surface, that is, each electrode assembly 22 may have a first end 224; alternatively, the two pole ears 222 of each electrode assembly 22 may also be located on different end surfaces, for example, the two pole ears 222 are respectively located on two oppositely arranged first end surfaces 224 of the electrode assembly 22, but the embodiments of the present application are not limited thereto.

[0083] Figure 6 A possible structural schematic diagram of a main body 221 of at least one electrode assembly 22 of an embodiment of the present application is shown; Figure 7 A front view of a main body 221 of at least one electrode assembly 22 according to an embodiment of the present application is shown; Figure 8A partial schematic diagram of the second electrode piece 2212 of the first electrode assembly 220 of the embodiment of the present application is shown, for example, Figure 8 It may be a schematic diagram of the development of a surface of at least part of the second pole piece 2212 that is perpendicular to the thickness direction Y; Fig. 9 FIG. 2 is a schematic diagram showing a surface of a main body 221 of at least one electrode assembly 22 of an embodiment of the present application that is perpendicular to the height direction Z. It should be understood that the battery cell 20 in the embodiment of the present application may include: Figure 4 Alternatively, it may include a plurality of electrode assemblies 22, Figures 6 to 9 The battery cell 20 includes two electrode assemblies 22 for illustration.

[0084] like Figures 6 to 9 As shown, at least one electrode assembly 22 of the embodiment of the present application satisfies at least one of the following conditions: the value range of H / T is [0.5, 20]; the value range of H / T is [1, 18]; the value range of L / T is [6, 80]; the value range of L / T is [8, 40]; the value range of H / L is [0.062, 0.4]; the value range of H / L is [0.08, 0.28]; the value range of V / T is [28000mm 2 , 96000mm 2 ]; the value range of V / T is [32000mm 2 , 72000mm 2 ]; the value range of V / H is [4000mm 2 , 56000mm 2 ]; the value range of V / H is [6000mm 2 , 28000mm 2 ]; the value range of V / L is [600mm 2 , 8400mm 2 ]; the value range of V / L is [1050mm 2 , 4400mm 2 ]; where L is the length of the first electrode assembly 220; T is the total thickness of at least one electrode assembly 22; H is the local height of the first electrode assembly 220, and the local height is the height of the portion of the positive electrode sheet of the first electrode assembly 220 coated with the positive electrode active material; V = L*T*H. In this way, the space utilization rate of the battery 10 including the battery cell 20 where the first electrode assembly 220 is located is optimal, that is, the space occupied by the mechanical structure inside the battery 10 except the electrode assembly 22 can be minimized.

[0085] In the embodiment of the present application, the parameter "L" represents the length of the first electrode assembly 220. Specifically, Figures 6 to 9As shown, in the length direction X, the total length of the first electrode assembly 220 is L.

[0086] In the embodiment of the present application, the parameter "T" is the total thickness of at least one electrode assembly 22. Specifically, Figures 6 to 9 As shown, in the thickness direction Y, the sum of the thicknesses of all electrode assemblies 22 in at least one electrode assembly 22 is T.

[0087] In the embodiment of the present application, the parameter "H" is the local height of the first electrode assembly 220, and the local height is the height of the portion of the positive electrode sheet of the first electrode assembly 220 coated with the positive electrode active material. Specifically, Figures 6 to 9 As shown, in the height direction Z, in order to avoid lithium deposition, the height of the positive electrode sheet included in the main body 221 of the first electrode assembly 220 is usually less than or equal to the height of the negative electrode sheet. Therefore, the parameter H in the embodiment of the present application represents the local height of the first electrode assembly 220. For example, Fig. 9 Taking the second electrode sheet 2212 as a positive electrode sheet as an example, the parameter H represents the height of the second electrode sheet 2212, and the parameter H does not include the height of the tab 222, nor the height of the separator extending beyond the positive electrode sheet, that is, the height of the portion of the positive electrode sheet of the first electrode assembly 220 coated with the positive active material. Figure 7 , the height represented by parameter H is slightly smaller than the height of the main body 221 .

[0088] In the embodiment of the present application, the parameter "V" represents the product of L, H, and T.

[0089] It should be understood that at least one electrode assembly 22 of the embodiment of the present application can satisfy: the value range of H / T is [0.5, 20]. Specifically, if H / T is less than 0.5, that is, the thickness of the battery cell 20 is too large and the height is too short, then when the length of the battery cell 20 is constant, the area of ​​the first end surface 224 where the tab 222 is located is large, which will cause the tab 222 to occupy a large space, thereby resulting in low space utilization of the battery cell 20.

[0090] On the contrary, if H / T is greater than 20, that is, the thickness of the battery cell 20 is thinner and the height is higher, in order to ensure the overcurrent requirement, the connecting member 23 electrically connected to the tab 222 needs to be thickened, which will increase the space occupied by the connecting member 23, and will also affect the proportion of the space occupied by the electrode assembly 22 in the battery cell 20, resulting in low space utilization of the battery cell 20. Therefore, H / T should not be set too small or too large, for example, H / T can be set to 0.5, 1, 1.5, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, etc.

[0091] Therefore, the value range of H / T in the embodiment of the present application can be set to [0.5, 20], or can also be set to [1, 18], or can also be set to [2, 12].

[0092] It should be understood that at least one electrode assembly 22 of the embodiment of the present application can satisfy: the value range of L / T is [6, 80]. Specifically, if L / T is less than 6, the length of the battery cell 20 will be too small and the thickness will be too large. The mechanical parts in the battery cell 20 other than the electrode assembly 22 will occupy a large space, which will lead to low space utilization of the battery cell 20. On the contrary, if L / T is greater than 80, the length of the battery cell 20 will be too large and the thickness will be too small. In order to ensure the overcurrent requirement, the connecting member 23 electrically connected to the tab 222 needs to be thickened, which will increase the space occupied by the connecting member 23. It will also affect the proportion of the space occupied by the electrode assembly 22 in the battery cell 20, resulting in low space utilization of the battery cell 20. Therefore, L / T can be set to 6, 8, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, etc. For example, the value range of L / T can be set to [6, 80], [8, 40] or [10, 25].

[0093] It should be understood that at least one electrode assembly 22 of the embodiment of the present application can satisfy: the value range of H / L is [0.062, 0.4]. Specifically, if H / L is too small, the height of the electrode assembly 22 will be too small, which will increase the difficulty of processing the electrode assembly 22. For example, for a wound electrode assembly 22, it will increase the difficulty in the winding process. On the contrary, if H / L is too large, the length of the electrode assembly 22 is small and the height is too large, which will affect the wetting efficiency of the electrode assembly 22 in the housing 21. Therefore, H / L can be set to 0.062, 0.07, 0.08, 0.09, 0.1, 0.13, 0.15, 0.18, 0.2, 0.23, 0.25, 0.28, 0.3, 0.33, 0.35, 0.38 or 0.4 to improve the wetting efficiency of the electrode assembly 22. For example, the value range of H / L can be set to [0.062, 0.4] or [0.08, 0.28].

[0094] It should be understood that at least one electrode assembly 22 of the embodiment of the present application can satisfy: the value range of V / T is [28000mm 2 , 96000mm 2]. Specifically, if V / T is too small, then when the volume of the battery cell 20 is constant, the thickness will be too thick, and the mechanical parts in the battery cell 20 other than the electrode assembly 22 will occupy a large space, resulting in low space utilization of the battery cell 20. On the contrary, if V / T is too large, then when the volume of the battery cell 20 is constant, the thickness will be too small. In order to ensure the overcurrent requirements, the connecting member 23 electrically connected to the pole ear 222 needs to be thickened, which will increase the space occupied by the connecting member 23, and will also affect the proportion of the space occupied by the electrode assembly 22 in the battery cell 20, resulting in low space utilization of the battery cell 20. Therefore, V / T should not be set too large or too small. For example, V / T can be set to 28000mm 2 、32000mm 2 、36000mm 2 、40000mm 2 、44000mm 2 、48000mm 2 、52000mm 2 、55000mm 2 、60000mm 2 、64000mm 2 、68000mm 2 、72000mm 2 、76000mm 2 、80000mm 2 、84000mm 2 、88000mm 2 、92000mm 2 or 96000mm 2 For example, the value range of V / T can be set to [28000mm 2 , 96000mm 2 ]、[32000mm 2 , 72000mm 2 ] or [36000mm 2 , 55000mm 2 ].

[0095] It should be understood that at least one electrode assembly 22 of the embodiment of the present application can satisfy: the value range of V / H is [4000mm 2 , 56000mm 2Specifically, if V / H is too small or too large, then when the volume of the battery cell 20 is constant, the height of the battery cell 20 will be too high or too low, and the mechanical parts in the battery cell 20 except the electrode assembly 22 will occupy a large space, resulting in low space utilization of the battery cell 20. Therefore, V / H should not be too small or too large. V / H can be set to 4000mm. 2 、6000mm 2 , 8000mm 2 , 10000mm 2 、12000mm 2 、14000mm 2 、16000mm 2 、18000mm 2 , 20000mm 2 、22000mm 2 、24000mm 2 、26000mm 2 、28000mm 2 、30000mm 2 、32000mm 2 、34000mm 2 、36000mm 2 、38000mm 2 、40000mm 2 、42000mm 2 、44000mm 2 、46000mm 2 、48000mm 2 , 50000mm 2 、52000mm 2 、54000mm 2 or 56000mm 2 For example, the range of V / H can be set to [4000mm 2 , 56000mm 2 ]、[6000mm 2 , 28000mm 2 ] or [10000mm 2 , 18000mm 2 ].

[0096] It should be understood that at least one electrode assembly 22 of the embodiment of the present application can satisfy: the value range of V / L is [600mm 2 , 8400mm 2]. Specifically, if V / L is too small, then when the volume of the battery cell 20 is constant, the length is too long, and the product of the height and thickness is too small. When the length of the battery cell 20 is constant, the area of ​​the first end surface 224 where the pole ear 222 is located is large, which will cause the pole ear 222 to occupy a large space, and thus cause the space utilization rate of the battery cell 20 to be low. On the contrary, if V / L is too large, then when the volume of the battery cell 20 is constant, the length of the battery cell 20 is short, and the mechanical parts in the battery cell 20 other than the electrode assembly 22 will occupy a large space, which will cause the space utilization rate of the battery cell 20 to be low. Therefore, V / L should not be too small or too large. V / L can be set to 600mm 2 , 800mm 2 、1050mm 2 , 1200mm 2 、1400mm 2 、1600mm 2 、1800mm 2 , 2000mm 2 、2200mm 2 、2400mm 2 、2600mm 2 、2800mm 2 、3000mm 2 、3200mm 2 、3400mm 2 、3600mm 2 、3800mm 2 , 4000mm 2 、4200mm 2 、4400mm 2 、4600mm 2 、4800mm 2 , 5000mm 2 、5300mm 2 、5600mm 2 、5900mm 2 、6200mm 2 、6500mm 2 、6800mm 2 、7100mm 2 、7400mm 2 、7700mm 2 , 8000mm 2 、8200mm 2 or 8400mm 2 For example, the range of V / L can be set to [600mm 2 , 8400mm 2 ]、[1050mm2 , 4400mm 2 ] or [1600mm 2 , 3000mm 2 ].

[0097] In the embodiment of the present application, the total thickness T of at least one electrode assembly 22 has a value range of [10mm, 80mm]. Specifically, if T is set too small, the battery cell 20 is too thin. In order to ensure the overcurrent requirement, the connecting member 23 electrically connected to the pole ear 222 needs to be thickened, which will increase the space occupied by the connecting member 23, and will also affect the proportion of the space occupied by the electrode assembly 22 in the battery cell 20, resulting in low space utilization of the battery cell 20. On the contrary, if T is set too large, the area of ​​the first end face 224 where the pole ear 222 is located will be larger when the length of the battery cell 20 is constant, which will cause the pole ear 222 to occupy a larger space, thereby resulting in low space utilization of the battery cell 20. Therefore, T should not be set too small or too large. For example, T can be set to be equal to 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm or 80mm. For example, the value range of T can be set to [10mm, 80mm], [15mm, 40mm] or [20mm, 30mm].

[0098] In the embodiment of the present application, the battery cell 20 may include one or more electrode assemblies 22. If the battery cell 20 includes only one electrode assembly 22, the thickness of the electrode assembly 22 will affect the thickness of the entire battery cell 20. For example, the thickness of the first electrode assembly 220 ranges from [7mm, 40mm]. If the thickness of the first electrode assembly 220 is set too small, on the one hand, it will increase the difficulty of processing, and on the other hand, it will also cause the thickness of the battery cell 20 to be thin. In order to ensure the overcurrent requirement, the connecting member 23 electrically connected to the pole ear 222 needs to be thickened, which will also increase the space occupied by the connecting member 23, and will also affect the proportion of the space occupied by the electrode assembly 22 in the battery cell 20, resulting in low space utilization of the battery cell 20. On the contrary, if the thickness of the first electrode assembly 220 is set too large, when the length of the battery cell 20 is constant, this will cause the pole ear 222 to occupy a larger space, thereby resulting in low space utilization of the battery cell 20. Therefore, the thickness range of the first electrode assembly 220 can be set to [7mm, 40mm], and the thickness of the first electrode assembly 220 can be equal to 7mm, 10mm, 12mm, 15mm, 17mm, 20mm, 22mm, 25mm, 27mm, 30mm, 32mm, 35mm, 37mm or 40mm.

[0099] For example, Figures 6 to 9 As shown, at least one electrode assembly 22 includes a plurality of electrode assemblies 22 arranged along the thickness direction Y of the first electrode assembly 220, and the total thickness of the plurality of electrode assemblies 22 is in the range of [25 mm, 80 mm]. This will not make the thickness of each electrode assembly 22 too small to increase the difficulty of processing, but will also improve the space utilization and energy density of the battery cell 20.

[0100] In the embodiments of the present application, Figures 6 to 9 As shown, the first electrode assembly 220 includes a corner area 223, and the length L1 of the corner area 223 and the length L of the first electrode assembly 220 satisfy: 0.025≤L1 / L≤0.25. Specifically, the corner area 223 is the area where the side arc surface of the first electrode assembly 220 is located. The first electrode assembly 220 may include two corner areas 223 arranged opposite to each other, and the sizes of the two corner areas 223 may be set to be the same, so as to facilitate processing and ensure the space utilization of the battery cell 20.

[0101] For any corner area 223, the ratio of the length L1 of the corner area 223 to the length L of the first electrode assembly 220 should not be too small. When the length L of the first electrode assembly 220 is constant, the length L1 of the corner area 223 of the first electrode assembly 220 will be too small, which will increase the difficulty of processing the electrode assembly 22. Moreover, too small L1 may cause excessive local extrusion pressure of the electrode assembly 22, which will affect the performance of the battery cell 20. On the contrary, if L1 / L is too large, then when the length L of the first electrode assembly 220 is constant, the length L1 of the corner area 223 of the first electrode assembly 220 will be too large, and the arc area will be too large, which will cause the gap between the first electrode assembly 220 and the shell 21 to be too large, reducing the space utilization rate of the battery cell 20. Therefore, L1 / L should not be set too small or too large. For example, L1 / L can be set to 0.025, 0.05, 0.06, 0.07, 0.08, 0.1, 0.13, 0.15, 0.18, 0.2, 0.23 or 0.25. For example, the value range of L1 / L can be set to [0.025, 0.25], or [0.05, 0.2].

[0102] It should be understood that the value of the length L1 of the corner area 223 of the embodiment of the present application can be set according to the actual application. For example, the value range of the length L1 of the corner area 223 can be set to [5mm, 40mm] or [10mm, 30mm] to avoid the length L1 of the corner area 223 being set too large or too small to affect the performance or space utilization of the battery cell 20. For example, the length L1 of the corner area 223 can be specifically set to be equal to 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm or 40mm.

[0103] Fig.10 A schematic cross-sectional view of a battery cell 20 according to an embodiment of the present application is shown, where the cross-sectional view is perpendicular to the thickness direction Y; Fig.11 A partial cross-sectional schematic diagram of a battery cell 20 according to an embodiment of the present application is shown. Fig.11 for Fig.10 The enlarged view of area A is shown. Fig.10 and Fig.11 As shown, the local height H of the first electrode assembly 220 and the height H1 of the housing 21 satisfy: H / H1≥80%, wherein the local height H is the height of the portion of the positive electrode sheet of the first electrode assembly 220 coated with the positive electrode active material. Setting H / H1≥80%, for example, setting H / H1 equal to 83%, 85%, 90% or a greater value, that is, making the first electrode assembly 220 occupy the internal space of the battery cell 20 as much as possible, then other mechanical components in the battery cell 20 except the electrode assembly 22 occupy less space, thereby improving the space utilization and energy density of the battery cell 20.

[0104] like Fig.10 and Fig.11 As shown, the housing 21 includes a first wall 213 and a second wall 214 intersecting each other, the first wall 213 is provided with an electrode terminal 24, the first end surface 224 of the first electrode assembly 220 faces the second wall 214, and the first end surface 224 is provided with a pole ear 222, and the pole ear 222 is electrically connected to the electrode terminal 24. The electrode terminal 24 and the pole ear 222 are arranged to correspond to the two intersecting walls of the housing 21, on the one hand, the area of ​​the connecting member 23 for electrically connecting the electrode terminal 24 and the pole ear can be increased, thereby ensuring the flow area, and on the other hand, the space occupied by the connecting member 23 can be reduced, thereby increasing the proportion of the internal space of the housing 21 occupied by the electrode assembly 22, so as to improve the energy density of the battery cell 20.

[0105] like Fig.10 and Fig.11As shown, the first wall 213 includes an electrode lead-out hole 2131, and the electrode terminal 24 covers the electrode lead-out hole 2131. The distance H2 between the axis of the electrode lead-out hole 2131 and the second wall 214 and the height H1 of the housing 21 satisfy: 5%≤H2 / H1≤50%. If H2 / H1 is set too small, the size of H2 will be too small, which will also cause the size of the electrode terminal 24 to be too small, which will cause the connection between the connecting member 23 and the electrode terminal 24 to be unstable, and will also cause the connection between the busbar component used to connect different battery cells 20 and the electrode terminal 24 to be unstable. On the contrary, if H2 / H1 is set too large, the size of the connecting member 23 connected to the electrode terminal 24 will be too large, which will increase the space occupied by the connecting member 23 to reduce the space utilization and energy density of the battery cell 20; and the over-large size of the connecting member 23 may cause the over-current path to be too long, and the temperature of the battery cell 20 may be too high during use, thereby affecting the safety performance of the battery cell 20. Therefore, H2 / H1 should not be set too small or too large. For example, H2 / H1 can be set to be equal to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%. For example, the value range of H2 / H1 can be set to [5%, 50%], or [10%, 40%].

[0106] In the embodiments of the present application, Figure 10 to Figure 11 As shown, according to the size restrictions on the battery cell 20 mentioned above, the value of the local height H of at least one electrode assembly 22 of the embodiment of the present application can be set according to the actual application. For example, the value range of the local height H of the electrode assembly 22 can be [50mm, 120mm] or [60mm, 110mm], which can avoid the increase in the processing difficulty of the electrode assembly 22 due to the H value being too small, and can also avoid the H value being too large to affect the space utilization of the battery cell 20 and affect other size settings of the battery cell 20. Specifically, the local height H of the electrode assembly 22 can be set to be equal to 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, 105mm, 110mm, 115mm or 120mm.

[0107] In the embodiments of the present application, Figure 10 to Figure 11As shown, according to the size restrictions on the battery cell 20 mentioned above, the value of the height H1 of the shell of the battery cell 20 in the embodiment of the present application can be set according to the actual application. For example, the value range of the height H1 of the shell 21 of the electrode assembly 22 can be [60mm, 130mm] or [70mm, 120mm], so as to avoid the increase of processing difficulty due to the value of H1 being too small, and to avoid the low space utilization of the battery cell 20 caused by the value of H1 being too large. Specifically, the height H1 of the shell of the battery cell 20 can be set to be equal to 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, 105mm, 110mm, 115mm, 120mm, 125mm, or 130mm.

[0108] In the embodiments of the present application, Figure 10 to Figure 11 As shown, according to the size restriction of the battery cell 20 mentioned above, the value of the distance H2 between the axis of the electrode lead-out hole 2131 and the second wall 214 in the embodiment of the present application can be set according to the actual application. For example, the value range of the distance H2 between the axis of the electrode lead-out hole 2131 and the second wall 214 can be set to [5mm, 65mm] or [10mm, 60mm], which can avoid the unstable connection between the connecting member 23 and the electrode terminal 24 caused by the H2 value being too small, and can also avoid the connection member 23 being too large and the current path being too long caused by the H2 value being too large, thereby avoiding affecting the safety performance of the battery cell 20. Specifically, the distance H2 between the axis of the electrode lead-out hole 2131 and the second wall 214 can be set to be equal to 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm or 65mm.

[0109] It should be understood that the electrode terminal 24 of the embodiment of the present application is used to be electrically connected to the electrode assembly 22 to output the electrical energy of the battery cell 20. In some embodiments, the electrode terminal 24 can be set according to the setting position of the pole ear 222 of the electrode assembly 22. For example, corresponding to the at least two pole ears included in the electrode assembly 22, the battery cell 20 may include at least two electrode terminals, and the two electrode terminals 24 include a positive electrode terminal and a negative electrode terminal, wherein the positive electrode terminal is used to be electrically connected to the positive pole ear 222a, and the negative electrode terminal is used to be electrically connected to the negative pole ear 222b. The positive electrode terminal can be directly connected to the positive pole ear 222a or indirectly connected, and the negative electrode terminal can be directly connected to the negative pole ear 222b or indirectly connected. For example, the positive electrode terminal is electrically connected to the positive pole ear 222a through a connecting member 23, and the negative electrode terminal is electrically connected to the negative pole ear 222b through a connecting member 23. In addition, the two electrode terminals of the embodiment of the present application can be set on the same wall of the housing 21, or on different walls.

[0110] In the embodiment of the present application, the housing 21 includes: a housing 211 having two openings 2111 arranged opposite to each other; and two cover plates 212, respectively covering the two openings 2111 of the housing. By providing the housing 211 with two openings 2111 arranged opposite to each other, it is convenient to insert the internal electrode assembly 22 into the housing. For example, the electrode assembly 22 can be inserted into the housing through any opening 2111, and the installation is more flexible. In particular, when the battery cell 20 includes multiple electrode assemblies 22, different electrode assemblies 22 can enter the hollow part of the housing 211 through the same or different openings to speed up the installation.

[0111] In the embodiment of the present application, the wall thickness of the shell 211 can be set according to the actual application; and the wall thickness of different walls of the shell 211 can be the same or different. For example, the value range of the wall thickness of the shell 211 is [0.05mm, 2mm]. If the wall thickness of the shell 211 is set too small, the strength requirement of the outer shell 21 cannot be guaranteed, resulting in insufficient strength of the battery cell 20, which in turn affects the safety of the battery cell 20. Therefore, the wall thickness of the shell 211 should not be set too small. For example, the wall thickness of the shell 211 is usually greater than or equal to. On the contrary, if the wall thickness of the shell 211 is set too large, then when the external dimensions of the battery cell 20 are constant, the larger the wall thickness of the shell 211, the smaller its internal space, which will reduce the space utilization of the battery cell 20. Therefore, the wall thickness of the housing 211 should not be set too large. For example, the wall thickness of the housing 211 is usually greater than or equal to 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.8mm or 2mm. For example, the wall thickness of the housing 211 may range from [0.05mm, 2mm], [0.15mm, 1.1mm] or [0.25mm, 0.6mm].

[0112] In the embodiment of the present application, the two cover plates 212 may be any two walls of the housing 21. For example, the two cover plates 212 include the wall with the smallest area of ​​the housing 21, so that the area required to be connected between the housing 211 and the cover plates 212 is minimized, which facilitates the connection between the two and improves the strength and processing efficiency of the battery cell 20.

[0113] In the embodiment of the present application, the electrode terminal 24 is located on the first wall 213 of the housing 21, and the first end surface 224 where the tab 222 is located faces the second wall 214 of the housing 21. The first wall 213 may belong to the housing 211, or may also belong to the two cover plates 212; similarly, the second wall 214 may belong to the housing 211, or may also belong to the two cover plates 212.

[0114] For example, the shell 211 includes a second wall 214, and the two cover plates 212 include a first wall 213. In this way, when assembling the battery cell 20, it is convenient for the connecting member 23 inside the shell 21 to connect to the electrode terminal 24 located on the cover plate 212, and it is also convenient for the connecting member 23 to pass through the two openings 2111 of the shell 211 and connect to the pole ear 222 inside the shell 21 to speed up the assembly.

[0115] In the embodiment of the present application, the second wall 214 is the wall with the smallest area of ​​the shell 211, that is, the first end face 224 where the pole ear 222 is located faces the wall with the smallest area of ​​the shell 211, so that the pole ear 222 or the first end face 224 where the pole ear 222 is located occupies a smaller space, avoiding space waste and improving the space utilization and energy density of the battery cell 20.

[0116] In the embodiment of the present application, the battery cell includes two electrode terminals 24, and the two electrode terminals 24 can be located on the same wall or different walls. For example, the two electrode terminals 24 are respectively located on the two cover plates 212, so that the connecting member 23 inside the battery cell 20 can be installed respectively through the two openings 2111 of the shell 211, thereby improving the processing and assembly efficiency of the battery cell 20; and the electrode terminals 24 are respectively arranged on the two cover plates 212, which can also reduce the probability of short circuit between the two tabs 222 electrically connected to the two electrode terminals 24.

[0117] In the embodiment of the present application, the first electrode assembly 220 includes two pole ears 222, and the two pole ears can be located on the same end face or different end faces. For example, the two pole ears 222 are both located on the first end face 224, or the first electrode assembly 220 includes two opposite first end faces 224, and the two pole ears 220 are respectively located on the two first end faces 224. Arranging the two pole ears 222 on the same first end face 224 can reduce the space occupied by the pole ears 222 in the height direction Z, and improve the space utilization rate of the main body 221 of the electrode assembly 22 inside the battery cell 20. Arranging the two pole ears 222 on two oppositely arranged first end faces 224 can realize the electrical connection between the pole ears 222 and the connecting member 23 from both sides at the same time, which can improve the processing efficiency of the battery cell 20.

[0118] Fig.12 FIG. 2 is a schematic diagram showing the structure of the cover plate 212 and the connecting member 23 of an embodiment of the present application. Fig.12 As shown, the battery cell 20 of the embodiment of the present application further includes: a connecting member 23, the connecting member 23 includes a first part 231 and a second part 232 connected to each other, the first part 231 is used to be electrically connected to the electrode terminal 24, and the second part 232 is used to be electrically connected to the pole tab 222. Specifically, the connecting member 23 of the embodiment of the present application includes two parts, and the two parts are electrically connected to the pole tab 222 and the electrode terminal 24 respectively, so that the structure of the connecting member 23 is more flexible, and a suitable connecting member 23 can be selected according to the positions of the pole tab 222 and the electrode terminal 24.

[0119] like Fig.12As shown, the first portion 231 and the second portion 232 of the embodiment of the present application intersect, for example, the first portion 231 may be arranged perpendicular to the second portion 232 to connect the pole tab 222 and the electrode terminal 24 located on different walls. Specifically, the first end surface 224 where the pole tab 222 is located faces the second wall 214, and the electrode terminal 24 is located on the first wall 213. When the first wall 213 intersects and is perpendicular to the second wall 214, the electrical connection between the pole tab 222 and the electrode terminal 24 can be achieved by arranging the first portion 231 perpendicular to the second portion 232.

[0120] In the embodiment of the present application, the first part 231 and the second part 232 are an integrally formed structure, which can ensure the strength of the connecting member 23 and facilitate the assembly of the battery cell 20. Alternatively, the first part 231 and the second part 232 are separate structures and are connected by welding, so that the structure of the connecting member 23 is more flexible. For example, the electrical connection between the first part 231 and the electrode terminal 24, and the electrical connection between the second part 232 and the pole ear 222 can be performed separately or simultaneously, making the processing and assembly process of the battery cell 20 more flexible.

[0121] like Fig.12 As shown, when assembling the battery cell 20, the connecting member 23 and the cover plate 212 can be fixed first, so that the connecting member 23 and the cover plate 212 can be assembled as a whole in the subsequent assembly process to improve the processing efficiency. For example, the connection between the connecting member 23 and the cover plate 212 can be achieved by connecting the first part 231 with the electrode terminal 24, and then the second part 232 of the connecting member 23 is connected to the pole ear 222, but the embodiment of the present application is not limited to this.

[0122] The battery cells 20 and the battery 10 of the embodiments of the present application can achieve optimal space utilization of the battery 10 including one or more battery cells 20 by reasonably setting the size of the electrode assembly 22 inside the battery cell 20, that is, the space occupied by the mechanical structure inside the battery 10 except the electrode assembly 22 can be minimized.

[0123] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, comprising: Housing (21); At least one electrode assembly (22) is contained in the housing (21), the at least one electrode assembly (22) comprising a first electrode assembly (220), the length of the first electrode assembly (220) being in the range of [300 mm, 800 mm]; The first electrode assembly (220) comprises: A first pole piece (2211) and a second pole piece (2212) with opposite polarities, the first pole piece (2211) and the second pole piece (2212) are wound around a winding axis, and the length direction (X) of the first electrode assembly (220) is perpendicular to the winding axis.

2. The battery cell according to claim 1, wherein: The at least one electrode assembly (22) satisfies at least one of the following conditions: The value range of H / T is [0.5, 20]; The value range of H / T is [1, 18]; The value range of L / T is [6, 80]; The value range of L / T is [8, 40]; The value range of H / L is [0.062, 0.4]; The value range of H / L is [0.08, 0.28]; The value range of V / T is [28000mm 2 , 96000mm 2 ]; The value range of V / T is [32000mm 2 , 72000mm 2 ]; The value range of V / H is [4000mm 2 , 56000mm 2 ]; The value range of V / H is [6000mm 2 , 28000mm 2 ]; The value range of V / L is [600mm 2 , 8400mm 2 ]; The value range of V / L is [1050mm 2 , 4400mm 2 ]; Wherein, L is the length of the first electrode assembly (220); T is the total thickness of the at least one electrode assembly (22); H is the local height of the first electrode assembly (220), and the local height is the height of the portion of the positive electrode plate of the first electrode assembly (220) coated with the positive electrode active material; V=L*T*H.

3. The battery cell according to claim 1, wherein: The local height H of the first electrode assembly (220) and the height H1 of the housing (21) satisfy: H / H1≥80%, The local height is the height of a portion of the positive electrode sheet of the first electrode assembly (220) coated with a positive electrode active material.

4. The battery cell according to claim 1, wherein: The thickness of the first electrode assembly (220) ranges from [7 mm to 40 mm].

5. The battery cell according to claim 1, wherein: The at least one electrode assembly (22) comprises a plurality of electrode assemblies (22) arranged along a thickness direction (Y) of the first electrode assembly (220), and the total thickness of the plurality of electrode assemblies (22) is in the range of [25 mm, 80 mm].

6. The battery cell according to claim 1, wherein: The first electrode assembly (220) comprises a corner region (223), and a length L1 of the corner region (223) and a length L of the first electrode assembly (220) satisfy: 0.025≤L1 / L≤0.

25.

7. The battery cell according to any one of claims 1 to 6, wherein: The housing (21) includes a first wall (213) and a second wall (214) intersecting each other. The first wall (213) is provided with an electrode terminal (24); the first end surface (224) of the first electrode assembly (220) faces the second wall (214); the first end surface (224) is provided with a pole ear (222); and the pole ear (222) is electrically connected to the electrode terminal (24).

8. The battery cell according to claim 7, wherein: The first wall (213) includes an electrode lead-out hole (2131), the electrode terminal (24) covers the electrode lead-out hole (2131), and the distance H2 between the axis of the electrode lead-out hole (2131) and the second wall (214) and the height H1 of the housing (21) satisfy: 5%≤H2 / H1≤50%.

9. The battery cell according to claim 7, wherein: The housing (21) comprises: The housing (211) has two openings (2111) arranged opposite to each other; Two cover plates (212) respectively cover the two openings (2111) of the housing.

10. The battery cell according to claim 9, wherein: The wall thickness of the shell (211) ranges from [0.05 mm to 2 mm].

11. The battery cell according to claim 9, wherein: The two cover plates (212) comprise the walls of the housing (21) with the smallest area.

12. The battery cell according to claim 9, wherein: The housing (211) includes the second wall (214), and the two cover plates (212) include the first wall (213).

13. The battery cell according to claim 12, wherein: The second wall (214) is the wall with the smallest area of ​​the housing (211).

14. The battery cell according to claim 9, wherein: The battery cell comprises two electrode terminals (24), and the two electrode terminals (24) are respectively located on the two cover plates (212).

15. The battery cell according to claim 7, wherein: The first electrode assembly (220) includes two electrode tabs (222); Wherein, the two tabs (222) are both located on the first end surface (224), or, The first electrode assembly (220) comprises two opposite first end surfaces (224), and the two electrode tabs (220) are respectively located on the two first end surfaces (224).

16. The battery cell according to claim 7, wherein: The battery cell further comprises: A connecting member (23), the connecting member (23) comprising a first portion (231) and a second portion (232) connected to each other, the first portion (231) being used for electrically connecting to the electrode terminal (24), and the second portion (232) being used for electrically connecting to the electrode tab (222).

17. The battery cell according to claim 16, wherein: The first part (231) and the second part (232) are an integrally formed structure; or, The first part (231) and the second part (232) are separate structures and are connected by welding.

18. A battery comprising: A plurality of battery cells according to any one of claims 1 to 17.

19. An electrical device comprising: A plurality of battery cells according to any one of claims 1 to 17, wherein the battery cells are used to provide electrical energy to the electrical device.

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