Battery cells, batteries, power consumption devices and energy storage devices

Abstract

The embodiments of the present application provide a battery cell, a battery, a power consumption device, and an energy storage device, wherein the battery cell includes a housing and at least one electrode assembly, the electrode assembly is accommodated in the housing, the housing is a cuboid, the size of the housing in a first direction is W1, the size of the housing in a second direction is T1, and the size of the housing in a third direction is H1, the first direction, the second direction, and the third direction are perpendicular to each other, the housing includes a first wall and a second wall disposed opposite each other along the first direction, a third wall and a fourth wall disposed opposite each other along the second direction, and a fifth wall and a sixth wall disposed opposite each other along the third direction, wherein a sum of thicknesses of the first wall and the second wall is a, a sum of thicknesses of the third wall and the fourth wall is b, and a sum of thicknesses of the fifth wall and the sixth wall is c, and (W1-a)*(T1-b)*(H1-c) / (W1*T1*H1)≧90%. In this way, the volumetric energy density of the battery cell can be improved using the same chemical material system.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to international application PCT / CN2023 / 101943 entitled "Battery Cell, Battery, Power Consumption Device and Energy Storage Device" filed on June 21, 2023, the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] This application relates to the field of battery technology, and in particular to battery cells, batteries, power consuming devices and energy storage devices. [Background technology]

[0003] With the development of new energy technologies, the applications of batteries are becoming more and more widespread, such as in mobile phones, laptops, battery cars, electric vehicles, energy storage devices, electric airplanes, electric steamers, electric toy cars, electric toy steamers, electric toy airplanes and power tools.

[0004] In the development of battery technology, how to improve the volumetric energy density of battery cells is one of the problems that needs to be solved urgently in battery technology. Summary of the Invention

[0005] The embodiments of the present application provide a battery cell, a battery, a power consumption device, and an energy storage device that can effectively improve the volumetric energy density of the battery cell.

[0006] According to a first aspect, an embodiment of the present application provides a battery cell, the battery cell including: a housing having a cuboid shape; a size of the housing in a first direction is W1; a size of the housing in a second direction is T1; and a size of the housing in a third direction is H1, the first direction, the second direction, and the third direction are perpendicular to each other; and at least one electrode assembly accommodated in the housing; the housing includes a first wall and a second wall disposed opposite each other along the first direction, a third wall and a fourth wall disposed opposite each other along the second direction, and a fifth wall and a sixth wall disposed opposite each other along the third direction; a sum of thicknesses of the first wall and the second wall is a, a sum of thicknesses of the third wall and the fourth wall is b, and a sum of thicknesses of the fifth wall and the sixth wall is c; and (W1-a)*(T1-b)*(H1-c) / (W1*T1*H1)≧90% is satisfied.

[0007] In the above technical solution, the ratio of the battery cell housing volume to the housing volume is set to 90% or more, thereby increasing the internal space of the housing and allowing a larger electrode assembly and more electrolyte to be accommodated inside the housing, thereby improving the volumetric energy density of the battery cell with the same chemical material system.

[0008] In some embodiments, (W1-a) / W1≧97.0%, (T1-b) / T1≧96.5%, and (H1-c) / H1≧96.5%, which can improve the size occupancy rate of the housing's internal space in three directions and further improve the volumetric energy density of the battery cell.

[0009] In some embodiments, the housing includes a case and one end cover, the case having an opening at one end along a third direction, the end cover covering the opening, the case including the first wall, the second wall, the third wall, the fourth wall, and the fifth wall integrally formed therewith, and the end cap being the sixth wall.

[0010] In some embodiments, the battery cell further includes a first insulating member and a second insulating member, the first insulating member being disposed between the fifth wall and the electrode assembly and abutting the fifth wall, the second insulating member being disposed between the sixth wall and the electrode assembly and abutting the sixth wall, the maximum size of the first insulating member in the third direction being d1, the maximum size of the second insulating member in the third direction being d2, and satisfying the following relationships: (W1-a-1.6 mm)*(T1-b-1.6 mm)*(H1-c-d1-d2) / (W1*T1*H1)≧88%, 0.3 mm≦d1≦1.2 mm, and 2 mm≦d2≦10 mm. In this manner, the space remaining for the electrode assembly inside the housing can be increased, allowing a larger-volume electrode assembly to be mounted, thereby further improving the volumetric energy density of the battery cell.

[0011] In some embodiments, the battery cell further includes a first insulating member and a second insulating member, the first insulating member being disposed between the fifth wall and the electrode assembly and abutting the fifth wall, the second insulating member being disposed between the sixth wall and the electrode assembly and abutting the sixth wall, a maximum size of the first insulating member in the third direction being d1, a maximum size of the second insulating member in the third direction being d2, and satisfying (W1-a-4mm)*(T1-b-4mm)*(H1-c-d1-d2) / (W1*T1*H1)≧85%, 0.3mm≦d1≦1.2mm, and 2mm≦d2≦10mm.

[0012] In some embodiments, the housing includes a case and two end caps, the case having two openings arranged opposite each other along the third direction, the two end caps respectively covering the openings on corresponding sides, the case including the first wall, the second wall, the third wall, and the fourth wall integrally formed therewith, and the two end caps being the fifth wall and the sixth wall, respectively.

[0013] In some embodiments, the battery cell further includes a third insulating member and a fourth insulating member, the third insulating member being disposed between the fifth wall and the electrode assembly and abutting the fifth wall, the fourth insulating member being disposed between the sixth wall and the electrode assembly and abutting the sixth wall, the third insulating member having a maximum size in the third direction of d3, the fourth insulating member having a maximum size in the third direction of d4, and satisfying (W1-a-1.6mm)*(T1-b-1.6mm)*(H1-c-d3-d4) / (W1*T1*H1)≧88%, 2mm≦d3≦10mm, and 2mm≦d4≦10mm.

[0014] In some embodiments, the battery cell further includes a third insulating member and a fourth insulating member, the third insulating member being disposed between the fifth wall and the electrode assembly and abutting the fifth wall, the fourth insulating member being disposed between the sixth wall and the electrode assembly and abutting the sixth wall, the third insulating member having a maximum size in the third direction of d3, the fourth insulating member having a maximum size in the third direction of d4, and satisfying (W1-a-4mm)*(T1-b-4mm)*(H1-c-d3-d4) / (W1*T1*H1)≧85%, 2mm≦d3≦10mm, and 2mm≦d4≦10mm.

[0015] In some embodiments, 3000 cm 3 ≦W1*T1*H1≦40000cm 3 In this way, on the one hand, when the housing volume-to-volume ratio is 90% or more, the housing wall thickness can be prevented from being too small, thereby satisfying the requirements for the structural strength and rigidity of the housing, and on the other hand, the capacity and current of the battery cell can be controlled within an appropriate range, reducing the heat generated by the battery cell and the risk of damage to components in the circuit.

[0016] In some embodiments, 3200 cm 3≦W1*T1*H1≦32000cm 3 is.

[0017] In some embodiments, 3720 cm 3 ≦W1*T1*H1≦12500cm 3 is.

[0018] In some embodiments, 4000 cm 3 ≦W1*T1*H1≦6000cm 3 is.

[0019] In some embodiments, the electrode assembly includes a main body and a tab extending from the main body, the main body being flat, the main body having a maximum size in the first direction of W2, the main body having a maximum size in the second direction of T2, and the main body having a maximum size in the third direction of H2, wherein (W2*T2*H2) / (W1*T1*H1)≧80% is satisfied. In this manner, the electrode assembly can fully utilize the internal space of the housing, and a situation where the housing has a large volume but the electrode assembly has a small volume is avoided, thereby improving the volumetric energy density of the battery cell and reducing movement of the electrode assembly within the housing.

[0020] In some embodiments, W2 / (W1-a)≧91.5%, T2 / (T1-b)≧93.2%, and H2 / (H1-c)≧94.0%.

[0021] In some embodiments, the electrode assembly has a wound structure, the main body includes a flat region, a first folded region, and a second folded region, the first folded region and the second folded region are located at opposite ends of the flat region along the first direction, the first folded region includes a plurality of first folded portions stacked together, a distance between an inner vertex of the first folded portion of an innermost layer of the plurality of first folded portions and an outer vertex of the first folded portion of an outermost layer of the plurality of first folded portions along the first direction is W3, the second folded region includes a plurality of second folded portions stacked together, a distance between an inner vertex of the second folded portion of an innermost layer of the plurality of second folded portions and an outer vertex of the second folded portion of an outermost layer of the plurality of second folded portions along the first direction is W4, and (W3 + W4) / W2≦30% is satisfied. In this way, the size occupancy rate of the first folding region and the second folding region in the first direction is reduced, and the size occupancy rate of the flat region in the first direction is increased, thereby reducing the volume occupancy rate of the gap between the folding region and the inner surface of the housing, thereby improving the effective utilization rate of the internal space of the housing and improving the volumetric energy density of the battery cell.

[0022] In some embodiments, the first wall, the second wall, the third wall, the fourth wall, the fifth wall, and the sixth wall are all made of an aluminum alloy, and the aluminum alloy has a mass percentage content of aluminum >= 96.7%, 0.05% <= copper <= 0.2%, iron <= 0.7%, manganese <= 1.5%, silicon <= 0.6%, zinc <= 0.1%, other single element content <= 0.05%, and total content of other elements <= 0.15%. In this way, a stronger aluminum alloy can be obtained, and using this aluminum alloy as the housing material can significantly improve the impact resistance of the housing and enhance the reliability of the battery cell.

[0023] In some embodiments, the housing includes a case and an end cap, the case has an opening, the end cap is fitted over the opening, the end cap is welded to the case, the case includes the first wall, the second wall, the third wall, the fourth wall, and the fifth wall that are integrally formed, the end cap is the sixth wall, the thicknesses of the first wall and the second wall are all a1, the thicknesses of the third wall and the fourth wall are all b1, the thickness of the fifth wall is c1, and the thickness of the sixth wall is c2, satisfying c2>c1, c1>a1, and c1>b1.

[0024] In some embodiments, 0.5 mm≦a1≦1.5 mm, 0.5≦b1≦1.5 mm, 1.0 mm≦c1≦2.5 mm, and 1.5 mm≦c2≦4 mm.

[0025] In some embodiments, the battery cell includes an electrode terminal, the electrode terminal is installed on the end cap or the fifth wall, and the electrode terminal is electrically connected to the electrode assembly.

[0026] In some embodiments, (W1-2*a1)*(T1-2*b1)*(H1-c1-c2) / (W1*T1*H1)≧95%.

[0027] In some embodiments, the housing includes a case and two end caps, the case has two openings arranged opposite each other along the third direction, the two end caps are respectively fitted over the openings on corresponding sides, and the end caps are welded to the case, the case includes the first wall, the second wall, the third wall, and the fourth wall which are integrally formed, the two end caps being the fifth wall and the sixth wall, respectively, the thicknesses of the first wall and the second wall are both a1, the thicknesses of the third wall and the fourth wall are both b1, the thickness of the fifth wall is c1, and the thickness of the sixth wall is c2, satisfying c2=c1, c1>a1, and c1>b1.

[0028] In some embodiments, 0.5 mm≦a1≦1.5 mm, 0.5≦b1≦1.5 mm, and 1.5 mm≦c2≦4 mm.

[0029] In some embodiments, the battery cell includes an electrode terminal, the electrode terminal is mounted on the end cap, and the electrode terminal is electrically connected to the electrode assembly.

[0030] In some embodiments, (W1-2*a1)*(T1-2*b1)*(H1-2*c1) / (W1*T1*H1)≧95%.

[0031] In some embodiments, T1 <W1、T1

[0032] In some embodiments, 40 mm≦T1≦150 mm.

[0033] In some embodiments, the third direction is parallel to the direction of gravity, the battery cell contains an electrolyte, and 120 mm≦H1≦400 mm.

[0034] In some embodiments, 150 mm≦W1≦1500 mm.

[0035] In some embodiments, the positive electrode material of the battery cell includes a lithium-containing phosphate, and the capacity of the battery cell is C, where C≧350 Ah and C / ((W1−a)*(T1−b)*(H1−c))≧118 Ah / L.

[0036] In some embodiments, the positive electrode material of the battery cell includes a lithium transition metal oxide, and the capacity of the battery cell is C, where C≧650 Ah and C / ((W1−a)*(T1−b)*(H1−c))≧190 Ah / L.

[0037] ​In some embodiments, the battery cell is a sodium ion battery, and the capacity of the battery cell is C, where C≧260 Ah, and C / ((W1−a)*(T1−b)*(H1−c))≧87 Ah / L.

[0038] According to a second aspect, an embodiment of the present application provides a battery, the battery including a battery housing and a battery cell according to any one of the embodiments of the first aspect, the battery cell being housed within the battery housing.

[0039] According to a third aspect, an embodiment of the present application provides a power consuming device, the device including a battery according to any one of the embodiments of the second aspect.

[0040] According to a fourth aspect, an embodiment of the present application provides an energy storage device including an energy storage housing and a plurality of battery cells according to any one of the embodiments of the first aspect, wherein the energy storage housing includes a battery chamber, and the plurality of battery cells are housed within the battery chamber.

[0041] In some embodiments, the battery cells include electrode terminals, and the electrode terminals are installed in the housing, where the sum of the volumes of the housings for the battery cells is V1, and the volume of the battery compartment is V2, satisfying 0.5≦V1 / V2≦0.95. In this way, the space utilization rate of the energy storage device can be improved, and by arranging more battery cells in the battery compartment of the energy storage housing, i.e., by arranging more energy providing structures in a unit space, the energy density can be improved, thereby improving capacity without increasing the occupied space. [Brief explanation of the drawings]

[0042] In order to more clearly explain the technical solutions of the embodiments of the present application, the following briefly introduces the drawings that need to be used in the embodiments. It should be understood that the following drawings only illustrate some embodiments of the present application, and should not be considered as limiting the scope. Those skilled in the art can also obtain other related drawings based on these drawings without any creative efforts. [Figure 1] 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application. [Figure 2] FIG. 1 is an exploded view of a battery according to some embodiments of the present application. [Figure 3] 1 is a structural schematic diagram of an energy storage device according to some embodiments of the present application. [Figure 4] FIG. 4 is a schematic diagram of the internal structure of the energy storage device shown in FIG. 3. [Figure 5] 1 is a structural schematic diagram of a battery cell according to some embodiments of the present application; [Figure 6] FIG. 6 is an exploded view of the battery cell shown in FIG. [Figure 7] 6 is an exploded cross-sectional view of the battery cell shown in FIG. 5 taken along the XZ plane. [Figure 8] 6 is an exploded cross-sectional view of the battery cell shown in FIG. 5 taken along the YZ plane. [Figure 9] 1 is a structural schematic diagram of a battery cell according to some other embodiments of the present application. [Figure 10] FIG. 10 is an exploded view of the battery cell shown in FIG. [Figure 11] 11 is an exploded cross-sectional view of the battery cell shown in FIG. 10 taken along the XZ plane. [Figure 12] 11 is an exploded cross-sectional view of the battery cell shown in FIG. 10 taken along the YZ plane. [Figure 13] FIG. 7 is a front view of the electrode assembly shown in FIG. 6. [Figure 14] FIG. 7 is a side view of the electrode assembly shown in FIG. 6. [Figure 15] FIG. 7 is a top view of the electrode assembly shown in FIG. 6. [Figure 16] FIG. 7 is a cross-sectional view of the electrode assembly shown in FIG. 6. [Figure 17] FIG. 10 is an exploded view of a battery cell according to some further embodiments of the present application. [Figure 18] FIG. 18 is a front view of the electrode assembly shown in FIG. 17. [Figure 19] FIG. 18 is a side view of the electrode assembly shown in FIG. 17. DETAILED DESCRIPTION OF THE INVENTION

[0043] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present application, the following will clearly describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. Based on the embodiments of the present application, all other embodiments that can be obtained by those skilled in the art without any creative efforts fall within the scope of protection of the present application.

[0044] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art of this application, and the terms used in the specification of this application are only for describing specific embodiments and are not intended to limit this application, and the terms "comprises," "has," and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover a non-exclusive "comprise." The terms "first," "second," etc. in the specification and claims of this application or the above-mentioned drawings are not intended to describe a specific order or a hierarchical relationship, but are intended to distinguish different objects.

[0045] An "embodiment" referred to in this application means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of this phrase in various places in the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, separate, or alternative embodiments of other embodiments.

[0046] In the embodiments of the present application, the same reference numerals refer to the same elements, and for the sake of brevity, detailed descriptions of the same elements in different embodiments will be omitted. The term "plurality" as used in the present application refers to two or more (including two).

[0047] In the present application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, or a magnesium ion battery, etc., and the embodiments of the present application are not limited thereto.

[0048] The battery referred to in the embodiments of this application refers to a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. The battery generally includes a battery casing for packaging one or more battery cells. The battery casing can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0049] A battery cell includes a housing, an electrode assembly, and an electrolyte. The housing is used to contain the electrode assembly and the electrolyte. The electrode assembly is composed of a positive electrode plate, a negative electrode plate, and a separator. The battery cell operates mainly through the movement of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector without the positive electrode active material layer protrudes from the positive electrode current collector coated with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer is called a positive electrode tab. For example, in a lithium-ion battery, the positive electrode current collector may be made of aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, etc. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector without the negative electrode active material layer protrudes from the negative electrode current collector coated with the negative electrode active material layer, and the negative electrode current collector without the negative electrode active material layer is called a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon. To prevent melting even when a large current is passed through, multiple positive electrode tabs are stacked, and multiple negative electrode tabs are stacked. The material of the separator may be PP (polypropylene) or PE (polyethylene). The electrode assembly may have a wound structure or a stacked structure, and the embodiments of the present application are not limited thereto.

[0050] The battery cell may further include an electrode terminal, which is installed in the housing and electrically connected to a tab of the electrode assembly to output electrical energy from the battery cell. The electrode terminal and the tab may be directly connected, for example, by direct welding. The electrode terminal and the tab may also be indirectly connected, for example, by a current collecting part. The current collecting part may be a metal conductor, for example, copper, iron, aluminum, steel, aluminum alloy, etc.

[0051] The development of battery technology requires simultaneous consideration of a wide range of design factors, including performance parameters such as safety, cycle life, discharge capacity, charge / discharge rate, etc. Volumetric energy density is also an important parameter for evaluating the merits and demerits of battery performance.

[0052] In battery cells, the housing is generally designed to be relatively thick to improve safety and reduce the risk of the housing bursting when the battery cell is subjected to an external impact or when the internal pressure of the battery cell is relatively large. However, a thicker housing reduces the internal space of the housing. In addition, to reduce the possibility of an internal short circuit occurring in the battery cell, several insulating members are generally installed inside the housing. These insulating members inevitably occupy some space, leaving very limited space for the electrode assembly, resulting in a relatively low volumetric energy density of the battery cell. The volume is relatively large, especially when the volume is 3000 cm or less. 3 For the above battery cells, the mass of the electrode assembly is large, the impact force on the housing is large, and the load that the housing must bear is also large, so the housing is generally designed to be thicker, which makes the problem of low volumetric energy density of large-volume battery cells more pronounced.

[0053] In view of this, the embodiments of the present application provide a battery cell in which the ratio of the volume of the housing to the volume of the battery is 90% or more, thereby increasing the internal space of the housing to accommodate a larger electrode assembly and a larger amount of electrolyte, and improving the volumetric energy density of the battery cell with the same chemical material system.

[0054] The battery cells described in the embodiments of the present application are applicable to batteries and power consuming devices that use batteries.

[0055] The power consuming devices may be vehicles, mobile phones, portable devices, laptops, steamships, spacecraft, electric toys, and power tools, etc. The vehicles may be fuel oil vehicles, gas vehicles, or new energy vehicles, and the new energy vehicles may be pure electric vehicles, hybrid vehicles, or range extender vehicles, etc. The spacecraft may include airplanes, rockets, space shuttles, and spaceships, etc. The electric toys may include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc. The power tools may include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not particularly limit the above power consuming devices.

[0056] In the following embodiments, for convenience of explanation, the power consuming device is a vehicle.

[0057] Referring to Fig. 1, Fig. 1 is a structural schematic diagram of a vehicle 1000 according to some embodiments of the present application. A battery 100 is installed inside the vehicle 1000, and the battery 100 may be installed at the bottom, head, or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000.

[0058] The vehicle 1000 may further include a controller 200 and a motor 300, where the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting the vehicle 1000, navigation, and operating power consumption needs during driving.

[0059] In some embodiments of the present application, the battery 100 can not only be the operating power source for the vehicle 1000, but can also provide driving power for the vehicle 1000 as a driving power source for the vehicle 1000, in place of, or in place of, fuel oil or natural gas.

[0060] 2, which is an exploded view of a battery 100 according to some embodiments of the present application. The battery 100 includes a battery cell 10 and a battery housing 20, and the battery cell 10 is housed within the battery housing 20.

[0061] Here, the battery housing 20 is a member that houses the battery cells 10, and the battery housing 20 provides an accommodation space for the battery cells 10. The battery housing 20 may have various structures. In some embodiments, the battery housing 20 may include a first portion 201 and a second portion 202, which are fitted together to define an accommodation space for accommodating the battery cells 10. The first portion 201 and the second portion 202 may have various shapes, such as a rectangular parallelepiped or a cylindrical shape. The first portion 201 may have a hollow structure with one side open, and the second portion 202 may also have a hollow structure with one side open. When the open side of the second portion 202 is fitted over the open side of the first portion 201, the battery housing 20 having the accommodation space is formed. The first part 201 may have a hollow structure with one side open, and the second part 202 may have a plate-like structure, and when the second part 202 is placed over the open side of the first part 201, it forms a battery housing 20 having an accommodation space. The first part 201 and the second part 202 may be sealed via a sealing member, which may be a sealing ring, a sealant, or the like.

[0062] The battery 100 may have one or more battery cells 10. When there are multiple battery cells 10, the multiple battery cells 10 may be connected in series, parallel, or series-parallel, and a series-parallel connection refers to both a series connection and a parallel connection among the multiple battery cells 10. A battery module may first be formed by connecting the multiple battery cells 10 in series, parallel, or series-parallel, and then the multiple battery modules may be connected in series, parallel, or series-parallel to form a single whole, which may then be housed in the battery casing 20. All of the battery cells 10 may be directly connected in series, parallel, or series-parallel, and then the whole made up of all the battery cells 10 may be housed in the battery casing 20.

[0063] In some embodiments, the battery 100 may further include bus bar members (not shown), and electrical connection may be established between the multiple battery cells 10 via the bus bar members, thereby realizing a series connection, a parallel connection, or a series-parallel connection of the multiple battery cells 10. The bus bar members may be made of a metal conductor, such as copper, iron, aluminum, stainless steel, or an aluminum alloy.

[0064] The battery cells described in the embodiments of the present application can also be applied to energy storage devices.

[0065] The role of energy storage devices in future energy application scenarios will become increasingly prominent. On the one hand, in new energy generation, wind power and solar power generation are characterized by intermittency and instability. The introduction of energy storage devices can effectively suppress the fluctuations in power generation, thereby improving the quality of electrical energy. On the other hand, energy storage devices can also "cut peaks and fill valleys," i.e., absorb excess power from the power grid during periods when the power grid's output power is in the valley, and then actively feed power back into the power grid during periods when the power grid's output power is at its peak. In this way, the peak power of the power grid can be significantly reduced, the power demand side management capability can be improved, and the application of renewable energy can be promoted.

[0066] 3 and 4, FIG. 3 is a structural schematic diagram of an energy storage device 2000 according to some embodiments of the present application, and FIG. 4 is an internal structural schematic diagram of the energy storage device 2000 shown in FIG.

[0067] The energy storage device 2000 includes an energy storage housing 400, a battery 100, and a control module (not shown). The internal space of the energy storage housing 400 is divided into a battery compartment 401 and an electrical compartment 402. The battery 100 is mounted in the battery compartment 401, and the control module is mounted in the electrical compartment 402. A support post 403 and a battery bracket 404 are installed in the battery compartment 401. The support post 403 is generally installed along the height direction of the energy storage housing 400, the battery bracket 404 is fixed to the support post 403, and the battery 101 is mounted on the battery bracket 404, making it easy to arrange multiple batteries 100 in the battery compartment 401. Of course, in other embodiments, the battery cells 10 may be placed directly in the battery chamber 401, eliminating the need to place the battery cells 10 in the battery housing 20 and then place the battery housing 20 in the battery chamber 401. This eliminates the need to install the uprights 403 and battery brackets 404 in the battery chamber 401, thereby improving the energy density of the energy storage device 2000.

[0068] 5 and 6, FIG. 5 is a structural schematic diagram of a battery cell 10 according to some embodiments of the present application, and FIG. 6 is an exploded view of the battery cell 10 shown in FIG.

[0069] The battery cell 10 may include a housing 1 and an electrode assembly 2. The electrode assembly 2 may be one or more.

[0070] The electrode assembly 2 is a component where an electrochemical reaction occurs within the battery cell 10. The electrode assembly 2 may include a positive electrode plate, a negative electrode plate, and a separator.

[0071] The housing 1 is a member for accommodating the electrode assembly 2. The housing 1 may have a cuboid shape, such as a rectangular parallelepiped or a cube.

[0072] The size of the housing 1 in the first direction X is W1, the size of the housing 1 in the second direction Y is T1, and the size of the housing 1 in the third direction Z is H1. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0073] In the following embodiments, for convenience of description, the first direction X is defined as the width direction of the battery cell 10, the second direction Y is defined as the thickness direction of the battery cell 10, and the third direction Z is defined as the height direction of the battery cell 10. In this case, W1 is the width of the battery cell 10, T1 is the thickness of the battery cell 10, and H1 is the height of the battery cell 10.

[0074] Referring to Figures 5 to 8, Figure 7 is an exploded cross-sectional view of the battery cell 10 shown in Figure 5 taken along the XZ plane, and Figure 8 is an exploded cross-sectional view of the battery cell 10 shown in Figure 5 taken along the YZ plane.

[0075] The housing 1 includes a first wall 101 and a second wall 102 arranged opposite each other along a first direction X, a third wall 103 and a fourth wall 104 arranged opposite each other along a second direction Y, and a fifth wall 105 and a sixth wall 106 arranged opposite each other along a third direction Z, and the six walls together enclose a space that accommodates the electrode assembly 2.

[0076] Here, the sum of the thicknesses of the first wall 101 and the second wall 102 is a, the sum of the thicknesses of the third wall 103 and the fourth wall 104 is b, and the sum of the thicknesses of the fifth wall 105 and the sixth wall 106 is c, and (W1-a)*(T1-b)*(H1-c) / (W1*T1*H1)≧90% is satisfied.

[0077] In this embodiment, the thicknesses of the first wall 101 and the second wall 102 may or may not be equal, the thicknesses of the third wall 103 and the fourth wall 104 may or may not be equal, and the thicknesses of the fifth wall 105 and the sixth wall 106 may or may not be equal.

[0078] Since a, b, and c are all greater than 0, it is understandable that 90%≦(W1-a)*(T1-b)*(H1-c) / (W1*T1*H1)<100%.

[0079] (W1-a)*(T1-b)*(H1-c) / (W1*T1*H1) may be any value between 90% and 100%, for example, 90%, 90.5%, 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 94.5%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, etc.

[0080] Here, (W1-a)*(T1-b)*(H1-c) may be understood to be the volume of the housing 1, i.e., the volume of the space enclosed by the inner surface of the housing 1, and W1*T1*H1 is the volume of the housing 1, which is approximately equal to the volume of the battery cell 10.

[0081] If the outer surfaces of the six walls of the housing 1 are all flat, W1, T1, and H1 are measured based on the outer surface of each wall. For example, if the outer surfaces of the fifth wall 105 and the sixth wall 106 are all flat, H1 is the distance between the outer surfaces of the fifth wall 105 and the sixth wall 106 along the third direction Z.

[0082] If a convex or concave portion is formed on the outer surface of any one of the walls of the housing 1, W1, T1, and H1 are measured based on the flat area of ​​this outer surface (i.e., the area other than the convex or concave portion). For example, if the outer surface of the fifth wall 105 is flat and a first convex portion is formed on the outer surface of the sixth wall 106, H1 is the distance along the third direction Z between the flat area of ​​the outer surface of the sixth wall 106 other than the first convex portion and the outer surface of the fifth wall 105. If a first convex portion is formed on the outer surface of the sixth wall 106 and a second convex portion is formed on the outer surface of the fifth wall 105, H1 is the distance along the height direction of the battery cell 10 between the flat area of ​​the outer surface of the fifth wall 105 excluding the second convex portion and the flat area of ​​the outer surface of the sixth wall 106 excluding the first convex portion.

[0083] If all six walls of the housing 1 are of uniform thickness, the distance between the outer and inner surfaces of each wall can be measured from any position on the wall, thereby obtaining the thickness of the wall.

[0084] If a wall of the housing 1 has a non-uniform thickness, the thickness of the wall is obtained by measuring the distance between the outer surface and the inner surface of the wall from the point where the wall is thickest. In other words, if the thickness of a wall is non-uniform, the maximum thickness of the wall is used to calculate a, b, or c.

[0085] In the embodiments of the present application, the ratio of the volume of the housing 1 of the battery cell 10 to the volume of the housing 1 is set to 90% or more, thereby increasing the internal space of the housing 1 and allowing a larger electrode assembly 2 to be accommodated, thereby improving the volumetric energy density of the battery cell 10 for the same chemical material system.

[0086] The following will be described in detail based on specific experimental data.

[0087] In the experiment, a rectangular case battery cell was selected as the battery cell 21, the case 11 had a hollow structure with one end open, and the number of end caps 12 was one.

[0088] [Table 1]

[0089] According to Table 1 above, when Examples 1-4 are compared with Comparative Example 1, if the positive electrode material of the battery cell 10 includes a lithium-containing phosphate, (W1-a)*(T1-b)*(H1-c) / (W1*T1*H1)≧0.9, and the volumetric energy density of the battery cell 10 can be effectively improved. When Examples 5-8 are compared with Comparative Example 2, if the positive electrode material of the battery cell 10 includes a lithium transition metal oxide, (W1-a)*(T1-b)*(H1-c) / (W1*T1*H1)≧0.9, and the volumetric energy density of the battery cell 10 can be effectively improved. When Examples 9-12 are compared with Comparative Example 3, if the battery cell 10 is a sodium-ion battery cell, (W1-a)*(T1-b)*(H1-c) / (W1*T1*H1)≧0.9, and the volumetric energy density of the battery cell 10 can be effectively improved.

[0090] The ratio of the volume of the housing 1 to the volume of the housing 1 can be made 90% or more, and the occupancy rate of the wall thickness of the housing 1 in three directions can be made uniform, improving the balance of the force received by the housing 1 in three directions.

[0091] In some embodiments, W1 and a satisfy (W1-a) / W1≧97.0%.

[0092] By setting the ratio of W1-a to W1 to 97.0% or more, if the width of the battery cell 10 remains unchanged, the width of the internal space of the exterior housing 1 can be increased to accommodate a wider electrode assembly 2, thereby improving the volumetric energy density of the battery cell 10 for the same chemical material system. (W1-a) / W1 may be any value between 97.0% and 100%, for example, 97.0%, 97.5%, 98%, 98.5%, 99%, 99.5%, etc.

[0093] In some embodiments, T1 and b satisfy (T1-b) / T1≧96.5%.

[0094] By setting the ratio of T1-b to T1 to 96.5% or more, if the thickness of the battery cell 10 remains unchanged, the width of the internal space of the housing 1 can be increased, thereby accommodating a thicker electrode assembly 2, and for the same chemical material system, the volumetric energy density of the battery cell 10 can be improved. (T1-b) / T1 may be any value between 96.5% and 100%, for example, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, etc.

[0095] In some embodiments, H1 and c satisfy (H1-c) / H1≧96.5%.

[0096] By setting the ratio of H1-c to H1 to 96.5% or more, if the height of the battery cell 10 does not change, the height of the internal space of the housing 1 can be increased to accommodate a taller electrode assembly 2, and the volumetric energy density of the battery cell 10 can be improved for the same chemical material system. (H1-c) / H1 may be any value between 96.5% and 100%, for example, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, etc.

[0097] In some embodiments, W1 and a satisfy (W1-a) / W1≧97.0%, T1 and b satisfy (T1-b) / T1≧96.5%, and H1 and c satisfy (H1-c) / H1≧96.5%.

[0098] By way of example, the housing 1 may include a case 11 and an end cap 12 .

[0099] The case 11 may be a hollow structure with an opening at one end and a closed end at the other end, or may be a hollow structure with openings at opposite ends. The opening is used for the electrode assembly 2 to enter the internal space of the case 11. The end cap 12 is a member that closes the opening of the case 11 and isolates the internal environment of the battery cell 10 from the external environment. The end cap 12 and the case 11 together define a sealed space for accommodating the electrode assembly 2, electrolyte, and other components. The end cap 12 may be connected to the case 11 by welding or roll sealing to seal the opening of the case 11. The shape of the end cap 12 may match the shape of the housing 1; for example, if the case 11 has a rectangular parallelepiped structure, the end cap 12 has a rectangular plate-like structure that matches the housing 1.

[0100] The battery cell 10 may have one or two end caps 12.

[0101] 6 , in an embodiment where the case 11 is a hollow structure with an opening formed at one end, one end cap 12 may be installed correspondingly, and the end cap 12 seals the opening at one end of the case 11, and the one end cap 12 defines a sealed space together with the case 11. In this embodiment, the case 11 includes a first wall 101, a second wall 102, a third wall 103, a fourth wall 104, and a fifth wall 105 that are integrally molded, where the first wall 101, the second wall 102, the third wall 103, and the fourth wall 104 are side walls of the case 11, the fifth wall 105 is a bottom wall of the case 11, and the sixth wall 106 is installed separately from the other five walls and is the end cap 12.

[0102] 10 , in an embodiment in which the case 11 has a hollow structure with openings formed at both ends, two corresponding end caps 12 may be installed, and the two end caps 12 respectively seal the two openings of the case 11, and the two end caps 12 define a sealed space together with the case 11. In this embodiment, the case 11 includes a first wall 101, a second wall 102, a third wall 103, and a fourth wall 104 that are integrally formed, the fifth wall 105 is installed separately from the other five walls, and the sixth wall 106 is also installed separately from the other five walls, with the fifth wall 105 being one end cap 12 and the sixth wall 106 being another end cap 12.

[0103] In order to reduce the possibility of interference between the electrode assembly 2 and the case 11 during assembly into the case 11 and to reduce the risk of damage to the electrode assembly 2, a certain fitting gap (i.e., a case-insertion gap) is left for the electrode assembly 2 when designing the case 11, and this fitting gap may be 0.8-2 mm.

[0104] In addition, an insulating member may be installed inside the housing 1 to reduce the possibility of an internal short circuit occurring in the battery cell 10, but the insulating member will inevitably occupy part of the internal space of the housing 1, thereby reducing the space left for the electrode assembly 2.

[0105] 7 and 8, in some embodiments of the present application, the housing 1 includes a case 11 and an end cap 12, the case 11 has an opening, the end cap 12 covers the opening, the case 11 includes an integrally molded first wall 101, a second wall 102, a third wall 103, a fourth wall 104, and a fifth wall 105, the end cap 12 is a sixth wall 106, the battery cell 10 further includes a first insulating member 141 and a second insulating member 142, the first insulating member 141 is in contact with the fifth wall 105, and the electrode assembly 2 and abuts against the fifth wall 105, and the second insulating member 142 is disposed between the sixth wall 106 and the electrode assembly 2 and abuts against the sixth wall 106, the maximum size of the first insulating member 141 in the third direction Z is d1, and the maximum size of the second insulating member 142 in the third direction Z is d2, satisfying (W1−a−1.6 mm)*(T1−b−1.6 mm)*(H1−c−d1−d2) / (W1*T1*H1)≧88%, 0.3 mm≦d1≦1.2 mm, and 2 mm≦d2≦10 mm.

[0106] In this embodiment, W1-a-1.6 mm means the maximum size of the internal space of the housing 1 left for the electrode assembly 2 along the first direction X when the sum of the fitting gap between the electrode assembly 2 and the first wall 101 and the fitting gap between the electrode assembly 2 and the second wall 102 is 1.6 mm. T1-b-1.6 mm means the maximum size of the internal space of the housing 1 left for the electrode assembly 2 along the second direction Y when the sum of the fitting gap between the electrode assembly 2 and the third wall 103 and the fitting gap between the electrode assembly 2 and the fourth wall 104 is 1.6 mm. H1-c-d1-d2 mean the maximum size of the internal space of the housing 1 left for the electrode assembly 2 along the third direction Z when a first insulating member 141 abutting against the fifth wall 105 is installed between the fifth wall 105 and the electrode assembly 2, and a second insulating member 142 abutting against the sixth wall 106 is installed between the sixth wall 106 and the electrode assembly 2. The first insulating member 141 may be a bottom support plate and the second insulating member 142 may be a bottom plastic.

[0107] By setting the ratio of (W1-a-1.6mm)*(T1-b-1.6mm)*(H1-c-d1-d2) to W1*T1*H1 to 88% or more, the space left inside the housing 1 for the electrode assembly 2 is increased, allowing an electrode assembly 2 with a larger volume to be placed therein, thereby further improving the volumetric energy density of the battery cell 10.

[0108] In some embodiments of the present application, (W1-a-4mm)*(T1-b-4mm)*(H1-c-d1-d2) / (W1*T1*H1)≧85%, 0.3mm≦d1≦10mm, and 2mm≦d2≦10mm are satisfied.

[0109] In this embodiment, W1-a-4 mm means the maximum size of the internal space of the housing 1 left for the electrode assembly 2 along the first direction X when the sum of the fitting gap between the electrode assembly 2 and the first wall 101 and the fitting gap between the electrode assembly 2 and the second wall 102 is 4 mm. T1-b-4 mm means the maximum size of the internal space of the housing 1 left for the electrode assembly 2 along the second direction Y when the sum of the fitting gap between the electrode assembly 2 and the third wall 103 and the fitting gap between the electrode assembly 2 and the fourth wall 104 is 4 mm. H1-c-d1-d2 mean the maximum size of the internal space of the housing 1 left for the electrode assembly 2 along the third direction Z when a first insulating member 141 abutting against the fifth wall 105 is installed between the fifth wall 105 and the electrode assembly 2, and a second insulating member 142 abutting against the sixth wall 106 is installed between the sixth wall 106 and the electrode assembly 2.

[0110] By setting the ratio of (W1-a-4mm)*(T1-b-4mm)*(H1-c-d1-d2) to W1*T1*H1 to 85% or more, the space left inside the housing 1 for the electrode assembly 2 is increased, allowing an electrode assembly 2 with a larger volume to be placed therein, thereby further improving the volumetric energy density of the battery cell 10.

[0111] 9 to 12, FIG. 9 is a structural schematic diagram of a battery cell according to some other embodiments of the present application, FIG. 10 is an exploded view of the battery cell shown in FIG. 9, FIG. 11 is a cross-sectional view of the battery cell shown in FIG. 9 taken along the XZ plane, and FIG. 12 is a cross-sectional view of the battery cell shown in FIG. 9 taken along the YZ plane.

[0112] In some embodiments of the present application, the housing 1 includes a case 11 and two end caps 12, the case 11 has two openings arranged opposite to each other along a third direction Z, the two end caps 12 are respectively fitted over the openings on the corresponding sides, the case 11 includes a first wall 101, a second wall 102, a third wall 103 and a fourth wall 104 integrally formed therewith, the two end caps 12 being fifth and sixth walls, respectively, the battery cell 10 further includes a third insulating member 143 and a fourth insulating member 144, the third insulating member 143 being The third insulating member 143 is disposed between the fifth wall 105 and the electrode assembly 2 and abuts against the fifth wall 105, and the fourth insulating member 144 is disposed between the sixth wall 106 and the electrode assembly 2 and abuts against the sixth wall 106. The third insulating member 143 has a maximum size in the third direction Z of d3, and the fourth insulating member 144 has a maximum size in the third direction Z of d4, and these satisfy (W1-a-1.6mm)*(T1-b-1.6mm)*(H1-c-d3-d4) / (W1*T1*H1)≧88%, 2mm≦d3≦10mm, and 2mm≦d4≦10mm.

[0113] In this embodiment, the third insulating member and the fourth insulating member may be the bottom plastic.

[0114] By setting the ratio of (W1-a-1.6mm)*(T1-b-1.6mm)*(H1-c-d3-d4) to W1*T1*H1 to 88% or more, the space left inside the housing 1 for the electrode assembly 2 is increased, allowing an electrode assembly 2 with a larger volume to be placed therein, thereby further improving the volumetric energy density of the battery cell 10.

[0115] In some embodiments of the present application, the following relationships are satisfied: (W1-a-4mm)*(T1-b-4mm)*(H1-c-d3-d4) / (W1*T1*H1)≧85%, 2mm≦d3≦10mm, and 2mm≦d4≦10mm.

[0116] By setting the ratio of (W1-a-4mm)*(T1-b-4mm)*(H1-c-d3-d4) to W1*T1*H1 to 85% or more, the space left inside the housing 1 for the electrode assembly 2 is increased, allowing an electrode assembly 2 with a larger volume to be placed therein, thereby further improving the volumetric energy density of the battery cell 10.

[0117] In some examples of the present application, W1, T1 and H1 are less than 3000 cm 3 ≦W1*T1*H1≦40000cm 3 That is, the volume of the housing 1 is 3000 cm 3 ~40,000cm 3 It is between.

[0118] W1*H1*H1<3000cm 3 In this case, in order to make the ratio of the volume of the housing 1 to the volume of the housing 1 90% or more, the thickness of the housing 1 needs to be designed to be relatively small, and the load that it can withstand is also relatively small, resulting in insufficient structural strength and rigidity of the housing 1, making it prone to deformation or breakage, which is detrimental to the safety of the battery cell 10.

[0119] W1*T1*H1>40000cm 3 In this case, the volume and capacity of the battery cell 10 are relatively large, the current when the battery cell 10 is discharged is relatively large, and the heat generation amount of the overcurrent element in the circuit is relatively large, which is likely to cause damage to the overcurrent element.

[0120] In this embodiment, the volume of the housing 1 is set to 3000 cm 3 ~40,000cm 3By setting the thickness between these values, on the one hand, the housing 1 can be made not too thin while satisfying the requirement that the ratio of the volume to the volume of the housing 1 be 90% or more, thereby satisfying the requirements for the structural strength and rigidity of the housing 1, and on the other hand, the capacity and current of the battery cell 10 can be controlled within an appropriate range, thereby reducing the risk of damage to the overcurrent element in the circuit.

[0121] W1*T1*H1 is 3000cm 3 ~40,000cm 3 Any value between, for example, 3000 cm 3 , 3100cm 3 , 3200cm 3 , 3300cm 3 , 3400cm 3 , 3500cm 3 , 3600cm 3 , 3700cm 3 , 3800cm 3 , 3900cm 3 , 4000cm 3 , 4050cm 3 , 4100cm 3 , 4200cm 3 , 4500cm 3 , 5000cm 3 , 10000cm 3 , 15000cm 3 , 20000cm 3 , 25000cm 3 , 30000cm 3 , 35000cm 3 , 40000cm 3 etc. may also be used.

[0122] In some embodiments, 3200 cm 3 ≦W1*T1*H1≦32000cm 3 is.

[0123] For example, W1*T1*H1 is 3200 cm 3 ~32000cm 3 Any value between, for example, 3250 cm 3 , 3350cm 3 , 3450cm3 , 3550cm 3 , 3650cm 3 , 3750cm 3 , 3850cm 3 , 3950cm 3 , 4650cm 3 , 6650cm 3 , 9500cm 3 , 12000cm 3 , 18000cm 3 , 31000cm 3 etc. may also be used.

[0124] In some embodiments, 3720 cm 3 ≦W1*T1*H1≦12500cm 3 is.

[0125] In some embodiments, 4000 cm 3 ≦W1*T1*H1≦6000cm 3 is.

[0126] Please refer to Figures 6 and 13 to 16. Figure 13 is a front view of two electrode assemblies 2 in Figure 6, Figure 14 is a side view of two electrode assemblies 2 in Figure 6, Figure 15 is a top view of two electrode assemblies 2 in Figure 6, and Figure 16 is a cross-sectional view of one electrode assembly 2 in Figure 6.

[0127] In some embodiments of the present application, the electrode assembly 2 includes a main body 21, a positive electrode tab 22, and a negative electrode tab 23, the positive electrode tab 22 and the negative electrode tab 23 extend from the main body 21, the main body 21 is flat, the maximum size of the main body 21 in a first direction X is W2, the maximum size of the main body 21 in a second direction Y is T2, and the maximum size of the main body 21 in a third direction Z is H2, and (W2*T2*H2) / (W1*T1*H1)≧80% is satisfied.

[0128] The electrode assembly 2 includes a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer, and the positive electrode active material layer coats a portion of the positive electrode current collector. The positive electrode active material layer and the area of ​​the positive electrode current collector where the positive electrode active material layer is coated form a positive electrode coated area, and the area of ​​the positive electrode current collector where the positive electrode active material layer is not coated forms a positive electrode tab 22, which protrudes from the positive electrode coated area. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer coats a portion of the negative electrode current collector. The area of ​​the negative electrode active material layer and the area of ​​the negative electrode current collector where the negative electrode active material layer is coated form a negative electrode coated area, and the area of ​​the negative electrode current collector where the negative electrode active material layer is not coated forms a negative electrode tab 23, which protrudes from the negative electrode coated area.

[0129] The positive electrode coating area and the negative electrode coating area are disposed opposite each other, and the positive electrode coating area, the negative electrode coating area and the separator form the main body 21 of the electrode assembly 2 .

[0130] The electrode assembly 2 may have a wound structure formed by winding a positive electrode plate, a separator, and a negative electrode plate, or a stacked structure formed by stacking a positive electrode plate, a separator, and a negative electrode plate. As can be understood, regardless of whether the electrode assembly 2 has a wound structure or a stacked structure, the body 21 may be flat.

[0131] It should be explained that when a plurality of electrode assemblies 2 are installed in the battery cell 10, W2 is the maximum overall size of the bodies 21 of the plurality of electrode assemblies 2 in the first direction X, T2 is the maximum overall size of the bodies 21 of the plurality of electrode assemblies 2 in the second direction Y, and H2 is the maximum overall size of the bodies 21 of the plurality of electrode assemblies 2 in the third direction Z. For example, as shown in Figures 6 and 15, two electrode assemblies 2 are installed in the housing 1 and are stacked along the second direction Y, and in this case, T2 is the maximum overall size of the bodies 21 of the two electrode assemblies 2 in the second direction Y.

[0132] In this embodiment, by setting (W2*T2*H2) / (W1*T1*H1) to 80% or more, the electrode assembly 2 can fully utilize the internal space of the housing 1, and a situation where the volume of the housing 1 is large but the volume of the electrode assembly 2 is small does not occur, thereby improving the volumetric energy density of the battery cell 10 and reducing the movement of the electrode assembly 2 within the housing 1.

[0133] (W2*T2*H2) / (W1*T1*H1) may be any value between 80% and 100%, for example, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 92%, 94%, 96%, etc.

[0134] In order to make the ratio of W2*T2*H2 to W1*T1*H1 greater than or equal to 80%, and to match the size in each direction of the body 21 of the electrode assembly 2 with the size in each direction of the internal space of the housing 1 to further reduce movement of the electrode assembly 2 within the housing 1, in some embodiments, W2 / (W1-a)≧91.5%, T2 / (T1-b)≧93.2%, and H2 / (H1-c)≧94.0% are satisfied.

[0135] Setting the ratio of W2 to W1-a to 91.5% or more can improve the space utilization rate in the first direction X inside the housing 1, and for the same chemical material system, can improve the volumetric energy density of the battery cell 10. The ratio of W2 to W1-a may be any value equal to or greater than 91.5%, such as 91.6%, 91.8%, 92.0%, 92.5%, 93.0%, 93.5%, 94.0%, 94.5%, 95.0%, etc.

[0136] Setting the ratio of T2 to T2-b to 93.2% or more can improve the space utilization rate in the second direction Y inside the housing 1, and for the same chemical material system, can improve the volumetric energy density of the battery cell 10. The ratio of T2 to T2-b may be any value equal to or greater than 93.2%, such as 93.5%, 94.0%, 94.5%, 95.0%, 95.5%, 96.0%, 96.5%, 97.0%, 97.5%, etc.

[0137] Setting the ratio of H2 to H1-c to 94.0% or more can improve the space utilization rate in the third direction Z inside the housing 1, and for the same chemical material system, can improve the volumetric energy density of the battery cell 10. The ratio of H2 to H1-c may be any value equal to or greater than 94.0%, such as 94.5%, 95.0%, 95.5%, 96.0%, 96.5%, 97.0%, 97.5%, 98.0%, or 98.5%.

[0138] 6 and 13 to 16, the electrode assembly 2 has a wound structure, the winding centerline of the electrode assembly 2 is set along the third direction Z, and the positive electrode tab 22 and the negative electrode tab 23 are located at the same end of the body 21 and are both installed toward the end cap 12. However, the embodiments of the present application are not limited thereto.

[0139] Referring to Figures 17 to 19, Figure 17 is an exploded view of a battery cell according to some further embodiments of the present application, Figure 18 is a front view of the electrode assembly in Figure 17, and Figure 19 is a top view of the electrode assembly in Figure 17.

[0140] In some further embodiments of the present application, the electrode assembly 2 has a wound structure, the winding center line of the electrode assembly 2 is set along the first direction X, the positive electrode tab 22 and the negative electrode tab 23 are located at opposite ends of the body 21, the positive electrode tab 22 is disposed toward the first wall 101, and the negative electrode tab 23 is disposed toward the second wall 102.

[0141] 16 , when the electrode assembly 2 has a wound structure, the main body 21 may include a flat region A, a first folding region b1, and a second folding region B2, with the first folding region b1 and the second folding region B2 being located at opposite ends of the flat region A. In the flat region A, the positive electrode plate 24, the negative electrode plate 25, and the separator 26 have a substantially flat shape. In the first folding region b1 and the second folding region B2, the positive electrode plate 24, the negative electrode plate 25, and the separator 26 all have a folded or arcuate shape.

[0142] In some embodiments of the present application, the first folding region b1 and the second folding region B2 are located at opposite ends of the flat region A along the first direction X, i.e., the first folding region b1, the flat region A, and the second folding region B2 are arranged along the first direction X, and the winding centerline direction of the electrode assembly 2 is in the third direction Z. In these embodiments, the first folding region b1 includes a plurality of first folding portions arranged in a stack, and the distance along the first direction X between the inner vertex of the first folding portion of the innermost layer of the plurality of first folding portions and the outer vertex of the first folding portion of the outermost layer of the plurality of first folding portions is W3. The second folding region B2 includes a plurality of second folding portions arranged in a stack, and the distance along the first direction X between the inner vertex of the second folding portion of the innermost layer of the plurality of second folding portions and the outer vertex of the second folding portion of the outermost layer of the plurality of second folding portions is W4, satisfying (W3 + W4) / W2≦30%.

[0143] The "first folded portion of the innermost layer of the plurality of first folded portions" refers to one of the plurality of first folded portions that is closest to the winding center line of the electrode assembly 2. When the innermost layer of the electrode assembly 2 is the separator 26, the first folded portion of this innermost layer is the folded portion of the separator 26. When the innermost layer of the electrode assembly 2 is the positive electrode plate 24, the first folded portion of this innermost layer is the folded portion of the positive electrode plate 24. When the innermost layer of the electrode assembly 2 is the negative electrode plate 25, the first folded portion of this innermost layer is the folded portion of the negative electrode plate 25.

[0144] The "inner vertex of the first folded portion of the innermost layer" refers to the point on the inner surface of the first folded portion of the innermost layer (i.e., the surface facing the winding centerline of the electrode assembly 2) that is farthest from the winding centerline of the electrode assembly 2.

[0145] The "second folding portion of the innermost layer of the plurality of second folding portions" refers to one second folding portion of the plurality of second folding portions that is closest to the winding center line of the electrode assembly 2. When the innermost layer of the electrode assembly 2 is the separator 26, the second folding portion of this innermost layer is the folding portion of the separator 26. When the innermost layer of the electrode assembly 2 is the positive electrode plate 24, the second folding portion of this innermost layer is the folding portion of the positive electrode plate 24. When the innermost layer of the electrode assembly 2 is the negative electrode plate 25, the second folding portion of this innermost layer is the folding portion of the negative electrode plate 25.

[0146] The "inner vertex of the second folded portion of the innermost layer" refers to the point on the inner surface of the second folded portion of the innermost layer (i.e., the surface facing the winding center line of the electrode assembly 2) that is farthest from the winding center line of the electrode assembly 2.

[0147] The housing 1 has a cuboid shape, and therefore, unlike the flat region A, the bent region and the inner surface of the housing 1 cannot be completely bonded together, and a gap exists between them. The larger the size of the bent region in the first direction X, the larger the gap becomes, and the lower the effective utilization rate of the internal space of the housing 1 becomes.

[0148] In this embodiment, W3 is approximately equal to the size of the first bending region b1 in the first direction X, and W4 is approximately equal to the size of the second bending region B2 in the first direction X. By setting the ratio of W2 to the sum of W3 and W4 to 30% or less, the size occupancy rate of the first bending region b1 and the second bending region B2 in the first direction X is reduced and the size occupancy rate of the flat region A in the first direction X is increased, thereby reducing the volume occupancy rate of the gaps and improving the effective utilization rate of the internal space of the housing 1 and the volumetric energy density of the battery cell 10.

[0149] Also, 3000cm 3 ≦W1*T1*H1≦40000cm 3 and (W2*T2*H2) / (W1*T1*H1)≧80%, the volume of the battery cell 10 is relatively large, and the volume of the electrode assembly 2 is also relatively large. For the same chemical material system, the larger the volume of the electrode assembly 2, the greater the mass of the electrode assembly 2. However, if the battery cell 10 is dropped or hit, the electrode assembly 2 will move within the housing 1, and at this time, the greater the mass of the electrode assembly 2, the greater the impact on the housing 1.

[0150] In order to enable each wall of the housing 1 to withstand a relatively large impact, reduce the risk of deformation of the housing 1, and improve the reliability of the battery cell 10, in some embodiments of the present application, the materials of the first wall 101, the second wall 102, the third wall 103, the fourth wall 104, the fifth wall 105, and the sixth wall 106 all include an aluminum alloy, which has a mass percentage content of aluminum≧96.7%, 0.05%≦copper≦0.2%, iron≦0.7%, manganese≦1.5%, silicon≦0.6%, zinc≦0.1%, other single element components≦0.05%, and the total content of other elements≦0.15%.

[0151] In this embodiment, by controlling the mass percentages of various elements within the above ranges, an aluminum alloy with higher strength can be obtained, and by using this aluminum alloy as the material for the housing 1, the impact resistance of the housing 1 can be significantly improved, and the reliability of the battery cell 10 can be improved.

[0152] 7 and 8 , in some embodiments of the present application, the housing 1 includes a case 11 and an end cap 12, the case 11 has an opening, the end cap 12 covers the opening, and the end cap 12 is welded to the case 11, the first wall 101, the second wall 102, the third wall 103, the fourth wall 104, and the fifth wall 105 are integrally molded to form the case 11, the sixth wall 106 is molded separately from the other five walls to form the end cap 12, the thicknesses of the first wall 101 and the second wall 102 are all a1, the thicknesses of the third wall 103 and the fourth wall 104 are all b1, the thickness of the fifth wall 105 is c1, and the thickness of the sixth wall 106 is c2, satisfying c2>c1, c1>a1, and c1>b1.

[0153] For a battery cell 10 having only one end cap, the battery cell 10 is generally used with the end cap facing up or facing down. When the battery cell 10 is used with the end cap facing up, particulate matter (e.g., carbon powder, metal chips, etc.) inside the battery cell 10 accumulates on the bottom of the case (i.e., the fifth wall 105) due to gravity, causing corrosion of the bottom of the case. After long-term corrosion, the strength of the bottom of the case decreases, which is unfavorable for resisting impacts from the electrode assembly 2 or external sources and affects the reliability of the battery cell 10. Therefore, in this embodiment, the fifth wall 105 is designed to be relatively thick, and is greater than the thicknesses of the first wall 101 and the second wall 102 and the third wall 103 and the fourth wall 104 (i.e., c1 > a1, c1 > b1).

[0154] Also, 3000cm 3 ≦W1*T1*H1≦40000cm 3 and (W2*T2*H2) / (W1*T1*H1)≧80%, the volume of the battery cell 10 is relatively large, and the volume of the electrode assembly 2 is also relatively large. For the same chemical material system, the larger the volume of the electrode assembly 2, the greater the amount of gas generated during cycling of the battery cell 10, and the greater the internal air pressure of the battery cell 10.

[0155] In order to reduce the risk that the welding seam between the end cap 12 and the case 11 cracks due to an increase in the internal pressure, in this embodiment, the thickness of the end cap 12 is designed to be relatively thick, and the thickness of the end cap 12 is made larger than the thickness of the fifth wall 105 (i.e., c2>c1), and it is possible to allow the formation of a welding seam with a larger width or thickness between the end cap 12 and the case 11, thereby improving the welding strength, reducing the risk that the welding seam cracks, and improving the reliability of the battery cell 10. Also, compared to increasing the thickness of the case 11 to form a welding seam with a larger width or thickness, increasing the thickness of the end cap 12 can reduce the amount of material used and reduce the cost. Increasing the thickness of the case 11 means increasing the thickness of at least the four walls of the first wall 101, the second wall 102, the third wall 103, and the fourth wall 104 welded to the end cap 12, and the amount of material used increases significantly and the cost is relatively high.

[0156] When the first wall 101, the second wall 102, the third wall 103, the fourth wall 104, and the fifth wall 105 are integrally formed and installed as a case, and the sixth wall 106 is used as the end cap 12, in some embodiments of the present application, the areas of the third wall 103 and the fourth wall 104 are larger than the areas of the first wall 101 and the second wall 102, and the areas of the third wall 103 and the fourth wall 104 are larger than the areas of the fifth wall 105 and the sixth wall 106, satisfying b1<a1.

[0157] In this embodiment, the third wall 103 and the fourth wall 104 are the two walls with the largest area of the housing 1, that is, the large surfaces of the battery cell 10. When the battery cell 10 cycles, the amount of expansion in the large surface direction of the electrode assembly 2 is much larger than the amount of expansion in other directions. In order to allow the electrode assembly 2 to expand in the large surface direction, in this embodiment, the thicknesses of the third wall 103 and the fourth wall 104 are designed to be relatively small, and the thicknesses of the third wall 103 and the fourth wall 104 are made smaller than the thicknesses of the first wall 101 and the second wall 102 (i.e., b1<a1).

[0158] When the first wall 101, the second wall 102, the third wall 103, the fourth wall 104, and the fifth wall 105 are integrally formed and installed to form the case 11, and the sixth wall 106 forms the end cap 12, in some embodiments of the present application, 0.5 mm≦a1≦1.5 mm, 0.5 mm≦b1≦1.5 mm, 1.0 mm≦c1≦2.5 mm, and 1.5 mm≦c2≦4 mm.

[0159] a1 may be any value between 0.5 mm and 1.5 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc.

[0160] If a1<0.5 mm, the thicknesses of the first wall 101 and the second wall 102 are too small, and the thicknesses of the third wall 103 and the fourth wall 104 are smaller than the first wall 101 and the second wall 102, making it difficult to ensure the structural strength of the housing 1 in the third direction Z and susceptible to deformation of the battery cells 10. If a1>1.5 mm, the thicknesses of the first wall 101 and the second wall 102 are too large, which is unfavorable for improving the volumetric energy density of the battery cells 10 and results in relatively high costs. In this embodiment, a1 is set to 0.5 mm to 1.5 mm, which ensures the volumetric energy density of the battery cells 10 while also ensuring the structural strength of the housing 1 in the third direction Z.

[0161] b1 may be any value between 0.5 mm and 1.5 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc.

[0162] When b1<0.5 mm, the thicknesses of the third wall 103 and the fourth wall 104 are too small, and when the electrode assembly 2 expands, the third wall 103 and the fourth wall 104 are easily extruded and ruptured. When b1>1.5 mm, the third wall 103 and the fourth wall 104 are relatively thick, and their structural strength and rigidity are also relatively high, making it difficult to absorb the expansion of the electrode assembly 2. This makes it easy for stress to concentrate inside the electrode assembly 2, resulting in the "lithium deposition" phenomenon and shortening the cycle life. In this embodiment, b1 is set to 0.5 mm to 1.5 mm, which ensures that the structural strength and rigidity of the third wall 103 and the fourth wall 104 are appropriate, allowing for the expansion of the electrode assembly 2 to be tolerated and preventing the electrode assembly 2 from being extruded and rupturing.

[0163] c1 may be any value between 1.0 mm and 2.5 mm, for example, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, etc.

[0164] If c1<1.0 mm, the thickness of the fifth wall 105 is too small, and after the fifth wall 105 is corroded over time by particulate matter accumulated thereon, the remaining thickness is smaller, and when the electrode assembly 2 moves within the housing 1, the fifth wall 105 is less able to withstand the impact of the electrode assembly 2 and is more likely to burst. If c1>2.5 mm, the thickness of the fifth wall 105 is too large, which is disadvantageous to improving the volumetric energy density of the battery cell 10 and is relatively expensive. In this embodiment, c1 is set to 1.0 mm to 2.5 mm, which ensures the volumetric energy density of the battery cell 10 and also ensures the fifth wall 105's ability to withstand the impact of the electrode assembly 2.

[0165] When the first wall 101, the second wall 102, the third wall 103, the fourth wall 104, and the fifth wall 105 are integrally formed to form the case 11, and the sixth wall 106 forms the end cap 12, the electrode terminal may be installed on the end cap 12 or on the fifth wall 105. The electrode terminal is electrically connected to the electrode assembly 2.

[0166] When the first wall 101, the second wall 102, the third wall 103, the fourth wall 104 and the fifth wall 105 are integrally formed and installed as a case, and the sixth wall 106 is an end cap, in order to further improve the volume occupancy rate of the internal space of the housing 1 and improve the volumetric energy density of the battery cell 10, in some embodiments of the present application, (W1-2*a1)*(T1-2*b1)*(H1-c1-c2) / (W1*T1*H1)≧95%.

[0167] 10 to 12 , in some embodiments of the present application, the housing 1 includes a case 11 and two end caps 12, the case 11 has two openings arranged opposite each other along the third direction Z, the two end caps 12 are respectively fitted over the openings on the corresponding sides, and the end caps 12 are welded to the case 11, the first wall 101, the second wall 102, the third wall 103, and the fourth wall 104 are integrally molded and form the case 11, the fifth wall 105 and the sixth wall 106 are respectively the two end caps 12, the thicknesses of the first wall 101 and the second wall 102 are all a1, the thicknesses of the third wall 103 and the fourth wall 104 are all b1, the thickness of the fifth wall 105 is c1, and the thickness of the sixth wall 106 is c2, satisfying c1=c2, c1>a1, and c2>b1.

[0168] In this embodiment, by setting the fifth wall 105 and the sixth wall 106 to have the same thickness (i.e., c1=c2), the same set of molds can be used to manufacture the two end caps 12 required for the battery cell 10, thereby reducing the number of molds and lowering manufacturing costs.

[0169] In the case of the battery cell 10 having two end caps 12, in order to reduce the risk that the welding seam between the end cap 12 and the case 11 cracks due to an increase in the internal air pressure, in this embodiment, the thickness of the end cap 12 is designed to be relatively thick, the thickness of the end cap 12 is made larger than the thicknesses of the first wall 101 and the second wall 102, and also made larger than the thicknesses of the third wall 103 and the fourth wall 104 (that is, c1 > a1, c1 > b1, c2 > a1, c2 > b1), and it is possible to allow a welding seam with a larger width or thickness to be formed between the end cap 12 and the case 11, thereby improving the welding strength, reducing the risk that the welding seam cracks, and improving the reliability of the battery cell 10. Also, in order to form a welding seam with a larger width or thickness, increasing the thickness of the end cap 12 can reduce the amount of material used and reduce the cost compared to increasing the thicknesses of the first wall 101, the second wall 102, the third wall 103, and the fourth wall 104.

[0170] When the first wall 101, the second wall 102, the third wall 103, and the fourth wall 104 are integrally formed and installed as the case 11, and the fifth wall 105 and the sixth wall 106 are each the end cap 12, in some embodiments of the present application, the areas of the third wall 103 and the fourth wall 104 are larger than the areas of the first wall 101 and the second wall 102, and the areas of the third wall 103 and the fourth wall 104 are larger than the areas of the fifth wall 105 and the sixth wall 106, satisfying b1 < a1.

[0171] In this embodiment, the third wall 103 and the fourth wall 104 are the two walls with the largest area of the housing 1, that is, the large surfaces of the battery cell 10. Generally, when the battery cell 10 cycles, the amount of expansion in the large surface direction of the electrode assembly 2 is much larger than the amount of expansion in other directions. In order to allow the electrode assembly 2 to expand in the large surface direction, in this embodiment, the thicknesses of the third wall 103 and the fourth wall 104 are designed to be relatively small, and the thicknesses of the third wall 103 and the fourth wall 104 are made smaller than the thicknesses of the first wall 101 and the second wall 102 (that is, b1 < a1).

[0172] When the first wall 101, the second wall 102, the third wall 103, and the fourth wall 104 are integrally formed and installed to form the case 11, and the fifth wall 105 and the sixth wall 106 each form the end cap 12, in some embodiments of the present application, 0.5 mm≦a1≦1.5 mm, 0.5≦b1≦1.5 mm, and 1.5 mm≦c1≦4 mm.

[0173] a1 may be any value between 0.5 mm and 1.5 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc.

[0174] If a1<0.5 mm, the thicknesses of the first wall 101 and the second wall 102 are too small, and the thicknesses of the third wall 103 and the fourth wall 104 are smaller than the first wall 101 and the second wall 102, making it difficult to ensure the structural strength of the housing 1 in the third direction Z and susceptible to deformation of the battery cells 10. If a1>1.5 mm, the thicknesses of the first wall 101 and the second wall 102 are too large, which is unfavorable for improving the volumetric energy density of the battery cells 10 and results in relatively high costs. In this embodiment, a1 is set to 0.5 mm to 1.5 mm, which ensures the volumetric energy density of the battery cells 10 while also ensuring the structural strength of the housing 1 in the third direction Z.

[0175] b1 may be any value between 0.5 mm and 1.5 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc.

[0176] When b1<0.5 mm, the thicknesses of the third wall 103 and the fourth wall 104 are too small, and when the electrode assembly 2 expands, the third wall 103 and the fourth wall 104 are easily extruded and ruptured. When b1>1.5 mm, the third wall 103 and the fourth wall 104 are relatively thick, and their structural strength and rigidity are also relatively high, making it difficult to absorb the expansion of the electrode assembly 2. This makes it easy for stress to concentrate inside the electrode assembly 2, resulting in the "lithium deposition" phenomenon and shortening the cycle life. In this embodiment, b1 is set to 0.5 mm to 1.5 mm, which ensures that the structural strength and rigidity of the third wall 103 and the fourth wall 104 are appropriate, allowing for the expansion of the electrode assembly 2 to be tolerated and preventing the electrode assembly 2 from being extruded and rupturing.

[0177] c1 and c2 may be any value between 1.5 mm and 4.0 mm, for example, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3.0 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4.0 mm, etc.

[0178] If c1 and c2 are smaller than 1.5 mm, the thickness of the end cap 12 is too small, and after the end cap 12 is corroded over time by particulate matter accumulated thereon, the remaining thickness is smaller, and if the electrode assembly 2 moves within the housing 1, the end cap 12 is less able to withstand the impact of the electrode assembly 2 and is more likely to burst. If c1 and c2 are larger than 4 mm, the thickness of the end cap 12 is too large, which is disadvantageous to improving the volumetric energy density of the battery cell 10 and is relatively expensive. In this embodiment, c1 and c2 are set to 1.5 mm to 4 mm, which ensures the volumetric energy density of the battery cell 10 and also ensures the end cap's ability to withstand the impact of the electrode assembly 2.

[0179] The first wall 101, the second wall 102, the third wall 103, and the fourth wall 104 are integrally formed and installed to form a case 11. When the fifth wall 105 and the sixth wall 106 are each an end cap 12, the electrode terminals are installed on the end cap 12, and the electrode terminals are electrically connected to the electrode assembly 2. Further, a positive electrode terminal 121 may be installed on one end cap 12, and a negative electrode terminal 122 may be installed on the other end cap 12.

[0180] When the first wall 101, the second wall 102, the third wall 103, and the fourth wall 104 are integrally formed and installed to form a case 11, and the fifth wall 105 and the sixth wall 106 are each an end cap 12, in order to further improve the volume occupancy rate of the internal space of the housing 1 and improve the volume energy density of the battery cell 10, in some embodiments of the present application, (W1 - 2*a1)*(T1 - 2*b1)*(H1 - 2*c1) / (W1*T1*H1) ≥ 95%.

[0181] In some embodiments of the present application, W1, T1, and H1 satisfy T1 < W1 and T1 < H1, that is, the third wall 103 and the fourth wall 104 are the two walls with the largest area of the housing 1.

[0182] In this embodiment, the thickness of the battery cell 10 is smaller than the width and height of the battery cell 10. The battery cell 10 is in a flat shape, the battery assembly is also in a flat shape, and the thickness direction of the electrode assembly 2 is the same as the thickness direction of the battery cell 10. In the case of a stacked electrode assembly 2, the thickness direction of the electrode assembly 2 is the stacking direction of the electrode plates. In the case of a wound electrode assembly 2, the main body 21 of the electrode assembly 2 includes a flat region A, a first bending region b1, and a second bending region B2, and the thickness direction of the electrode assembly 2 is the stacking direction in the flat region A of the electrode plates.

[0183] Whether it is a stacked electrode assembly or a wound electrode assembly, the thickness of the electrode assembly 2 must not be too large, otherwise the heat from the inner electrode plates cannot be dissipated in a timely manner, causing the temperature of the inner electrode plates to become too high and easily resulting in thermal runaway.Since the thickness of the electrode assembly 2 must not be too large, the thickness of the battery cell 10 must also not be too large.

[0184] When the thickness of the battery cell 10 is limited, the volume of the battery cell 10 is 3000 cm 3 To achieve the above, in some embodiments of the present application, the width and height of the battery cell 10 are both greater than or equal to twice the thickness of the battery cell 10, i.e., W1 / T1≧2 and H1 / T1≧2.

[0185] However, if the width of the battery cell 10 exceeds 10 times the thickness or the height exceeds 10 times the thickness, the battery cell 10 will have the appearance of a long and thin rectangular parallelepiped, and the rigidity of the entire battery cell 10 will be insufficient, making it prone to deformation. Therefore, in some embodiments of the present application, W1, T1, and H1 satisfy 2≦W1 / T1≦10 and 2≦H1 / T1≦10, thereby not only allowing the battery cell 10 to have a relatively large volume, but also ensuring that the overall rigidity of the battery cell 10 is relatively large and less prone to deformation.

[0186] In some embodiments of the present application, W1 and H1 satisfy 0.7≦W1 / H1≦1.6.

[0187] When W1 / H1<0.7, the width of the battery cell 10 is much smaller than the height, and the third wall 103 and the fourth wall 104, which are the two walls of the housing 1 with the largest area, are slender plates that make it difficult to ensure the structural strength and rigidity of the battery cell 10 in the width direction. When the first wall 101 and / or the second wall 102 are subjected to an external force along the width direction of the battery cell 10, the third wall 103 and the fourth wall 104 are prone to bending deformation.

[0188] When W1 / H1>1.6, the width of the battery cell 10 is much larger than the height, and the third wall 103 and the fourth wall 104, which are the two walls of the housing 1 with the largest area, are slender plates that make it difficult to ensure the structural strength and rigidity of the battery cell 10 in the height direction. When the fifth wall 105 and / or the sixth wall 106 are subjected to an external force along the height direction of the battery cell 10, the third wall 103 and the fourth wall 104 are likely to bend and deform.

[0189] In this embodiment, the ratio of W1 to H1 is set to between 0.7 and 1.6, making the width and height of the battery cell 10 relatively close to each other, thereby improving the structural strength and rigidity of the battery cell 10 in the width and height directions and reducing the possibility of deformation of the battery cell 10.

[0190] W1 / H1 may be any value between 0.7 and 1.6, for example, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, and the like.

[0191] In some embodiments of the present application, 40 mm≦T1≦150 mm, and T1 may be any value between 40 mm and 150 mm, such as 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 105 mm, 110 mm, 115 mm, 120 mm, 125 mm, 130 mm, 135 mm, 140 mm, 145 mm, 150 mm, etc.

[0192] When T1<40 mm, the value of b needs to be set small to satisfy (T1-b) / T1≧96.5%. However, if the value of b is too small, it is difficult to ensure the structural strength and rigidity of the third wall 103 and the fourth wall 104.

[0193] If T1>150mm, it is likely that the heat dissipation path of the inner layer electrode plate of the electrode assembly 2 will be too long, and the heat of the inner layer electrode plate will not be able to dissipate outward in a timely manner, causing the temperature of the inner layer electrode plate to be too high, which is likely to cause thermal runaway.

[0194] In this embodiment, by setting T1 between 40 mm and 150 mm, it is possible to increase the thickness-wise size occupancy of the internal space of the housing 1 by the battery cell 10, thereby not only improving the volumetric energy density of the battery cell 10 but also ensuring the timely heat dissipation of the inner layer electrode plates of the electrode assembly 2.

[0195] In some embodiments of the present application, the height direction of the battery cell 10 is parallel to the direction of gravity, the battery cell 10 contains an electrolyte, and H1 satisfies 120 mm≦H1≦400 mm. H1 may be any value between 120 mm and 400 mm, such as 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, 210 mm, 220 mm, 230 mm, 240 mm, 250 mm, 260 mm, 270 mm, 280 mm, 290 mm, 300 mm, 310 mm, 320 mm, 330 mm, 340 mm, 350 mm, 360 mm, 370 mm, 380 mm, 390 mm, or 400 mm.

[0196] When H1<120 mm, the value of c needs to be set small to satisfy (H1-c) / H1≧96.5%. However, the fifth wall 105 and / or the sixth wall 106 are end caps, and if the value of c is too small, the weld seam between the end cap and the case becomes relatively small, making it difficult to ensure the weld strength.

[0197] If H1>400 mm, the height of the battery cell 10 and the electrode assembly 2 are too high, and the height direction of the battery cell 10 is parallel to the direction of gravity. If the electrode assembly 2 is too high, the electrolyte will have difficulty reaching the top of the electrode assembly 2, and the top of the electrode assembly 2 will not be sufficiently infiltrated by the electrolyte and will not function, resulting in a decrease in the energy density of the battery cell 10.

[0198] In this embodiment, by setting H1 between 120 mm and 400 mm, it is possible to improve the occupancy rate of the height of the battery cell 10 in the internal space of the housing 1 and improve the volumetric energy density of the battery cell 10, as well as ensure that the top of the electrode assembly 2 can be sufficiently infiltrated with the electrolyte.

[0199] In some embodiments of the present application, 150 mm≦W1≦1500 mm, and W1 may be any value between 150 mm and 1500 mm, such as 150 mm, 200 mm, 250 mm, 300 mm, 350 mm, 400 mm, 450 mm, 500 mm, 550 mm, 600 mm, 650 mm, 700 mm, 750 mm, 800 mm, 850 mm, 900 mm, 950 mm, 1000 mm, 1050 mm, 1100 mm, 1150 mm, 1200 mm, 1250 mm, 1300 mm, 1350 mm, 1400 mm, 1450 mm, 1500 mm, etc.

[0200] When W1<150 mm, the value of a needs to be set small to satisfy (W1-a) / W1≧97.0%. However, if the value of a is too small, it is difficult to ensure the structural strength and rigidity of the first wall 101 and the second wall 102, and the heat dissipation of the electrode assembly 2 is limited. T1 should not be too large, which limits the infiltration of the electrode assembly 2. H1 should not be too large. If T1 is also relatively small, the volume of the battery cell 10 is 3000 cm. 3 The above conditions cannot be satisfied, and it is difficult to guarantee the volumetric energy density of the battery cell 10.

[0201] When W1>1500 mm, T1 and H1 are limited, so the difference between W1 and T1 becomes relatively large, and the difference between W1 and H1 becomes relatively large, causing the entire battery cell 10 to have a long, narrow rectangular parallelepiped structure, resulting in insufficient structural strength and rigidity of the entire battery cell 10.

[0202] In this embodiment, by setting W1 between 150 mm and 1500 mm, it is possible to increase the widthwise size occupancy of the battery cell 10 in the internal space of the housing 1, thereby not only improving the volumetric energy density of the battery cell 10 but also ensuring the structural strength and rigidity of the entire battery cell 10.

[0203] In some embodiments of the present application, the battery cell 10 is a lithium-ion battery, the positive electrode active material of the battery cell 10 includes a lithium-containing phosphate, and the capacity of the battery cell 10 is C, where C≧350 Ah and C / ((W1−a)*(T1−b)*(H1−c))≧118 Ah / L. As a specific example, the lithium-containing phosphate may include one or more of lithium iron phosphate, lithium manganese phosphate, lithium cobalt phosphate, and lithium nickel phosphate, but is not limited thereto.

[0204] In some embodiments of the present application, the positive electrode active material of the battery cell 10 includes a lithium transition metal oxide, and the capacity of the battery cell 10 is C, where C≧650 Ah and C / ((W1−a)*(T1−b)*(H1−c))≧190 Ah / L. As a specific example, the lithium transition metal oxide may include, but is not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide.

[0205] In some embodiments of the present application, the battery cell 10 is a sodium ion battery, and the capacity of the battery cell 10 is C, where C≧260 Ah and C / ((W1−a)*(T1−b)*(H1−c))≧87 Ah / L.

[0206] An embodiment of the present application provides a battery 100, which includes a battery housing 20 and a battery cell 10 according to any of the above embodiments, the battery cell 10 being housed within the battery housing 20.

[0207] An embodiment of the present application provides a power consuming device including a battery according to any one of the above embodiments.

[0208] An embodiment of the present application provides an energy storage device 2000 including an energy storage housing 400 and a battery cell 10 according to any one of the above embodiments, wherein the energy storage housing 400 includes a battery compartment 401, and the battery cell 10 is accommodated within the battery compartment 401.

[0209] In some embodiments of the present application, the sum of the volumes of the plurality of battery cells 10 is V1, the volume of the battery chamber 401 is V2, and the relationship 0.5≦V1 / V2≦0.95 is satisfied. V1 / V2 may be any value between 0.5 and 0.95, such as 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, etc.

[0210] V1 is the sum of the volumes of all the battery cells 10 in the battery compartment, and if the volumes of all the battery cells 10 in the battery compartment 401 are equal, V1 is the product of the volume of each battery cell 10 and the number of battery cells 10. V2 is the volume of the three-dimensional space defined by the inner contour of the battery compartment 401. In the energy storage device 2000, V1 / V2 can be defined as the space utilization rate.

[0211] In this embodiment, by limiting the ratio of the sum of the volumes of the battery cells 10 to the volume of the battery compartment, i.e., V1 / V2≧0.5, the space utilization rate of the energy storage device 2000 can be improved, and more battery cells 10 can be arranged in the battery compartment 401 of the energy storage housing 400, i.e., more energy providing structures can be arranged in a unit space, thereby improving the energy density and thereby increasing the capacity without increasing the occupied space.

[0212] In some embodiments of the present application, the ratio of the sum of the volumes of the plurality of battery cells 10 to the volume of the battery chamber 401 satisfies V1 / V2≧0.55.

[0213] In some embodiments of the present application, the ratio of the sum of the volumes of the plurality of battery cells 10 to the volume of the battery chamber 401 satisfies V1 / V2≧0.65.

[0214] In some embodiments of the present application, the ratio of the sum of the volumes of the plurality of battery cells 10 to the volume of the battery chamber 401 satisfies V1 / V2≧0.75.

[0215] As will be understood by those skilled in the art, other components used in combination with the battery cell 10 occupy the internal space of the battery compartment, including a liquid cooling system, a control system, a wiring harness, etc., so the peak value of V1 / V2 is generally 95%, i.e., V1 / V2≦95%.

[0216] It should be noted that, unless contradictory, the embodiments and features in the embodiments in the present application can be combined with each other.

[0217] The above examples are only intended to illustrate the technical solution of the present application and are not intended to limit the present application, and those skilled in the art may make various modifications and variations to the present application, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application. [Explanation of symbols]

[0218] 1 - housing, 11 - case, 12 - end cap, 101 - first wall, 102 - second wall, 103 - third wall, 104 - fourth wall, 105 - fifth wall, 106 - sixth wall, 121 - positive electrode terminal, 122 - negative electrode terminal, 141 - first insulating member, 142 - second insulating member, 143 - third insulating member, 144 - fourth insulating member, 2 - electrode assembly, 21 - body, 22 - positive electrode tab, 23 - negative electrode tab, 24 - positive electrode plate, 25 - negative electrode plate, 26 - separator, 10 - battery cell, 20 - battery housing, 201 - first part, 202 - second part, 100 - battery, 200 - controller, 300 - motor, 400 - energy storage housing, 401 - Battery compartment, 402 - electrical compartment, 403 - upright, 404 - battery bracket, 1000 - vehicle, 2000 - energy storage device, A - flat area, b1 - first bending area, B2 - second bending area, X - first direction, Y - second direction, Z - third direction.

Claims

1. A battery cell whose housing has a volume of 3000 cm ３ the housing is a cuboid, the housing includes a case and end caps, the case has an opening, the end caps are fitted over the opening, and the end caps are welded to the case, the case includes a first wall, a second wall, a third wall, a fourth wall, and a fifth wall that are integrally formed, the first wall and the second wall are disposed opposite each other along a first direction, the third wall and the fourth wall are disposed opposite each other along a second direction, and the fifth wall and the end cap are disposed opposite each other along a third direction, the first direction, the second direction, and the third direction are perpendicular to each other, an electrode terminal installed on the end cap or the fifth wall; at least one electrode assembly, the electrode assembly being contained within the housing, the electrode assembly including a body and a tab extending from the body, the tab being electrically connected to the electrode terminal; an electrolyte contained within the housing; Here, the size of the housing in the first direction is W １ and the size of the housing in the second direction is T １ and the size of the housing in the third direction is H １ the sum of the thicknesses of the first wall and the second wall is a, the sum of the thicknesses of the third wall and the fourth wall is b, the sum of the thicknesses of the fifth wall and the end cap is c, and (W １ −a)*(T １ −b)*(H １ −c) / (W １ *T １ *H １ ) ≧ 90%, 40 mm ≦ T １ ≦150mm, 120mm≦H １ ≦400mm, 150mm≦W １ A battery cell characterized by satisfying the following:

2. (W １ −a)*(T １ −b)*(H １ −c) / (W １ *T １ *H １ ) ≧92%, and optionally, (W １ −a)*(T １ −b)*(H １ −c) / (W １ *T １ *H １ 2. The battery cell according to claim 1, wherein the % yield is ≥ 95%.

3. (W １ -a) / W １ ≧97.0%, (T １ -b) / T １ ≧96.5%, and (H １ -c) / H １ 3. The battery cell according to claim 1, wherein the electrical conductivity is ≧96.5%.

4. the battery cell further includes a first insulating member and a second insulating member, the first insulating member being disposed between the fifth wall and the electrode assembly and abutting against the fifth wall, and the second insulating member being disposed between the end cap and the electrode assembly and abutting against the end cap; The maximum size of the first insulating member in the third direction is d １ and the maximum size of the second insulating member in the third direction is d ２ and (W １ -a-1.6mm)*(T １ -b-1.6mm)*(H １ -c-d １ -d ２ ) / (W １ *T １ *H １ ) ≧88%, 0.3 mm ≦ d １ ≦1.2 mm and 2 mm≦d ２ 4. The battery cell according to claim 1, wherein the thickness satisfies the following condition: ≦10 mm.

5. the battery cell further includes a first insulating member and a second insulating member, the first insulating member being disposed between the fifth wall and the electrode assembly and abutting against the fifth wall, and the second insulating member being disposed between the end cap and the electrode assembly and abutting against the end cap; The maximum size of the first insulating member in the third direction is d １ and the maximum size of the second insulating member in the third direction is d ２ and (W １ -a-4mm)*(T １ -b-4mm)*(H １ -c-d １ -d ２ ) / (W １ *T １ *H １ ) ≧85%, 0.3 mm ≦ d １ ≦1.2 mm and 2 mm≦d ２ 5. The battery cell according to claim 1, wherein the thickness satisfies the following condition: ≦10 mm.

6. W １ *T １ *H １ ≦40000 cm ３ 2. The battery cell according to claim 1, wherein:

7. 3200 cm ３ ≦W １ *T １ *H １ ≦32000 cm ３ 7. The battery cell according to claim 6, wherein:

8. 3720 cm ３ ≦W １ *T １ *H １ ≦12500 cm ３ 8. The battery cell according to claim 7, wherein:

9. 4000 cm ３ ≦W １ *T １ *H １ ≦6000 cm ３ 9. The battery cell according to claim 8, wherein:

10. The main body is a flat body, The number of the electrode assemblies is one, and the maximum size of the body in the first direction is W ２ and the maximum size of the body in the second direction is T ２ and the maximum size of the body in the third direction is H ２ and (W ２ *T ２ *H ２ ) / (W １ *T １ *H １ ) ≧80% is satisfied, Alternatively, the number of the electrode assemblies is a plurality, and the maximum size of the entire body of the plurality of electrode assemblies in the first direction is W ２ and the maximum size of the entire body of the plurality of electrode assemblies in the second direction is T ２ and the maximum size H of the entire body of the plurality of electrode assemblies in the third direction is ２ (W ２ *T ２ *H ２ ) / (W １ *T １ *H １ 10. The battery cell according to claim 1, wherein the battery cell satisfies a condition of ≥ 80%.

11. W ２ / (W １ -a) ≧91.5%, T ２ / (T １ -b) ≧93.2% and H ２ / (H １ 11. The battery cell according to claim 10, wherein -c) is ≥ 94.0%.

12. the electrode assembly has a wound structure, the main body includes a flat region, a first folded region, and a second folded region, the first folded region and the second folded region being located at both ends of the flat region along the first direction, respectively; The first folding region includes a plurality of first folding portions that are stacked and disposed, and a distance between an inner vertex of the first folding portion of an innermost layer and an outer vertex of the first folding portion of an outermost layer in the plurality of first folding portions along the first direction is W ３ and The second folding region includes a plurality of second folding portions that are stacked and disposed, and a distance between an inner vertex of the second folding portion of an innermost layer and an outer vertex of the second folding portion of an outermost layer in the plurality of second folding portions along the first direction is W ４ and (W ３ +W ４ ) / W ２ 12. The battery cell according to claim 10, wherein the solubility of the battery cell satisfies ≦30%.

13. 13. The battery cell of claim 1, wherein the first wall, the second wall, the third wall, the fourth wall, the fifth wall, and the end caps are all made of an aluminum alloy, and the aluminum alloy has mass percentage contents of aluminum≧96.7%, 0.05%≦copper≦0.2%, iron≦0.7%, manganese≦1.5%, silicon≦0.6%, zinc≦0.1%, other single element content≦0.05%, and total content of other elements≦0.15%.

14. The thickness of the first wall and the second wall is a １ and the thickness of the third wall and the fourth wall is b １ and the thickness of the fifth wall is c １ and the thickness of the end cap is c ２ and c ２ >c １ , c １ >a １ , c １ >b １ The battery cell according to any one of claims 1 to 13, wherein the following is satisfied:

15. 0.5 mm≦a １ ≦1.5mm, 0.8≦b １ ≦1.5mm, 1.0mm≦c １ ≦2.5mm, 1.5mm≦c ２ 15. The battery cell of claim 14, wherein the thickness is ≦4 mm.

16. 1.2 mm≦c １ ≦2.5mm, 2.5mm≦c ２ 16. The battery cell of claim 15, wherein the thickness is ≦4 mm.

17. (W １ −2*a １ ) * (T １ -2*b １ ) * (H １ -c １ -c ２ ) / (W １ *T １ *H １ 17. The battery cell according to claim 14, wherein the % yield is ≥ 95%.

18. T １ <W １ and T １ <H １ 18. The battery cell according to claim 1, wherein:

19. 2≦W １ / T １ ≦10 and / or 2≦H １ / T １ ≦10 and / or 0.7≦W １ / H １ 19. The battery cell according to claim 1, wherein the ρ is ≦1.

6.

20. The positive electrode material of the battery cell includes a lithium-containing phosphate, and the capacity of the battery cell is C, C≧350 Ah, C / ((W １ −a)*(T １ −b)*(H １ 20. The battery cell according to claim 1, wherein -c))≧118 Ah / L is satisfied.

21. The positive electrode material of the battery cell includes a lithium transition metal oxide, and the capacity of the battery cell is C, C≧650 Ah, C / ((W １ −a)*(T １ −b)*(H １ The battery cell according to any one of claims 1 to 19, characterized in that -c))≧190 Ah / L is satisfied.

22. The battery cell is a sodium ion battery, and the capacity of the battery cell is C, C≧260 Ah, C / ((W １ −a)*(T １ −b)*(H １ 20. The battery cell according to claim 1, wherein the capacity of the battery cell satisfies the following condition:-c))≧87 Ah / L.

23. A battery comprising the battery cell of any one of claims 1 to 22.

24. 24. A power consuming device according to claim 23, comprising a battery for providing electrical energy to said power consuming device.

25. 1. An energy storage device, comprising: an energy storage housing having a battery compartment; and a plurality of battery cells according to any one of claims 1 to 22 installed in the battery compartment.

26. The sum of the volumes of the housings of the battery cells is V １ and the volume of the battery compartment is V ２ and 0.5≦V １ / V ２ 26. The energy storage device of claim 25, wherein the energy storage device satisfies ≦0.95.

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