Battery device and electric device

Abstract

Provided in the present application are a battery device and an electric device. The battery device comprises a fixing assembly, an elastic assembly and at least one battery assembly, wherein each battery assembly comprises a battery cell containing a solid electrolyte; the fixing assembly comprises two first fixing members arranged opposite each other in a first direction, and at least one battery assembly is sandwiched between the two first fixing members; and the elastic assembly has a compression displacement in the first direction, and abuts at least between the at least one battery assembly and the first fixing members. The battery device has a 0% state of charge and a 100% state of charge. In the 0% state of charge, the elastic assembly has a first compression displacement amount in the first direction, and the elastic assembly abuts against the battery assembly with a first compression force F1. In the 100% state of charge, the elastic assembly has a second compression displacement amount in the first direction, and abuts against the battery assembly with a second compression force F2. The second compression displacement amount is greater than the first compression displacement amount, and (F2-F1) / F1 ranges from 0 to 0.1.

Description

Battery devices and electrical appliances

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese patent application 202411539007.0 entitled "Battery Device and Power Consumption Device", filed on October 31, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of batteries, specifically to a battery device and an electrical device. Background Technology

[0004] Battery devices are characterized by high capacity and long lifespan, and are therefore widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0005] As batteries are used more widely, the requirements for battery performance are becoming increasingly stringent, and the cycle life of battery devices still needs to be further improved. Summary of the Invention

[0006] This application is made in view of the above-mentioned problems, and its purpose is to provide a battery device and an electrical device that can improve the stress uniformity of battery cells, thereby improving the cycle life of the battery device.

[0007] In a first aspect, embodiments of this application propose a battery device, which includes a fixing component, an elastic component, and at least one battery component, each battery component including a single battery cell containing a solid electrolyte; the fixing component includes two first fixing members disposed opposite each other along a first direction, with at least one battery component sandwiched between the two first fixing members; the elastic component has a compressive displacement along the first direction and at least abuts against at least one battery component and the first fixing member, wherein the battery device includes a 0% state of charge and a 100% state of charge, in the 0% state of charge, the elastic component has a first compressive displacement along the first direction, and the elastic component abuts against the battery component with a first compressive force F1; in the 100% state of charge, the elastic component has a second compressive displacement along the first direction, and the elastic component abuts against the battery component with a second compressive force F2, the second compressive displacement being greater than the first compressive displacement, and (F2-F1) / F1 being 0 to 0.1.

[0008] Therefore, when the above conditions are met in the embodiments of this application, the first compression force F1 and the second compression force F2 are kept basically constant, so that the force on the battery assembly during use is kept basically constant, and the solid-solid interface can make stable and good contact, thereby improving the electrochemical performance of the battery device and increasing the cycle life of the battery device.

[0009] In some embodiments, multiple battery modules are configured and arranged along a first direction, with an elastic component abutting between adjacent battery modules. The elastic component can further improve the stress stability of the battery modules and improve the electrochemical performance of the battery device.

[0010] In some embodiments, the elastic component is an annular member with its axis parallel to a first direction. The annular member includes a first end and a second end opposite to each other along the first direction. The diameter of the cross section of the annular member perpendicular to the first direction gradually decreases in the direction from the first end to the second end. One of the first end and the second end abuts against the battery assembly, and the other abuts against the first fixing member.

[0011] The ring-shaped structure keeps the forces acting on the battery module essentially constant, and the solid-solid interface can maintain stable and good contact, thereby improving the electrochemical performance of the battery device.

[0012] In some implementations, the first end abuts against the battery module. The relatively large cross-section of the first end is more conducive to the uniform transmission of force to the battery module.

[0013] In some embodiments, the elastic component includes multiple annular members arranged sequentially along a first direction. Multiple annular members enable smaller compressive deformation of each annular member, more stable compressive forces generated by each annular member, and a substantially constant force on the battery assembly, resulting in stable and good contact at the solid-solid interface, thereby improving the electrochemical performance of the battery device.

[0014] In some embodiments, the first end of the annular member facing the battery assembly abuts against the battery assembly, and the first end of the annular member facing the first fixing member abuts against the first fixing member. The cross-section of the first end is relatively large, which is more conducive to uniform force transmission to the battery assembly.

[0015] In some embodiments, the first end of the annular member facing the battery assembly abuts against the battery assembly, and the second end of the annular member facing the first fixing member abuts against the first fixing member. The relatively large cross-section of the first end is more conducive to the uniform transmission of force to the battery assembly.

[0016] In some embodiments, the ratio D / d of the diameter D of the first end to the diameter d of the second end is 1.7 to 2.5. When the diameters of the first end and the second end 52 are within the above range, the compressive displacement of the elastic component when it is assembled into the battery device, under compression, can change with the changes in the battery component, but the resulting compressive force remains essentially constant. This allows the forces acting on the battery component to remain stable, thereby effectively improving the electrochemical performance of the battery device.

[0017] In some embodiments, the ratio h0 / t of the second compression displacement h0 to the average thickness t of the annular member is 1.1 to 1.8. When the second compression displacement and the average thickness t of the annular member are within the above range, the compressive force generated by the elastic component when it is assembled into the battery device can be kept basically constant, so that the force on the battery component can be kept stable, thereby effectively improving the electrochemical performance of the battery device.

[0018] In some embodiments, the average thickness of the annular member is 3 mm to 8 mm.

[0019] In some implementations, the second compression displacement is 5 mm to 8 mm.

[0020] In some embodiments, the first compression displacement is 5 mm to 8 mm. When the first compression displacement is within the above range, the compressive force generated by the elastic component when it is assembled into the battery device remains essentially constant, so that the force on the battery component can remain stable, thereby effectively improving the electrochemical performance of the battery device.

[0021] In some embodiments, the elastic modulus of the elastic component is from 50 GPa to 250 GPa, and optionally from 80 GPa to 210 GPa; when the elastic modulus of the elastic component is within the above range, the elastic component is in a compressed state in the battery device, and the compressive force is substantially constant.

[0022] In some embodiments, the Poisson's ratio of the elastic component is between 0.2 and 0.4. When the Poisson's ratio of the elastic component is within this range, the elastic component is in a compressed state within the battery device, and the compressive force is substantially constant.

[0023] In some implementations, the main material of the elastic component includes one or more of spring steel and shape memory alloy.

[0024] In some implementations, the shape memory alloy material includes one or more of nickel-titanium alloys and copper-nickel alloys.

[0025] In some embodiments, the battery device further includes a support component disposed between the battery component and the elastic component, with the projection of the battery component located within the projection of the support component along a first direction. The support component provides support to the elastic component, facilitating the uniform transfer of the compressive force generated by the elastic component to the battery component. This results in uniform stress distribution throughout the battery component, uniform current density distribution across the electrodes, and uniform lithium intercalation speed at the negative electrode, reducing the risk of lithium plating and improving the reliability of the battery device.

[0026] In some embodiments, the elastic modulus of the support component is from 1 GPa to 210 GPa, and can be selected as 50 GPa to 210 GPa. The support component has high stiffness and is not easily deformed. By placing it between the battery component and the elastic component, it can evenly transmit the compressive force generated by the elastic component to the battery component, so that the battery component is subjected to uniform stress, which can further improve the reliability of the battery device.

[0027] In some implementations, the main body material of the support component includes one or more of aluminum alloy and carbon alloy steel.

[0028] In some embodiments, each battery assembly includes a buffer member and a plurality of battery cells arranged along a first direction, with a buffer member disposed between adjacent battery cells. The buffer member can further buffer the volume changes of the battery cells, and can also uniformly transmit external forces to all parts of the battery cells, making the stress on the battery cells more uniform. Furthermore, because the buffer member has a certain elastic deformation capability, it can uniformly fit with the surface of the battery cells, which can alleviate the problem of uneven local stress caused by the unevenness of the battery cell surface, improve the uniformity of current density at all parts of the electrode, and the uniformity of lithium intercalation speed of the negative electrode, thereby reducing the risk of lithium plating and improving the reliability of the battery device.

[0029] In some embodiments, a buffer member is also disposed at at least one end of the battery assembly along the first direction. The buffer member can further buffer the volume changes of the individual battery cells, improving the reliability of the battery device.

[0030] In some embodiments, the first fixing member includes a main body and a protrusion. The protrusion is connected to the main body and protrudes from the main body in a first direction. An elastic component is sleeved outside the protrusion and is movably connected to it. The protrusion serves a limiting function, preventing the elastic component from easily detaching from the first fixing member and the battery assembly. Furthermore, the protrusion also serves a positioning function, allowing the elastic component to compress and deform along the protrusion, enabling it to apply force to the battery assembly within a preset position, thus making the battery assembly more stable under stress.

[0031] In some embodiments, the fixing assembly further includes two second fixing members disposed opposite to each other along a second direction. The two second fixing members are fixedly connected by a first fixing member, and the battery assembly is located between the two second fixing members, wherein the second direction is perpendicular to the first direction. The first fixing member and the second fixing member are fixedly connected; the fixing assembly clamps and fixes the battery assembly, applying a pre-tightening force to the battery assembly, thereby improving the solid-solid interface contact in the battery assembly and enhancing the electrochemical performance of the battery assembly.

[0032] In some embodiments, the battery cell includes a casing with two first surfaces and two second surfaces. The two first surfaces are disposed opposite each other along a first direction and connected by the second surfaces. The area of ​​the first surfaces is larger than that of the second surfaces. Because the area of ​​the first surfaces is relatively large, they deform more significantly during the cyclic charging and discharging of the battery device. By placing the first surfaces against the elastic component, the stress stability of the battery assembly can be improved more effectively.

[0033] Secondly, this application proposes an electrical device including a battery device as described in any embodiment of the first aspect of this application. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0035] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0036] Figure 2 is an exploded schematic diagram of a battery pack provided in some embodiments of this application;

[0037] Figure 3 is a schematic diagram of the structure of a battery module provided in some embodiments of this application.

[0038] Figure 4 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0039] Figure 5 is a schematic diagram of the structure of the electrode assembly of a battery cell provided in some embodiments of this application;

[0040] Figure 6 is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0041] Figure 7 is a schematic diagram of the structure of a battery device provided in some other embodiments of this application;

[0042] Figure 8 is a structural schematic diagram of a battery device provided in some other embodiments of this application;

[0043] Figure 9 is a schematic diagram of the structure of a battery device provided in some other embodiments of this application;

[0044] Figure 10 is a schematic diagram of the structure of the elastic component of the battery device provided in some embodiments of this application;

[0045] The accompanying drawings may not be drawn to scale.

[0046] The reference numerals in the attached drawings are explained as follows: X, first direction; Y, second direction; 1, vehicle; 2, battery pack; 3, controller; 4, motor; 5, housing; 5a, first housing section; 5b, second housing section; 5c, accommodating space; 6, battery module; 7, battery device; 30, battery assembly; 31, battery cell; 311, outer casing; 3111, first surface; 3112, second surface; 312, electrode assembly; 3121, positive electrode; 3122, negative electrode; 3123, solid electrolyte layer; 32, buffer component; 40, fixing component; 41, first fixing component; 411, main body; 412, protrusion; 42, second fixing component; 50, elastic component; 51, first end; 52, second end; 60, support component. Detailed Implementation

[0047] The following detailed description discloses embodiments of the battery device and power-consuming device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0048] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0049] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0050] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0051] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0052] In this application, the term "implementation" means that a specific feature, structure, or characteristic described in connection with an implementation may be included in at least one implementation of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same implementation, nor is it a separate or alternative implementation mutually exclusive with other implementations.

[0053] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0054] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0055] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0056] In this application, "multiple" refers to two or more (including two). In the embodiments of this application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged after discharge to activate the active materials and continue to be used.

[0057] In this application, the battery cell may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium lithium-ion battery cells, sodium-ion battery cells, magnesium-ion battery cells, lithium metal battery cells, sodium metal batteries, etc., and the embodiments of this application are not limited to these. The battery cell may be cylindrical, flat, cuboid, or other shapes, and the embodiments of this application are not limited to these shapes either. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells, and the embodiments of this application are not limited to these types either.

[0058] The battery device mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery device mentioned in this application may include a battery module or a battery pack. A battery device generally includes a housing for encapsulating one or more battery cells. The housing can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0059] Solid-state and semi-solid-state battery cells both include solid electrolytes, which have higher thermal and chemical stability and can withstand higher temperatures and mechanical stresses, thus improving the reliability of battery cells.

[0060] The main transport between the electrode and the solid electrolyte is through the solid-solid interface. In order for active ions such as lithium ions and sodium ions to be transported smoothly between the electrode and the solid electrolyte, the battery cells are usually fixed in the fixing assembly to form a battery device. Then, a certain pre-tightening force is applied to the battery cells by the fixing assembly to ensure good contact between the electrode and the solid electrolyte interface.

[0061] However, during the cyclic charging and discharging of a battery device, the volume of the individual battery cells expands or contracts. During the expansion of the individual battery cells, the individual battery cells exert a certain expansion pressure on the fixed assembly. During the contraction of the individual battery cells, the force exerted by the individual battery cells on the fixed assembly decreases. The force exerted by the individual battery cells on the fixed assembly is unstable, which in turn makes the force exerted by the fixed assembly on the individual battery cells unstable. This results in the solid-solid interface not being able to maintain a stable and good contact, which may deteriorate the electrochemical performance of the battery device, such as cycle life.

[0062] In view of this, this application proposes a battery device in which an elastic component is provided between a fixed component and a battery cell. The battery cell transmits force to the fixed component through the elastic component. During the expansion or contraction of the battery cell, the elastic component can be compressed to different degrees in accordance with the volume change of the battery cell. However, the compressive force generated by the elastic component remains basically stable, so that the force exerted by the elastic component on the fixed component remains basically stable. Thus, the force exerted by the fixed component on the battery cell through the elastic component remains basically stable, so that the solid-solid interface can have stable and good contact, thereby improving the electrochemical performance of the battery device and increasing the cycle life of the battery device.

[0063] The battery cells described in this application are applicable to battery devices and electrical devices that use battery devices.

[0064] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools 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, impact drills, concrete vibrators, and electric planers, etc. The embodiments of this application do not impose special limitations on the above-mentioned electrical devices.

[0065] For ease of explanation, the following implementation method uses a vehicle as an example of an electrical device.

[0066] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application.

[0067] As shown in Figure 1, a battery pack 2 is installed inside the vehicle 1. The battery pack 2 can be located at the bottom, front, or rear of the vehicle 1. The battery pack 2 can be used to power the vehicle 1; for example, the battery pack 2 can serve as the operating power source for the vehicle 1.

[0068] Vehicle 1 may also include controller 3 and motor 4. Controller 3 is used to control battery pack 2 to supply power to motor 4, for example, for the power needs of vehicle 1 during start-up, navigation and driving.

[0069] In some embodiments of this application, the battery pack 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0070] Figure 2 is an exploded view of a battery provided in some embodiments of this application. As shown in Figure 2, the battery pack 2 includes a housing 5 and a battery cell 31 (not shown in Figure 2), with the battery cell 31 housed within the housing 5.

[0071] The housing 5 is used to house the battery cell 31, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, and together define a housing space 5c for housing the battery cell 31. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a may be a plate-like structure, with the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c; alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c. Of course, the first housing portion 5a and the second housing portion 5b can be various shapes, such as cylinders, cuboids, etc.

[0072] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0073] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0074] In battery pack 2, there can be one or more battery cells 31. If there are multiple battery cells 31, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 31 are connected in both series and parallel. Multiple battery cells 31 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 31 is housed in the housing 5. Alternatively, multiple battery cells 31 can first be connected in series, parallel, or in a mixed manner to form battery modules 6, and then multiple battery modules 6 can be connected in series, parallel, or in a mixed manner to form a whole assembly, which is then housed in the housing 5.

[0075] The battery cell 31 can be the smallest unit that makes up the battery.

[0076] Figure 3 is a schematic diagram of the battery module shown in Figure 2.

[0077] In some embodiments, as shown in Figure 3, there are multiple battery cells 31. These multiple battery cells 31 are first connected in series, parallel, or in a mixed manner to form a battery module 6. The multiple battery modules 6 are then connected in series, parallel, or in a mixed manner to form a whole, which is housed in a casing.

[0078] Multiple battery cells 31 in battery module 6 can be electrically connected through a busbar to achieve parallel, series, or mixed connection of the multiple battery cells 31 in battery module 6. There can be one or more busbars, and each busbar is used to electrically connect at least two battery cells 31.

[0079] Figure 4 is a schematic diagram of the structure of a battery cell 31 provided in some embodiments of this application; Figure 5 is a schematic diagram of the structure of the electrode assembly 312 of a battery cell 31 provided in some embodiments of this application.

[0080] As shown in Figures 4 and 5, in some embodiments, the battery cell 31 includes an electrode assembly 312 and a housing 311, with the electrode assembly 312 housed within the housing 311.

[0081] The internal cavity formed by the outer shell 311 can be used to accommodate the electrode assembly 312, the electrolyte, and other components. The outer shell 311 can be of various shapes, such as a cylinder or a cuboid. The shape of the outer shell 311 can be determined according to the specific shape of the electrode assembly 312. For example, if the electrode assembly 312 has a cylindrical structure, the outer shell 311 can be a cylindrical structure. If the electrode assembly 312 has a cuboid structure, the outer shell 311 can be a cuboid structure.

[0082] The outer casing 311 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc. The embodiments of this application do not impose any special restrictions on this.

[0083] The electrode assembly 312 housed within the housing 311 may be one or more. In this embodiment, the electrode assembly 312 may be a wound structure or a stacked structure, and may be a stacked structure.

[0084] The electrode assembly 312 includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell 31, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrodes. Optionally, the electrode assembly 312 also includes a separator disposed between the positive and negative electrodes, which can reduce the risk of short circuit between the positive and negative electrodes while allowing active ions to pass through.

[0085] In some embodiments, the positive electrode can be a positive electrode sheet 3121, which may include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector, the positive electrode film layer including a positive electrode active material.

[0086] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0087] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, titanium, silver-surfaced aluminum, or stainless steel can be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0088] As an example, when the battery cell 31 in this embodiment is a lithium-ion battery or a lithium metal battery, the positive electrode active material may include one or more of the following materials: phosphates, layered transition metal oxides, and their respective modified compounds; optionally, the positive electrode active material may include layered transition metal oxides and their respective modified compounds, which is beneficial to improving the energy density of the battery cell 31. However, this application is not limited to these materials, and other conventional materials that can be used as the positive electrode film layer of a battery may also be used. These positive electrode active materials may be used alone or in combination of two or more.

[0089] Examples of phosphates may include, but are not limited to, one or more of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0090] Layered transition metal oxides include those with the general formula Li a Ni b Co c M d O e A f One or more of the compounds and their modified compounds. 0.8≤a≤1.2, 0.3≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M includes one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A includes one or more of N, F, S and Cl.

[0091] Examples of layered transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, and lithium nickel cobalt manganese oxides (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.80 Co 0.15 Al 0.05 One or more of O2 and its modified compounds.

[0092] When the battery cell 31 in the embodiments of this application is a sodium-ion battery or a sodium metal battery, the positive electrode active material may include, but is not limited to, one or more of sodium-containing transition metal oxides, polyanionic materials (such as phosphates, fluorophosphates, pyrophosphates, sulfates, etc.), and Prussian blue materials.

[0093] As an example, positive electrode active materials for sodium-ion batteries may include NaFeO2, NaCoO2, NaCrO2, NaMnO2, NaNiO2, and NaNi 1 / 2 Ti 1 / 2 O2, NaNi 1 / 2 Mn 1 / 2 O2, Na 2 / 3 Fe 1 / 3 Mn 2 / 3 O2, NaNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, NaFePO4, NaMnPO4, NaCoPO4, Prussian blue materials, with the general formula X p M' q (PO4) r O x Y 3-x One or more of the materials. In general formula X p M' q (PO4) r O x Y 3-x In the given condition, 0 < p ≤ 4, 0 < q ≤ 2, 1 ≤ r ≤ 3, 0 ≤ x ≤ 2, and X includes H. + Li + Na+ K + and NH4 + One or more of the following, M' is a transition metal cation, optionally one or more of V, Ti, Mn, Fe, Co, Ni, Cu and Zn, and Y is a halide anion, optionally one or more of F, Cl and Br.

[0094] In the embodiments of this application, the modified compounds of the above-mentioned positive electrode active materials can be doped and / or surface coated to modify the positive electrode active materials, such as carbon coating modification, fast ion conductor coating modification, etc.

[0095] During the charging and discharging process, the battery cell 31 undergoes the insertion and extraction of active ions such as Li, resulting in a different molar content of Li in the battery cell 31 at different discharge states. In the examples of positive electrode active materials in this application, the molar content of Li refers to the initial state of the material, i.e., the state before feeding. When the positive electrode active material is applied to the battery system, the molar content of Li may change after charge-discharge cycles.

[0096] In the embodiments of this application, the molar content of oxygen (O) in the positive electrode active materials is only a theoretical value. Oxygen release from the crystal lattice will cause the molar content of oxygen (O) to change. In reality, the molar content of oxygen (O) will fluctuate.

[0097] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the positive electrode, a positive electrode film layer may or may not be provided on the surface of the foamed metal. As an example, lithium source material, potassium metal, or sodium metal may also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0098] In some embodiments, the positive electrode film layer may optionally include a positive electrode conductive agent. This application does not impose particular limitations on the type of positive electrode conductive agent. As an example, the positive electrode conductive agent includes one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the mass percentage of the positive electrode conductive agent in the positive electrode film layer is ≤5 wt%.

[0099] In some embodiments, the positive electrode film layer may optionally include a positive electrode binder. This application does not impose particular limitations on the type of positive electrode binder. As an example, the positive electrode binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins. In some embodiments, the mass percentage of the positive electrode binder in the positive electrode film layer is ≤5 wt%.

[0100] The positive electrode film is typically formed by coating a positive electrode slurry onto a positive electrode current collector, followed by drying and cold pressing. The positive electrode slurry is usually formed by dispersing the positive electrode active material, optional conductive agent, optional binder, and any other components in a solvent and stirring until homogeneous. The solvent can be N-methylpyrrolidone (NMP), but is not limited to this.

[0101] In some embodiments, the battery cell 31 is an ion-type battery such as a lithium-ion battery, and the negative electrode can be a negative electrode sheet 3122. The negative electrode sheet 3122 may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector. The negative electrode film layer includes a negative electrode active material.

[0102] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0103] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0104] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cell 31. As an example, the negative electrode active material may include one or more of the following materials: carbon materials (e.g., carbon materials include one or more of artificial graphite, natural graphite, soft carbon, and hard carbon), silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may include one or more of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may include one or more of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode films may also be used. These negative electrode films may be used alone or in combination of two or more.

[0105] In some embodiments, the negative electrode film layer may optionally include a negative electrode conductive agent. This application does not impose particular limitations on the type of negative electrode conductive agent. As an example, the negative electrode conductive agent may include one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon fibers. In some embodiments, the mass percentage of the negative electrode conductive agent in the negative electrode film layer is ≤5 wt%.

[0106] In some embodiments, the negative electrode film layer may optionally include a negative electrode binder. This application does not impose particular limitations on the type of negative electrode binder. As an example, the negative electrode binder may include one or more of the following: styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, waterborne acrylic resins (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS). In some embodiments, the mass percentage of the negative electrode binder in the negative electrode film layer is ≤5 wt%.

[0107] In some embodiments, the negative electrode film layer may optionally include other additives. As an example, other additives may include thickeners, such as sodium carboxymethyl cellulose (CMC-Na), PTC thermistor materials, etc. In some embodiments, the mass percentage of other additives in the negative electrode film layer is ≤2 wt%.

[0108] In some embodiments, the battery cell 31 also includes an electrolyte. During the charging and discharging process of the battery cell 31, active ions repeatedly insert and extract between the positive and negative electrode plates, and the electrolyte plays a role in conducting active ions between the positive and negative electrode plates. The embodiments of this application do not impose any particular limitation on the type of electrolyte, and it can be selected according to actual needs.

[0109] The electrolyte may include a solid electrolyte layer 3123. When the electrolyte is a solid electrolyte layer 3123, it can be used alone or in combination with a liquid electrolyte, i.e., an electrolyte solution. Optionally, the electrolyte is a solid electrolyte.

[0110] In some embodiments, the solid electrolyte includes one or more of sulfide solid electrolytes, oxide solid electrolytes, halide solid electrolytes, and polymer solid electrolytes.

[0111] Sulfide solid electrolytes include one or more of the following: sulfide crystalline solid electrolytes, sulfide glass, and glass-ceramic solid electrolytes.

[0112] In some embodiments, the sulfide solid electrolyte includes Li 10 GeP2S 12 Li6PS5Cl, Li 10 SnP2S 12 One or more of Li2S-P2S5, Li2S-SiS2 and Li2S-B2S3.

[0113] Oxide solid electrolytes are classified into two categories according to their material structure: crystalline oxide electrolytes and glassy oxide electrolytes (amorphous oxide electrolytes). Crystalline oxide electrolytes include one or more types such as perovskite, NASICON, LISICON, and garnet, while glassy oxide electrolytes include LiPON type electrolytes.

[0114] In some embodiments, the oxide solid electrolyte includes Li 3.3 La 0.56 TiO3, LiTi2(PO4)3, Li 14 Zn(GeO4)4, Li7La3Zr2O 12 Li 1+x Al x Ti 2-x (PO4)3 (0 < x < 2), Li 7-a La3Zr 2-a M a O 12 (M includes one or more of Ta and Nb; 0 < a < 2), Li b La 2 / 3-b TiO3 (0 < b < 2), LiAlO2, Li2ZrO3 and Li4Ti5O 12 One or more of them.

[0115] In some embodiments, the halide solid electrolyte includes one or more of Li3YCl6, Li3ErCl6, Li3YBr6, Li3InBr6, and Li3InCl6.

[0116] Polymer solid electrolytes (SPEs) are primarily composed of a polymer matrix and an electrolyte salt. The electrolyte salt may include lithium salts, specifically one or more of lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), and lithium tetrafluoroborate (LiBF4). The electrolyte salt may also include sodium salts, specifically one or more of sodium hexafluorophosphate (NaPF6), sodium perchlorate (NaClO4), sodium hexafluoroarsenate (NaAsF6), and sodium tetrafluoroborate (NaBF4).

[0117] In some embodiments, the SPE includes one or more of the following: epoxy compounds, polyester compounds, polyalkoxy compounds, polyolefin compounds, polyacrylonitrile (PAN), and monoionic polymer electrolytes. For example, epoxy compounds include one or more of polyethylene oxide (PEO) and polypropylene oxide (PPO). Polyolefin compounds include one or more of polyvinylidene fluoride (PVDF) and polyvinylidene chloride (PVDC). Polyester compounds include one or more of polycarbonate compounds and polymethyl methacrylate (PMMA). Polycarbonate compounds include one or more of polypropylene carbonate and polytrimethylene carbonate.

[0118] Furthermore, the polymer matrix can be hybridized with inorganic particles, including metal oxide nanoparticles such as MgO, Al2O3, and SiO2, as well as one or more of zeolites and montmorillonite. The addition of inorganic particles can reduce crystallinity, and the interactions between the polymer matrix, lithium salt, and inorganic particles can improve conductivity and ion transference number. Inorganic particles can also adsorb trace impurities such as moisture in the electrolyte and improve mechanical properties.

[0119] As shown in Figure 6, in some embodiments, the battery device 7 includes a fixing component 40, an elastic component 50, and at least one battery component 30. Each battery component 30 includes a battery cell 31 containing a solid electrolyte. The fixing component 40 includes two first fixing members 41 disposed opposite to each other along a first direction X, with at least one battery component 30 sandwiched between the two first fixing members 41. The elastic component 50 has a compressive displacement along the first direction X and at least abuts against at least one battery component 30 and the first fixing member 41.

[0120] The battery assembly 30 includes one or more battery cells 31. When there are multiple battery cells 31, the multiple battery cells 31 can be arranged along the first direction X. Each battery cell 31 includes a solid electrolyte, and can be understood as a solid-state battery cell.

[0121] At least one battery assembly 30 is taken as a whole, and all battery assemblies 30 are located between two first fixing members 41. In other words, the two first fixing members 41 are arranged opposite each other along the first direction X, and all battery assemblies 30 are clamped therein, which can give the battery assembly 30 a pre-tightening force along the first direction X.

[0122] Furthermore, the battery device 7 also includes an elastic component 50, which has elastic deformation capability, such as compression deformation capability. The elastic component 50 is disposed between the battery assembly 30 and the first fixing member 41 and is in a compressed state, having a compression displacement in the first direction X, so that the elastic component 50 abuts between the battery assembly 30 and the first fixing member 41, and can transmit force between the battery assembly 30 and the first fixing member 41. The elastic component 50 can be compressed to different degrees with the volume change of the battery assembly 30, but the compressive force generated by the elastic component 50 remains basically stable, so that the force of the elastic component 50 on the fixing member 40 is basically stable. The elastic component 50 can play a pressure compensation role for the battery assembly 30. Thus, the force of the fixing member 40 acting on the battery cell 31 through the elastic component 50 remains basically stable, so that the solid-solid interface can have stable and good contact, thereby improving the electrochemical performance of the battery device 7 and increasing the cycle life of the battery device 7.

[0123] Specifically, during the cyclic charging and discharging process of the battery device 7, the volume of the battery assembly 30 undergoes different degrees of volume change, and the elastic component 50 undergoes different degrees of compression deformation accordingly. The battery device 7 is in different states, for example, the battery device 7 includes a 0% state of charge and a 100% state of charge. In the 0% state of charge, the volume expansion of the battery assembly 30 is relatively small, and the battery assembly 30 exerts a force on the elastic component 50. The elastic component 50 has a first compressive displacement along the first direction X, and the elastic component 50 abuts against the battery assembly 30 with a first compressive force F1. Above; When the battery device 7 is 100% charged, the volume expansion of the battery component 30 is relatively large. The battery component 30 exerts a force on the elastic component 50, and the elastic component 50 has a second compressive displacement along the first direction X. The elastic component 50 abuts against the battery component 30 with a second compressive force F2. (F2-F1) / F1 is 0 to 0.1, so that the first compressive force F1 and the second compressive force F2 remain basically constant, so that the force on the battery component 30 remains basically constant, and the solid-solid interface can have stable and good contact, thereby improving the electrochemical performance of the battery device 7.

[0124] In this embodiment of the application, when the battery cell 31 is charged at a 1C rate to the cutoff upper limit voltage, the battery cell 31 can be considered to be in a 100% state of charge (SOC).

[0125] When the battery cell 31 is discharged at a 1C rate to the cutoff upper limit voltage, the battery cell 31 can be considered to be in a 0% state of charge (SOC).

[0126] In the embodiments of this application, (F2-F1) / F1 is from 0 to 0.1. Indicatively, (F2-F1) / F1 can be 0, 0.0001, 0.0005, 0.001, 0.005, 0.008, 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, or a range of any two of the above values. When (F2-F1) / F1 is 0, it indicates that the first compressive force F1 and the second compressive force F2 are the same.

[0127] At least one battery component 30 can be one battery component 30 or multiple battery components 30. When there are multiple battery components 30, the multiple battery components 30 can be arranged sequentially along the first direction X. Of course, some of the multiple battery components 30 are arranged along the first direction X, and other battery components 30 are arranged along the second direction, with the first direction X and the second direction being perpendicular.

[0128] As shown in Figure 7, among the multiple battery components 30 arranged along the first direction X, an elastic component 50 can be further arranged between two adjacent battery components 30. That is, the elastic component 50 abuts between two adjacent battery components 30. The elastic component 50 can further improve the stress stability of the battery component 30 and improve the electrochemical performance of the battery device 7.

[0129] For example, the battery assembly 30 consists of three battery assemblies 30 arranged along the first direction X, defined as a first battery assembly, a second battery assembly, and a third battery assembly, respectively. An elastic component 50 is provided between the first and second battery assemblies, and between the second and third battery assemblies. In other words, an elastic component 50 is provided between any two adjacent battery assemblies 30, which helps to further improve the stress stability of the battery assembly 30. Alternatively, an elastic component 50 is provided between the first and second battery assemblies, but not between the second and third battery assemblies. This approach can simultaneously improve the electrochemical performance and energy density of the battery device 7.

[0130] In some embodiments, the elastic component 50 may be an elastic plate having the above-mentioned characteristics, such as a rubber pad.

[0131] In other embodiments, the elastic component 50 is an annular component with its axis parallel to the first direction X. The annular component includes a first end 51 and a second end 52 that are opposite to each other along the first direction X. The diameter of the cross section of the annular component perpendicular to the first direction X gradually decreases in the direction from the first end 51 to the second end 52. One of the first end 51 and the second end 52 abuts against the battery assembly 30, and the other abuts against the first fixing member 41.

[0132] It should be noted that the cross section of the annular component perpendicular to the first direction X can be understood as the cross section of the annular component parallel to its own radial direction, and the diameter of this cross section can be understood as the average outer diameter.

[0133] The annular member can withstand the force along the first direction X, such as the force exerted by the battery assembly 30. This force causes the annular member to deform, for example, the annular member is compressed along the first direction X. The outer periphery of the first end 51 extends outward along the radial direction of the annular member, and the inner periphery of the second end 52 is compressed and deformed inward along the first direction X. This allows the first end 51 and the second end 52 to abut between the battery assembly 30 and the first fixing member 41, thus playing a buffering role and maintaining a constant force exerted by the first fixing member 41 on the battery assembly 30.

[0134] Optionally, the first end 51 can abut against the battery assembly 30. The cross-section of the first end 51 is relatively large, which is more conducive to the uniform transmission of force to the battery assembly 30. Of course, in some alternative embodiments, the second end 52 can abut against the battery assembly 30.

[0135] The elastic component 50 may include one or more ring-shaped members.

[0136] In the case where the elastic component 50 includes an annular member, the first end 51 of the annular member can abut against the battery assembly 30, and correspondingly, the second end 52 abuts against the first fixing member 41.

[0137] When the elastic component 50 includes multiple annular members, the multiple annular members can be arranged in the same way or in different ways.

[0138] As shown in Figure 8, for example, the elastic component 50 includes three annular members, defined as a first annular member, a second annular member, and a third annular member, respectively. These are, in the direction from the battery assembly 30 towards the first fixing member 41, the first end 51, the second end 52, the first end 51, the second end 52, and the first end 51 and the second end 52 of the third annular member, respectively. In this case, the first end 51 of the annular member facing the battery assembly 30 abuts against the battery assembly 30, and the second end 52 of the annular member facing the first fixing member 41 abuts against the fixing member 40.

[0139] As shown in Figure 9, for example, in the direction from the battery assembly 30 to the first fixing member 41, the first end 51 of the first annular member, the second end 52 of the first annular member, the second end 52 of the second annular member, and the first end 51 of the second annular member are respectively. In this case, the first end 51 of the annular member facing the battery assembly 30 abuts against the battery assembly 30, and the first end 51 of the annular member facing the first fixing member 41 abuts against the fixing member 40. The contact surface between the elastic member 50 and the battery assembly 30 is relatively large, and the contact surface between the elastic member 50 and the first fixing member 41 is relatively large, which is more conducive to the uniform transmission of force.

[0140] As shown in Figures 9 and 10, optionally, the ratio D / d of the diameter D of the first end 51 to the diameter d of the second end 52 is 1.7 to 2.5, for example, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, or a range of any two of the above values. Figure 9 shows the diameter D of the first end 51 and the diameter d of the second end 52. The diameter D of the first end 51 and the diameter d of the second end 52 can be obtained by testing the relevant dimensions of the elastic component 50 in its uncompressed state.

[0141] The diameters of the first end 51 and the second end 52 are within the aforementioned range, which allows the elastic component 50 to be assembled into the battery device 7. When in a compressed state, the compression displacement can change with the changes in the battery component 30, but the compression force generated remains basically constant, so that the force on the battery component 30 can remain stable, thereby effectively improving the electrochemical performance of the battery device 7.

[0142] Optionally, the ratio h0 / t of the second compression displacement h0 to the average thickness t of the annular member is 1.1 to 1.8, for example, 1.1, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.8 or any range of two of the above values.

[0143] The second compression displacement can be the maximum displacement of the elastic component 50 assembled in the battery device 7. It is related to the expansion deformation of the battery component 30. When the second compression displacement and the average thickness t of the annular member are within the above range, the compressive force generated by the elastic component 50 when it is assembled in the battery device 7 can be kept basically constant, so that the force on the battery component 30 can be kept stable, thereby effectively improving the electrochemical performance of the battery device 7.

[0144] For example, the average thickness of the annular component is 3 mm to 8 mm, such as 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm or any range of two of the above values.

[0145] For example, the second compression displacement is 5mm to 8mm, such as 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm or any range of two of the above values.

[0146] For example, the first compression displacement is 5 mm to 8 mm, such as 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm or any range of two of the above values.

[0147] Optionally, the elastic modulus of the elastic component 50 is between 50 GPa and 250 GPa, for example, 50 GPa, 80 GPa, 100 GPa, 150 GPa, 160 GPa, 170 GPa, 180 GPa, 190 GPa, 200 GPa, 210 GPa, 220 GPa, 230 GPa, 240 GPa, 250 GPa, or any combination of two of the above values. Optionally, the elastic modulus of the elastic component 50 is between 80 GPa and 210 GPa. When the elastic modulus of the elastic component 50 is within the above range, the elastic component 50 is in a compressed state within the battery device 7, and the compressive force is substantially constant.

[0148] Optionally, the Poisson's ratio of the elastic component 50 is from 0.2 to 0.4, for example, 0.2, 0.25, 0.3, 0.35, 0.4, or any combination of two of the above values. When the Poisson's ratio of the elastic component 50 is within the above range, the elastic component 50 is in a compressed state in the battery device 7, and the compressive force is substantially constant.

[0149] For example, the main material of the elastic component 50 may include metal. In this embodiment, the main material refers to the material with the highest mass percentage in the elastic component 50, such as a material with a mass percentage greater than 80%, or even a material with a mass percentage of 100%.

[0150] For example, the main body material of the elastic component 50 includes one or more of steel and shape memory alloy.

[0151] Optionally, the steel material includes spring steel. For example, spring steel includes one or more of spring steel 60Si2MnA, spring steel 50CrVA, spring steel 60Si2MnCrV, spring steel 60Si2CrV, and spring steel 55SiCrV. 60Si2MnA, etc., represent the grade.

[0152] Optionally, the shape memory alloy material includes one or more of nickel-titanium alloys and copper-nickel alloys.

[0153] In some embodiments, the battery device 7 further includes a support component 60, which is disposed between the battery component 30 and the elastic component 50, and along the first direction X, the projection of the battery component 30 lies within the projection of the support component 60. The support component 60 can support the elastic component 50, which facilitates the uniform transmission of the compressive force generated by the elastic component 50 to the battery component 30, resulting in uniform stress distribution throughout the battery component 30, uniform current density distribution across the electrodes, and uniform lithium intercalation speed at the negative electrode. This reduces the risk of lithium plating and improves the reliability of the battery device 7.

[0154] Optionally, the elastic modulus of the support component 60 is from 1 GPa to 210 GPa, such as 1 GPa, 10 GPa, 20 GPa, 30 GPa, 40 GPa, 50 GPa, 60 GPa, 70 GPa, 80 GPa, 90 GPa, 100 GPa, 110 GPa, 120 GPa, 130 GPa, 140 GPa, 150 GPa, 160 GPa, 170 GPa, 180 GPa, 190 GPa, 200 GPa, 210 GPa, or any range of two of the above values. Optionally, the elastic modulus of the support component 60 is from 50 GPa to 210 GPa.

[0155] The support component 60 has high rigidity and is not easily deformed. When placed between the battery component 30 and the elastic component 50, it can evenly transmit the compressive force generated by the elastic component 50 to the battery component 30, so that the battery component 30 is subjected to uniform force.

[0156] For example, the thickness of the support component 60 is 0.5 mm to 5 mm, such as 0.5 mm, 1.5 mm, 2.5 mm, 3.5 mm, 4.5 mm, 5 mm or any range of two of the above values.

[0157] For example, the main body material of the support component 60 includes metal.

[0158] For example, the main body material of the support component 60 includes one or more of aluminum alloy and carbon alloy steel.

[0159] For example, aluminum alloys include one or more of aluminum-silicon-magnesium 6061 alloy and aluminum alloy 7050.

[0160] For example, carbon alloy steel includes one or more of carbon alloy steel Q235 and carbon alloy steel Q255.

[0161] The fixing component 40 is used to fix and clamp the battery assembly 30. In some embodiments, the fixing component 40 includes a first fixing member 41, which includes a main body portion 411 and a protrusion portion 412. The protrusion portion 412 is connected to the main body portion 411 and protrudes from the main body portion 411 along a first direction X. An elastic component 50 is sleeved on the protrusion portion 412 and is movably connected to the protrusion portion 412.

[0162] The protrusion 412 can serve as a limiting part, allowing the elastic component 50 to be fitted outside the protrusion 412, making it difficult for the elastic component 50 to detach from the first fixing member 41 and the battery assembly 30; and the protrusion 412 can also serve as a positioning part, allowing the elastic component 50 to be compressed and deformed along the protrusion 412, so that the elastic component 50 can apply force to the battery assembly 30 within a preset position, making the battery assembly 30 more stable under force.

[0163] Specifically, the elastic component 50 includes an annular member that is sleeved outside the protrusion 412 and movably connected to the protrusion 412.

[0164] In other embodiments, at least a portion of the elastic component 50 is embedded in the first fixing member 41, which can support the elastic component 50 and reduce the risk of the elastic component 50 detaching from the first fixing member 41 and the battery assembly 30.

[0165] Specifically, the elastic component 50 includes an annular member, at least a portion of which is embedded in the first fixing member 41.

[0166] In other embodiments, the fixing component 40 may further include two second fixing members 42, which are arranged opposite each other along the second direction Y. The two second fixing members 42 are fixedly connected by a first fixing member 41, and the battery assembly 30 is located between the two second fixing members 42, wherein the second direction Y is perpendicular to the first direction X.

[0167] The first fixing member 41 and the second fixing member 42 can be fixedly connected by welding, bolting or other means; the battery assembly 30 is clamped and fixed by the fixing component 40, and a pre-tightening force is applied to the battery assembly 30 to improve the good contact of the solid-solid interface in the battery assembly 30.

[0168] In some embodiments, when the outer casing 311 of the battery cell 31 has a cuboid or flat structure, the outer casing 311 includes two first surfaces 3111 and two second surfaces 3112. The two first surfaces 3111 are arranged opposite each other along a first direction X, and the two first surfaces 3111 are connected by the second surfaces 3112. The area of ​​the first surface 3111 is larger than the area of ​​the second surface 3112. Of course, in other embodiments, the two second surfaces 3112 may be arranged opposite each other along the first direction X. The second surface 3112 can be understood as the side surface of the battery cell 31.

[0169] The first surface 3111 has a relatively large area, and during the cyclic charging and discharging of the battery device 7, the deformation of the first surface 3111 is relatively greater. By placing the first surface 3111 against the elastic component 50, the stress stability of the battery component 30 can be improved more effectively. Of course, in some other embodiments, the elastic component 50 can abut against the second surface 3112.

[0170] Each battery assembly 30 includes one or more battery cells 31. When the battery assembly 30 includes multiple battery cells 31, the multiple battery cells 31 in the battery assembly 30 are arranged along the first direction X. In some embodiments, each battery assembly 30 also includes a buffer member 32, which is disposed between two adjacent battery cells 31 to further buffer the volume change of the battery cell 31. Moreover, the buffer member 32 can also uniformly transmit external forces to all parts of the battery cell 31, so that the force on the battery cell 31 is relatively uniform. Furthermore, since the buffer member 32 has a certain elastic deformation capability, the buffer member 32 can uniformly fit with the surface of the battery cell 31, which can alleviate the problem of uneven local force caused by the unevenness of the surface of the battery cell 31, improve the uniformity of current density at all parts of the electrode, and the uniformity of lithium intercalation speed of the negative electrode, which can reduce the risk of lithium plating and improve the reliability of the battery device 7.

[0171] Optionally, the buffer member 32 is also disposed at at least one end of the battery assembly 30 along the first direction X, optionally at both ends, thereby more effectively buffering the volume change of the battery cell 31.

[0172] Optionally, the elastic modulus of the buffer member 32 is from 0.1 MPa to 1000 MPa, for example, 0.1 MPa, 50 MPa, 100 MPa, 150 MPa, 200 MPa, 250 MPa, 300 MPa, 350 MPa, 400 MPa, 450 MPa, 500 MPa, 550 MPa, 600 MPa, 650 MPa, 700 MPa, 750 MPa, 800 MPa, 850 MPa, 900 MPa, 950 MPa, 1000 MPa, or a range consisting of any two of the above values.

[0173] For example, the main material of the buffer member 32 includes one or more of silicone rubber and polyurethane.

[0174] In the case where the embodiment of this application includes the elastic component 50, the elastic component 50 can provide pressure compensation to the battery component 30, thereby stabilizing the force on the battery component 30, reducing the risk of creep relaxation of the buffer member 32, improving the service life and elastic deformation capability of the buffer member 32, stabilizing the force on the battery component 30, ensuring good contact at the solid-solid interface, and improving electrochemical performance.

[0175] In one specific embodiment of this application, the battery device 7 includes a battery assembly 30, a fixing assembly 40, and an elastic assembly 50. The battery assembly 30 includes a buffer member 32 and a plurality of battery cells 31 containing solid electrolytes arranged along a first direction X. The buffer member 32 is located between two adjacent battery cells 31. The fixing assembly 40 includes two first fixing members 41 arranged opposite to each other along the first direction X, with the battery assembly 30 sandwiched between the two first fixing members 41. The elastic assembly 50 is an annular member that has a compressive displacement along the first direction X and abuts against the battery assembly. Between 30 and the first fixing member 41, wherein the battery device 7 includes a 0% charge state and a 100% charge state, in the 0% charge state, the elastic member 50 has a first compression displacement along the first direction X, and the elastic member 50 abuts against the battery device 30 with a first compression force F1; in the 100% charge state, the elastic member 50 has a second compression displacement along the first direction X, and the elastic member 50 abuts against the battery device 30 with a second compression force F2, the second compression displacement is greater than the first compression displacement, and (F2-F1) / F1 is 0 to 0.1.

[0176] In this application, the elastic modulus and Poisson's ratio of the material are well-known in the art and can be tested using instruments and methods well-known in the art. For example, the elastic modulus can be tested according to the test method of GB / T 1041-2008 "Determination of compressibility of plastics", and the axial strain can be obtained through compression test. Poisson's ratio can be calculated by combining the measurement of transverse strain.

[0177] In this application, the thickness of components, etc., are terms known in the art and can be measured using instruments and methods known in the art, such as micrometers.

[0178] In this application, the compressive force of the elastic component 50 is a well-known concept in the art and can be tested using instruments and methods known in the art. For example, in accordance with standard ISO 7500-1, the elastic component 50 is removed by disassembling the battery device 7 and a universal testing machine is used to test the compressive force of the elastic component 50 under a preset compression displacement.

[0179] Example

[0180] The following embodiments describe the contents disclosed in this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of the embodiments of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0181] Example 1

[0182] The battery device includes a battery assembly, a fixing assembly, and an elastic assembly. The battery assembly includes a buffer member and a plurality of battery cells containing solid electrolytes arranged along a first direction. The buffer member is located between two adjacent battery cells. The fixing assembly includes two first fixing members arranged opposite to each other along the first direction, with the battery assembly sandwiched between the two first fixing members. The elastic assembly is an annular member that has a compressive displacement along the first direction and abuts against the battery assembly and the first fixing members.

[0183] Examples 2-1 to 2-3

[0184] The battery device was prepared using a method similar to that of Example 1, except that the material of the elastic component was adjusted.

[0185] Examples 3-1 and 3-2

[0186] The battery device was prepared using a method similar to that of Example 1, except that the thickness of the elastic component was adjusted.

[0187] Comparative Example 1

[0188] The battery device includes a battery assembly and a fixing assembly. The battery assembly includes a buffer pad and a plurality of battery cells containing solid electrolyte arranged along a first direction. The buffer pad is located between two adjacent battery cells. The fixing assembly includes two first fixing members arranged opposite to each other along the first direction, and the battery assembly is sandwiched between the two first fixing members.

[0189] Performance testing

[0190] 1. Cycle life of the battery device

[0191] At 25°C, the battery devices prepared in the examples and comparative examples were charged at a 1C rate and discharged at a 1C rate to conduct a full charge-discharge cycle test until the capacity of the battery device decayed to 80% of the initial capacity, and the number of cycles was recorded.

[0192] 2. Lithium plating test of battery device

[0193] At 25°C, the battery devices prepared in the examples and comparative examples were fully charged at 1C and fully discharged at 1C 10 times. Then, the battery devices were fully charged at 1C. The negative electrode was then disassembled and the lithium deposition on the surface of the negative electrode was observed.

[0194] in,

[0195] A lithium deposition area of ​​0 to 1% on the negative electrode surface is considered to indicate no lithium deposition.

[0196] A lithium plating area on the negative electrode surface of greater than 1% and less than or equal to 5% is considered slight lithium plating.

[0197] A lithium plating area on the negative electrode surface of greater than 5% and less than or equal to 40% is considered moderate lithium plating.

[0198] A lithium plating area greater than 40% on the negative electrode surface is considered severe lithium plating.

[0199] Test Results

[0200] The test results are shown in Table 1.

[0201] Table 1

[0202] As can be seen from Table 1,

[0203] In Example 1,

[0204] The first surface dimension of the battery cell in the battery module is 100mm by 100mm;

[0205] The diameter D of the first end of the ring component is 100mm±20mm, d is 50mm±10mm, and D / d is 2.

[0206] Comparative Example 1 has a buffer pad made of silicone rubber placed between two adjacent battery cells. The buffer pad may creep and loosen during use, which may cause pressure fluctuations in the battery cells during use, changes in the solid-solid contact interface, and rapid degradation of electrochemical performance, thus worsening cycle life.

[0207] The embodiments of this application provide an elastic component, which stabilizes the force on the battery component during use, with (F2-F1) / F1 being less than or equal to 0.1. This ensures stable and good contact between the solid and solid interfaces, thereby improving the electrochemical performance of the battery device and increasing its cycle life.

[0208] When different materials are used, the elastic modulus of the elastic component ranges from 50 GPa to 250 GPa; the Poisson's ratio of the elastic component ranges from 0.2 to 0.4. All of these can ensure the stability of the battery module under stress and the stable and good contact of the solid-solid interface, thereby improving the electrochemical performance of the battery device and increasing the cycle life of the battery device.

[0209] When the elastic component uses a ring-shaped member, by adjusting the thickness of the ring-shaped member, the ratio of the second compression displacement h0 to the average thickness t of the ring-shaped member, h0 / t, can be 1.1 to 1.8. This can also make the battery component stable under stress, which is beneficial to improving the electrochemical performance of the battery device and increasing the cycle life of the battery device.

[0210] Example 4

[0211] The battery device was prepared using a method similar to that of Example 1, except that the material of the support component was adjusted.

[0212] The test results are shown in Table 2.

[0213] Table 2

[0214] As shown in Table 2,

[0215] The support component can uniformly transmit forces, resulting in more even stress distribution throughout the battery module. With different sizes and thicknesses, the support component exhibits an elastic modulus ranging from 1 GPa to 210 GPa, demonstrating high stiffness and resistance to deformation. This ensures uniform stress distribution within the battery module, improves cycle life, and reduces the risk of lithium plating. Examples 1 and 4 show only slight lithium plating on the negative electrode, or even none at all. Of course, in this embodiment, the support component may not be necessary; uniform force transmission can be achieved through the contact between the elastic component and the battery module.

[0216] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery device, comprising: At least one battery assembly, each of the battery assemblies comprising a battery cell containing a solid electrolyte; The fixing component includes two first fixing members disposed opposite each other along a first direction, with at least one battery component sandwiched between the two first fixing members; as well as An elastic component having a compressive displacement along the first direction and at least abutting between the at least one battery assembly and the first fixing member. in, The battery device includes 0% state of charge and 100% state of charge. In the 0% charged state, the elastic component has a first compressive displacement along the first direction, and the elastic component abuts against the battery assembly with a first compressive force F1; At the 100% charged state, the elastic component has a second compressive displacement along the first direction, and the elastic component abuts against the battery assembly with a second compressive force F2. The second compression displacement is greater than the first compression displacement, and (F2-F1) / F1 is between 0 and 0.

1.

2. The battery device according to claim 1, wherein, The battery assembly is configured as a plurality of battery assemblies, which are arranged along the first direction, and the elastic component abuts between two adjacent battery assemblies.

3. The battery device according to claim 1 or 2, wherein, The elastic component is a ring-shaped member, the axis of which is parallel to the first direction, and the ring-shaped member includes a first end and a second end that are opposite to each other along the first direction. In the direction from the first end to the second end, the diameter of the cross-section of the annular member perpendicular to the first direction gradually decreases. One of the first end and the second end abuts against the battery assembly, and the other abuts against the first fixing member.

4. The battery device according to claim 3, wherein, The first end abuts against the battery assembly.

5. The battery device according to claim 3 or 4, wherein, The elastic component includes multiple annular members, which are arranged sequentially along the first direction.

6. The battery device according to claim 5, wherein, The first end of the annular member facing the battery assembly of the plurality of annular members abuts against the battery assembly; the first end of the annular member facing the first fixing member of the plurality of annular members abuts against the first fixing member; or The first end of the annular member facing the battery assembly abuts against the battery assembly, and the second end of the annular member facing the first fixing member abuts against the first fixing member.

7. The battery device according to any one of claims 1 to 6, wherein, The first compression displacement is 5 mm to 8 mm.

8. The battery device according to any one of claims 1 to 7, wherein, The second compression displacement is 5mm to 8mm.

9. The battery device according to any one of claims 1 to 8, wherein, The elastic modulus of the elastic component is 50 GPa to 250 GPa; and / or The Poisson's ratio of the elastic component is between 0.2 and 0.

4.

10. The battery device according to any one of claims 1 to 9, wherein, The main material of the elastic component includes one or more of spring steel and shape memory alloy.

11. The battery device according to claim 10, wherein, The shape memory alloy material includes one or more of nickel-titanium alloys and copper-nickel alloys.

12. The battery device according to any one of claims 1 to 11, wherein, The battery device further includes a support component disposed between the battery assembly and the elastic component, and the projection of the battery assembly is located within the projection of the support component along the first direction.

13. The battery device according to claim 12, wherein, The main body material of the support component includes one or more of aluminum alloy and carbon alloy steel.

14. The battery device according to any one of claims 1 to 13, wherein, Each of the battery components includes: Buffer components; and Multiple battery cells are arranged along the first direction, and a buffer member is provided between two adjacent battery cells.

15. The battery device according to claim 14, wherein, The buffer member is also disposed at at least one end of the at least one battery assembly along the first direction.

16. The battery device according to any one of claims 1 to 15, wherein, The first fixing member includes a main body and a protrusion. The protrusion is connected to the main body and protrudes from the main body along the first direction. The elastic component is sleeved outside the protrusion and is movably connected to the protrusion.

17. The battery device according to any one of claims 1 to 16, wherein, The fixing component further includes two second fixing members disposed opposite each other along a second direction. The two second fixing members are fixedly connected by the first fixing member, and the battery assembly is located between the two second fixing members, wherein the second direction is perpendicular to the first direction.

18. The battery device according to any one of claims 1 to 17, wherein, The battery cell includes a casing, which includes two first surfaces and two second surfaces. The two first surfaces are arranged opposite each other along the first direction and are connected by the second surfaces. The area of ​​the first surfaces is larger than the area of ​​the second surfaces.

19. An electrical device comprising a battery device as claimed in any one of claims 1 to 18.

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