Battery device and electrical device

Abstract

The present disclosure belongs to the technical field of batteries. Disclosed are a battery device and an electrical device. Battery cell assemblies are located in a case, the battery cell assemblies are arranged in at least two layers, the at least two layers of the battery cell assemblies are arranged in a preset direction, the battery cell assembly in each layer comprises at least one battery cell, the battery cell assembly in one layer is a first assembly, all the battery cell assemblies except the first assembly are located on one side of the first assembly in the preset direction, and the low-temperature resistance of at least one battery cell of the battery cell assembly in at least one layer is less than the minimum low-temperature resistance of the battery cell of the first assembly.

Description

A battery device and an electrical device

[0001] Cross-references to related applications

[0002] This disclosure is based on and claims priority to Chinese Patent Application No. 202422800012.4, filed on November 15, 2024, entitled “A Battery Device and an Electric Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of battery technology, and more particularly to a battery device and an electrical device. Background Technology

[0004] Batteries are increasingly used in daily life and industry. For example, new energy vehicles equipped with batteries are widely used, and batteries are also increasingly being applied in energy storage. However, among related technologies, the capacity utilization rate of battery devices is relatively low. Summary of the Invention

[0005] To address the aforementioned technical problems, this disclosure provides a battery device and an electrical device to improve the capacity utilization rate of the battery device.

[0006] This disclosure is achieved through the following technical solution.

[0007] A first aspect of this disclosure provides a battery device, comprising:

[0008] Box;

[0009] The battery cell assembly is located inside the housing. The battery cell assembly has at least two layers, and the arrangement direction of the at least two layers of battery cell assemblies is a preset direction. Each layer of battery cell assembly includes at least one battery cell. One layer of battery cell assembly is the first assembly. All battery cell assemblies except the first assembly are located on one side of the first assembly along the preset direction. The low temperature resistance of at least one battery cell in the at least one layer of battery cell assembly is less than the minimum low temperature resistance of the battery cell in the first assembly.

[0010] In this embodiment, the battery cell with the worst low-temperature performance is placed on the other battery cell components besides the first component, so that the first component as a whole has better low-temperature performance. This allows the charge retention rate of each layer of battery cell components to be as close as possible at lower temperatures, which is beneficial to improving the overall capacity utilization rate of the battery device.

[0011] In one embodiment, in the battery cells of the first component, each battery cell is of one type: a sodium battery and a first type of battery. The positive electrode active material of the first type of battery is one of ternary positive electrode material, lithium cobalt oxide, lithium nickel oxide, lithium-rich manganese-based material, and lithium manganese oxide.

[0012] In this embodiment of the disclosure, both the sodium battery and the first type of battery are batteries with good low-temperature resistance. Each cell of the first component is of one type, either a sodium battery or a first type of battery, which makes the first component have good low-temperature resistance.

[0013] In one embodiment, the ternary cathode material is a lithium nickel cobalt manganese ternary or a lithium nickel cobalt aluminum ternary.

[0014] In this embodiment of the disclosure, the battery cell has a higher specific capacity and a higher mass energy density.

[0015] In one embodiment, one of the battery cell components is a second component, and all other battery cell components except the second component are located on the side of the second component facing the first component along a predetermined direction; in the battery cells of the second component, each battery cell is of the type of sodium battery or a second type of battery, and the positive electrode active material of the second type of battery is one of lithium iron phosphate and lithium vanadium phosphate.

[0016] In this embodiment, the second component has better safety, and the second component is closest to the main body of the device along a preset direction, which improves the safety of the second component and is beneficial to improving the safety of the electrical device.

[0017] In one embodiment, the lithium iron phosphate is lithium iron phosphate or lithium manganese iron phosphate.

[0018] In this embodiment, lithium iron phosphate and lithium manganese iron phosphate are used as the positive electrode materials of the battery, which makes the battery safe and stable.

[0019] In one embodiment, the number of layers of the battery cell assembly is greater than or equal to three layers, and in the other battery cell assemblies located between the first and second assemblies, each battery cell is of one type: sodium battery, first type battery, and second type battery.

[0020] In this embodiment, the battery cells located in the middle layer can be adapted according to actual needs, and the battery device has good flexibility.

[0021] In one embodiment, among the at least three battery cells stacked along a preset direction, the battery cell corresponding to the first component is a sodium battery.

[0022] In this embodiment of the disclosure, the battery cells of the first component use sodium batteries, which can effectively improve the charge retention rate of the first component, reduce the gap in charge retention rate between the first component and other battery cell components, and improve the capacity utilization rate of the battery device.

[0023] In one embodiment, among the at least three battery cells stacked along a preset direction, the type of battery cell corresponding to the second component is a second type of battery.

[0024] In this embodiment, the second type of battery with the best safety is placed in the second component closest to the main body of the device. This improves the safety of the main body of the device while increasing the utilization rate of the battery capacity.

[0025] In one embodiment, among at least three battery cells stacked along a preset direction, the mass energy density of the battery cell corresponding to the first component is the first energy density, the mass energy density of the battery cell corresponding to the second component is the second energy density, and the mass energy density of the battery cell located between the first component and the second component is the third energy density. Both the first energy density and the second energy density are less than the third energy density.

[0026] In this embodiment of the disclosure, the second component can provide a buffer for the high energy density battery cells, thereby improving the safety of the main body of the device.

[0027] In one embodiment, among the at least three battery cells stacked along a preset direction, the battery cell located between the first component and the second component is of the first type of battery.

[0028] In this embodiment, the battery device can achieve a balance between high capacity utilization, good safety, and high energy density, thus achieving a comprehensive performance across various aspects.

[0029] In one embodiment, among at least three battery cells stacked along a preset direction, the battery cell corresponding to the first component is of type 1 battery, the battery cell corresponding to the second component is of type 2 sodium battery, and the battery cell located between the first component and the second component is of type 2 battery.

[0030] In this embodiment of the disclosure, the second type of battery with better safety separates the first type of battery and the sodium battery, so that the sodium battery is in a safer environment and the low-temperature performance of the battery cells is reduced due to damage to the sodium battery.

[0031] In one embodiment, among at least three battery cells stacked along a preset direction, the battery cell corresponding to the first component is of type 1 battery, the battery cell corresponding to the second component is of type 2 battery, and the battery cell located between the first component and the second component is of type sodium battery.

[0032] In this embodiment of the disclosure, the second type of battery with poor low-temperature performance is kept as far away from the low-temperature environment as possible to reduce the impact of low temperature on the individual cells of the second component.

[0033] In one embodiment, among at least three battery cells stacked along a preset direction, the battery cell corresponding to the first component is a sodium battery, the battery cell corresponding to the second component is a second type of battery, and the battery cell located between the first component and the second component is a sodium battery.

[0034] In this embodiment of the disclosure, when the battery device has good low-temperature resistance, both the second type of battery and the sodium battery have good safety, thus improving the overall safety of the battery device.

[0035] In one embodiment, among at least three battery cells stacked along a preset direction, the battery cell corresponding to the first component is a sodium battery, the battery cell corresponding to the second component is a sodium battery, and the battery cell located between the first component and the second component is a first-type battery.

[0036] In this embodiment, the first type of battery cell with higher mass energy density is not closest to the main body of the device, which makes the overall safety of the battery device better.

[0037] In one embodiment, among at least three battery cells stacked along a preset direction, the battery cell corresponding to the first component is of type 1 battery, the battery cell corresponding to the second component is of type 2 battery, and the battery cell located between the first component and the second component is of type 1 battery.

[0038] In this embodiment of the disclosure, the battery device has low-temperature resistance when the mass energy density of the battery device is high.

[0039] In one embodiment, the sodium battery is a sodium-ion battery or a sodium metal battery, and sodium-ion batteries and sodium metal batteries have better low-temperature resistance than lithium batteries.

[0040] In this embodiment, both sodium-ion batteries and sodium metal batteries exhibit good low-temperature resistance.

[0041] In one embodiment, the battery cells in the same layer of battery cell assembly are of the same type.

[0042] In this embodiment, it is easy to install and arrange the battery cells, and the arrangement of the battery cells is simple.

[0043] In one embodiment, at least two battery cells in at least one layer of battery cell assembly are of different types.

[0044] In this embodiment of the disclosure, it is advantageous to make comprehensive use of the characteristics of different types of battery cells.

[0045] In one embodiment, the battery device further includes a first switch located within the housing, the first switch being used to connect or disconnect at least two layers of battery cell assemblies in parallel.

[0046] In this embodiment of the disclosure, the charging current of each battery cell assembly is reduced, thereby reducing the situation where the charging current exceeds the allowable current of each battery cell assembly due to the large charging current. This allows the battery cell assemblies of each layer to be charged simultaneously within the allowable current range, thereby alleviating the low-temperature lithium plating of the battery cells.

[0047] In one embodiment, the battery device further includes a second switch located within the housing, the second switch being used to connect or disconnect at least two battery cells in the same layer of the battery cell assembly.

[0048] In this embodiment of the disclosure, the current flowing between individual battery cells in the same layer is reduced, which reduces the situation where the charging current exceeds the allowable current of the individual battery cells due to a large charging current. This allows the individual battery cells in the same layer to be charged simultaneously within the allowable current range, thereby alleviating the low-temperature lithium plating of the battery cells.

[0049] In one embodiment, the battery device further includes a temperature regulating device, wherein all battery cell components except the first component are located on the side of the first component facing away from the temperature regulating device along a preset direction.

[0050] In this embodiment of the disclosure, the impact of the temperature control device on battery cells with poor low-temperature performance is reduced.

[0051] In one embodiment, the temperature control device is a water-cooled plate.

[0052] In this embodiment of the disclosure, the water-cooled plate is beneficial for rapidly cooling the heat-generating battery cell assembly.

[0053] A second aspect of this disclosure provides an electrical device, comprising:

[0054] Main body of the device;

[0055] The battery device described above has a housing installed on the main body of the device. All battery cell components except the first component are located on the side of the first component facing the main body of the device along a preset direction.

[0056] In this embodiment of the disclosure, it is beneficial to improve the charge retention rate of the first component, thereby improving the capacity utilization rate of the battery device.

[0057] In one embodiment, the battery cell is a square battery, and the large surface of the battery cell is arranged in a crisscross pattern with the vertical direction.

[0058] In this embodiment of the disclosure, the battery cells are arranged in a flat position, which facilitates the stacking of at least two layers of battery cell assemblies in the vertical direction.

[0059] Invention Effects

[0060] This disclosure provides a battery device and an electrical device in which at least one battery cell in at least one layer of battery cell assembly has a lower low-temperature resistance than the minimum low-temperature resistance of a battery cell in a first assembly, so that the battery cell with the worst low-temperature resistance is not placed in the first assembly. The battery device is mounted on the device body of the electrical device. When the ambient temperature is low, the side of the battery device facing away from the device body along a predetermined direction is not shielded by the device body and is greatly affected by the ambient temperature, resulting in a lower temperature. The side of the battery device facing closer to the device body along the predetermined direction is isolated from the outside by the device body and is less affected by the ambient temperature. Moreover, the temperature on the device body side is higher, and the temperature on the side of the battery device facing closer to the device body along the predetermined direction is also higher. The first component is located on the side of the housing away from the main body of the device along a preset direction. The first component is in a low-temperature environment. The battery cell with the worst low-temperature resistance is not in the first component. The battery cell with the worst low-temperature resistance is placed on other battery cell components except the first component. The battery cell with the worst low-temperature resistance is placed in a higher temperature area, so that the first component as a whole has good low-temperature resistance. Thus, at a low temperature, the charge retention rate of each layer of battery cell components can be as close as possible, which is beneficial to improving the overall capacity utilization rate of the battery device. Attached Figure Description

[0061] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0062] Figure 1 is a schematic diagram of the structure of a battery cell assembly according to an embodiment of this disclosure;

[0063] Figure 2 is a circuit connection diagram of the first switch and the battery cell assembly according to an embodiment of this disclosure;

[0064] Figure 3 is a schematic diagram of the structure of the battery device according to an embodiment of this disclosure;

[0065] Figure 4 is a schematic diagram of the stacking of battery cells according to an embodiment of the present disclosure. The figure shows that sodium batteries, first type batteries and second type batteries are stacked in sequence along a preset direction.

[0066] Figure 5 is a schematic diagram of the stacking of battery cells according to an embodiment of the present disclosure. The figure shows that sodium batteries, second type batteries and first type batteries are stacked in sequence along a preset direction.

[0067] Figure 6 is a schematic diagram of the stacking of battery cells according to an embodiment of the present disclosure. The figure shows that the first type of battery, sodium battery and second type of battery are stacked in sequence along a preset direction.

[0068] Figure 7 is a schematic diagram of the stacking of battery cells according to an embodiment of the present disclosure. The figure shows that sodium batteries, sodium batteries and second type batteries are stacked sequentially along a preset direction.

[0069] Figure 8 is a schematic diagram of the stacking of battery cells according to an embodiment of the present disclosure. The figure shows that sodium batteries, first type batteries and sodium batteries are stacked in sequence along a preset direction.

[0070] Figure 9 is a schematic diagram of the stacking of battery cells according to an embodiment of the present disclosure. The figure shows that the first type of battery, the second type of battery, and the first type of battery are stacked in sequence along a preset direction.

[0071] Figure 10 is a schematic diagram showing the connection between the battery device and the device body according to an embodiment of this disclosure;

[0072] Figure 11 is a structural schematic diagram of a vehicle according to an embodiment of this disclosure.

[0073] Explanation of reference numerals in the attached drawings: 1. Housing; 2. Battery cell assembly; 21. First assembly; 22. Second assembly; 23. Battery cell; 231. Large surface; 232. Terminal post; 3. First switcher; 10. Battery device; 20. Electrical device; 210. Main body of the device; 220. Motor; 230. Controller; A. Sodium battery; B. Type I battery; C. Type II battery. Detailed Implementation

[0074] The embodiments of the technical solutions disclosed herein will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solutions disclosed herein and are therefore intended to limit the scope of protection of this disclosure.

[0075] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure; the terms “comprising” and “having” and any variations thereof in embodiments of this disclosure are intended to cover non-exclusive inclusion.

[0076] In the description of the embodiments of this disclosure, technical terms such as "first," "second," and "third" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

[0077] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0078] In the description of the embodiments of this disclosure, 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, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0079] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0080] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0081] In related technologies, battery devices include at least two layers of battery cell assemblies, each comprising at least one battery cell. During discharge, the low temperature increases ion migration resistance within the battery cell, making it difficult for the cell to fully discharge. Similarly, during charging, the low temperature further increases ion migration resistance, hindering full charging. This low temperature also prevents the full utilization of the battery cell's capacity, resulting in low charge retention. The varying distances from the battery cell assemblies to the housing and the different temperatures at each location lead to significant differences in charge retention rates between different layers. Battery cells located at lower temperatures exhibit lower charge retention rates, reducing the overall capacity utilization of the battery device.

[0082] This disclosure provides a battery device 10, which includes a housing 1 and battery cell assemblies 2. The battery cell assemblies 2 are located inside the housing 1. All battery cell assemblies 2 except for the first assembly 21 are located on one side of the first assembly 21 along a predetermined direction. The low-temperature resistance of at least one battery cell 23 in at least one layer of battery cell assemblies 2 is less than the minimum low-temperature resistance of the battery cell 23 in the first assembly 21. The battery cell 23 with the worst low-temperature resistance is not in the first assembly 21, so that the first assembly 21 as a whole has better low-temperature resistance, which is beneficial to improving the overall capacity utilization rate of the battery device 10.

[0083] The battery device 10 of this disclosure embodiment can be used in the power consumption device 20 and the energy storage device.

[0084] An electrical device is a device that uses electrical energy as its energy source to perform a corresponding function by consuming electrical energy. For example, the electrical device 20 can be, but is not limited to, a mobile phone, tablet, laptop, electric toy, power tool, electric vehicle, electric car, ship, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.

[0085] Energy storage devices are devices that store electrical energy.

[0086] The power device 20 of this embodiment is shown in Figures 10 and 11. The power device 20 includes a device body 210 and a battery device 10. The housing 1 is installed on the device body 210. All battery cell assemblies 2 except the first assembly 21 are located on the side of the first assembly 21 facing the device body 210 along a preset direction.

[0087] The main body 210 refers to the main structure that consumes electrical energy to perform the corresponding function.

[0088] For example, the power-consuming device 20 can be a mobile phone, and the device body 210 is the part that can realize communication and other functions. The battery device 10 supplies power to the part that can realize communication and other functions.

[0089] For example, the electrical device 20 can be a vehicle, and the main body 210 is a part that provides seating for people and can travel on the road. The battery device 10 supplies power to the part that provides seating for people and can travel on the road.

[0090] In this embodiment of the present disclosure, the first component 21 is furthest away from the device body 210 along a preset direction. The first component 21 is in a low-temperature environment. The first component 21 in the low-temperature environment uses a low-temperature resistant battery cell 23, which is beneficial to improve the power retention rate of the first component 21, thereby improving the power capacity utilization rate of the battery device 10.

[0091] In one embodiment, please refer to Figures 1 and 10. The battery cell 23 is a square battery, and the large surface 231 of the battery cell 23 is arranged intersecting the vertical direction.

[0092] It should be noted that the up and down direction refers to the direction parallel to the direction of gravity.

[0093] For example, the device body 210 and the battery device 10 are arranged in a vertical direction.

[0094] It is understandable that the terminal post 232 of the battery cell 23 is located on the surface of the battery cell 23 other than the large surface 231.

[0095] For example, the large surface 231 of the battery cell 23 is arranged perpendicularly to the vertical direction.

[0096] In this embodiment of the disclosure, the large surface 231 of the battery cell 23 is arranged in a cross direction with the vertical direction, so that the battery cell 23 is arranged flat, which facilitates the stacking of at least two layers of battery cell assembly 2 in the vertical direction.

[0097] It is understood that the large surface 231 of the battery cell 23 is not limited to being arranged intersecting the vertical direction. For example, the large surface 231 of the battery cell 23 is arranged parallel to the vertical direction.

[0098] It is understood that the battery cell 23 is not limited to a prismatic battery. Exemplarily, the battery cell 23 can be a cylindrical battery, a pouch battery, or a combination of prismatic batteries, cylindrical batteries, and pouch batteries.

[0099] The following description uses a vehicle as an example of an electrical device 20 in this embodiment.

[0100] Referring to Figure 11, the vehicle provided in the embodiments of this disclosure can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery device 10 is installed inside the vehicle, and the battery device 10 can be located at the bottom, front, or rear of the vehicle. The battery device 10 can be used to power the vehicle; for example, the battery device 10 can serve as the vehicle's operating power source. The vehicle may also include a controller 230 and a motor 220. The controller 230 can be used to control the battery device 10 to supply power to the motor 220. For example, the battery device 10 can be used to meet the vehicle's power needs during starting, navigation, and driving.

[0101] In some embodiments of this disclosure, the battery device 10 can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0102] For example, the battery cell 23 is a secondary battery, which means that the battery cell 23 can be used again after being discharged by recharging to activate the active materials.

[0103] A battery cell 23 typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the negative and positive electrodes. During charging or discharging of the battery cell 23, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0104] For example, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0105] For example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0106] For example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For instance, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0107] Exemplarily, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this disclosure is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one 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 iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn1 / 3 O2 (also known as NCM) 333 LiNi 0.5 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) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0108] For example, the negative electrode can be a negative electrode sheet, which may include a negative electrode current collector.

[0109] For example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For instance, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0110] For example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0111] For example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0112] Exemplarily, the negative electrode active material may be a negative electrode active material known in the art for use in battery cell 23. Exemplarily, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this disclosure is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for battery cell 23 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0113] For example, the negative electrode can be made of 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 negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0114] For example, negative electrode active material may be filled or / and deposited in the negative electrode current collector.

[0115] For example, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0116] In one embodiment, the battery cell 23 further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This disclosure does not impose specific limitations on the type of electrolyte, which can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0117] In one embodiment, the battery cell 23 may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. Exemplarily, the casing may be a sealed structure or a non-sealed structure. Exemplarily, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly for encapsulating the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0118] In one embodiment, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0119] Please refer to Figures 1 and 3 for the battery device 10 of the embodiments of this disclosure. The battery device 10 includes a housing 1 and a battery cell assembly 2. The battery cell assembly 2 is located inside the housing 1. The battery cell assembly 2 has at least two layers. The arrangement direction of the at least two layers of battery cell assemblies 2 is a preset direction. Each layer of battery cell assembly 2 includes at least one battery cell 23. One layer of battery cell assembly 2 is a first assembly 21. All battery cell assemblies 2 except the first assembly 21 are located on one side of the first assembly 21 along the preset direction. The low temperature resistance of at least one battery cell 23 in at least one layer of battery cell assembly 2 is less than the minimum low temperature resistance of the battery cell 23 in the first assembly 21.

[0120] The battery cell capacity retention rate is the ratio of the amount of electricity charged or discharged to the capacitance of the battery cell 23.

[0121] The low-temperature resistance of the battery cell 23 is determined by measuring its charge retention rate at low temperatures. The lower the low-temperature resistance of the battery cell 23, the lower its charge retention rate at low temperatures. Conversely, the higher the low-temperature resistance of the battery cell 23, the higher its charge retention rate at low temperatures.

[0122] The low-temperature resistance of battery cell 23 was tested in a laboratory at a temperature of -20 degrees Celsius. At -20 degrees Celsius, the battery cell 23 was continuously charged until it could no longer be charged. The ratio of the amount of charge that battery cell 23 could take in to the amount of discharge that battery cell 23 could release until it could no longer be discharged was calculated based on the charge and discharge amounts of battery cell 23 and its capacitance.

[0123] Tests conducted at -20 degrees Celsius showed that sodium battery A retained 90% or more of its charge, battery B retained 70% or more of its charge, and battery C retained less than 90% of its charge. Sodium battery A exhibited greater low-temperature resistance than battery B, and battery B retained 60% or less of its charge.

[0124] For example, temperatures below zero degrees Celsius are considered low temperatures.

[0125] Battery cell assembly 2 is used to provide voltage and capacity.

[0126] For example, the battery cell assembly 2 includes at least two battery cells 23, which are connected in series, in parallel or in a mixed manner through a busbar component.

[0127] For example, the battery cell assembly 2 can be a battery module, which is formed by arranging and fixing at least two battery cells 23 to form an independent module. For example, the battery module can be formed by binding at least two battery cells 23 together with cable ties.

[0128] For example, the battery cell assembly 2 can be a battery module, and the battery cell assembly 2 can be housed in the housing 1 by fixing the battery module in the housing 1.

[0129] For example, the battery cell assembly 2 can also be housed in the housing 1 by directly fixing at least two battery cells 23 to the housing 1.

[0130] For example, the housing 1 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 1 forms a closed space to house the sodium battery A single cell assembly.

[0131] For example, the housing 1 can be part of the vehicle's chassis structure. For instance, a portion of the housing 1 can be at least a part of the vehicle's floor, or a portion of the housing 1 can be at least a part of the vehicle's crossbeams and longitudinal beams.

[0132] In this embodiment, at least one battery cell 23 in at least one layer of battery cell assembly 2 has a lower low-temperature resistance than the minimum low-temperature resistance of battery cell 23 in the first assembly 21, so that the battery cell 23 with the worst low-temperature resistance is not placed in the first assembly 21. The battery device 10 is installed on the device body 210 of the power consumption device 20. When the ambient temperature is low, the side of the battery device 10 away from the device body 210 along the preset direction is not shielded by the device body 210, and the side of the battery device 10 away from the device body 210 along the preset direction is greatly affected by the ambient temperature, resulting in a lower temperature. The side of the battery device 10 close to the device body 210 along the preset direction is isolated from the outside by the device body 210, and the side of the battery device 10 close to the device body 210 along the preset direction is less affected by the ambient temperature, and the temperature on the side of the device body 210 is higher. Therefore, the temperature on the side of the battery device 10 close to the device body 210 along the preset direction will also be higher. The first component 21 is located on the side of the housing 1 away from the main body 210 of the device along a preset direction. The first component 21 is in a low-temperature environment. The battery cell 23 with the worst low-temperature resistance is not in the first component 21. The battery cell 23 with the worst low-temperature resistance is set on other battery cell components 2 besides the first component 21. The battery cell 23 with the worst low-temperature resistance is set in a higher temperature area, so that the first component 21 as a whole has good low-temperature resistance. Thus, at a low temperature, the power retention rate of each layer of battery cell components 2 can be as close as possible, which is beneficial to improving the overall capacity utilization rate of the battery device 10.

[0133] In this embodiment, the battery cell 23 has different allowable currents at different temperatures; as the temperature decreases, the allowable current of the battery cell 23 decreases accordingly. When the charging current of the battery cell 23 exceeds the allowable current, lithium crystals will precipitate in the battery cell 23. Battery cells 23 with better low-temperature resistance also have larger allowable currents. Since these battery cells 23 with better low-temperature resistance are disposed in the first component 21, in low-temperature environments, the difference between the allowable current of the battery cells 23 at the lower temperature of the first component 21 and the allowable current of the battery cells 23 in other layers besides the first component 21 can be reduced, which helps alleviate low-temperature lithium deposition in the battery cells 23.

[0134] For ease of explanation, as shown in the figure, the direction indicated by arrow R1 is the preset direction.

[0135] For example, the preset direction is parallel to the up and down direction.

[0136] In one embodiment, please refer to Figures 1, 4 to 9. In the battery cells 23 of the first component 21, each battery cell 23 is of the type of sodium battery A and first type battery B. The positive electrode active material of the first type battery B is one of ternary positive electrode material, lithium cobalt oxide, lithium nickel oxide, lithium-rich manganese-based material and lithium manganese oxide.

[0137] Sodium battery A is a battery that achieves charging or discharging by the migration of sodium elements between the positive and negative electrodes.

[0138] Sodium battery A has better low-temperature resistance.

[0139] Ternary cathode materials are battery cathode materials composed of three chemical components (elements) or elements (simple substances and compounds).

[0140] Lithium-rich manganese-based materials are composite cathode materials based on lithium manganese oxide compounds. The chemical formula of lithium-rich manganese-based materials is Li₂MnO₃·LiMO₂, where M is typically a binary or ternary combination of nickel, cobalt, manganese, or one of these three elements. Batteries made from lithium-rich manganese-based materials have high mass energy density.

[0141] Lithium manganese oxide materials are cathode materials that mainly contain lithium manganese oxide (LiMn2O4) compounds, and are usually spinel phase.

[0142] In this embodiment of the disclosure, both sodium battery A and first-type battery B are batteries with good low-temperature resistance. Each cell 23 of the first component 21 is of the type of sodium battery A and first-type battery B, which makes the first component 21 have good low-temperature resistance.

[0143] It is understood that the type of each battery cell 23 in the first component 21 is not limited to either sodium battery A or first type battery B. Exemplarily, the positive electrode active material of the battery cell 23 in the first component 21 is a Prussian blue-based compound material or a polyanionic compound material.

[0144] In one embodiment, the ternary cathode material is a lithium nickel cobalt manganese ternary or a lithium nickel cobalt aluminum ternary.

[0145] Lithium-nickel-cobalt-manganese ternary cathode materials are battery cathode materials containing three elements: nickel, cobalt, and manganese.

[0146] For example, the lithium-nickel-cobalt-manganese ternary lithium-ion battery can be lithium nickel-cobalt-manganese oxide.

[0147] For example, the lithium-nickel-cobalt-manganese ternary material can be made from nickel salt, cobalt salt, and manganese salt as raw materials, and the proportion of nickel, cobalt, and manganese can be adjusted according to actual needs.

[0148] Lithium-nickel-cobalt-aluminum ternary cathode materials are battery cathode materials containing three elements: nickel, cobalt, and aluminum.

[0149] For example, the lithium-nickel-cobalt-aluminum ternary lithium-ion battery can be lithium nickel-cobalt-aluminum oxide.

[0150] For example, a lithium-nickel-cobalt-aluminum ternary lithium battery can be a material made from nickel salt, cobalt salt, and aluminum salt, and the proportion of nickel, cobalt, and aluminum can be adjusted according to actual needs.

[0151] In this embodiment, lithium nickel cobalt manganese ternary and lithium nickel cobalt aluminum ternary are used as the positive electrode materials of the battery, which enables the battery cell 23 to have a higher specific capacity and a higher mass energy density.

[0152] In one embodiment, please refer to Figures 1, 3 to 9. One of the battery cell components 2 is a second component 22. All battery cell components 2 except the second component 22 are located on the side of the second component 22 facing the first component 21 along a preset direction. In the battery cells 23 of the second component 22, each battery cell 23 is of the type of sodium battery A or second type battery C. The positive electrode active material of the second type battery C is one of lithium iron phosphate and lithium vanadium phosphate.

[0153] Lithium iron phosphate is a phosphate compound containing iron and lithium elements.

[0154] Lithium vanadium phosphate is a phosphate compound containing vanadium and lithium.

[0155] In this embodiment, sodium battery A and second type battery C have better safety. The battery cells 23 of the second component 22 are of the types of sodium battery A and second type battery C, which makes the second component 22 have better safety. The second component 22 is closest to the device body 210 along a preset direction, which improves the safety of the second component 22 and is conducive to improving the safety of the electrical device 20.

[0156] It is understood that the type of each battery cell 23 in the second component 22 is not limited to either sodium battery A or second-type battery C. For example, the type of battery cell 23 corresponding to the second component 22 is first-type battery B.

[0157] In one embodiment, the lithium iron phosphate is lithium iron phosphate or lithium manganese iron phosphate.

[0158] In this embodiment, the lithium iron phosphate is lithium iron phosphate or lithium manganese iron phosphate. Lithium iron phosphate and lithium manganese iron phosphate, as positive electrode materials of the battery, do not contain harmful heavy metal elements, making the battery safe and stable.

[0159] In one embodiment, referring to Figures 1, 4 to 9, the battery cell assembly 2 has three or more layers. Among the battery cells 23 of the other battery cell assemblies 2 located between the first assembly 21 and the second assembly 22, each battery cell 23 is of one of sodium battery A, first type battery B, and second type battery C.

[0160] For example, the number of layers in the battery cell assembly 2 is three, four, or five.

[0161] In this embodiment of the disclosure, the type of battery cell 23 of the battery cell assembly 2 between the first component 21 and the second component 22 is not limited, and the battery cell 23 located in the middle layer can be adapted according to actual needs, and the battery device 10 has good flexibility.

[0162] It is understood that the number of layers in the battery cell module 2 is not limited to three or more layers. For example, the battery cell module 2 has two layers.

[0163] In one embodiment, referring to Figures 1, 4, 5, 7 and 8, among the at least three battery cells 23 stacked along a preset direction, the type of battery cell 23 corresponding to the first component 21 is sodium battery A.

[0164] The projection areas of at least three battery cells 23 along a preset direction at least partially overlap.

[0165] In this embodiment of the disclosure, sodium battery A has the best low-temperature performance among the three types of batteries. The first component 21 is located at a low temperature. The battery cells 23 of the first component 21 use sodium battery A, which can effectively improve the charge retention rate of the first component 21, reduce the gap in charge retention rate between the first component 21 and other battery cell components 2 besides the first component 21, and improve the capacity utilization rate of the battery device 10.

[0166] It is understood that the type of battery cell 23 corresponding to the first component 21 is not limited to sodium battery A. For example, the type of battery cell 23 corresponding to the first component 21 is a first type battery B.

[0167] In one embodiment, referring to Figures 1, 4, 6, 7 and 9, among the at least three battery cells 23 stacked along a preset direction, the type of battery cell 23 corresponding to the second component 22 is a second type of battery C.

[0168] In this embodiment, the second type of battery C has better safety. The second component 22 is the closest to the device body 210 among all battery cell components 2. The second type of battery C with the best safety is placed at the second component 22 closest to the device body 210. Under the premise of improving the capacity utilization rate of the battery device 10, it is beneficial to improve the safety of the device body 210.

[0169] It is understood that the type of battery cell 23 corresponding to the second component 22 is not limited to the second type of battery C. For example, the battery cell 23 corresponding to the second component 22 is the first type of battery B.

[0170] In one embodiment, among at least three battery cells 23 stacked along a preset direction, the mass energy density of the battery cell 23 corresponding to the first component 21 is the first energy density, the mass energy density of the battery cell 23 corresponding to the second component 22 is the second energy density, and the mass energy density of the battery cell 23 located between the first component 21 and the second component 22 is the third energy density. Both the first energy density and the second energy density are less than the third energy density.

[0171] Mass energy density is the ratio of the energy of a single battery cell 23 to the mass of the single battery cell 23.

[0172] The most common method for measuring the mass energy density of a single battery cell 23 is a discharge test. The basic principle is to discharge the battery to a specified voltage to obtain its discharge energy and charge. By measuring the battery's mass, the energy density of the single battery cell 23 can be calculated.

[0173] In this embodiment, the battery cell assembly 2 located between the first assembly 21 and the second assembly 22 uses a battery cell 23 with a high mass energy density, which helps the battery device 10 adapt to scenarios with high energy requirements. The high mass energy density battery cell 23 is disposed between the first assembly 21 and the second assembly 22, and the second assembly 22 is disposed between the high mass energy density battery cell 23 and the device body 210. The second assembly 22 can provide a buffer for the high mass energy density battery cell 23, improving the safety of the device body 210.

[0174] It is understood that the first energy density and the second energy density are not limited to being less than the third energy density. For example, the first energy density is equal to the third energy density. For example, the second energy density is equal to the third energy density.

[0175] In one embodiment, referring to Figures 1, 4, 8 and 9, among the at least three battery cells 23 stacked along a preset direction, the battery cell 23 located between the first component 21 and the second component 22 is of type B first battery.

[0176] In this embodiment, the battery cell 23 of the first component 21 is a sodium battery A with good low-temperature resistance, the battery cell 23 of the second component 22 is a second type of battery C with high safety, and the battery cell 23 of the battery cell assembly 2 between the first component 21 and the second component 22 is a first type of battery B with high mass energy density. This allows the battery device 10 to balance high capacity utilization, good safety and high mass energy density. The battery device 10 has a variety of performance characteristics and its performance in all aspects is relatively balanced.

[0177] It is understood that the type of battery cell 23 located between the first component 21 and the second component 22 is not limited to the first type of battery B. For example, the type of battery cell 23 located between the first component 21 and the second component 22 is the second type of battery C.

[0178] In one embodiment, referring to FIG1, among at least three battery cells 23 stacked along a preset direction, the battery cell 23 corresponding to the first component 21 is of type B first battery, the battery cell 23 corresponding to the second component 22 is of type A sodium battery, and the battery cell 23 located between the first component 21 and the second component 22 is of type C second battery.

[0179] In this embodiment, the battery cells 23 of the first component 21, which is in a low-temperature environment, use a first-type battery B with a high mass energy density. The first-type battery B has certain low-temperature resistance, which is better than that of the second-type battery C. The battery cells 23 of the second component 22 use sodium batteries A. The battery cells 23 of the battery cell assembly 2 between the first component 21 and the second component 22 use second-type batteries C. The second-type batteries C, which have better safety, separate the first-type battery B and the sodium batteries A, so that the sodium batteries A are in a safer environment and prevent the low-temperature resistance of the battery cells 23 from decreasing due to damage to the sodium batteries A.

[0180] It is understood that the type of battery cell 23 corresponding to the second component 22 is not limited to sodium battery A. For example, among at least three battery cells 23 stacked along a preset direction, the type of battery cell 23 corresponding to the first component 21 is first type battery B, the type of battery cell 23 corresponding to the second component 22 is second type battery C, and the type of battery cell 23 located between the first component 21 and the second component 22 is second type.

[0181] In one embodiment, referring to Figures 1 and 6, among at least three battery cells 23 stacked along a preset direction, the battery cell 23 corresponding to the first component 21 is of type B first battery, the battery cell 23 corresponding to the second component 22 is of type C second battery, and the battery cell 23 located between the first component 21 and the second component 22 is of type A sodium battery.

[0182] In this embodiment, the first component 21 of the first type of battery B with higher mass energy density is located away from the main body 210 of the power-consuming device 20 along a preset direction to improve the safety of the main body 210. The sodium battery A is located between the first component 21 and the second component 22 to improve the low-temperature resistance of the battery device 10. The temperature at the second component 22 is relatively high. The second type of battery C, which has the worst low-temperature resistance among the three types of batteries, is located in the second component 22 to keep the second type of battery A, which has poor low-temperature resistance, away from the low-temperature environment as much as possible, thereby reducing the impact of low temperature on the battery cells 23 of the second component 22.

[0183] It is understood that the battery cell 23 located between the first component 21 and the second component 22 is of type sodium battery A. For example, among at least three battery cells 23 stacked along a predetermined direction, the battery cell 23 corresponding to the first component 21 is of type first battery B, the battery cell 23 corresponding to the second component 22 is of type second battery C, and the battery cell 23 located between the first component 21 and the second component 22 is of type second.

[0184] In one embodiment, referring to Figures 1 and 7, among at least three battery cells 23 stacked along a preset direction, the battery cell 23 corresponding to the first component 21 is of type sodium battery A, the battery cell 23 corresponding to the second component 22 is of type second battery C, and the battery cell 23 located between the first component 21 and the second component 22 is of type sodium battery A.

[0185] In this embodiment, the battery cell 23 corresponding to the first component 21 is a sodium battery A with good low-temperature resistance. Given the good low-temperature resistance of the battery device 10, both the second type of battery C and the sodium battery A have good safety, thus improving the overall safety of the battery device 10. The battery device 10 uses a combination of two types of battery cells 23, resulting in fewer types of battery cells 23 and simplifying the control of the battery cells 23 by the power battery management system.

[0186] It is understood that the type of battery cell 23 located between the first component 21 and the second component 22 is not limited to sodium battery A. For example, among at least three battery cells 23 stacked along a preset direction, the type of battery cell 23 corresponding to the first component 21 is sodium battery A, the type of battery cell 23 corresponding to the second component 22 is second type battery C, and the type of battery cell 23 between the first component 21 and the second component 22 is second type battery C.

[0187] In one embodiment, referring to Figures 1 and 8, among at least three battery cells 23 stacked along a preset direction, the battery cell 23 corresponding to the first component 21 is of type sodium battery A, the battery cell 23 corresponding to the second component 22 is of type sodium battery A, and the battery cell 23 located between the first component 21 and the second component 22 is of type first battery B.

[0188] In this embodiment, the battery cell 23 corresponding to the first component 21 is a sodium battery A with good low-temperature resistance. Under the condition of the low-temperature resistance of the battery device 10, the battery cell 23 located between the first component 21 and the second component 22 is a first type battery B with high mass energy density. The first type battery B cell 23 with high mass energy density is not the closest to the device body 210, so the overall safety of the battery device 10 is better.

[0189] It is understood that the type of battery cell 23 located between the first component 21 and the second component 22 is not limited to the first type of battery B. For example, among at least three battery cells 23 stacked along a preset direction, the type of battery cell 23 corresponding to the first component 21 is sodium battery A, the type of battery cell 23 corresponding to the second component 22 is sodium battery A, and the type of battery cell 23 located between the first component 21 and the second component 22 is the second type of battery C.

[0190] In one embodiment, referring to Figures 1 and 9, among at least three battery cells 23 stacked along a preset direction, the battery cell 23 corresponding to the first component 21 is of type B first battery, the battery cell 23 corresponding to the second component 22 is of type C second battery, and the battery cell 23 located between the first component 21 and the second component 22 is of type B first battery.

[0191] In this embodiment, the first type of battery B has a higher mass energy density. Compared with the second type of battery C, the first type of battery B has better low-temperature resistance. The battery cell 23 located between the first component 21 and the second component 22 uses the first type of battery B. The battery cell 23 of the first component 21 also uses the first type of battery B. The number of first type of batteries B in the battery device 10 is relatively large. When the mass energy density of the battery device 10 is high, the battery device 10 has low-temperature resistance.

[0192] It is understood that the type of battery cell 23 located between the first component 21 and the second component 22 is not limited to the first type of battery B. For example, the type of battery cell 23 corresponding to the first component 21 is the first type of battery B, the type of battery cell 23 corresponding to the second component 22 is the second type of battery C, and the type of battery cell 23 located between the first component 21 and the second component 22 is the second type of battery C.

[0193] In one embodiment, sodium battery A is a sodium-ion battery or a sodium metal battery, and sodium-ion batteries and sodium metal batteries have better low-temperature resistance than lithium batteries.

[0194] Sodium-ion batteries are batteries in which sodium ions migrate between the positive and negative electrodes to achieve charging and discharging.

[0195] Sodium metal batteries are batteries that use sodium metal as the negative electrode material for charging and discharging.

[0196] In this embodiment of the disclosure, sodium battery A can be a sodium-ion battery or a sodium metal battery. Both sodium-ion batteries and sodium metal batteries have good low-temperature resistance.

[0197] In one embodiment, the battery cells 23 of the same layer of battery cell assembly 2 are of the same type.

[0198] In this embodiment, the battery cells 23 in the same layer are of the same type, which facilitates the installation and arrangement of the battery cells 23 and makes the arrangement of the battery cells 23 simple.

[0199] In one embodiment, at least two battery cells 23 of at least one layer of battery cell assembly 2 are of different types.

[0200] In this embodiment of the disclosure, at least one layer of battery cell assembly 2 is arranged with different types of battery cells 23, which is beneficial to make comprehensive use of the characteristics of different types of battery cells 23.

[0201] In one embodiment, referring to FIG2, the battery device 10 further includes a first switch 3 located inside the housing 1, the first switch 3 being used to connect or disconnect at least two layers of battery cell assemblies 2 in parallel.

[0202] In this embodiment, the first switch 3 is used to connect at least two layers of battery cell assembly 2 in parallel, reducing the charging current of each layer of battery cell assembly 2 and minimizing the possibility of exceeding the allowable current of each layer of battery cell assembly 2 due to excessive charging current. This allows each layer of battery cell assembly 2 to be charged simultaneously within the allowable current range, thereby alleviating low-temperature lithium plating of the battery cells 23. When each layer of battery cell 23 needs charging, the first switch 3 is connected to each layer of battery cell assembly 2. When a layer of battery cell assembly 2 is fully charged, the first switch 3 is disconnected from the fully charged battery cell assembly 2, and the first switch 3 continues to be connected to the partially charged battery cell assembly 2 so that the partially charged battery cell assembly 2 can continue to be charged.

[0203] It is understood that the first switch 3 is not limited to connecting or disconnecting at least two layers of battery cell assembly 2 in parallel. Exemplarily, the first switch 3 is used to connect two layers of battery cell assembly 2 in series.

[0204] In one embodiment, the battery device 10 further includes a second switch located within the housing 1, the second switch being used to connect or disconnect at least two battery cells 23 in the same layer of the battery cell assembly 2.

[0205] In this embodiment, at least two battery cells 23 in the same layer of the battery cell assembly 2 are connected in parallel, reducing the current flowing between the battery cells 23 in the same layer. This reduces the possibility of the charging current exceeding the allowable current of the battery cell 23, allowing the battery cells 23 in the same layer to be charged simultaneously within the allowable current range, thereby alleviating the low-temperature lithium plating of the battery cells 23. When all battery cells 23 in the same layer need to be charged, a second switch is connected to each battery cell 23 to charge the battery cells 23. When some battery cells 23 are fully charged, the second switch is disconnected from the fully charged battery cells 23, and the second switch continues to be connected to the partially charged battery cells 23 to continue charging the partially charged battery cells 23.

[0206] It is understood that the second switch is not limited to connecting or disconnecting at least two battery cells 23 in the same layer of battery cell assembly 2. Exemplarily, the second switch is used to connect two battery cells 23 in the same layer of battery cell assembly 2 in series.

[0207] In one embodiment, the battery device 10 further includes a temperature regulating device, wherein all battery cell components 2 except the first component 21 are located on the side of the first component 21 that is away from the temperature regulating device along a preset direction.

[0208] The temperature control device is a component that exchanges heat with the battery cell 23.

[0209] The temperature control device can regulate the temperature of the battery cell 23.

[0210] In this embodiment, all battery cell assemblies 2 except for the first assembly 21 are located on the side of the first assembly 21 facing away from the temperature regulating device along a preset direction. The temperature regulating device is located at the first assembly 21, reducing the impact of the temperature regulating device on the battery cells 23 with poor low-temperature resistance. The temperature regulating device is located on the side of all battery cell assemblies 2 facing away from the device body 210 along a preset direction. All battery cell assemblies 2 are located between the temperature regulating device and the device body 210. In low-temperature environments, the temperature regulating device can help isolate the battery cell assemblies 2 from the low temperature environment.

[0211] Understandably, the location of the temperature control device is not limited.

[0212] In one embodiment, the temperature control device is a water-cooled plate.

[0213] In this embodiment, the temperature regulating device is a water-cooled plate. The water-cooled plate has a good temperature regulating effect, which is beneficial for quickly cooling down the heat-generating battery cell assembly 2.

[0214] It is understood that the temperature control device is not limited to a water-cooled plate. For example, the temperature control device is an air-cooled device.

[0215] This disclosure provides a charging method, which includes charging the battery cell assembly 2 layer by layer, wherein the charging power of each layer of battery cell assembly 2 decreases sequentially according to the charging order.

[0216] In this embodiment of the disclosure, the battery cell assembly 2 with a larger charging power is charged first, which can charge the battery device 10 to the corresponding capacity more quickly and improve the charging rate of the battery device 10.

[0217] In one embodiment, in a low-temperature environment, the battery cell assembly 2 with better low-temperature resistance can be charged first. During the charging process, the battery cell assembly 2 dissipates heat, heating the battery cell 23 of the battery cell assembly 2 with poor low-temperature resistance for a period of time before charging the battery cell assembly 2 with poor low-temperature resistance.

[0218] In one embodiment, when the vehicle is overtaking, starting, or stopping, a battery cell assembly 2 with good low-temperature resistance is used to power the vehicle.

[0219] In one embodiment, the battery device 10 includes a housing 1 and battery cell assembly 2. The battery cell assembly 2 is located inside the housing 1. The battery cell assembly 2 has at least two layers, and the arrangement direction of the at least two layers of battery cell assembly 2 is a preset direction. Each layer of battery cell assembly 2 includes at least one battery cell 23. One layer of battery cell assembly 2 is a first assembly 21. All battery cell assemblies 2 except the first assembly 21 are located on one side of the first assembly 21 along the preset direction. The low-temperature resistance of at least one battery cell 23 in at least one layer of battery cell assembly 2 is less than the minimum low-temperature resistance of the battery cell 23 in the first assembly 21. Regarding temperature control, in the battery cells 23 of the first component 21, each battery cell 23 is of type one of sodium battery A and first type battery B. The positive electrode active material of the first type battery B is one of ternary positive electrode material, lithium cobalt oxide, lithium nickel oxide, lithium-rich manganese-based material, and lithium manganese oxide. The ternary positive electrode material is lithium nickel cobalt manganese ternary or lithium nickel cobalt aluminum ternary. One battery cell assembly 2 is the second component 22. All battery cell assemblies 2 except the second component 22 are located on the side of the second component 22 facing the first component 21 along a preset direction. In the battery cells 23 of the second component 22, each battery cell 23 is of type sodium battery A. Or one of the second type of battery C, wherein the positive electrode active material of the second type of battery C is one of lithium iron phosphate and lithium vanadium phosphate, wherein the lithium iron phosphate is lithium iron phosphate or lithium manganese iron phosphate, the number of layers of the battery cell assembly 2 is greater than or equal to three, and among the at least three battery cells 23 stacked along a predetermined direction, the type of battery cell 23 corresponding to the first assembly 21 is sodium battery A, the type of battery cell 23 corresponding to the second assembly 22 is second type battery C, and the type of battery cell 23 located between the first assembly 21 and the second assembly 22 is first type battery B, wherein sodium battery A is sodium-ion battery or sodium metal battery, and the low temperature resistance of sodium-ion battery and sodium metal battery is higher than that of lithium The battery has good low-temperature resistance. The battery cells 23 in the same layer of battery cell assembly 2 are of the same type. The battery device 10 also includes a first switch 3 located in the housing 1. The first switch 3 is used to connect or disconnect at least two layers of battery cell assembly 2 in parallel. The battery device 10 also includes a second switch located in the housing 1. The second switch is used to connect or disconnect at least two battery cells 23 in the same layer of battery cell assembly 2 in parallel. The battery device 10 also includes a temperature regulating device. All battery cell assemblies 2 except the first assembly 21 are located on the side of the first assembly 21 away from the temperature regulating device along a preset direction. The temperature regulating device is a water-cooled plate.

[0220] The above embodiments are merely illustrative of the technical solutions of this disclosure and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure, and all should be covered within the scope of this disclosure. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way.

Claims

1. A battery device, comprising: Box; A battery cell assembly is located inside the housing. The battery cell assembly has at least two layers, and the arrangement direction of the at least two layers of battery cell assemblies is a preset direction. Each layer of the battery cell assembly includes at least one battery cell. One layer of the battery cell assembly is a first assembly. All battery cell assemblies except the first assembly are located on one side of the first assembly along the preset direction. The low-temperature resistance of at least one battery cell in at least one layer of the battery cell assembly is less than the minimum low-temperature resistance of the battery cell in the first assembly.

2. The battery device of claim 1, wherein, In the battery cells of the first component, each battery cell is of one type: a sodium battery and a first type of battery. The positive electrode active material of the first type of battery is one of ternary positive electrode material, lithium cobalt oxide, lithium nickel oxide, lithium-rich manganese-based material, and lithium manganese oxide.

3. The battery device of claim 2, wherein, The ternary cathode material is either lithium nickel cobalt manganese ternary or lithium nickel cobalt aluminum ternary.

4. The battery device of claim 2, wherein, One of the battery cell components is a second component, and all other battery cell components except the second component are located on the side of the second component facing the first component along the preset direction; in the battery cells of the second component, each battery cell is of the type of either a sodium battery or a second type of battery, and the positive electrode active material of the second type of battery is either lithium iron phosphate or lithium vanadium phosphate.

5. The battery device of claim 4, wherein, The lithium iron phosphate is either lithium iron phosphate or lithium manganese iron phosphate.

6. The battery device according to claim 4 or 5, wherein The battery cell assembly has three or more layers. Among the battery cells in the other battery cell assemblies located between the first assembly and the second assembly, each battery cell is of one of the sodium battery, the first type of battery, and the second type of battery.

7. The battery device of claim 6, wherein, Of the at least three battery cells stacked along the preset direction, the type of the battery cell corresponding to the first component is the sodium battery.

8. The battery device of claim 7, wherein, Among the at least three battery cells stacked along the preset direction, the type of the battery cell corresponding to the second component is the second type of battery.

9. The battery device of claim 8, wherein, In at least three battery cells stacked along the preset direction, the mass energy density of the battery cell corresponding to the first component is the first energy density, the mass energy density of the battery cell corresponding to the second component is the second energy density, and the mass energy density of the battery cell located between the first component and the second component is the third energy density. Both the first energy density and the second energy density are less than the third energy density.

10. The battery device of claim 9, wherein, Of the at least three battery cells stacked along the preset direction, the battery cell located between the first component and the second component is of the first type of battery.

11. The battery device of claim 6, wherein, In the at least three battery cells stacked along the preset direction, the battery cell corresponding to the first component is of the first type of battery, the battery cell corresponding to the second component is of the sodium battery type, and the battery cell located between the first component and the second component is of the second type of battery.

12. The battery device of claim 6, wherein, In the at least three battery cells stacked along the preset direction, the battery cell corresponding to the first component is of the first type of battery, the battery cell corresponding to the second component is of the second type of battery, and the battery cell located between the first component and the second component is of the sodium battery type.

13. The battery device of claim 6, wherein, In the at least three battery cells stacked along the preset direction, the battery cell corresponding to the first component is of the sodium battery type, the battery cell corresponding to the second component is of the second type of battery type, and the battery cell located between the first component and the second component is of the sodium battery type.

14. The battery device of claim 6, wherein, In the at least three battery cells stacked along the preset direction, the battery cell corresponding to the first component is of the sodium battery type, the battery cell corresponding to the second component is of the sodium battery type, and the battery cell located between the first component and the second component is of the first type of battery type.

15. The battery device of claim 6, wherein, In at least three battery cells stacked along the preset direction, the battery cell corresponding to the first component is of the first type of battery, the battery cell corresponding to the second component is of the second type of battery, and the battery cell located between the first component and the second component is of the first type of battery.

16. The battery device according to any one of claims 2 to 15, wherein The sodium battery is a sodium-ion battery or a sodium metal battery, and the sodium-ion battery and the sodium metal battery have better low-temperature resistance than lithium batteries.

17. The battery device according to any one of claims 1 to 16, wherein The battery cells in the same layer of the battery cell assembly are of the same type.

18. The battery device according to any one of claims 1 to 16, wherein At least two of the battery cells in at least one layer of the battery cell assembly are of different types.

19. The battery device according to any one of claims 1 to 16, wherein The battery device also includes a first switch located within the housing, the first switch being used to connect or disconnect at least two layers of the battery cell assembly.

20. The battery device according to any one of claims 1 to 16, wherein The battery device also includes a second switch located inside the housing, the second switch being used to connect or disconnect at least two battery cells in the same layer of the battery cell assembly.

21. The battery device according to any one of claims 1 to 16, wherein The battery device further includes a temperature regulating device, and all battery cell components except the first component are located on the side of the first component away from the temperature regulating device along the preset direction.

22. The battery device of claim 21, wherein, The temperature control device is a water-cooled plate.

23. An electrical appliance, comprising: Main body of the device; According to any one of claims 1 to 22, the housing is mounted on the main body of the device, and all battery cell assemblies except the first assembly are located on the side of the first assembly facing the main body of the device along the preset direction.

24. The powered device of claim 23, wherein, The battery cell is a square battery, and the large surface of the battery cell is arranged in a crisscross pattern with the vertical direction.

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