Battery apparatus and electric apparatus

Abstract

A battery apparatus (100) and an electric apparatus. The battery apparatus (100) comprises a casing (10), a battery cell assembly (20), and a heating component (30). An accommodating space is provided inside the casing (10), and the battery cell assembly (20) is located within the accommodating space, the battery cell assembly (20) comprising a plurality of battery cells (21) arranged in a first direction (X), and the first direction (X) intersecting with a height direction (Z) of the casing (10). The heating component (30) is located within the accommodating space and is provided between the battery cell assembly (20) and a bottom wall of the casing (10), the heating component (30) comprising a heating element (31) and protective layers (32), the protective layers (32) being respectively provided on two sides of the heating element (31) in the height direction (Z) of the casing (10), and the protective layers (32) on the two sides of the heating member (31) being connected to each other.

Description

Battery devices and electrical appliances

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application 202411595155.4, filed on November 8, 2024, entitled “Battery Device and Power Consumption Device”, the entire contents of which are incorporated herein by reference. Technical Field

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

[0004] Batteries operating in low-temperature environments will have their charging and discharging performance affected and their lifespan impacted. When using heating films to heat the individual cells inside the battery, the problem is the poor reliability of the heating film. Summary of the Invention

[0005] In view of the above problems, this application provides a battery device and an electrical device that can improve the uneven heating of the battery.

[0006] In a first aspect, this application provides a battery device, comprising:

[0007] The box has internal storage space;

[0008] A battery cell assembly is located within a housing space. The battery cell assembly includes a plurality of battery cells arranged along a first direction, which intersects with the height direction of the housing.

[0009] The heating element is located within the housing space and is disposed between the battery cell assembly and the bottom wall of the housing. The heating element includes a heating element and a protective layer. Protective layers are provided on both sides of the heating element along the height direction of the housing. The protective layers on both sides of the heating element are connected to each other. The protective layers are insulated from the heating element. The heating element is configured to generate heat when energized and to heat the battery cell assembly.

[0010] The protective layer of the heating element protects the heating element and prevents foreign metal objects from piercing it, thereby reducing the probability of damage to the heating element and improving its reliability. Especially when there are multiple heating elements, it can reduce the probability of foreign metal objects inside the box piercing some of the heating elements and causing them to malfunction. This allows multiple heating elements to heat the battery cells simultaneously, ensuring that the battery cells are heated evenly.

[0011] In some embodiments, the protective layer of the heating element facing the bottom wall of the housing consists of at least two layers.

[0012] This provides multiple layers of protection, reducing the probability of metal foreign objects on the bottom wall of the enclosure piercing the heating element and improving the reliability of the heating element's operation.

[0013] In some embodiments, the protective layer having at least two layers includes:

[0014] Insulating film layer;

[0015] The reinforcing layer is located on the side of the insulating film layer away from the heating element, and the reinforcing layer is connected to the insulating film layer.

[0016] When there are metal foreign objects on the bottom wall of the housing, the reinforcing layer acts as the first layer of protection to prevent the metal foreign objects from penetrating into the heating element. When the first layer of protection fails, the insulating film layer can further prevent the metal foreign objects from piercing the heating element, thereby improving the reliability of the heating element's operation.

[0017] In some embodiments, the reinforcing layer includes any one of an epoxy resin layer, a ceramic composite layer, a nylon-polyester resin composite insulating film layer, or a polyurea coating.

[0018] This improves the resistance of the heating element to metal puncture, thereby enhancing the reliability of the heating element's operation.

[0019] In some embodiments, the thickness of the reinforcing layer is S, and the value of S ranges from 0.1 mm to 0.5 mm.

[0020] The reinforcing layer S = 0.1mm, which can basically prevent metal foreign objects from piercing the heating element. As S increases, it becomes more difficult for metal foreign objects to pierce the heating element, and the reliability of the heating element is higher. However, the reinforcing layer will occupy a large space in the housing, affecting the capacity of the battery device. Therefore, while balancing the puncture resistance of the reinforcing layer and the space occupied by the reinforcing layer, the value of S is set to be in the range of 0.1mm-0.5mm.

[0021] In some embodiments, the value of S ranges from 0.15mm to 0.25mm.

[0022] With S = 0.15mm, the ability of the reinforcing layer to prevent metal foreign objects from piercing the heating element can be further improved. While taking into account the space occupied by the reinforcing layer, the value of S is set to 0.15mm-0.25mm. This can reduce the impact on the battery capacity while meeting the reinforcing layer's requirement for resistance to puncture by metal foreign objects.

[0023] In some embodiments, the heating component further includes an adhesive layer located on the side of the reinforcing layer opposite to the insulating layer, and the reinforcing layer is bonded to the bottom wall of the housing via the adhesive layer.

[0024] Therefore, the probability of the heating component deviating from the predetermined position can be reduced during the installation and operation of the heating component, thereby enabling the heating component to heat the battery cell assembly at the predetermined position, so as to improve the uneven heating of the battery cell assembly caused by deviation from the predetermined position.

[0025] In some embodiments, the battery device further includes a structural adhesive layer located within the housing space and between the battery cell assembly and the bottom wall of the housing. The battery cell assembly is bonded to the bottom wall of the housing via the structural adhesive layer, and the heating element is located within the structural adhesive layer.

[0026] The structural adhesive layer can fix the heating component and battery cell assembly to the bottom wall of the housing, so that the battery cell assembly will not shake inside the housing during operation, thereby improving the reliability and safety of the battery cell assembly. In addition, the structural adhesive layer can position the heating component at a predetermined position on the bottom wall of the housing, so that the heating component heats the battery cell at the predetermined position, thereby improving the uneven heating of the battery cell assembly caused by deviation from the predetermined position.

[0027] In some embodiments, the heating element has a first heating zone, a second heating zone, and a third heating zone. The second heating zone has the first heating zone on one side along the first direction, and the second heating zone has the third heating zone on the other side along the first direction. The first heating zone and the third heating zone are used to heat different battery cells on the outermost side along the first direction. The dimension of the first heating zone along the first direction is L1, the dimension of the second heating zone along the first direction is L2, and the dimension of the third heating zone along the first direction is L3. The resistance of the first heating zone is R1, the resistance of the second heating zone is R2, and the resistance of the third heating zone is R3. R2 / L2 < R1 / L1, and R2 / L2 < R3 / L3.

[0028] When the external ambient temperature is low, the battery cell closest to the side wall of the housing is more affected by the ambient temperature and has a lower temperature. R2 / L2 is set to be less than R1 / L1 and R2 / L2 is less than R3 / L3. Under the unit length of the heating element along the first direction, the heat generated by the first heating zone and the third heating zone of the heating element is greater than the heat generated by the second heating zone, so as to improve the situation of the battery cells at both ends of the battery cell assembly being too low.

[0029] In some embodiments, the first heating zone, the second heating zone, and the third heating zone each have a bent portion. The length of the first heating zone is L4 along the extending direction of the first heating zone, the length of the second heating zone is L5 along the extending direction of the second heating zone, and the length of the third heating zone is L6 along the extending direction of the third heating zone, where L4 / L1 > L5 / L2 and L6 / L3 > L5 / L2.

[0030] Therefore, under the premise that the cross-sections and materials of the first heating zone, the second heating zone and the third heating zone remain unchanged, L4 / L1>L5 / L2 and L6 / L3>L5 / L2 can increase the resistance of the heating element per unit length in the first heating zone and the third heating zone along the first direction. Under the premise that the current remains unchanged, the heating element can generate more heat per unit length in the first heating zone and the third heating zone along the first direction, thereby improving the situation of the battery cells at both ends being too low in temperature.

[0031] In some embodiments, the number of heating elements is one, and the heating element has three heating sections connected in series. One heating section is located in the second heating zone, and the other two heating sections are located in the first heating zone and the third heating zone respectively.

[0032] Therefore, compared with setting multiple heating elements, the structure of the heating element can be simplified, thus saving costs.

[0033] In some embodiments, the heating component includes at least two heating elements connected in parallel, the at least two heating elements being configured to heat the battery cell assembly individually or simultaneously.

[0034] The effects of external ambient temperature changes on individual battery cells within the battery device vary. By installing two parallel heating elements, the system can control at least two heating elements to work individually or simultaneously, based on the impact of the external environment on the individual battery cells. This allows the temperature of the individual battery cells to be adjusted according to changes in the external ambient temperature, thereby reducing excessive energy consumption by the heating elements and improving the battery device's range.

[0035] In some embodiments, the battery device further includes a control switch, each heating element is connected in series with the control switch to form a parallel branch, each parallel branch is connected in parallel, and the battery cell is used to supply power to the parallel branch.

[0036] Therefore, by controlling the opening and closing of the switch according to the external ambient temperature, each parallel branch can be operated or shut down individually, thereby enabling more flexible adjustment of the temperature of the battery cells to reduce the impact of low temperature on the battery cells and save energy.

[0037] In some embodiments, there are two heating elements, one of which is a first heating element and the other is a second heating element. The first heating element is located on one side of the second heating element along the second direction. At least a portion of the first heating element and at least a portion of the second heating element are used to heat the outermost battery cell in the battery cell assembly along the first direction. The second direction intersects the first direction and the height direction of the housing, respectively.

[0038] Therefore, two heating elements can be used to simultaneously or individually heat the battery cells at both ends of the battery cell assembly along the first direction, and can switch according to changes in the external environment. In particular, when the temperature of the external environment is not too low, one heating element can be turned on to save energy and improve the battery device's range.

[0039] In some embodiments, the number of battery cells in the battery cell assembly is three or more. The first heating element includes a first heating part, a second heating part and a third heating part. The second heating part is connected in series with the first heating part on one side along the first direction, and the second heating part is connected in series with the third heating part on the other side along the first direction. The first heating part and the third heating part are respectively used to heat different battery cells on the outermost side of the battery cell assembly along the first direction. The second heating part is used to heat the battery cells in the middle of the battery cell assembly.

[0040] Therefore, the heating of different battery cells on the outermost side of the battery cell assembly along the first direction can be achieved through the first heating part and the third heating part. The second heating part can heat different battery cells on the outermost side of the first direction and can heat the battery cells in the middle. The first heating part, the second heating part and the third heating part can be set as areas with different heat generation according to the temperature changes of the battery cells when affected by the environment, so as to facilitate the adjustment of the temperature of the battery cells at different positions.

[0041] In some embodiments, the second heating element is a straight resistance wire with the same length direction as the first direction. The straight resistance wire has a first connection end and a second connection end. The first connection end is connected in series with the first heating element, and the second connection end is connected in series with the third heating element.

[0042] The second heating element is a straight resistance wire. Compared to the second heating element which is a bent resistance wire, under the premise that the dimensions of the two ends of the heating element along the first direction remain unchanged and the voltage applied to the two ends of the heating element remains unchanged, the straight resistance wire is shorter than the bent heating element, so its resistance is smaller and the current passing through it is larger. This allows the first heating element and the third heating element to generate higher heat, thereby reducing the impact of the low temperature of the external environment on the outermost battery cell of the battery cell assembly.

[0043] In some embodiments, the first heating element and the third heating element each have a first bending portion.

[0044] Therefore, while keeping the dimensions of the first heating element and the third heating element unchanged along the first direction, the extension length of the first heating element and the third heating element can be increased by increasing the number of the first bending parts, thereby increasing the resistance of the first heating element and the third heating element.

[0045] In some embodiments, the second heating element includes a first heating segment, a second heating segment, and a third heating segment. The first heating segment is connected in series at one end of the second heating segment along a first direction, and the third heating segment is connected in series at the other end of the second heating segment along the first direction. The first heating segment and the third heating segment are used to heat the different battery cells on the outermost side of the battery cell assembly along the first direction, and the second heating segment is used to heat the battery cells in the middle of the battery cell assembly.

[0046] Therefore, the first heating segment can be combined with the first heating element, and the third heating segment can be combined with the third heating element to heat different battery cells on the outermost side of the battery cell assembly along the first direction, or the first heating segment can be combined with the third heating element, and the third heating segment can be combined with the first heating element to heat different battery cells on the outermost side of the battery cell assembly along the first direction; by controlling the opening and closing of the switch, the first heating segment and the third heating segment can be made to work or not work at the same time, and the first heating element and the third heating element can be made to work or not work at the same time, so as to more flexibly adjust the temperature of the battery cell assembly.

[0047] In some embodiments, the first heating segment, the second heating segment, and the third heating segment each have a second bending portion.

[0048] Therefore, the overall length of the second heating element can be increased by bending the first, second, and third heating sections to increase the heating area of ​​the battery cell, thereby enabling the battery cell to be heated more evenly.

[0049] In some embodiments, the dimension of the second heating segment along the second direction is D1, the maximum dimension between the second heating segment and the second heating part along the second direction is D2, and the value range of D1 / D2 is 0.1-0.98.

[0050] A value of D1 / D2 = 0.1 is sufficient to meet the heating area requirements of the individual cells in the battery module. As D1 / D2 increases, the heating area of ​​the individual cells in the battery module also increases, and the resistance of the second heating section also increases, which will increase manufacturing costs. In order to balance manufacturing costs and improve the temperature of the individual cells, the value range of D1 / D2 is set to 0.7-0.98.

[0051] In some embodiments, the value of D1 / D2 ranges from 0.7 to 0.95. Considering manufacturing costs and ensuring that the battery cells in the middle of the battery cell assembly can perform well at low temperatures, the value of D1 / D2 is set to 0.7-0.95.

[0052] In some embodiments, the value of D1 ranges from 25mm to 90mm.

[0053] D1 = 25mm, which can basically meet the heating area of ​​the battery cells in the middle of the battery cell assembly. As D1 increases, the heating area of ​​the battery cells also increases. When D1 is too large, it will increase the manufacturing cost. In order to balance manufacturing cost and improve the temperature of the battery cells, the value of D1 is set between 25mm and 90mm. At the same time, it can meet the heating requirements of battery cells of different specifications.

[0054] In some embodiments, the value of D1 ranges from 40mm to 60mm. This can further increase the heat-receiving area of ​​the battery cell and reduce the manufacturing cost of the heat-generating components.

[0055] In some embodiments, there are multiple battery cell assemblies, and each battery cell assembly is provided with a heating element between itself and the bottom wall of the housing.

[0056] Therefore, during the process of heating the battery cells simultaneously, some of the heat is transferred to the bottom wall of the enclosure. The bottom wall of the enclosure can heat multiple battery cells at the same time, so that the multiple battery cells are heated more evenly.

[0057] Secondly, this application provides an electrical device, including the battery device of the first aspect, which is used to provide electrical energy to the electrical device.

[0058] Since the electrical device includes all the technical features of the aforementioned battery device, and its effect is the same as described above, it will not be repeated here.

[0059] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0060] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0061] Figure 1 is an exploded view of a battery cell according to an embodiment of this application;

[0062] Figure 2 is an exploded view of a battery device according to an embodiment of this application;

[0063] Figure 3 is a structural diagram of an electrical device for a vehicle according to an embodiment of this application;

[0064] Figure 4 is an exploded view of a heating component according to an embodiment of this application;

[0065] Figure 5 is a schematic diagram of the structure of a heating element according to an embodiment of this application;

[0066] Figure 6 is an exploded view of another heating component according to an embodiment of this application;

[0067] Figure 7 is a top view of the heating element in Figure 6;

[0068] Figure 8 is a circuit diagram of the current formed by the heating element and the heat-generating element in this application.

[0069] The reference numerals in the detailed embodiments are as follows: 1000, vehicle; 100, battery device; 10, housing; 11, first housing; 12, second housing; 20, battery cell assembly; 21, battery cell; 211, outer casing; 2111, end cap; 21111, electrode terminal; 2112, housing; 212, electrode assembly; 213, pressure relief mechanism; 214, current collector; 30. Heating component; 31. Heating element; 311. First heating element; 312. Second heating element; 313. First heating zone; 3131. First heating part; 3132. First heating segment; 314. Second heating zone; 3141. Second heating part; 3142. Second heating segment; 315. Third heating zone; 3151. Third heating part; 3152. Third heating segment; 32. Protective layer; 321. Reinforcing layer; 322. Insulating film layer; 33. Adhesive layer; 40. Control switch; 50. Fuse; X, First direction; Y, Second direction; Z, Height direction. Detailed Implementation

[0070] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0071] 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 application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0072] In the description of the embodiments of this application, technical terms such as "first" and "second" 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 and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0073] 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 application. 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.

[0074] In the description of the embodiments 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, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0075] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0076] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0077] In the description of the embodiments of this application, 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0078] The battery casing contains multiple battery cells. In low-temperature environments, these cells need to be heated to reduce the impact of low temperatures on their performance. Currently, the heating film used to heat multiple battery cells suffers from poor reliability, leading to significant temperature differences between the cells and affecting their performance.

[0079] In view of this, this application provides a battery device in which a heating element is disposed between the bottom wall of the housing and the battery cell assembly. The protective layer of the heating element protects the heating element and can prevent metal foreign objects from piercing the heating element, thereby reducing the probability of damage to the heating element and improving the reliability of the heating element. In particular, when there are multiple heating elements, it can reduce the probability that metal foreign objects in the housing will pierce some of the heating elements, causing the heating elements to be damaged and unable to work. Thus, multiple heating elements can heat the battery cell assembly at the same time, so that the battery cell assembly is heated evenly.

[0080] Referring to Figure 1, a battery cell 21 generally includes an electrode assembly 212. The electrode assembly 212 includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the negative and positive electrodes. During the charging and discharging process of the battery cell 21, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits between them while allowing active ions to pass through.

[0081] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0082] As an 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.

[0083] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, 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 material 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 material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0084] As an example, 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 application 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 may 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 oxide may 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 Mn 1 / 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.

[0085] 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, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, a positive electrode active material is filled and / or deposited within the foamed metal.

[0086] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0087] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, 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 material substrate 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 material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0088] As an 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.

[0089] As an 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.

[0090] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cell 21. As an example, 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 application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for battery cell 21 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0091] In some embodiments, the negative 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 negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0092] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0093] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0094] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0095] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0096] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0097] In some embodiments, the battery cell 21 also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel-like, or solid.

[0098] Liquid electrolytes include electrolyte salts and solvents.

[0099] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0100] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0101] In some embodiments, the electrolyte may optionally include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell 21, such as additives that improve the overcharge / fast charge performance of the battery cell 21, additives that improve the high-temperature performance of the battery cell 21, additives that improve the low-temperature performance of the battery cell 21, etc.

[0102] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0103] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0104] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0105] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0106] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0107] In some embodiments, the electrode assembly 212 is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0108] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0109] In some embodiments, the electrode assembly 212 may be cylindrical, flat, or polygonal in shape.

[0110] In some embodiments, the electrode assembly 212 is provided with tabs that can conduct current from the electrode assembly 212. The tabs include a positive tab and a negative tab.

[0111] In some embodiments, referring to FIG1, the battery cell 21 may include a casing 211. The casing 211 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.

[0112] In some embodiments, the housing 211 can be a sealed structure or a non-sealed structure. As an example, when the housing 211 is a non-sealed structure, it serves to protect the electrode assembly 212, and a sealing bag is included between the housing 211 and the electrode assembly 212. The sealing bag is used to encapsulate the electrode assembly 212 and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film. When the housing 211 is a sealed structure, it is used to encapsulate the electrode assembly 212 and the electrolyte, among other components.

[0113] As an example, the battery cell 21 can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells. This application does not have any particular limitations.

[0114] In some embodiments, referring to FIG1, the housing 211 includes an end cap 2111 and a housing 2112, the housing 2112 having an opening, and the end cap 2111 covering the opening. The housing 2112 may have one or more openings. The end cap 2111 may also be provided with one or more.

[0115] In some embodiments, referring to FIG1, at least one electrode terminal 21111 is provided on the housing 211, and the electrode terminal 21111 is electrically connected to the electrode tab. The electrode terminal 21111 can be directly connected to the electrode tab, or it can be indirectly connected to the electrode tab through the current collector 214. The electrode terminal 21111 can be provided on the end cover 2111 or on the housing 2112.

[0116] In some embodiments, referring to Figure 1, a pressure relief mechanism 213 is provided on the housing 211. The pressure relief mechanism 213 is used to release the internal gas of the battery cell 21.

[0117] As an example, the internal pressure or temperature of the battery cell 21 is actuated to release the internal pressure or temperature when it reaches a predetermined threshold. When the internal pressure or temperature of the battery cell 21 reaches the predetermined threshold, the pressure relief mechanism 213 is activated or a weak structure in the pressure relief mechanism 213 is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released. The threshold design varies depending on the design requirements. The threshold may depend on the materials of one or more of the positive electrode, negative electrode, electrolyte, and separator in the battery cell 21.

[0118] As an example, the pressure relief mechanism 213 can be integrally formed with the housing 211.

[0119] As an example, the pressure relief mechanism 213 can also be separately configured and connected to the housing 211.

[0120] The term "actuation" as used in this application refers to the pressure relief mechanism 213 being activated or undergoing a certain state, thereby releasing the internal pressure and temperature of the battery cell 21. The actions of the pressure relief mechanism 213 may include, but are not limited to: movement of components within the pressure relief mechanism 213 to form an exhaust channel, rupture, breakage, tearing, or opening of at least a portion of the pressure relief mechanism 213, etc. When the pressure relief mechanism 213 is actuated, the high-temperature, high-pressure substances inside the battery cell 21 are discharged outwards from the actuated portion as waste. This method enables pressure and temperature relief in the battery cell 21 under controllable pressure or temperature conditions, thereby preventing potentially more serious accidents.

[0121] In some embodiments, when the housing 211 is a non-sealed structure, the pressure relief mechanism 213 can be configured as a through hole for discharging gas inside the battery cell 21.

[0122] The emissions from the battery cell 21 mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0123] Referring to Figure 2, the battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies 20 for providing voltage and capacity. The battery cell assembly 20 may include multiple battery cells 21, which are connected in series, parallel, or mixed connection via a busbar.

[0124] In some embodiments, the battery cell assembly 20 is typically formed by arranging a plurality of battery cells 21.

[0125] As an example, the battery cell assembly 20 can be a battery module, which is formed by arranging and fixing multiple battery cells 21 together. As an example, the battery module can be formed by bundling multiple battery cells 21 together with cable ties.

[0126] In some embodiments, the battery device 100 may be a battery pack, which includes a housing 10 and one or more battery cell assemblies 20, the battery cell assemblies 20 being housed within the housing 10.

[0127] As an example, the battery cell assembly 20 can be a battery module, which can be housed in the housing 10 by fixing the battery module in the housing 10.

[0128] As an example, the battery cell assembly 20 can also be housed in the housing 10 by directly fixing multiple battery cells 21 to the housing 10.

[0129] As an example, referring to Figure 2, the housing 10 may include a first housing 11 and a second housing 12. The first housing 11 and the second housing 12 are fastened together to form a closed space inside the housing 10 to house the battery cell assembly 20. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing 11 may be a top cover or a bottom plate.

[0130] As an example, the housing 10 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 10 forms an enclosed space to house the battery cell assembly 20.

[0131] In some embodiments, referring to FIG3, the housing 10 may be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 10 may be at least a portion of the floor of the vehicle 1000, or a portion of the housing 10 may be at least a portion of the crossbeams and longitudinal beams of the vehicle 1000.

[0132] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells 21, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles 1000, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0133] For ease of explanation, the following embodiments are described with reference to Figures 1, 2, and 4-8, using a battery device 100 from some embodiments of this application as an example.

[0134] The battery device 100 includes a housing 10, a battery cell assembly 20, and a heating element 30. The housing 10 has an internal accommodating space. The battery cell assembly 20 is located within this accommodating space and includes multiple battery cells 21 arranged along a first direction X, which intersects the height direction Z of the housing 10. The heating element 30 is located within the accommodating space and is disposed between the battery cell assembly 20 and the bottom wall of the housing 10. The heating element 30 includes a heating element 31 and a protective layer 32. Protective layers 32 are respectively provided on both sides of the heating element 31 along the height direction Z of the housing 10. The protective layers 32 on both sides of the heating element 31 are interconnected and insulated from the heating element 31. The heating element 31 is configured to generate heat when energized and to heat the battery cell assembly 20.

[0135] The number of battery cell modules 20 can be one or more. For example, multiple battery cell modules 20 can be arranged in a roughly rectangular array within the housing 10. They can also be arranged in a straight line, depending on the actual usage requirements.

[0136] The cross-sectional shape of the heating element 31 includes, but is not limited to, a circle, a rectangle, or an ellipse.

[0137] Optionally, the heating component 30 can be fixed to the housing 10 by means of bonding or hot-melt welding. Alternatively, a positioning groove can be provided on the inner surface of the bottom wall of the housing 10 to place the heating component 30 in the positioning groove, so as to reduce the probability of the heating component 30 deviating from the predetermined position during the assembly process.

[0138] The housing 10 can be, but is not limited to, the structures listed in the above embodiments. For example, the first housing 11 can be a structure similar to a tray, and the second housing 12 can be a structure with a top wall and side walls, with the second housing 12 located above the first housing 11, and the first housing 11 and the second housing 12 fastened together. The first housing 11 can also be a structure with a bottom wall and side walls, and the second housing 12 can be a plate-like structure. The side of the second housing 12 facing the first housing 11 can also be provided with a groove structure to accommodate the battery cell 21.

[0139] The heating element 30 is located between the bottom wall of the housing 10 and the battery cell assembly 20. It can transfer heat to the bottom wall of the housing 10 and then transfer it to the battery cell 21 through the bottom wall in the form of thermal radiation. Since the bottom wall covers the battery cell assembly 20, the radiation surface is relatively large, so that multiple battery cells 21 can be heated evenly.

[0140] The protective layer 32 can be one or more layers. For example, the protective layer 32 can be an insulating film layer 322 with insulating function. The protective layer 32 on at least one side of the heating element 31 can also be at least two layers, providing at least two layers of protection for the heating element 31. This can prevent metal foreign objects from piercing the heating element 30, thereby reducing the probability of damage to the heating element 31 and improving the reliability of the heating element 30. Especially when there are multiple heating elements 30, it can reduce the probability that metal foreign objects in the housing 10 will pierce some of the heating elements 30, causing damage and failure of the heating elements 30. This allows multiple heating elements 30 to heat the battery cell assembly 20 simultaneously, making the battery cell assembly 20 more evenly heated.

[0141] In some embodiments, the protective layer 32 of the heating element 31 facing the bottom wall of the housing 10 has at least two layers.

[0142] The protective layer 32 of the heating element 31 facing away from the housing 10 can be one layer or two or more layers.

[0143] When the protective layer 32 is multi-layered, the materials of the multiple protective layers 32 can be the same or different.

[0144] This provides multiple layers of protection, reducing the probability of metal foreign objects on the bottom wall of the housing 10 piercing the heating element 30, thereby improving the reliability of the heating element 30.

[0145] In some embodiments, referring to Figures 4 and 6, the protective layer 32 having at least two layers includes an insulating film layer 322 and a reinforcing layer 321. The reinforcing layer 321 is located on the side of the insulating film layer 322 opposite to the heat-generating element 31, and the reinforcing layer 321 is connected to the insulating film layer 322.

[0146] The insulating film layer 322 includes, but is not limited to, any one of the following: polyimide film layer, polyvinyl fluoride film layer, polyamide film layer, polyphenylene ether film layer, silicon oxide layer, silicon nitride layer, or aluminum nitride layer.

[0147] As an example, along the height direction Z of the housing 10, both the protective layer 32 of the heating element 31 facing the bottom wall of the housing 10 and the protective layer 32 of the heating element 31 away from the bottom wall of the housing 10 can include an insulating film layer 322 and a reinforcing layer 321. On the same side of the heating element 31 along the height direction Z of the housing 10, the reinforcing layer 321 is located on the side of the insulating film layer 322 away from the heating element 31. The insulating film layer 322 is fixed to the heating element 31 by adhesive bonding to initially fix the heating element 13. The reinforcing layers 321 on both sides of the heating element 31 can be connected by hot-melt welding to form an integral structure.

[0148] The insulating film layers 322 on both sides of the heating element 31 can be made of the same material or different materials.

[0149] When there is a metal foreign object on the bottom wall of the housing 10, the reinforcing layer 321 serves as the first layer of protection to prevent the metal foreign object from penetrating into the heating element 30. When the first layer of protection fails, the insulating film layer 322 can further prevent the metal foreign object from piercing the heating element 31, thereby improving the reliability of the heating element 30.

[0150] In some embodiments, the reinforcing layer 321 includes any one of an epoxy resin layer, a ceramic composite layer, a nylon-polyester resin composite insulating film layer, or a polyurea coating.

[0151] Ceramic composite layers include, but are not limited to, ceramic silicone layers or ceramic polymer coatings.

[0152] This improves the resistance of the heating element 30 to metal puncture, thereby enhancing the reliability of the heating element 30 in operation.

[0153] In some embodiments, the thickness of the reinforcing layer 321 is S, and the value of S ranges from 0.1 mm to 0.5 mm.

[0154] The reinforcing layer 321, with a thickness of S = 0.1 mm, can essentially prevent metallic foreign objects from piercing the heating element 31. As S increases, it becomes more difficult for metallic foreign objects to pierce the heating element 31, thus increasing the reliability of the heating element 30. However, the reinforcing layer 321 occupies a significant amount of space in the housing 10, affecting the capacity of the battery device 100. Therefore, considering both the puncture resistance of the reinforcing layer 321 and the space occupied by it, the value of S is set to a range of 0.1 mm to 0.5 mm.

[0155] In some embodiments, the value of S ranges from 0.15mm to 0.25mm.

[0156] S = 0.15mm, which can further improve the ability of the reinforcing layer 321 to prevent metal foreign objects from piercing the heating element 31. While taking into account the space occupied by the reinforcing layer 321, the value of S is set to 0.15mm-0.25mm. On the one hand, this can reduce the impact on the capacity of the battery device 100, and on the other hand, it can meet the requirement of the reinforcing layer 321 to resist the piercing of metal foreign objects.

[0157] In some embodiments, referring to Figures 4 and 6, the heating component 30 further includes an adhesive layer 33, which is located on the side of the reinforcing layer 321 away from the insulating layer, and the reinforcing layer 321 is bonded to the bottom wall of the housing 10 through the adhesive layer 33.

[0158] The adhesive layer 33 can be a double-sided adhesive layer, or it can be formed by applying adhesive to the outer surface of the reinforcing layer 321 and allowing it to solidify.

[0159] The adhesive layer 33 can be a thermally conductive adhesive layer. That is, the reinforcing layer 321 is bonded to the bottom wall of the housing 10 by a thermally conductive adhesive. The adhesive solidifies to form an adhesive layer, so that some heat can be transferred to the bottom wall of the housing 10 through the heating element, and then transferred to the battery cell assembly 20 through the bottom wall of the housing 10.

[0160] Therefore, the probability of the heating component 30 deviating from the predetermined position can be reduced during installation and operation, thereby enabling the heating component 30 to heat the battery cell assembly 20 at the predetermined position, so as to improve the uneven heating of the battery cell assembly 20 caused by deviation from the predetermined position.

[0161] In some embodiments, the battery device 100 further includes a structural adhesive layer located within the receiving space and disposed between the battery cell assembly 20 and the bottom wall of the housing 10. The battery cell assembly 20 is bonded to the bottom wall of the housing 10 through the structural adhesive layer, and the heating component 30 is located within the structural adhesive layer.

[0162] As an example, the reinforcing layer 321 is bonded to the bottom wall of the housing 10 through the adhesive layer 33, and then glue is poured into the bottom wall of the housing 10. The glue can be an adhesive with insulating properties. The electrode unit assembly 20 is fixed by the glue, and the heating component 30 is immersed in the glue. After the glue solidifies, a structural adhesive layer is formed.

[0163] The structural adhesive layer can fix the heating component 30 and the battery cell assembly 20 to the bottom wall of the housing 10, so that the battery cell assembly 20 will not shake inside the housing 10 during operation, thereby improving the reliability and safety of the battery cell assembly 20. In addition, the structural adhesive layer can position the heating component 30 at a predetermined position on the bottom wall of the housing 10, so that the heating component 30 heats the battery cell 21 at the predetermined position, thereby improving the uneven heating caused by the battery cell assembly 20 deviating from the predetermined position.

[0164] In some embodiments, referring to Figures 5 and 7, the heating element 31 has a first heating region 313, a second heating region 314, and a third heating region 315. The second heating region 314 has the first heating region 313 on one side along the first direction X, and the second heating region 314 has the third heating region 315 on the other side along the first direction X. The first heating region 313 and the third heating region 315 are respectively used to heat different battery cells 21 on the outermost side along the first direction X. The size of the first heating region 313 along the first direction X is L1, the size of the second heating region 314 along the first direction X is L2, and the size of the third heating region 315 along the first direction X is L3. The resistance of the first heating region 313 is R1, the resistance of the second heating region 314 is R2, and the resistance of the third heating region 315 is R3. R2 / L2 < R1 / L1, R2 / L2 < R3 / L3.

[0165] Without changing the material and cross-section of the first heating zone 313, the second heating zone 314, and the third heating zone 315, the number of bends in the first heating zone 313 and the third heating zone 315 can be increased. That is, the heating element 31 of the first heating zone 313 and the third heating zone 315 is coiled more densely than that of the second heating zone 314. This makes the resistance of the first heating zone 313 and the third heating zone 315 per unit length along the first direction X greater than the resistance of the second heating zone 314 per unit length along the first direction X. As a result, under the same current, the first heating zone 313 and the third heating zone 315 generate more heat per unit length in the first direction X, thereby reducing the impact of the external ambient temperature on the battery cells 21 at both ends. Alternatively, the first heating zone 313 and the third heating zone 315 can be made of materials with a higher resistivity than the second heating zone 314, so that the resistance of the first heating zone 313 and the third heating zone 315 per unit length along the first direction X is greater than the resistance of the second heating zone 314 per unit length along the first direction X. As a result, under the same current, the first heating zone 313 and the third heating zone 315 generate more heat per unit length in the first direction X.

[0166] When the ambient temperature is low, the battery cell 21 closest to the side wall of the housing 10 is more affected by the ambient temperature and has a lower temperature. R2 / L2 is set to be less than R1 / L1 and R2 / L2 is less than R3 / L3. Under the unit length of the heating element 31 along the first direction X, the heat generated by the first heating zone 313 and the third heating zone 315 of the heating element 31 is greater than the heat generated by the second heating zone 314, so as to improve the situation of the battery cells 21 at both ends of the battery cell assembly 20 having too low a temperature.

[0167] In some embodiments, referring to Figures 5 and 7, the first heating region 313, the second heating region 314, and the third heating region 315 each have a bent portion. The length of the first heating region 313 is L4 along the extending direction of the first heating region 313, the length of the second heating region 314 is L5 along the extending direction of the second heating region 314, and the length of the third heating region 315 is L6 along the extending direction of the third heating region 315. L4 / L1 > L5 / L2, and L6 / L3 > L5 / L2.

[0168] The bent part refers to the bent portion of the heating element 31.

[0169] L4 is the length of the first heating zone 313 when unfolded into a straight line, L5 is the length of the second heating zone 314 when unfolded into a straight line, and L6 is the length of the third heating zone 315 when unfolded into a straight line.

[0170] Therefore, under the premise that the cross-sections and materials of the first heating zone 313, the second heating zone 314 and the third heating zone 315 remain unchanged, L4 / L1>L5 / L2 and L6 / L3>L5 / L2, the resistance of the heating element 31 per unit length along the first direction X in the first heating zone 313 and the third heating zone 315 can be increased. Under the premise that the current remains unchanged, the heating element 31 can generate more heat per unit length along the first direction X in the first heating zone 313 and the third heating zone 315, thereby improving the situation of the battery cells 21 at both ends being too low in temperature.

[0171] In some embodiments, please refer to FIG5, the number of heating elements 31 is one, and the heating element 31 has three heating sections connected in series. One heating section is located in the second heating zone 314, and the other two heating sections are located in the first heating zone 313 and the third heating zone 315 respectively.

[0172] As shown in Figure 5, the three heating sections corresponding to the three heating zones in the heating element are connected in series to form a resistance wire or resistance sheet. The resistance wire or resistance sheet in the three heating sections is formed by bending and coiling.

[0173] The three heating sections can all be configured to have bent portions, or the first heating zone 313 and the third heating zone 315 can be configured to have bent portions, while the second heating zone 314 can be configured as a straight heating wire. When using a material with high resistivity, the heating sections can be omitted, and all three heating sections can be straight heating wires.

[0174] The resistivity of the heating element 31 can be set to a range of 0.07 Ωmm. 2 / m-50Ωmm 2 / m. The high resistivity of the heating element 31 reduces the number of bends.

[0175] Therefore, compared with setting multiple heating elements 31, the structure of the heating element 31 can be simplified, thus saving costs.

[0176] In some embodiments, the material of the heating element 31 includes, but is not limited to, any one of stainless steel, copper-manganese alloy, tungsten-molybdenum alloy, iron-chromium-aluminum alloy, iron-nickel-aluminum alloy, nickel-chromium-aluminum alloy, nickel-chromium alloy, nickel-molybdenum-aluminum alloy, iron-nickel-chromium-molybdenum-copper alloy, gold-nickel-copper alloy, gold-nickel-chromium alloy, and gold-palladium-iron-aluminum alloy.

[0177] In some embodiments, referring to Figures 7 and 8, the heating component 30 includes at least two parallel heating elements 31, which are configured to heat the battery cell assembly 20 individually or simultaneously.

[0178] When the length of the battery cell 21 in the battery cell assembly 20 is large, such as a blade battery cell 21, the heating area of ​​the battery cell assembly 20 is large. When using two parallel heating elements 31, the coiled length of the heating element 31 is large, which is difficult to manufacture. Moreover, if the heating element 31 is damaged, heating of the entire battery cell assembly 20 will stop. In this case, it is possible to set more than three parallel heating elements 31 in the heating element 30. The specific number of heating elements 31 can be determined according to the length of a single battery cell 21 in the blade battery cell assembly 20. This improves the reliability of the heating element 30 during operation, facilitates the manufacturing of the heating element 30, and allows for convenient adjustment of the local temperature of the battery cell assembly 20. Using at least two parallel heating elements 31 makes heating the battery cell assembly 20 more flexible. When the length of the battery cell 21 in the battery cell assembly 20 is small, two parallel heating elements 31 can be set so that one or two heating elements 31 can be selectively operated during the heating process according to the ambient temperature.

[0179] The effects of external ambient temperature changes on the battery cell assembly 20 within the battery device 100 vary. By setting up two parallel heating elements 31, the operation of at least two heating elements 31 can be controlled individually or simultaneously according to the influence of the external environment on the battery cell assembly 20. The temperature of the battery cell 21 can be adjusted according to the temperature changes of the external environment, thereby reducing excessive power consumption by the heating elements 31 and improving the battery device 100's range.

[0180] In some embodiments, referring to Figures 7 and 8, the battery device 100 further includes a control switch 40, each heating element 31 is connected in series with the control switch 40 to form a parallel branch, each parallel branch is connected in parallel, and the battery cell 21 is used to supply power to the parallel branch.

[0181] As an example, the battery device 100 also includes a fuse 50 connected in series with multiple parallel branches, and the battery cell 21 supplies power to the parallel branches as a power source.

[0182] The control switch 40 includes, but is not limited to, relays, ordinary switches, push-button switches, rotary switches, or smart switches. The control switch 40 can be determined based on the specific operating environment of the battery device 100. For example, if the battery device 100 is used in a vehicle, the control switch 40 can be a relay, and the control unit of the battery device 100 can control the opening and closing of the relay based on the difference between the external environment and the internal environment of the battery device 100. For example, if overheating occurs during the heating process of the battery device 100, it can be shut off manually by operating the control switch 40.

[0183] Therefore, by controlling the opening and closing of the switch 40 according to the external ambient temperature, each parallel branch can be operated or shut down individually, thereby enabling more flexible adjustment of the temperature of the battery cell 21 to reduce the impact of low temperature on the battery cell 21 and save energy.

[0184] In some embodiments, referring to Figures 7 and 8, there are two heating elements 31. One heating element 31 is a first heating element 311, and the other heating element 31 is a second heating element 312. The first heating element 311 is located on one side of the second heating element 312 along the second direction Y. At least a portion of the first heating element 311 and at least a portion of the second heating element 312 are used to heat the outermost battery cell 21 in the battery cell assembly 20 along the first direction X. The second direction Y intersects the first direction X and the height direction Z of the housing 10.

[0185] One of the first heating element 311 and the second heating element 312 can be a main heating wire, and the other can be an auxiliary heating wire. That is, during the heating process, the main heating wire plays a primary heating role, while the auxiliary heating wire plays an auxiliary heating role. The heat output of the main heating wire during operation can be set to be greater than that of the auxiliary heating wire. The auxiliary heating wire can assist in heating the outermost battery cell 21 along the first direction X in the battery cell assembly 20 during the heating process. When the external ambient temperature is too low, the auxiliary heating wire operates to reduce the heat loss of the outermost battery cell 21, thereby reducing the difference in operating temperature between the outermost battery cell 21 and the middle battery cell 21. When the external ambient temperature is not particularly low, the heat loss of the outermost battery cell 21 is small, and in this case, the auxiliary heating wire can be turned off, while the main heating wire operates. When the external ambient temperature is high, for example, if the battery device 100 is used in a vehicle, both the main heating wire and the auxiliary heating wire can be turned off during summer driving.

[0186] Therefore, the battery cells 21 at both ends along the first direction X in the battery cell assembly 20 can be heated simultaneously or individually by two heating elements 31, so as to switch according to the changes in the external environment. In particular, when the temperature of the external environment is not too low, one heating element 31 can be turned on to save energy and thus improve the battery life of the battery device 100.

[0187] In some embodiments, the number of battery cells 21 in the battery cell assembly 20 is three or more. The first heating element 311 includes a first heating part 3131, a second heating part 3141 and a third heating part 3151. The second heating part 3141 is connected in series with the first heating part 3131 on one side along the first direction X, and the second heating part 3141 is connected in series with the third heating part 3151 on the other side along the first direction X. The first heating part 3131 and the third heating part 3151 are respectively used to heat different battery cells 21 on the outermost side along the first direction X in the battery cell assembly 20, and the second heating part 3141 is used to heat the battery cells 21 in the middle of the battery cell assembly 20.

[0188] The battery cell 21 in the middle of the battery cell assembly 20 refers to the battery cell 21 between the two outermost battery cells 21 along the first direction X in the battery cell assembly 20.

[0189] As an example, the first heating element 3131 is located in the first heating region, the second heating element 3141 is located in the second heating region, and the third heating element 3151 is located in the third heating region. The first heating element 3131 and the third heating element 3151 each have a bent portion, allowing them to be coiled longer within a limited area to obtain higher heat while maintaining a constant current, thereby improving the low temperature condition of the two outermost battery cells 21 of the battery cell assembly 20 along the first direction X. The second heating element 3141 can be configured as a resistance wire with a bent portion or as a straight resistance wire.

[0190] As an example, the ratio of the length of the heating element 31 of the first heating part 3131 to the dimension of the first heating part 3131 along the first direction X is P1, the ratio of the length of the heating element 31 of the second heating part 3141 to the dimension of the second heating part 3141 along the first direction X is P2, and the ratio of the length of the heating element 31 of the third heating part 3151 to the dimension of the third heating part 3151 along the first direction X is P3, wherein P1 is greater than P2 and P3 is greater than P2.

[0191] Therefore, the first heating part 3131 and the third heating part 3151 can be used to heat the different battery cells 21 on the outermost side of the battery cell assembly 20 along the first direction X. The second heating part 3141 can heat the different battery cells 21 on the outermost side of the first direction X. The second heating part 3141 can heat the battery cells 21 in the middle. According to the temperature change of the battery cells 21 when affected by the environment, the first heating part 3131, the second heating part 3141 and the third heating part 3151 can be set into areas with different heat generation, so as to facilitate the adjustment of the temperature of the battery cells 21 at different positions.

[0192] In some embodiments, please refer to FIG7, the second heating element 3141 is a straight resistance wire, the length direction of the straight resistance wire is the same as the first direction X, the straight resistance wire has a first connection end and a second connection end, the first connection end is connected in series with the first heating element 3131, and the second connection end is connected in series with the third heating element 3151.

[0193] A straight resistance wire refers to a resistance wire that extends in a straight line.

[0194] The first connecting section and the first heating element 3131 can be connected by welding or integral molding, and the second connecting section and the third heating element 3151 can be connected by welding or integral molding.

[0195] The second heating element 3141 is a straight resistance wire. Compared with the second heating element 3141 being a bent resistance wire, under the premise that the dimensions of the two ends of the heating element 31 along the first direction X remain unchanged and the voltage applied to the two ends of the heating element 31 remains unchanged, the straight resistance wire has a smaller resistance value and a larger current passing through it, which enables the first heating element 3131 and the third heating element 3151 to generate higher heat. This reduces the impact of the low temperature of the external environment on the outermost battery cell 21 of the battery cell assembly 20.

[0196] In some embodiments, referring to Figures 5 and 7, the first heating part 3131 and the third heating part 3151 each have a first bending part.

[0197] Therefore, while keeping the dimensions of the first heating part 3131 and the third heating part 3151 unchanged along the first direction X, the extension length of the first heating part 3131 and the third heating part 3151 can be increased by increasing the number of bending parts, thereby increasing the resistance of the first heating part 3131 and the third heating part 3151.

[0198] In some embodiments, referring to FIG7, the second heating element 312 includes a first heating segment 3132, a second heating segment 3142 and a third heating segment 3152. The first heating segment 3132 is connected in series at one end of the second heating segment 3142 along the first direction X, and the third heating segment 3152 is connected in series at the other end of the second heating segment 3142 along the first direction X. The first heating segment 3132 and the third heating segment 3152 are used to heat the different battery cells 21 on the outermost side of the battery cell assembly 20 along the first direction X, and the second heating segment 3142 is used to heat the battery cells 21 in the middle of the battery cell assembly 20.

[0199] The connection between the second heating segment 3142 and the first heating segment 3132 and the third heating segment 3152 can be either welded or integrally formed.

[0200] As an example, the first heating segment 3132 is located in the first heating zone, the second heating segment 3142 is located in the second heating zone, and the third heating segment 3152 is located in the third heating zone.

[0201] The first heating segment 3132, the second heating segment 3142, and the third heating segment 3152 can all be straight resistance wires. Alternatively, at least one of the three heating segments 3132, 3142, and 3152 can be configured as a heating element 31 with a bent portion. For example, the first heating segment 3132, the second heating segment 3142, and the third heating segment 3152 can all be straight resistance wires, and each of the three heating segments 3132, 3142, and 3152 includes multiple parallel straight resistance wires, i.e., three parallel straight resistance wires connected in series. In this case, a material with a high resistivity, such as a resistivity greater than 1 Ωmm, can be used. 2 / m of conductive material. When the resistivity is less than 1Ω / mm². 2 / m and greater than 0.07Ωmm 2 When using materials of / m, the first heating section 3132, the second heating section 3142 and the third heating section 3152 can be configured as heating elements 31 with multiple bends. By increasing the number of bends, the heating area of ​​the first heating section 3132, the second heating section 3142 and the third heating section 3152 can be increased.

[0202] As an example, the ratio of the length of the heating element 31 of the first heating segment 3132 to the dimension of the first heating segment 3132 along the first direction X is Q1, the ratio of the length of the heating element 31 of the second heating segment 3142 to the dimension of the second heating segment 3142 along the first direction X is Q2, and the ratio of the length of the heating element 31 of the third heating segment 3152 to the dimension of the third heating segment 3152 along the first direction X is Q3, wherein Q1 is greater than Q2 and Q3 is greater than Q2.

[0203] Therefore, the first heating segment 3132 can be combined with the first heating element 3131, and the third heating segment 3152 can be combined with the third heating element 3151 to heat different battery cells 21 on the outermost side of the battery cell assembly 20 along the first direction X. Alternatively, the first heating segment 3132 can be combined with the third heating element 3151, and the third heating segment 3152 can be combined with the first heating element 3131 to heat different battery cells 21 on the outermost side of the battery cell assembly 20 along the first direction X. By controlling the opening and closing of the switch 40, the first heating segment 3132 and the third heating segment 3152 can be made to work or not work at the same time, and the first heating element 3131 and the third heating element 3151 can be made to work or not work at the same time, so that the temperature of the battery cell assembly 20 can be adjusted more flexibly.

[0204] In some embodiments, the first heating segment 3132, the second heating segment 3142 and the third heating segment 3152 each have a second bending portion.

[0205] Therefore, the overall length of the second heating element 312 can be increased by bending the first heating section 3132, the second heating section 3142 and the third heating section 3152, so as to increase the heating area of ​​the battery cell 21 and make the battery cell 21 heat up more evenly.

[0206] In some embodiments, referring to FIG7, the dimension of the second heating segment 3142 along the second direction Y is D1, the maximum dimension between the second heating segment 3142 and the second heating part 3141 along the second direction Y is D2, and the value range of D1 / D2 is 0.1-0.98.

[0207] D1 / D2 = 0.1, which can basically meet the heating area of ​​the battery cell 21 in the middle of the battery cell assembly 20. As D1 / D2 increases, the heating area of ​​the battery cell 21 in the middle of the battery cell assembly 20 also increases, which will also increase the manufacturing cost. In order to balance the manufacturing cost and improve the temperature of the battery cell 21, the value range of D1 / D2 is set to 0.1-0.98.

[0208] In some embodiments, referring to Figure 7, the value range of D1 / D2 is 0.7-0.95. Considering manufacturing costs and ensuring that the battery cell 21 in the middle of the battery cell assembly 20 can perform well at low temperatures, the value range of D1 / D2 is set to 0.7-0.95.

[0209] In some embodiments, please refer to Figure 7, where the value of D1 ranges from 25mm to 90mm.

[0210] D1 = 25mm, which can basically meet the heating area of ​​the battery cell 21 in the middle of the battery cell assembly 20. As D1 increases, the heating area of ​​the battery cell 21 also increases. When D1 is too large, it will increase the manufacturing cost. In order to balance the manufacturing cost and improve the temperature of the battery cell 21, the value of D1 is set between 25mm and 90mm. At the same time, it can meet the heating requirements of battery cells 21 of different specifications.

[0211] In some embodiments, referring to Figure 7, the value of D1 ranges from 40mm to 60mm. This further increases the heat-receiving area of ​​the battery cell 21 and reduces the manufacturing cost of the heat-generating components.

[0212] In some embodiments, please refer to FIG2, there are multiple battery cell assemblies 20, and each battery cell assembly 20 is provided with a heating element 30 between it and the bottom wall of the housing 10.

[0213] For example, multiple battery cell modules 20 can be arranged along the first direction X, or multiple battery cell modules 20 can be arranged in a rectangular array, depending on the space of the housing 10 and the capacity requirements of the battery device 100.

[0214] Therefore, during the process of heating the battery cell assembly 20 while the heating component 30 is working simultaneously, some of the heat is transferred to the bottom wall of the housing 10. The bottom wall of the housing 10 can heat multiple battery cell assemblies 20 at the same time, so that the multiple battery cell assemblies 20 are heated more evenly.

[0215] In some embodiments, the bottom wall of the housing 10 may be made of metal, for example, aluminum alloy or steel.

[0216] For ease of explanation, the following embodiments use the electrical device of this application as an example.

[0217] The electrical device includes the battery device 100 of the above embodiments. The battery device 100 is used to provide electrical energy to the electrical device. The electrical device can be, but is not limited to, the examples listed above.

[0218] Since the electrical device includes all the technical features of the battery device 100 described above, and its effect is the same as described above, it will not be repeated here.

[0219] In a first optional embodiment of the battery device 100, referring to Figures 2, 4, and 6, the battery device 100 includes a housing 10, a battery cell assembly 20, and a heating element 30. The housing 10 has an internal accommodating space. The battery cell assembly 20 is located within this accommodating space and includes multiple battery cells 21 arranged along a first direction X, which intersects the height direction Z of the housing 10. The heating element 30 is located within the accommodating space and is disposed between the battery cell assembly 20 and the bottom wall of the housing 10. The heating element 30 includes a heating element 31 and a protective layer 32. Protective layers 32 are respectively provided on both sides of the heating element 31 along the height direction Z of the housing 10. The protective layers 32 on both sides of the heating element 31 are interconnected, thermally connected to the heating element 31, and insulated. Each protective layer 32 on both sides of the heating element 31 is a double layer. The heating element 31 is used to heat the battery cell assembly 20. The protective layer 32 includes a reinforcing layer 321 and an insulating film layer 322. Along the height Z direction of the housing 10, reinforcing layers 321 are provided on both sides of the heating element 31. An insulating film layer 322 is provided between the reinforcing layer 321 and the heating element 31, and the insulating film layer 322 is thermally connected to the heating element 31. The reinforcing layer 321 can be, but is not limited to, an epoxy resin layer. The thickness of the reinforcing layer 321 is S, and the value of S ranges from 0.1mm to 0.5mm. The heating element 30 also includes an adhesive layer 33, which is located on the side of the reinforcing layer 321 away from the insulating layer. The reinforcing layer 321 is bonded to the bottom wall of the housing 10 through the adhesive layer 33.

[0220] In this embodiment, the protective layer 32 reduces the probability of the heating element 31 being damaged due to puncture of the heating element 30, thereby improving the reliability of the heating element 30. Especially when there are multiple battery cell assemblies 20, each battery cell assembly 20 has a heating element 30 at its bottom, which reduces the probability of some of the multiple heating elements 30 being damaged. This allows multiple heating elements 30 to heat multiple battery cell assemblies 20 simultaneously, making the battery cell assemblies 20 more evenly heated. In addition, multiple heating elements 30 transfer some heat to the bottom wall of the housing 10. Since the bottom wall has a large area, it transfers heat to multiple battery cell assemblies 20 by thermal radiation, which makes the multiple battery cell assemblies 20 more evenly heated.

[0221] In a second optional embodiment of the battery device 100, referring to Figures 2 and 4-7, the battery device 100 includes a housing 10, a battery cell assembly 20, and a heating element 30. The housing 10 has an internal accommodating space. The battery cell assembly 20 is located within this accommodating space and includes multiple battery cells 21 arranged along a first direction X, which intersects the height direction Z of the housing 10. The heating element 30 is located within the accommodating space and is disposed between the battery cell assembly 20 and the bottom wall of the housing 10. The heating element 30 includes a heating element 31 and a protective layer 32. Protective layers 32 are respectively provided on both sides of the heating element 31 along the height direction Z of the housing 10. The protective layers 32 on both sides of the heating element 31 are interconnected, and are thermally conductively connected to and insulated from the heating element 31. At least one side of the heating element 31 has at least two protective layers 32. The heating element 31 is used to heat the battery cell assembly 20. The heating element 31 has a first heating zone 313, a second heating zone 314, and a third heating zone 315. The second heating zone 314 has the first heating zone 313 on one side along the first direction X, and the second heating zone 314 has the third heating zone 315 on the other side along the first direction X. The first heating zone 313 and the third heating zone 315 are used to heat different battery cells 21 on the outermost side along the first direction X. The first heating zone 313 has a dimension of L1 along the first direction X, the second heating zone 314 has a dimension of L2 along the first direction X, and the third heating zone 315 has a dimension of L3 along the first direction X. The resistance of the first heating zone 313 is R1, the resistance of the second heating zone 314 is R2, and the resistance of the third heating zone 315 is R3. R2 / L2 < R1 / L1, R2 / L2 < R3 / L3. The first heating zone 313, the second heating zone 314 and the third heating zone 315 each have a bent portion. The length of the first heating zone 313 is L4 along the extending direction of the first heating zone 313, the length of the second heating zone 314 is L5 along the extending direction of the second heating zone 314, and the length of the third heating zone 315 is L6 along the extending direction of the third heating zone 315. L4 / L1 > L5 / L2, and L6 / L3 > L5 / L2.

[0222] In this embodiment, with the cross-sections and materials of the first heating zone 313, the second heating zone 314, and the third heating zone 315 remaining unchanged, L4 / L1 > L5 / L2 and L6 / L3 > L5 / L2. This increases the resistance per unit length of the heating element 31 in the first heating zone 313 and the third heating zone 315 along the first direction X. Under the premise of constant current, this makes the heating element 31 generate more heat per unit length in the first heating zone 313 and the third heating zone 315 along the first direction X, thereby improving the situation where the temperature of the battery cells 21 at both ends is too low, reducing the temperature difference during the heating process of different battery cells 21, and thus reducing the impact of low temperature on the performance of the battery cells 21.

[0223] In a third optional embodiment of the battery device 100, referring to Figures 2, 4, and 5, the battery device 100 includes all the features of the second optional embodiment. The number of heating elements 31 is one, and each heating element 31 has three heating sections connected in series. One heating section is located in the second heating zone 314, and the other two heating sections are located one-to-one in the first heating zone 313 and the third heating zone 315. Each heating section has multiple bends.

[0224] In the fourth optional embodiment of the battery device 100, referring to Figures 2 and 6-8, the battery device 100 includes all the features of the second optional embodiment. The heating component 30 includes two parallel heating elements 31, which are configured to heat the battery cell assembly 20 individually or simultaneously. The battery device 100 also includes a control switch 40. Each heating element 31 is connected in series with the control switch 40 to form a parallel branch. Each parallel branch is connected in parallel, and the battery cell 21 is used to supply power to the parallel branch. One heating element 31 is a first heating element 311, and the other heating element 31 is a second heating element 312. The first heating element 311 is located on one side of the second heating element 312 along the second direction Y. At least a portion of the first heating element 311 and at least a portion of the second heating element 312 are used to heat the outermost battery cell 21 in the battery cell assembly 20 along the first direction X. The second direction Y intersects the first direction X and the height direction Z of the housing 10. The battery cell assembly 20 contains three or more battery cells 21. The first heating element 311 includes a first heating section 3131, a second heating section 3141, and a third heating section 3151. The second heating section 3141 is connected in series with the first heating section 3131 on one side along the first direction X, and the second heating section 3141 is connected in series with the third heating section 3151 on the other side along the first direction X. The first heating section 3131 and the third heating section 3151 are used to heat different battery cells 21 on the outermost side along the first direction X in the battery cell assembly 20, respectively. The second heating section 3141 is used to heat the battery cells 21 in the middle of the battery cell assembly 20. The first heating section 3131 and the first heating segment 3132 form a first heating zone, the second heating section 3141 and the second heating segment 3142 form a second heating zone, and the third heating section 3151 and the third heating segment 3152 form a third heating zone. The second heating element 3141 is a straight resistance wire, the length of which is in the same direction as the first direction X. The straight resistance wire has a first connecting end and a second connecting end. The first connecting end is connected in series with the first heating element 3131, and the second connecting end is connected in series with the third heating element 3151. The first heating element 3131 and the third heating element 3151 each have a bent portion. The first heating segment 3132, the second heating segment 3142, and the third heating segment 3152 each have a bent portion. The dimension of the second heating segment 3142 along the second direction Y is D1, and the maximum dimension between the second heating segment 3142 and the second heating element 3141 along the second direction Y is D2. The value range of D1 / D2 is 0.7-0.95. The value range of D1 is 25mm-90mm.

[0225] In this embodiment, two parallel heating elements 31 are used, and their operation is controlled by a control switch 40. This allows for more flexible adjustment of the heating temperature of multiple battery cells 21, especially when the external ambient temperature changes. Based on these changes, the two control switches 40 can be used to control the operation of the two heating elements 31 simultaneously, individually, or without operation. For example, in high summer temperatures, the two heating elements 31 are not operating; at lower temperatures, the second heating element 312 can be controlled to operate; and in extremely low temperatures, such as in frigid winter regions, both heating elements 31 can be controlled to operate simultaneously. The specific on / off state of the two heating elements 31 can be set according to the ambient temperature and the temperature tolerance of the battery cells 21.

[0226] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application 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 application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. 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, wherein, include: A housing, the interior of which has a storage space; A battery cell assembly is located within the accommodating space. The battery cell assembly includes a plurality of battery cells arranged along a first direction, which intersects the height direction of the housing. A heating element is located within the accommodating space and disposed between the battery cell assembly and the bottom wall of the housing. The heating element includes a heating element and a protective layer. The protective layer is provided on both sides of the heating element along the height direction of the housing. The protective layers on both sides of the heating element are connected to each other. The protective layer is insulated from the heating element. The heating element is configured to generate heat when energized and to heat the battery cell.

2. The battery device according to claim 1, wherein, The protective layer of the heating element facing the bottom wall of the housing consists of at least two layers.

3. The battery device according to claim 2, wherein, The protective layer having at least two layers includes: Insulating film layer; A reinforcing layer is located on the side of the insulating film layer opposite to the heating element, and the reinforcing layer is connected to the insulating film layer.

4. The battery device according to claim 3, wherein, The reinforcing layer includes any one of an epoxy resin layer, a ceramic composite layer, a nylon-polyester resin composite insulating film layer, or a polyurea coating.

5. The battery device according to claim 3 or 4, wherein, The thickness of the reinforcing layer is S, and the value of S ranges from 0.1 mm to 0.5 mm.

6. The battery device according to claim 5, wherein, The value of S ranges from 0.15mm to 0.25mm.

7. The battery device according to any one of claims 3-5, wherein, The heating component also includes an adhesive layer located on the side of the reinforcing layer opposite to the insulating layer, and the reinforcing layer is bonded to the bottom wall of the housing through the adhesive layer.

8. The battery device according to any one of claims 3-7, wherein, The battery device further includes a structural adhesive layer located within the accommodating space and between the battery cell assembly and the bottom wall of the housing. The battery cell assembly is bonded to the bottom wall of the housing via the structural adhesive layer, and the heating element is located within the structural adhesive layer.

9. The battery device according to any one of claims 1-8, wherein, The heating element has a first heating zone, a second heating zone, and a third heating zone. The first heating zone is located on one side of the second heating zone along the first direction, and the third heating zone is located on the other side of the second heating zone along the first direction. The first heating zone and the third heating zone are respectively used to heat different battery cells on the outermost side along the first direction. The dimension of the first heating zone along the first direction is L1, the dimension of the second heating zone along the first direction is L2, and the dimension of the third heating zone along the first direction is L3. The resistance of the first heating zone is R1, the resistance of the second heating zone is R2, and the resistance of the third heating zone is R3. R2 / L2 < R1 / L1, R2 / L2 < R3 / L3.

10. The battery device according to claim 9, wherein, The first heating zone, the second heating zone, and the third heating zone each have a bent portion. The length of the first heating zone is L4 along the extending direction of the first heating zone, the length of the second heating zone is L5 along the extending direction of the second heating zone, and the length of the third heating zone is L6 along the extending direction of the third heating zone. L4 / L1 > L5 / L2, and L6 / L3 > L5 / L2.

11. The battery device according to claim 9 or 10, wherein, The heating element is one in number, and the heating element has three heating sections connected in series. One heating section is located in the second heating zone, and the other two heating sections are located in the first heating zone and the third heating zone respectively.

12. The battery device according to any one of claims 1-11, wherein, The heating component includes at least two heating elements connected in parallel, and the at least two heating elements connected in parallel are configured to heat the battery cell assembly individually or simultaneously.

13. The battery device according to claim 12, wherein, The battery device also includes a control switch, each of the heating elements is connected in series with the control switch to form a parallel branch, each of the parallel branches is connected in parallel, and the battery cell is used to supply power to the parallel branch.

14. The battery device according to claim 13, wherein, The heating element is of two types: a first heating element and a second heating element. The first heating element is located on one side of the second heating element along the second direction. At least a portion of the first heating element and at least a portion of the second heating element are used to heat the outermost battery cell in the battery cell assembly along the first direction, and the second direction intersects the first direction and the height direction of the housing, respectively.

15. The battery device according to claim 14, wherein, The number of battery cells in the battery cell assembly is three or more. The first heating element includes a first heating part, a second heating part, and a third heating part. The second heating part is connected in series with the first heating part on one side along the first direction, and the second heating part is connected in series with the third heating part on the other side along the first direction. The first heating part and the third heating part are used to heat different battery cells on the outermost side of the battery cell assembly along the first direction, and the second heating part is used to heat the battery cells in the middle of the battery cell assembly.

16. The battery device according to claim 15, wherein, The second heating element is a straight resistance wire, the length direction of which is the same as the first direction. The straight resistance wire has a first connecting end and a second connecting end. The first connecting end is connected in series with the first heating element, and the second connecting end is connected in series with the third heating element; and / or, the first heating element and the third heating element each have a first bending portion.

17. The battery device according to claim 15 or 16, wherein, The second heating element includes a first heating segment, a second heating segment, and a third heating segment. The first heating segment is connected in series at one end of the second heating segment along the first direction, and the third heating segment is connected in series at the other end of the second heating segment along the first direction. The first heating segment and the third heating segment are used to heat the different battery cells on the outermost side of the battery cell assembly along the first direction, and the second heating segment is used to heat the battery cells in the middle of the battery cell assembly.

18. The battery device according to claim 17, wherein, The first heating segment, the second heating segment, and the third heating segment each have a second bending portion.

19. The battery device according to claim 17 or 18, wherein, The dimension of the second heating segment along the second direction is D1, and the maximum dimension between the second heating segment and the second heating part along the second direction is D2. The value range of D1 / D2 is 0.1-0.

98.

20. The battery device according to claim 19, wherein, The value range of D1 / D2 is 0.7-0.

95.

21. The battery device according to claim 19 or 20, wherein, The value of D1 ranges from 25mm to 90mm.

22. The battery device according to claim 21, wherein, The value of D1 ranges from 40mm to 60mm.

23. The battery device according to any one of claims 1-22, wherein, The number of battery cell assemblies is multiple, and each battery cell assembly is provided with a heating element between itself and the bottom wall of the housing.

24. An electrical appliance, wherein, Includes the battery device as described in any one of claims 1-23, the battery device being used to provide electrical energy to the electrical device.

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