Battery cell, battery device and electric apparatus

Abstract

Disclosed in the embodiments of the present application are a battery cell, a battery device and an electric apparatus. The battery cell comprises: a casing; a first electrode terminal disposed on the casing and electrically insulated from the casing; and an electrode assembly accommodated in the casing and comprising first electrode sheets and second electrode sheets, which have opposite polarities, wherein the first electrode sheets and the second electrode sheets are alternately stacked in the direction of the thickness of the electrode assembly. The electrode assembly circumferentially comprises two oppositely arranged first end faces and two oppositely arranged second end faces, and the area of each second end face is greater than that of each first end face. Each first electrode sheet is provided with a first tab, and each second electrode sheet is provided with a second tab. The first tabs are electrically connected to the first electrode terminal, the second tabs are electrically connected to the casing, and the second tabs are located on the second end faces. According to the battery cell, the battery device and the electric apparatus provided in the embodiments of the present application, the performance and reliability of the battery cell can be improved.

Description

Battery cell, battery device and electric equipment

[0001] Cross-reference to Related Applications

[0002] This application claims priority to Chinese Patent Application No. 202421931181.5, filed on August 9, 2024, entitled “Battery cell, battery device and electric equipment”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of batteries, and more particularly, to a battery cell, a battery device and an electric equipment. BACKGROUND

[0004] Energy saving and emission reduction is 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 energy-saving and environmentally friendly advantages. For electric vehicles, battery technology is an important factor for their development.

[0005] In the development of battery technology, how to improve the performance of the battery device cannot be ignored. The battery device usually includes a plurality of battery cells, therefore, the performance of the battery cell in the charging and discharging process directly affects the performance of the battery device, and how to improve the performance of the battery cell is an urgent technical problem to be solved in the development of battery technology. SUMMARY

[0006] The embodiments of the present application provide a battery cell, a battery device and an electric equipment, which can improve the performance and reliability of the battery cell.

[0007] In a first aspect, a battery cell is provided, the battery cell comprising: a housing; a first electrode terminal disposed in the housing and electrically insulated from the housing; an electrode assembly accommodated in the housing, the electrode assembly comprising first and second pole pieces of opposite polarity, the first and second pole pieces being alternately stacked along a thickness direction of the electrode assembly, a circumferential direction of the electrode assembly comprising two oppositely disposed first end faces and two oppositely disposed second end faces, an area of the second end face being greater than an area of the first end face, the first pole piece being provided with a first tab, the second pole piece being provided with a second tab, the first tab being electrically connected to the first electrode terminal, the second tab being electrically connected to the housing, the second tab being located at the second end face.

[0008] Therefore, the battery cell in the embodiments of the present application is not the second end face where the second tab is located is the end face with the smallest area of the electrode assembly. Compared with the case where the second tab is arranged on the other end face, on the one hand, the size of the second tab can be increased, thereby increasing the contact area between the second tab and the shell, reducing the impedance, reducing the heat concentration, and helping to improve the heat dissipation capacity of the battery cell; on the other hand, the potential difference of the tab where the second tab is located can be reduced, especially when the lengths of the edges of the different end faces of the electrode assembly are greatly different, the potential difference can be effectively reduced, the energy loss in the charging and discharging process of the battery cell is reduced, and the performance and reliability of the battery cell are improved. Further, the first tab of the electrode assembly is electrically connected with the first electrode terminal of the battery cell, the first electrode terminal is arranged on the shell but is electrically insulated from the shell, and the second tab located on the second end face is electrically connected with the shell, which can simplify the structure of the second tab, and also save or simplify the connecting member required for electrical connection with the second tab, thereby reducing the structural complexity of the battery cell; on the other hand, the heat dissipation of the shell can also be utilized to improve the heat dissipation capacity of the battery cell during use, thereby improving the reliability of the battery cell.

[0009] In some embodiments, the electrode assembly includes at least one first tab and at least one second tab, and the total width of the at least one second tab is greater than the total width of the at least one first tab. On the one hand, the total width of the at least one second tab is different from the total width of the at least one first tab, which can improve the flexibility of the size design of the at least one first tab and the at least one second tab; on the other hand, increasing the size of the second tab can increase the contact area between the second tab and the shell, reduce the impedance, reduce the heat concentration, and help to improve the heat dissipation capacity of the battery cell.

[0010] In some embodiments, the ratio of the total width of the at least one second tab to the width of the second end face is in the range of [0.5, 0.95] along the width direction of the at least one second tab. Increasing the total width of the at least one second tab can improve the effect of potential balance, and also effectively increase the overcurrent area, reduce the heat concentration, and help to dissipate heat. However, the ratio of the total width of the at least one second tab to the width of the second end face should be less than 0.95 to protect the second tab and reduce the influence of other components on the second tab.

[0011] In some embodiments, the first tab is located on the first end face, and the first end face and the second end face are different end faces of the electrode assembly, so as to reduce the interference between the first tab and the second tab, reduce the processing difficulty, and arrange the first tab and the second tab on different end faces to facilitate increasing the size of the first tab and the second tab, thereby reducing the heat concentration caused by current concentration, and being beneficial to heat dissipation.

[0012] In some embodiments, the first tab and the second tab are respectively located at two oppositely arranged second end surfaces, which can increase the size of the first tab, thereby increasing the contact area between the first tab and the shell, reducing the impedance, reducing the heat concentration, and helping to improve the heat dissipation capacity of the battery monomer.

[0013] In some embodiments, the second end surface is provided with a plurality of second tabs distributed along the length direction of the electrode assembly, which can reduce the potential difference of the electrode assembly, thereby reducing the weight of the electrode assembly, and further reducing the weight of the battery monomer and the battery device, and improving the energy density.

[0014] In some embodiments, the second end surface is provided with a plurality of second tabs distributed along the thickness direction of the electrode assembly, which can further reduce the weight of the electrode assembly, and further reduce the weight of the battery monomer and the battery device, and improve the energy density.

[0015] In some embodiments, the second end surface is provided with a plurality of second tabs distributed along the length direction of the electrode assembly, which can reduce the potential difference of the electrode assembly, thereby reducing the weight of the electrode assembly, and further reducing the weight of the battery monomer and the battery device, and improving the energy density. On the other hand, considering that the electrode assembly needs to be compacted when assembled into the inside of the shell, staggered distribution can save the space occupied by the second tab, improve the space utilization rate inside the battery monomer, and further improve the energy density of the battery monomer.

[0016] In some embodiments, the first tab is a positive tab, and the second tab is a negative tab. The negative tab located at the second end surface can reduce the potential difference of the negative tab, especially when the lengths of the edges of the different end surfaces of the electrode assembly are greatly different, for example, the second end surface has the longest edge of the electrode assembly, and the length of the longest edge of the electrode assembly is greatly different from the lengths of the other edges, which can effectively reduce the potential difference. In addition, for lithium-ion batteries or sodium-ion batteries, reducing the potential difference can reduce the metal precipitation of the negative tab, and can also reduce the energy loss in the charging and discharging process of the battery monomer, thereby improving the performance and reliability of the battery monomer.

[0017] In some embodiments, the electrode assembly further comprises: a separation film for separating the first tab and the second tab, and the height of the second lug protruding from the separation film is in the range of [3mm, 8mm]. By setting the height of the second lug protruding from the separation film to be greater than or equal to 3mm, the contact area between the second lug and the shell can be increased, thereby increasing the effect of current and potential balancing, and the reliability of the electrical connection between the second lug and the shell can also be improved. Conversely, by setting the height of the second lug protruding from the separation film to be less than or equal to 8mm, the second lug can occupy less space inside the battery monomer, thereby improving the energy density of the battery monomer. In addition, the weight of the electrode assembly can also be reduced, thereby reducing the weight of the battery monomer and the battery device.

[0018] In some embodiments, the shell further comprises: a housing having an opening; and a cover plate configured to cover the opening of the housing, the cover plate being provided with the first electrode terminal, and the first electrode terminal being electrically insulated from the cover plate to facilitate processing and assembly.

[0019] In some embodiments, the cover plate is further provided with a second electrode terminal, and the second electrode terminal is electrically connected to the housing through the cover plate. This facilitates processing and enables electrical connection between multiple battery monomers through the second electrode terminal and the first electrode terminal, for example, by welding a busbar to the second electrode terminal to achieve electrical connection between multiple battery monomers. In addition, welding the busbar to the second electrode terminal can also improve the stability and reliability of the connection between multiple battery monomers.

[0020] In some embodiments, the second lug is welded to the shell to improve the connection reliability between the second lug and the shell, improve the stability of the electrical connection between the second lug and the shell, and thereby improve the reliability of the battery monomer.

[0021] In some embodiments, the second lug is welded to the shell to improve the connection reliability between the second lug and the shell, improve the stability of the electrical connection between the second lug and the shell, and thereby improve the reliability of the battery monomer.

[0022] In some embodiments, the second lug is welded to the shell to improve the connection reliability between the second lug and the shell, improve the stability of the electrical connection between the second lug and the shell, and thereby improve the reliability of the battery monomer.

[0023] In some embodiments, the electrical device is a vehicle, a ship, or a spacecraft. BRIEF DESCRIPTION OF DRAWINGS

[0024] FIG. 1 is a schematic diagram of a vehicle according to an embodiment of the present application;

[0025] FIG. 2 is an exploded structural schematic diagram of a battery device according to an embodiment of the present application;

[0026] FIG. 3 is a structural schematic diagram of a battery cell according to an embodiment of the present application;

[0027] FIG. 4 is a partially exploded structural schematic diagram of a battery cell according to an embodiment of the present application;

[0028] FIG. 5 is a structural schematic diagram of an electrode assembly according to an embodiment of the present application;

[0029] FIG. 6 is a side view schematic diagram of an electrode assembly according to an embodiment of the present application;

[0030] FIG. 7 is a top view schematic diagram of an electrode assembly according to an embodiment of the present application;

[0031] FIG. 8 is a cross-sectional schematic diagram of an electrode assembly according to an embodiment of the present application;

[0032] FIG. 9 is a cross-sectional schematic diagram of an electrode assembly according to another embodiment of the present application;

[0033] FIG. 10 is a structural schematic diagram of an electrode assembly according to another embodiment of the present application;

[0034] FIG. 11 is a side view schematic diagram of an electrode assembly according to another embodiment of the present application;

[0035] FIG. 12 is a structural schematic diagram of an electrode assembly according to yet another embodiment of the present application;

[0036] FIG. 13 is a side view schematic diagram of an electrode assembly according to yet another embodiment of the present application;

[0037] FIG. 14 is a cross-sectional schematic diagram of a battery cell according to an embodiment of the present application;

[0038] FIG. 15 is a partially cross-sectional enlarged schematic diagram of a battery cell according to an embodiment of the present application;

[0039] FIG. 16 is a cross-sectional schematic diagram of a cover plate of a battery cell according to an embodiment of the present application;

[0040] FIG. 17 is an exploded structural schematic diagram of a cover plate according to an embodiment of the present application;

[0041] FIG. 18 is a structural schematic diagram of a battery cell according to another embodiment of the present application;

[0042] FIG. 19 is a structural schematic diagram of an electrode assembly according to yet another embodiment of the present application.

[0043] In the drawings, the drawings are not drawn according to the actual proportions. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described below with reference to the drawings.

[0045] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0046] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the description of the present application and the claims and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the description of the present application and the claims or the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0047] In the present application, the phrase "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiments, nor is it necessarily mutually exclusive or alternative embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0048] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium; can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0049] In the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the associated objects before and after it.

[0050] In the embodiments of the present application, the same reference signs 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, and the overall thickness, length, width, and other dimensions of the integrated device are only exemplary and should not constitute any limitation on the present application.

[0051] In the present application, "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0052] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging.

[0053] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., and the present application is not limited thereto.

[0054] In some implementations, the battery cell in the embodiments of the present application can be a metal battery, specifically, the metal battery can include a lithium metal secondary battery, a sodium metal battery, or a magnesium metal battery, etc., and the present application is not limited thereto.

[0055] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting, and at the same time, the active ions can pass through.

[0056] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material arranged on at least one surface of the positive electrode current collector.

[0057] As an example, the positive electrode current collector has two opposite surfaces in the thickness direction of itself, and the positive electrode active material is arranged on any one or both of the two opposite surfaces of the positive electrode current collector.

[0058] As an example, the positive electrode current collector can employ a metal foil, a foam metal, or a composite current collector. For example, as a metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, or the like can be employed. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, or a foam carbon, or the like. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, and a silver alloy, or the like) on a polymer material base material (a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0059] As an example, the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material can also be used. These positive electrode active materials can be used alone only one or two or more can be used in combination. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFeP04 (which can also be referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnP04), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0060] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0061] As an example, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is disposed on either one or both of the two opposite surfaces of the negative electrode current collector.

[0062] As an example, the negative electrode current collector can employ a metal foil, a foam metal, or a composite current collector. For example, as a metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, or the like can be employed. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, or a foam carbon, or the like. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, a copper alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, and a silver alloy, or the like) on a polymer material base material (a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0063] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0064] In some embodiments, the separator is a separator film. The type of separator film is not particularly limited in the present application, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0065] For example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride, and ceramic.

[0066] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive electrode and the negative electrode.

[0067] In some embodiments, the battery cell further includes an electrolyte, which functions to conduct ions between the positive electrode and the negative electrode. The type of electrolyte is not particularly limited in the present application, and can be selected as needed. The electrolyte can be in a liquid state, a gel state, or a solid state.

[0068] In some embodiments, the electrode assembly is provided with a tab, which can lead current out of the electrode assembly. The tab includes a positive tab and a negative tab.

[0069] In some embodiments, the battery cell can include a housing. The housing is used to package components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc. The housing includes a shell body and an end cover.

[0070] The battery device mentioned in the embodiments of the present application can include one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel, or in a mixed connection through a busbar.

[0071] In some embodiments, the battery device can be a battery pack, which includes a box body and battery cells or battery modules housed in the box body.

[0072] In some embodiments, the box body can be part of the chassis structure of a vehicle. For example, part of the box body can be at least part of the floor of the vehicle, or part of the box body can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0073] In some embodiments, the battery device can be located in an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0074] The development of battery technology needs to consider various design factors, such as energy density, cycle life, discharge capacity, and charge-discharge rate. Considering that the shapes of the electrode assemblies inside battery cells of different shapes are also different, the placement of the tabs in different areas of the electrode assembly will affect the performance of the electrode assembly. For example, for a cuboid battery cell, the electrode assembly inside is also usually cuboid. Because the sizes of the different end faces of the cuboid electrode assembly are different, the placement of the tabs of the electrode assembly will affect the performance of the battery cell.

[0075] The battery cell provided by the embodiments of the present application includes a shell, a first electrode terminal, and an electrode assembly. The first electrode terminal is arranged in the shell and is electrically insulated from the shell. The electrode assembly is accommodated in the shell. The electrode assembly includes first and second polar plates with opposite polarities. The first and second polar plates are alternately stacked along the thickness direction of the electrode assembly. The electrode assembly includes two oppositely arranged first end faces and two oppositely arranged second end faces in the circumferential direction. The area of the second end face is greater than that of the first end face. The first polar plate is provided with a first tab, and the second polar plate is provided with a second tab. The second tab is located at the second end face. In this way, the second end face where the second tab is located is not the end face with the smallest area of the electrode assembly. Compared with the case where the second tab is arranged at other end faces, on the one hand, the size of the second tab can be increased, thereby increasing the contact area between the second tab and the shell, reducing the impedance, reducing the heat concentration, and helping to improve the heat dissipation capacity of the battery cell. On the other hand, the potential difference of the polar plate where the second tab is located can be reduced. Especially when the lengths of the edges of different end faces of the electrode assembly are greatly different, the potential difference can be effectively reduced, the energy loss during the charge-discharge process of the battery cell is reduced, and the performance and reliability of the battery cell are improved.

[0076] Further, the first tab of the electrode assembly is electrically connected to the first electrode terminal of the battery cell. The first electrode terminal is arranged in the shell but is electrically insulated from the shell. The second tab located at the second end face is electrically connected to the shell. On the one hand, the structure of the second tab can be simplified, and the connection member required for electrical connection with the second tab can also be saved or simplified, thereby reducing the structural complexity of the battery cell. On the other hand, the shell can also be used for heat dissipation, thereby improving the heat dissipation capacity of the battery cell during use and improving the reliability of the battery cell.

[0077] The technical solutions described in the embodiments of the present application are applicable to various electric equipment using battery devices.

[0078] The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The vehicle can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, etc. The spacecraft includes an airplane, a rocket, a space shuttle, a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game machine, an electric automobile toy, an electric ship toy, and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, and an electric planer, etc. The electric device is not specially limited in the embodiments of the present application.

[0079] The following embodiments take the vehicle as an example for convenience of description.

[0080] For example, as shown in FIG. 1, it is a structural schematic diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, etc. The vehicle 1 can be provided with a motor 40, a controller 30, and a battery device 10 inside. The controller 30 is used to control the power supply of the battery device 10 to the motor 40. For example, the battery device 10 can be arranged at the bottom, the front, or the rear of the vehicle 1. The battery device 10 can be used for power supply of the vehicle 1. For example, the battery device 10 can be used as an operating power source of the vehicle 1, and is used for the circuit system of the vehicle 1, such as the power demand for starting, navigation, and operation of the vehicle 1. In another embodiment of the present application, the battery device 10 can not only be used as an operating power source of the vehicle 1, but also be used as a driving power source of the vehicle 1, to replace or partially replace the fuel or natural gas to provide driving power for the vehicle 1.

[0081] For example, FIG. 2 shows a partial structural schematic diagram of the battery device 10 according to an embodiment of the present application. As shown in FIG. 2, the battery device 10 according to an embodiment of the present application can include a plurality of battery monomers 20 to meet different power requirements. The shape of the battery monomer 20 according to an embodiment of the present application can be set according to actual application. For example, the battery monomer 20 can be a cylinder as shown in FIG. 2, or can be a cuboid or other shape different from that shown in FIG. 2, which is not limited in the embodiments of the present application.

[0082] It should be understood that, as shown in FIG. 2, the battery device 10 of the embodiments of the present application can also include a box 11, which can be used to accommodate a plurality of battery cells 20. The box 11 of the embodiments of the present application is hollow inside, and the plurality of battery cells 20 are accommodated in the box 11. The box 11 can include two parts, which are referred to as a first box part 111 and a second box part 112 herein, and the first box part 111 and the second box part 112 are buckled together. The shapes of the first box part 111 and the second box part 112 can be determined according to the shapes of the components accommodated inside, for example, can be determined according to the shape of the combination of the plurality of battery cells 20 accommodated inside, and at least one of the first box part 111 and the second box part 112 has an opening. For example, as shown in FIG. 2, the first box part 111 and the second box part 112 can each be a hollow cuboid and each have an opening face, the opening of the first box part 111 and the opening of the second box part 112 are oppositely arranged, and the first box part 111 and the second box part 112 are buckled to each other to form a box 11 having a closed cavity, which can be used to accommodate the plurality of battery cells 20. The plurality of battery cells 20 combined in parallel or in series or in a hybrid manner are placed in the box 11 formed after the buckling of the first box part 111 and the second box part 112.

[0083] For another example, unlike that shown in FIG. 2, only one of the first box part 111 and the second box part 112 can be a hollow cuboid having an opening, and the other can be a plate-shaped to cover the opening. Taking the second box part 112 as a hollow cuboid having an opening and the first box part 111 as a plate-shaped as an example, the first box part 111 covers the opening of the second box part 112 to form a box 11 having a closed cavity, which can be used to accommodate the plurality of battery cells 20.

[0084] In some embodiments, the battery device 10 can also include other components. For example, the battery device 10 can also include a current collecting component, which can be used to achieve electrical connection between the plurality of battery cells 20, for example, in parallel or in series or in a hybrid manner. Specifically, the current collecting component can achieve electrical connection between the battery cells 20 by connecting the electrode terminals 23 of the battery cells 20; or the current collecting component can also achieve electrical connection between the battery cells 20 by connecting other components of the battery cells 20. The current collecting component can be fixed to the corresponding components of the battery cells 20 by welding, for example, can be fixed to the electrode terminals 23, the sealing structure or the shell, etc. by welding, and the embodiments of the present application are not limited thereto.

[0085] FIG. 3 shows a structural schematic diagram of a battery cell 20 according to an embodiment of the present application; FIG. 4 shows an exploded structural schematic diagram of a housing 21 of the battery cell 20 according to an embodiment of the present application, for example, the housing 21 shown in FIG. 4 can be the housing 21 of the battery cell 20 shown in FIG. 3; FIG. 5 shows a structural schematic diagram of an electrode assembly 22 of the battery cell 20 according to an embodiment of the present application, for example, the electrode assembly 22 shown in FIG. 5 can be the electrode assembly 22 included in the battery cell 20 shown in FIG. 3; FIG. 6 and FIG. 7 respectively show schematic diagrams of the electrode assembly 22 of the battery cell 20 according to an embodiment of the present application from two different angles, for example, FIG. 6 and FIG. 7 can respectively be schematic diagrams of the electrode assembly 22 shown in FIG. 5 from different angles.

[0086] In the embodiments of the present application, the battery cell 20 includes a housing 21, a first electrode terminal 231, and an electrode assembly 22. Specifically, as shown in FIG. 3 to FIG. 7, the first electrode terminal 231 is disposed on the housing 21 and electrically insulated from the housing 21; the electrode assembly 22 is accommodated in the housing 21, the electrode assembly 22 includes first and second polar plates 225 and 226 with opposite polarities, the first and second polar plates 225 and 226 are alternately stacked along a thickness direction of the electrode assembly 22, a circumferential direction of the electrode assembly 22 includes two oppositely disposed first end faces 2201 and two oppositely disposed second end faces 2202, an area of the second end face 2202 is greater than an area of the first end face 2201, the first polar plate 225 is provided with a first tab 221, the second polar plate 226 is provided with a second tab 222, the first tab 221 is electrically connected to the first electrode terminal 231, the second tab 222 is electrically connected to the housing 21, and the second tab 222 is located on the second end face 2202.

[0087] It should be understood that the shape of the battery cell 20 according to the embodiments of the present application can be flexibly set according to actual application, i.e., the battery cell 20 can be any polyhedral structure, for example, can be set as a cuboid or a cylinder, etc. Specifically, as shown in FIG. 3 to FIG. 7, the housing 21 of the battery cell 20 can include multiple walls, so that the battery cell 20 is a polyhedral structure. For example, the housing 21 can be a cuboid or an approximate cuboid, the housing 21 can include six walls, each wall being rectangular or approximately rectangular. In addition, the shape of the outside of the battery cell 20 can be the same as or different from the shape of the electrode assembly 22 inside it. For example, if the electrode assembly 22 is a cuboid structure, the housing 21 can also be a cuboid structure in general, but the embodiments of the present application are not limited thereto.

[0088] The embodiments of the present application mainly take a rectangular battery monomer 20 as an example for description, in addition, in order to facilitate description, the embodiments of the present application define three reference directions. The thickness direction of the battery monomer 20 is direction Y, the height direction of the battery monomer 20 is direction Z, and the length direction of the battery monomer 20 is direction X, wherein the thickness direction Y, the height direction Z and the length direction X of the battery monomer 20 are perpendicular to each other, and the thickness direction Y of the battery monomer 20 is smaller than the size of the length direction X.

[0089] It should be understood that the electrode assembly 22 of the embodiments of the present application is a component in the battery monomer 20 where an electrochemical reaction occurs, and the electrode assembly 22 in the battery monomer 20 can be provided as one or more according to actual use requirements. For any one electrode assembly 22, the electrode assembly 22 includes a first polar piece 225 and a second polar piece 226 with opposite polarities, and the electrode assembly 22 is a laminated electrode assembly. Specifically, the first polar piece 225 and the second polar piece 226 are alternately and laminatedly arranged along the thickness direction of the electrode assembly 22, that is, the thickness direction of the electrode assembly 22 is the lamination direction of the electrode assembly 22, and here the thickness direction of the electrode assembly 22 is taken as the thickness direction Y of the battery monomer 20 as an example.

[0090] In the embodiments of the present application, the circumferential direction of the laminated electrode assembly 22 includes two oppositely arranged first end faces 2201 and two oppositely arranged second end faces 2202, wherein the circumferential direction of the electrode assembly 22 is a direction around the lamination direction of the electrode assembly 22, and the first end face 2201 and the second end face 2202 of the circumferential direction of the electrode assembly 22 can be parallel to the lamination direction of the electrode assembly 22, or approximately parallel to the lamination direction of the electrode assembly 22, that is, the first end face 2201 and the second end face 2202 are not surfaces perpendicular to the lamination direction of the electrode assembly 22.

[0091] In the embodiments of the present application, the area of the second end face 2202 is greater than the area of the first end face 2201, that is, the second end face 2202 is not the end face with the smallest area of the electrode assembly 22. As shown in FIGS. 3 to 7, taking the cuboid or approximately cuboid electrode assembly 22 as an example, in the case that the second end face 2202 is not the end face with the smallest area, the second end face 2202 has the longest side 2203 of the electrode assembly 22.

[0092] It should be understood that the first tab 225 of the electrode assembly 22 of the embodiment of the present application is provided with the first tab 221, for example, the portion of the first tab 225 without the active material layer is laminated to form the first tab 221, and the second tab 226 is provided with the second tab 222, for example, the portion of the second tab 226 without the active material layer is laminated to form the second tab 222. The first tab 225 and the second tab 226 of the embodiment of the present application are opposite in polarity, and therefore, the first tab 221 and the second tab 222 are also opposite in polarity. For example, the first tab 221 can be a positive tab, and the second tab can be a negative tab; or the first tab 221 can be a negative tab, and the second tab can be a positive tab. The positive tab can be formed by laminating the portion of the positive tab without the positive active material layer, and the negative tab can be formed by laminating the portion of the negative tab without the negative active material layer. In addition, the first tab 221 and the second tab 222 of the electrode assembly 22 of the embodiment of the present application can be located at the same or different end faces of the electrode assembly 22.

[0093] The second tab 222 of the battery cell 20 of the embodiment of the present application is located at the second end face 2202. For the case that the second end face 2202 is not the end face with the smallest area of the electrode assembly 22, compared with the case that the second tab 222 is arranged at other end faces, on the one hand, the size of the second tab 222 can be increased, thereby increasing the contact area between the second tab 222 and the shell 21, reducing the impedance, reducing the heat concentration, and helping to improve the heat dissipation capacity of the battery cell 20; on the other hand, the potential difference of the tab where the second tab 222 is located can be reduced, especially when the lengths of the edges of different end faces of the electrode assembly 22 are greatly different, for example, the second end face 2202 has the longest edge 2203 of the electrode assembly 22, and the length of the longest edge 2203 of the electrode assembly 22 is greatly different from the lengths of other edges, which can more effectively reduce the potential difference and reduce the energy loss during the charging and discharging process of the battery cell 20, thereby improving the performance and reliability of the battery cell 20.

[0094] Further, in the embodiment of the present application, the battery cell 20 can also be provided with an electrode terminal 23, which is used to be electrically connected with the electrode assembly 22 to output the electric energy of the battery cell 20. Specifically, as shown in FIGS. 3 to 7, the battery cell 20 can include at least one first electrode terminal 231, which is arranged at the shell 21 but is electrically insulated from the shell, for example, the first electrode terminal 231 can be located at any position of the shell 21 of the battery cell 20, for example, can be located at any one wall of the shell 21.

[0095] The first tab 221 of the electrode assembly 22 is electrically connected with the first electrode terminal 231 of the battery monomer 20, and the second tab 222 located at the second end face 2202 is electrically connected with the shell 21. On the one hand, the structure of the second tab 222 can be simplified, and the connection member required for electrical connection of the second tab 222 can be saved or simplified, thereby reducing the structural complexity of the battery monomer 20. On the other hand, the shell 21 can be used for heat dissipation, thereby improving the heat dissipation capability of the battery monomer 20 during use, and improving the reliability of the battery monomer 20.

[0096] FIGS. 8 and 9 respectively show cross-sectional views of different types of electrode assemblies 22, for example, the electrode assemblies 22 shown in FIGS. 8 to 9 can be included in the battery monomer 20 of any embodiment of the present application. The cross-section is perpendicular to the length direction X of the battery monomer 20, and for the convenience of description, the tabs included in each tab sheet are not shown here. As shown in FIGS. 8 to 9, the electrode assembly 22 of the embodiment of the present application is a laminated electrode assembly, and the specific structure of the electrode assembly 22 can be set according to actual application. For example, the electrode assembly 22 of the embodiment of the present application can include a tab portion and a tab sheet main body portion 223. Specifically, the tab portion can include positive and negative tabs, the positive tabs can be formed by laminating the portions of the positive tab sheets on which the positive active material layers are not coated, and the portions of the positive tab sheets on which the positive active material layers are coated can form the tab sheet main body portion 223 by lamination; the negative tabs can be formed by laminating the portions of the negative tab sheets on which the negative active material layers are not coated, and the portions of the negative tab sheets on which the negative active material layers are coated can form the tab sheet main body portion 223 by lamination.

[0097] In some embodiments, as shown in FIG. 8, the electrode assembly 22 includes a plurality of first tab sheets 225 and a plurality of second tab sheets 226, the plurality of first tab sheets are provided with first tabs 221, and the plurality of second tab sheets are provided with second tabs 222; the plurality of first tab sheets 225 and the plurality of second tab sheets 226 are alternately laminated in the thickness direction of the electrode assembly 22. Since the plurality of first tab sheets 225 and the plurality of second tab sheets 226 are alternately laminated in the thickness direction of the electrode assembly 22, for any end face of the circumferential direction of the electrode assembly 22, the first tabs 221 and the second tabs 222 can be arranged, which is convenient for processing. For example, each of the two oppositely arranged first end faces 2201 and the two oppositely arranged second end faces 2202 of the electrode assembly 22 can be used to arrange the tabs.

[0098] For another example, as shown in FIG. 9, the electrode assembly 22 includes a plurality of first tabs 225 and a plurality of second tabs 226, the second tabs 226 can include at least one bending segment and a plurality of stacking segments, each bending segment is used to connect two stacking segments, the plurality of stacking segments of the second tabs 226 and the plurality of first tabs 225 are alternately stacked along the thickness direction of the electrode assembly 22 to form another kind of stacked electrode assembly 22. As shown in FIG. 9, the second lug 222 of the electrode assembly 22 cannot be disposed on the end face where the bending segment of the second tab 226 is located, for example, the second end face 2202 where the second lug 222 is located can be perpendicular to the bending segment. While the first lug 221 of the first tab 225 is limited by the bending segment of the second tab 226, the lug of each first tab 225 does not extend towards the bending segment of the second tab 226, that is, the first lug 221 can be disposed on any end face of the electrode assembly 22 in the circumferential direction.

[0099] Alternatively, contrary to FIG. 9, the electrode assembly 22 can also include a plurality of first tabs 225 and a plurality of second tabs 226, the first tabs 225 include at least one bending segment and a plurality of stacking segments, the plurality of second tabs 226 and the plurality of stacking segments of the first tabs 225 are alternately stacked along the thickness direction of the electrode assembly 22 to form another kind of stacked electrode assembly 22. Then, the first lug 221 of the electrode assembly 22 cannot be disposed on the end face where the bending segment of the first tab 225 is located, for example, the end face where the first lug 221 is located can be perpendicular to the bending segment. While the second lug 222 of the second tab 226 is limited by the bending segment of the first tab 225, the lug of each second tab 226 does not extend towards the bending segment of the first tab 225, that is, the second lug 222 can be disposed on any end face of the electrode assembly 22 in the circumferential direction.

[0100] It should be understood that the battery cell 20 of the embodiments of the present application also includes a separator 224 for isolating the first tab 225 and the second tab 226. The polarity of the first tab 225 and the second tab 226 of the embodiments of the present application is opposite. For example, if the first tab 225 is a positive tab, the second tab 226 is a negative tab; if the first tab 225 is a negative tab, the second tab 226 is a positive tab. In FIGS. 8-9, the first tab 225 is taken as a positive tab and the second tab 226 is taken as a negative tab as an example, the size of the positive tab is slightly smaller than the size of the negative tab, which can reduce the phenomenon of lithium or sodium precipitation for lithium ion battery cells or sodium ion battery cells to improve the performance of the battery cell 20.

[0101] It should be understood that the first tab 221 and the second tab 222 of the embodiments of the present application are opposite in polarity. In some embodiments, the first tab 221 is a positive tab, and the second tab 222 is a negative tab, that is, the negative tab is electrically connected to the shell 21, and the positive tab is electrically connected to the first electrode terminal 231. By arranging the negative tab at the second end face 2202, the potential difference of the negative tab sheet where the negative tab is located can be reduced, especially when the lengths of the edges of different end faces of the electrode assembly 22 are greatly different, for example, the second end face 2202 has the longest side 2203 of the electrode assembly 22, and the length of the longest side 2203 of the electrode assembly 22 is greatly different from the lengths of other sides. The potential difference can be effectively reduced. In addition, for lithium-ion batteries or sodium-ion batteries, reducing the potential difference can reduce the metal precipitation of the negative tab sheet, and also can reduce the energy loss during the charging and discharging process of the battery monomer 20, and improve the performance and reliability of the battery monomer 20.

[0102] In the embodiments of the present application, the second tab 222 is electrically connected to the shell 21. For example, the second tab 222 can be in direct contact with the shell 21, so that the second tab 222 is electrically connected to the shell 21, without the need for additional connection methods such as welding between the two, to simplify the processing process.

[0103] For another example, the second tab 222 is welded to the shell 21, to improve the connection reliability between the second tab 222 and the shell 21, improve the stability of the electrical connection between the second tab 222 and the shell 21, and further improve the reliability of the battery monomer 20.

[0104] In the embodiments of the present application, the second tab 222 is located at the second end face 2202, and the first tab 221 can be located at the same end face or different end faces as the second tab 222.

[0105] In some embodiments, the first tab 221 and the second tab 222 are not located at the same end face of the electrode assembly 22, to reduce the interference between the first tab 221 and the second tab 222, reduce the processing difficulty, and arrange the first tab 221 and the second tab 222 at different end faces, to facilitate increasing the size of the first tab 221 and the second tab 222, to reduce the heat concentration caused by current concentration, and facilitate heat dissipation.

[0106] In some embodiments, as shown in FIGS. 3-9, the first tab 221 is located at the first end face 2201. Considering that the first tab 221 is electrically connected to the first electrode terminal 231, the arrangement position of the first tab 221 can be related to the first electrode terminal 231; the first electrode terminal 231 is usually located at a wall with a smaller area of the shell 21, and the first tab 221 is located at the first end face 2201 with a smaller area, to improve the integration of the battery monomer 20, and facilitate processing.

[0107] In some embodiments, the first tab 221 and the second tab 222 are respectively located at two opposite second end surfaces 2202. On the one hand, the size of the first tab 221 can be increased, thereby increasing the contact area between the first tab 221 and the shell 21, reducing impedance, reducing heat concentration, and helping to improve the heat dissipation capacity of the battery monomer 20. On the other hand, the potential difference of the tab where the first tab 221 is located can be reduced, thereby reducing the energy loss of the battery monomer 20 during charging and discharging, and improving the performance and reliability of the battery monomer 20.

[0108] In some embodiments, the electrode assembly 22 includes at least one first tab 221 and at least one second tab 222, and the total width L2 of the at least one second tab 222 is greater than the total width L1 of the at least one first tab 221. On the one hand, the total width L2 of the at least one second tab 222 is different from the total width L1 of the at least one first tab 221, which can improve the flexibility of the size design of the at least one first tab 221 and the at least one second tab 222. On the other hand, increasing the size of the second tab 222 can increase the contact area between the second tab 222 and the shell 21, reduce impedance, reduce heat concentration, and help improve the heat dissipation capacity of the battery monomer 20.

[0109] In some embodiments, along the width direction Z of the at least one second tab 222, the ratio of the total width L2 of the at least one second tab 222 to the width L0 of the second end surface 2202 is in the range of [0.5, 0.95]. Increasing the total width L2 of the at least one second tab 222 can improve the effect of potential equalization and effectively increase the flow area, reduce heat concentration, and help heat dissipation. However, the ratio of the total width L2 of the at least one second tab 222 to the width L0 of the second end surface 2202 should be less than 0.95 to protect the second tab 222 and reduce the influence of other components on the second tab 222.

[0110] In some embodiments, along the width direction Z of the at least one second tab 222, the ratio of the total width L2 of the at least one second tab 222 to the width L0 of the second end surface 2202 can be any of the following values or any two of the following values: 0.5, 0.53, 0.55, 0.58, 0.6, 0.63, 0.65, 0.68, 0.7, 0.73, 0.75, 0.78, 0.8, 0.83, 0.85, 0.88, 0.9, 0.93, and 0.95.

[0111] It should be understood that the calculation of the total width L1 of the at least one first tab 221 is related to the number of the first tabs 221 included in the electrode assembly 22, and the calculation of the total width L2 of the at least one second tab 222 is related to the number of the second tabs 222 included in the electrode assembly 22. For example, taking the second tab 222 as an example, as shown in FIGS. 5-7, if the electrode assembly 22 includes one second tab 222, and the size of the second tab 222 along the width direction Z thereof is L2, then the total width L2 of the at least one second tab 222 of the electrode assembly 22 is equal to the width L2 of the one second tab 222. For another example, if the electrode assembly 22 includes a plurality of second tabs 222, then the total width L2 of the at least one second tab 222 of the electrode assembly 22 is equal to the sum of the widths of the plurality of second tabs 222.

[0112] It should be understood that if the electrode assembly 22 includes a plurality of second tabs 222, the arrangement of the plurality of second tabs 222 can be set according to actual application.

[0113] FIG. 10 shows a structural schematic diagram of the electrode assembly 22 of the battery cell 20 according to an embodiment of the present application, for example, FIG. 10 can be another possible structural schematic diagram of the electrode assembly 22 included in the battery cell 20 shown in FIG. 3; and FIG. 11 shows a side view schematic diagram of the electrode assembly 22 of the battery cell 20 according to an embodiment of the present application, for example, FIG. 11 can be another angle schematic diagram of the electrode assembly 22 shown in FIG. 10.

[0114] In some embodiments, the second end surface 2202 is provided with a plurality of second tabs 222 distributed at intervals along the length direction Z of the electrode assembly 22, so as to reduce the weight of the electrode assembly 22, and further reduce the weight of the battery cell 20 and the battery device 10, and improve the energy density, under the condition of reducing the potential difference of the electrode assembly 22. It should be understood that the length direction Z of the electrode assembly 22 is the extension direction Z of the longest side 2203 of the electrode assembly 22, and the length direction Z of the electrode assembly 22 is taken as the length direction Z of the battery cell 20 according to an embodiment of the present application.

[0115] In some embodiments, the widths of different second tabs 222 among the plurality of second tabs 222 spaced along the length direction Z of the electrode assembly 22 can be the same or different. For example, if the widths of different second tabs 222 among the plurality of second tabs 222 spaced along the length direction Z of the electrode assembly 22 are the same, as shown in FIGS. 10 and 11, and each second tab 222 has a width L3, then the total width L2 of at least one second tab 222 is equal to the product of the number of the plurality of second tabs 222 spaced along the length direction Z of the electrode assembly 22 and the width L3. For another example, if the widths of different second tabs 222 among the plurality of second tabs 222 spaced along the length direction Z of the electrode assembly 22 are different, then the total width L2 of at least one second tab 222 is equal to the sum of the widths of the plurality of second tabs 222.

[0116] In some embodiments, the second end surface 2202 is provided with a plurality of second tabs 222 spaced along the thickness direction Y of the electrode assembly 22, so as to reduce the weight of the electrode assembly 22, and reduce the weight of the battery cell 20 and the battery device 10, and improve the energy density. It should be understood that the thickness direction Y of the electrode assembly 22 is the stacking direction of the electrode assembly 22, and is perpendicular to the extension direction Z of the longest side 2203 of the electrode assembly 22; in addition, the thickness direction Y of the electrode assembly 22 is taken as the thickness direction Y of the battery cell 20 in the embodiments of the present application.

[0117] FIG. 12 shows a structural schematic diagram of the electrode assembly 22 of the battery cell 20 according to an embodiment of the present application, for example, FIG. 12 can be another possible structural schematic diagram of the electrode assembly 22 included in the battery cell 20 shown in FIG. 3; FIG. 13 shows a side view schematic diagram of the electrode assembly 22 of the battery cell 20 according to an embodiment of the present application, for example, FIG. 13 can be another angle schematic diagram of the electrode assembly 22 shown in FIG. 12.

[0118] In some embodiments, the second end surface 2202 is provided with a plurality of rows of second tabs 222 distributed along the length direction Z of the electrode assembly 22, each row of second tabs 222 includes a plurality of second tabs 222 spaced apart along the thickness direction Y of the electrode assembly 22, and adjacent two rows of second tabs 222 are distributed in a staggered manner. Specifically, as shown in FIGS. 12 and 11, the second end surface 2202 is provided with a plurality of rows of second tabs 222 distributed along the length direction Z of the electrode assembly 22, and one row of second tabs 222 is identified as a second tab row 2221. The second end surface 2202 is provided with a plurality of second tab rows 2221 distributed along the length direction Z of the electrode assembly 22. For any second tab row 2221, it includes a plurality of second tabs 222 spaced apart along the thickness direction Y of the electrode assembly 22, for example, each second tab row 2221 can include a plurality of second tabs 222 distributed along the thickness direction Y of the electrode assembly 22. Moreover, the number of second tabs 222 included in different second tab rows 2221 can be the same or different.

[0119] As shown in FIGS. 12 and 13, for any two adjacent second tab rows 2221, the second tabs 222 included therein are distributed in a staggered manner, for example, in the length direction Z of the electrode assembly 22, and in the thickness direction Y of the electrode assembly 22. In this way, on the one hand, the weight of the electrode assembly 22 can be reduced under the condition of reducing the potential difference of the electrode assembly 22, thereby reducing the weight of the battery monomer 20 and the battery device 10, and improving the energy density. On the other hand, considering that the electrode assembly 22 needs to be subjected to compaction treatment when assembled into the inside of the shell 21, the staggered distribution can save the space occupied by the second tabs 222, improve the space utilization rate inside the battery monomer 20, and further improve the energy density of the battery monomer 20.

[0120] FIG. 14 shows a cross-sectional view of the battery cell 20 according to embodiments of the present application, for example, the cross-section can be perpendicular to the height direction Z of the battery cell 20. FIG. 15 shows a partial cross-sectional view of the battery cell 20 according to embodiments of the present application, for example, FIG. 15 can be a partial enlarged view of the region A of FIG. 14. As shown in FIG. 14 and FIG. 15, the electrode assembly 22 after the compaction process is located in the casing 21. For the electrode assembly 22 after the compaction process, the tabs can be locally bent or curved, for example, the second tab 222 is bent along the thickness direction Y of the electrode assembly 22 after the compaction process. Therefore, for the electrode assembly 22 as shown in FIG. 12 and FIG. 13, the multiple second tabs 222 are distributed with gaps, and after the compaction process, the gaps can be used to accommodate the curved second tabs 222, reduce the space occupied by the second tabs 222 in the thickness direction Y of the electrode assembly 22, improve the internal space utilization of the battery cell 20, and further improve the energy density of the battery cell 20.

[0121] In embodiments of the present application, the electrode assembly 22 further comprises a separator 224 for separating the first tab 225 and the second tab 226.

[0122] In some embodiments, the size of the second tab 222 according to embodiments of the present application can be set according to actual application. For example, the height L4 of the second tab 222 protruding from the separator 224 can be in the range of [3mm, 8mm]. Setting the height L4 of the second tab 222 protruding from the separator 224 to be greater than or equal to 3mm can increase the contact area between the second tab 222 and the casing 21, thereby increasing the effect of current and potential equalization, and can also improve the reliability of the electrical connection between the second tab 222 and the casing 21. Conversely, setting the height L4 of the second tab 222 protruding from the separator 224 to be less than or equal to 8mm can reduce the space occupied by the second tab 222 inside the battery cell 20, thereby improving the energy density of the battery cell 20, and also reducing the weight of the electrode assembly 22, thereby reducing the weight of the battery cell 20 and the battery device 10.

[0123] In some embodiments, the height L4 of the second tab 222 protruding from the separator 224 can be any of the following values or between any two of the following values: 3mm, 3.3mm, 3.5mm, 3.8mm, 4mm, 4.3mm, 4.5mm, 4.8mm, 5mm, 5.3mm, 5.5mm, 5.8mm, 6mm, 6.3mm, 6.5mm, 6.8mm, 7mm, 7.3mm, 7.5mm, 7.8mm and 8mm.

[0124] In the embodiments of the present application, the size of the first tab 221 can also be set according to actual application. For example, the height L5 of the first tab 221 protruding from the isolation film 224 is generally greater than the height L4 of the second tab 222 protruding from the isolation film 224, so as to facilitate the electrical connection between the first tab 221 and the first electrode terminal 231. For another example, taking the electrical connection between the first tab 221 and the first electrode terminal 231 through the connecting member 25 as an example, the height L5 of the first tab 221 protruding from the isolation film 224 can be set in the range of [20mm, 30mm], so as to facilitate assembly.

[0125] It should be understood that, for the electrode assembly 22 after being compacted, the tabs can be locally bent or curved. For example, the second tab 222 can be curved along the thickness direction Y of the electrode assembly 22 after being compacted, and the straight height L6 of the curved second tab 222 protruding from the isolation film 224 is less than the height L4 before being curved. For example, as shown in FIGS. 14 and 15, the straight height L5 of the curved second tab 222 protruding from the isolation film 224 is generally in the range of [0.8mm, 2mm], but the embodiments of the present application are not limited thereto.

[0126] In the embodiments of the present application, the shell 21 of the battery cell 20 can include a housing 211 and a cover plate 212. Specifically, the housing 211 has an opening 2111, for example, through which the electrode assembly 22 is accommodated in the housing 211; and the cover plate 212 is used to cover the opening 2111 of the housing 211 to isolate the external environment.

[0127] FIG. 16 shows a cross-sectional view of the cover plate 212 in the embodiments of the present application, for example, the cover plate 212 shown in FIG. 16 can be the cover plate 212 of the battery cell 20 shown in FIGS. 3 and 4, and the cross section is perpendicular to the thickness direction Y of the battery cell 20. FIG. 17 shows an exploded structural view of the cover plate 212 in the embodiments of the present application, for example, the cover plate 212 shown in FIG. 17 can be the exploded structure of the cover plate 212 shown in FIG. 14. As shown in FIGS. 16 and 17, the housing 211 in the embodiments of the present application can be a hollow structure with at least one end forming an opening 2111, and the shape of the cover plate 212 can be adapted to the shape of the housing 211, and the cover plate 212 is used to cover the opening 2111 of the housing 211, so that the shell 21 isolates the internal environment of the battery cell 20 from the external environment. For example, if the housing 211 is a hollow structure with one end forming an opening 2111, the cover plate 212 can be provided as one; or, differently, the housing 211 can be a hollow structure with opposite ends forming openings 2111, so as to facilitate the internal electrode assembly 22 to enter the inside of the housing from either side, improve the installation efficiency, and correspondingly, the cover plate 212 can be provided as two, and the two cover plates 212 cover the openings 2111 at the two ends of the housing 211, but the embodiments of the present application are not limited thereto.

[0128] The material of the shell 211 can include one or more, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the cover plate 212 can also be one or more, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the cover plate 212 can be the same as or different from the material of the shell 211, and the materials of different walls of the shell 211 can also be the same or different.

[0129] In some embodiments, for a sodium ion battery cell, the current collectors of the positive electrode tab and the negative electrode tab included in the electrode assembly 22 can both be aluminum foil, the positive electrode tab and the negative electrode tab can both be electrically connected to the shell 211, and the material of the shell 211 can be aluminum or steel. For a lithium ion battery cell, if the material of the shell 211 is aluminum, lithium ions and the aluminum shell are easy to form a lithium-aluminum alloy, so when the second tab 222 of the electrode assembly 22 of the lithium ion battery is electrically connected to the shell 211, the material of the shell 211 cannot usually be aluminum.

[0130] The shell 211 and the cover plate 212 of the embodiments of the present application are matched in shape, for example, as shown in FIGS. 16 and 17, the shell 211 can be an approximate cuboid structure, and the cover plate 212 is an approximate rectangular plate structure matched with the shell 211. The cover plate 212 can be any one wall of the shell 21, for example, the cover plate 212 can be the largest wall or the smallest wall among the multiple walls included in the shell 21, or it can also be other walls, and the embodiments of the present application are not limited thereto. Alternatively, the cover plate 212 can also be other structures, for example, the cover plate 212 can also be a groove structure with an opening to cover the opening 2111 of the shell 211, and the embodiments of the present application are not limited thereto.

[0131] For ease of illustration, the shell 21 is taken as an approximate cuboid as shown in FIGS. 3 to 4; the shell 211 is a hollow structure with one end open, and correspondingly, as shown in FIGS. 16 and 17, the opening 2111 of the shell 211 is covered by the cover plate 212 with an approximate rectangular surface, for example, the sealing connection between the shell 211 and the cover plate 212 can be achieved by welding to form a closed cavity for placing the electrode assembly 22, thereby improving the sealing reliability.

[0132] In some embodiments, as shown in FIGS. 16 and 17, the cover plate 212 of the embodiments of the present application can include a top cover plate 2121 and a support 2122 for supporting the top cover plate 2121 and components arranged on the cover plate 212.

[0133] In the embodiments of the present application, the first electrode terminal 231 is arranged on the shell 21, and the first electrode terminal 231 can be arranged on any wall of the shell 21. For example, the cover plate 212 is provided with the first electrode terminal 231, and the first electrode terminal 231 is electrically insulated from the cover plate 212 to facilitate processing and assembly. As shown in FIGS. 16 and 17, the first electrode terminal 231 of the embodiments of the present application is used to be electrically connected with the first tab 221, for example, the first electrode terminal 231 can be electrically connected with the first tab 221 through the connecting member 25. The first electrode terminal 231 can be a positive electrode terminal, and the first tab 221 is a positive tab; conversely, the first electrode terminal 231 can be a negative electrode terminal, and the first tab 221 is a negative tab.

[0134] It should be understood that the structure of the first electrode terminal 231 of the embodiments of the present application can be arranged according to actual application, for example, as shown in FIGS. 16 and 17, the cover plate 212 can include a first electrode lead-out hole 2123 corresponding to the first electrode terminal 231, and the first electrode terminal 231 is electrically connected with the first tab 221 below through the first electrode lead-out hole 2123. For example, at least part of the first electrode terminal 231 can be accommodated in the first electrode lead-out hole 2123, but the embodiments of the present application are not limited thereto.

[0135] As shown in FIGS. 16 and 17, the first electrode terminal 231 can include a first pole 2311 and a first fixing structure 2312, and the first pole 2311 is fixed with the cover plate 212 through the first fixing structure 2312, for example, the first fixing structure 2312 can be a riveting block, and the first pole 2311 is riveted with the cover plate 212 through the riveting block.

[0136] Further, the first electrode terminal 231 further includes an insulating piece for electrically insulating the first electrode terminal 231 from the cover plate 212. For example, the insulating piece can include a first insulating structure 2313 and a second insulating structure 2314, and the first electrode terminal 231 is electrically insulated from the cover plate 212 through the first insulating structure 2313 and the second insulating structure 2314.

[0137] It should be understood that the second tab 222 of the embodiments of the present application is electrically connected with the shell 21, for example, the second tab 222 can be in contact with any wall of the shell 211 to achieve electrical connection with the shell 211.

[0138] In some embodiments, the battery cell 20 of the embodiments of the present application can further comprise a second electrode terminal 232, which is electrically connected with the shell 211, and further electrically connected with the second tab 222 to output electric energy. For example, the second electrode terminal 232 can be a positive electrode terminal, and the second tab 222 is a positive tab; conversely, the second electrode terminal 232 can be a negative electrode terminal, and the second tab 222 is a negative tab. The second electrode terminal 232 is electrically connected with the second tab 222 through the shell 211, which can save the connecting member, simplify the structure of the battery cell 20, reduce the weight of the battery cell 20, and facilitate the processing and assembly of the battery cell 20. In addition, the second electrode terminal 232 can also be used to realize the electrical connection between a plurality of battery cells 20. For example, the electrical connection between a plurality of battery cells 20 can be realized by welding the second electrode terminal 232 with the busbar, and welding the busbar with the second electrode terminal 232 can also improve the connection stability and reliability between a plurality of battery cells 20.

[0139] It should be understood that the second electrode terminal 232 of the embodiments of the present application can be located at any one wall of the battery cell 20, and the second electrode terminal 232 can be located at the same or different wall as the first electrode terminal 231. For example, the second electrode terminal 232 and the first electrode terminal 231 can be located at the same wall to facilitate processing and assembly.

[0140] In some embodiments, the cover plate 212 is further provided with the second electrode terminal 232, which is electrically connected with the shell 211 through the cover plate 212. The second electrode terminal 232 and the first electrode terminal 231 are both arranged on the cover plate 212, which facilitates processing and facilitates the electrical connection between a plurality of battery cells 20 through the second electrode terminal 232 and the first electrode terminal 231.

[0141] It should be understood that the structure of the second electrode terminal 232 of the embodiments of the present application can be set according to actual application, for example, as shown in FIGS. 16 and 17, the cover plate 212 can comprise a second electrode lead-out hole 2124 corresponding to the second electrode terminal 232. For example, at least part of the second electrode terminal 232 can be accommodated in the second electrode lead-out hole 2124, but the embodiments of the present application are not limited thereto.

[0142] As shown in FIGS. 16 and 17, the second electrode terminal 232 can comprise a second pole 2321 and a second fixing structure 2322, the second pole 2321 is fixed with the cover plate 212 through the second fixing structure 2322, for example, the second fixing structure 2322 can be a riveting block, the second pole 2321 is riveted and electrically connected with the cover plate 212 through the riveting block, and further electrically connected with the second tab 222 through the cover plate 212.

[0143] In some embodiments, the cover plate 212 can also be provided with other structures. For example, the battery cell 20 can also include a pressure relief mechanism 24, which can be provided on the cover plate 212. The pressure relief mechanism 24 refers to an element or component that is actuated when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold, to release the internal pressure or temperature. The threshold value is designed differently according to different design requirements. The threshold value can depend on the material of one or more of the positive electrode tab, the negative electrode tab, the electrolyte, and the separator film in the battery cell 20.

[0144] The "actuation" mentioned in the present application refers to the pressure relief mechanism 24 generating an action or being activated to a certain state, so that the internal pressure and temperature of the battery cell 20 can be released. The action generated by the pressure relief mechanism 24 can include but is not limited to at least one of the following: the pressure relief mechanism 24 is broken, cracked, torn or opened, etc. When the pressure relief mechanism 24 is actuated, the high-temperature and high-pressure substances inside the battery cell 20 will be discharged outward from the actuated part as the discharge. In this way, the battery cell 20 can be relieved of pressure and temperature in a controllable manner, thereby avoiding potential more serious accidents.

[0145] The discharge from the battery cell 20 mentioned in the present application includes but is not limited to: electrolyte, dissolved or split positive and negative electrode tabs, fragments of the separator film, high-temperature and high-pressure gas generated by the reaction, flame, etc.

[0146] It should be understood that the structure of the pressure relief mechanism 24 of the embodiments of the present application can be set according to actual application. For example, the pressure relief mechanism 24 can include a pressure relief sheet 241, which can be provided with a notch, so that when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold, the notch of the pressure relief sheet 241 is damaged, and the pressure inside the battery cell 20 is released in time. The pressure relief mechanism 24 can also include a protective sheet 242 to protect the pressure relief sheet 241 and improve the service life of the pressure relief mechanism 24.

[0147] In some embodiments, the battery cell 20 can also be provided with only the first electrode terminal 231, without the second electrode terminal 232. FIG. 18 shows a structural schematic diagram of a battery cell 20 according to another embodiment of the present application. As shown in FIG. 18, the battery cell 20 can include at least one first electrode terminal 231, without the second electrode terminal 232. When a plurality of battery cells 20 are electrically connected as shown in FIG. 18, the electrical connection of the two battery cells 20 can be achieved by directly electrically connecting the first electrode terminal 231 of one battery cell 20 with the housing 211 of another battery cell 20, which can reduce the number of electrode terminals of the battery cell 20, facilitate processing, simplify the structure, and further reduce the weight of the battery cell 20.

[0148] It should be understood that, in the above description, the second end face 2202 where the second tab 222 is located is mainly taken as an example which is not the area-smallest end face of the electrode assembly 22, or alternatively, the second end face 2202 where the second tab 222 of the electrode assembly 22 is located can also be other end faces of the electrode assembly 22.

[0149] FIG. 19 shows a structural schematic diagram of an electrode assembly 22 according to another embodiment of the present application. As shown in FIG. 19, the electrode assembly 22 includes a first tab 221 and a second tab 222 with opposite polarities, wherein the electrode assembly 22 includes multiple second tabs 222 located at different end faces, the first tab 221 is electrically connected to the first electrode terminal 231 of the battery monomer 20, and the multiple second tabs 222 are all electrically connected to the shell 21 of the battery monomer 20. By arranging the second tabs 222 at multiple end faces of the electrode assembly 22, the overcurrent area can be effectively increased, the charging and discharging rate of the battery monomer 20 can be improved, the heat dissipation performance can be improved, and thus the performance and reliability of the battery monomer 20 can be improved. In addition, for electrode assemblies 22 of different sizes, by arranging the second tabs 222 at multiple end faces, the potential difference of the electrode assembly 22 can be reduced, the energy loss during the charging and discharging process of the battery monomer 20 can be reduced, and the performance and reliability of the battery monomer 20 can be improved.

[0150] In some embodiments, taking the first tab 221 located at the first end face 2201 and the second tab 222 located at the second end face 2202 as an example, as shown in FIG. 19, the electrode assembly 22 can include multiple second end faces 2202, and the multiple second end faces 2202 can be arranged intersectingly or opposingly, and the second end face 2202 and the first end face 2201 can be the same end face or different end faces. For example, FIG. 19 takes an example of the electrode assembly including two opposingly arranged second end faces 2202, which are arranged along the extension direction of the longest side 2203 of the electrode assembly 22, so as to reduce the potential difference of the electrode assembly 22; in FIG. 19, the second end face 2202 and the first end face 2201 are different end faces, so as to reduce the mutual influence between the first tab 221 and the second tab 222.

[0151] It should be understood that, for any one of the second end faces 2202 of the electrode assembly 22, the arrangement of the second tab 222 can refer to the related description of FIGS. 5 to 13, and for the sake of brevity, will not be repeated here.

[0152] According to some embodiments of the present application, the present application further provides a battery device 10 including the battery monomer 20 according to any one of the above schemes.

[0153] According to some embodiments of the present application, the present application further provides a power-consuming device including the battery device 10 according to any one of the above schemes, and the battery device 10 is used to provide electric energy for the power-consuming device.

[0154] The electric device can be a device or system of any of the application batteries described above.

[0155] According to some embodiments of the present application, referring to FIGS. 3-17, the present application provides a battery cell, comprising: a housing 21; a first electrode terminal 231, the first electrode terminal 231 being disposed on the housing 21 and electrically insulated from the housing 21; an electrode assembly 22 accommodated in the housing 21, the electrode assembly 22 comprising first and second polar plates 225 and 226 of opposite polarity, the first and second polar plates 225 and 226 being alternately stacked along a thickness direction of the electrode assembly 22, a circumferential direction of the electrode assembly 22 comprising two oppositely disposed first end faces 2201 and two oppositely disposed second end faces 2202, an area of the second end face 2202 being greater than an area of the first end face 2201, the first polar plate 225 being provided with a first tab 221, the second polar plate 226 being provided with a second tab 222, the first tab 221 being electrically connected to the first electrode terminal 231, the second tab 222 being electrically connected to the housing 21, the second tab 222 being located at the second end face 2202, and the first tab 221 being located at the first end face 2201; or, the first and second tabs 221 and 222 being respectively located at the two oppositely disposed second end faces 2202. The first tab 221 is a positive electrode tab, and the second tab 222 is a negative electrode tab. The electrode assembly 22 comprises at least one first tab 221 and at least one second tab 222, a total width of the at least one second tab 222 being greater than a total width of the at least one first tab 221.

[0156] The second end face 2202 is provided with a plurality of second tabs 222 distributed at intervals along a length direction of the electrode assembly 22. Alternatively, the second end face 2202 is provided with a plurality of second tabs 222 distributed at intervals along a thickness direction of the electrode assembly 22. Alternatively, the second end face 2202 is provided with a plurality of columns of second tabs 222 distributed along the length direction of the electrode assembly 22, each column of second tabs 222 comprising a plurality of second tabs 222 distributed at intervals along the thickness direction of the electrode assembly 22, and adjacent two columns of second tabs 222 being distributed in a staggered manner.

[0157] The electrode assembly 22 further comprises a separator 224 for separating the first and second polar plates 225 and 226, and a height of the second tab 222 protruding from the separator 224 is in a range of [3mm, 8mm].

[0158] The shell 21 comprises a shell body 211 having an opening 2111, and a cover plate 212 used to cover the opening 2111 of the shell body 211, the cover plate 212 being provided with a first electrode terminal 231 electrically insulated from the cover plate 212. The cover plate 212 is further provided with a second electrode terminal 232 electrically connected to the shell body 211 through the cover plate 212.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the same. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some or all of the technical features. Such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any way as long as there is no structural conflict. 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, characterized by, include: Outer shell (21); A first electrode terminal (231) is disposed on the housing (21) and electrically insulated from the housing (21); An electrode assembly (22) is housed within the outer casing (21). The electrode assembly (22) includes a first electrode (225) and a second electrode (226) with opposite polarities. The first electrode (225) and the second electrode (226) are alternately stacked along the thickness direction of the electrode assembly (22). The circumferential direction of the electrode assembly (22) includes two opposing first end faces (2201) and two opposing second end faces (2202). The area of ​​the second end face (2202) is larger than the area of ​​the first end face (2201). The first electrode (225) is provided with a first tab (221), and the second electrode (226) is provided with a second tab (222). The first tab (221) is electrically connected to the first electrode terminal (231), and the second tab (222) is electrically connected to the outer casing (21). The second tab (222) is located on the second end face (2202).

2. The battery cell of claim 1, wherein, The electrode assembly (22) includes at least one first tab (221) and at least one second tab (222), the total width of the at least one second tab (222) being greater than the total width of the at least one first tab (221).

3. The battery cell of claim 2, wherein, Along the width direction of the at least one second tab (222), the ratio of the total width of the at least one second tab (222) to the width of the second end face (2202) ranges from [0.5, 0.95].

4. The battery cell according to any one of claims 1 to 3, characterized in that, The first electrode tab (221) is located on the first end face (2201).

5. The battery cell according to any one of claims 1 to 4, characterized in that, The first electrode (221) and the second electrode (222) are located on two oppositely arranged second end faces (2202).

6. The battery cell of any one of claims 1 to 5, wherein, The second end face (2202) is provided with a plurality of second tabs (222) spaced apart along the length direction of the electrode assembly (22).

7. The battery cell of claim 6, wherein, The second end face (2202) is provided with a plurality of second tabs (222) spaced apart along the thickness direction of the electrode assembly (22).

8. The battery cell of claim 6, wherein, The second end face (2202) is provided with multiple rows of second tabs (222) distributed along the length direction of the electrode assembly (22). Each row of second tabs (222) includes multiple second tabs (222) spaced apart along the thickness direction of the electrode assembly (22). Adjacent rows of second tabs (222) are staggered.

9. The battery cell of any one of claims 1 to 8, wherein, The first electrode (221) is a positive electrode, and the second electrode (222) is a negative electrode.

10. The battery cell of any one of claims 1 to 9, wherein, The electrode assembly (22) also includes: A separator (224) is used to isolate the first electrode (225) and the second electrode (226). The height of the second electrode tab (222) protruding from the separator (224) is in the range of [3mm, 8mm].

11. The battery cell of any one of claims 1 to 10, wherein, The outer casing (21) includes: A shell (211) having an opening (2111); A cover plate (212) for covering the opening (2111) of the shell (211), the cover plate (212) being provided with the first electrode terminal (231), the first electrode terminal (231) being electrically insulated from the cover plate (212).

12. The battery cell of claim 11, wherein, The cover plate (212) is further provided with a second electrode terminal (232), the second electrode terminal (232) being electrically connected with the shell (211) through the cover plate (212).

13. The battery cell of any one of claims 1 to 12, wherein, The second lug (222) is welded to the shell (21).

14. A battery device characterized by comprising: Comprising: The battery cell according to any one of claims 1 to 13.

15. An electrical device, characterized by Comprising: A battery device comprising the battery cell according to any one of claims 1 to 13, the battery device being configured to supply power to the power consuming device.

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