Battery pole piece structure integrated with planar heat generator

Abstract

The application provides a battery pole piece structure integrated with a planar heating body, which comprises an insulating and sealed planar heating body and a first battery pole piece and a second battery pole piece respectively attached to the two side surfaces of the planar heating body; the planar heating body comprises an electrothermal conversion layer made of conductive material, and is used for electrothermal conversion when connected to an external power supply; and the first battery pole piece and the second battery pole piece are integrated with the planar heating body to form an integrated heating pole piece composite structure by physical attachment. The planar heating body and the battery pole piece are integrated into a composite structure, which has the characteristics of compact structure, short heat exchange distance and high heating uniformity; and the defects of long heat conduction path, large temperature difference and low energy efficiency of the existing external heating scheme of the battery are effectively overcome, so that the low-temperature rapid heating requirement of the power battery and the energy storage battery in an extreme environment is met.

Description

Technical Field

[0001] This invention relates to the field of low-temperature thermal management technology for power batteries, and in particular to a battery electrode structure with an integrated planar heating element. Background Technology

[0002] In recent years, the rapid development of new energy vehicles and large-scale energy storage industries has placed higher demands on the environmental adaptability of battery systems. Lithium-ion batteries and lithium metal batteries, as core energy storage components, have electrochemical reaction rates, active material activity, and charge-discharge cycle life that are highly dependent on the operating temperature range. When the ambient temperature is below 0℃, the viscosity of the electrolyte inside the battery increases significantly, and the ion migration efficiency decreases; lithium metal dendrites are prone to puncturing the separator on the negative electrode side, posing a safety risk; the battery's discharge capacity, retention rate, and output power will decrease significantly; and low-temperature charging may even trigger an irreversible internal lithium plating reaction, directly triggering battery safety hazards. Conversely, when the ambient temperature is above 60℃, the SEI film and electrolyte inside the battery are prone to decomposition and gas production, leading to battery bulging, internal short circuits, and other faults, significantly shortening its service life.

[0003] To meet the requirements of battery use in extreme environments, the industry typically adopts external heating solutions to improve the low-temperature performance of batteries. Currently, the mainstream heating solutions include the following three categories: First, heating components are set between the external end plates of the battery module, and heat is transferred through the air medium or structural components between the end plates to achieve overall heating of the module; second, heating elements are arranged on the large side of the battery cell to heat the individual battery cells through contact heat transfer; and third, a heating plate is set at the bottom of the module to supply heat through thermal conduction of the module structure. However, these traditional solutions are all module-level or cell-level heating structures, which have significant technical drawbacks: First, the heat conduction path is long, and heat needs to be transferred through multiple layers of media such as the module shell, cell shell, and insulation layer to the electrode reaction area, resulting in high thermal resistance and significant heat loss, leading to low heating energy efficiency. Second, the heating uniformity is poor. Due to the limited space for the heating components and the thermal conductivity of the heat transfer medium, the maximum temperature difference between different cells within the module and between different electrode areas within the cell often exceeds 10°C during the heating process, which can easily lead to uneven local thermal stress inside the battery and cause irreversible damage to the internal structure of the battery with long-term use. Third, additional space needs to be reserved on the outside of the battery module or cell for the installation of heating components, which is not conducive to improving the energy density of the battery system. Fourth, the heating response speed is slow. The heat from the external heat source needs to pass through multiple layers of thermal conduction interfaces to reach the core area of ​​the electrochemical reaction of the electrode. It often takes several minutes from the start of heating to the core area of ​​the battery reaching the target temperature, which is difficult to meet the demand for rapid heating. Summary of the Invention

[0004] This invention provides a battery electrode structure with an integrated planar heating element to solve one or more technical problems encountered in the prior art.

[0005] In a first aspect, the present invention provides a battery electrode structure with an integrated planar heating element, comprising an insulated and sealed planar heating element and a first battery electrode and a second battery electrode respectively attached and fixed to the two sides of the planar heating element; the planar heating element includes an electrothermal conversion layer made of conductive material, the planar heating element is used to perform electrothermal conversion when connected to an external power source, and the first battery electrode and the second battery electrode are physically attached to the planar heating element to form an integrated heating electrode composite structure.

[0006] In a preferred embodiment, both the first and second battery electrodes include current collectors and electrode active materials; the first and second battery electrodes are fixedly and compositely connected to the planar heating element by one of the following methods: hot pressing, bonding, or ultrasonic bonding.

[0007] In a preferred embodiment, the planar heating element includes a high-temperature resistant insulating substrate selected from polyester polymer film, polyimide polymer film, and special high-temperature resistant engineering polymer film; an electrothermal conversion layer disposed on the surface of the insulating substrate; at least one pair of conductive electrodes disposed on both sides of the electrothermal conversion layer and electrically connected to the electrothermal conversion layer; and an encapsulation film that encapsulates the insulating substrate, the electrothermal conversion layer, and the conductive electrodes into an integral planar heating element, wherein the conductive electrodes are electrically connected to an external power source.

[0008] In a preferred embodiment, the electrothermal conversion layer is a conductive heating film formed by physical vapor deposition on the surface of an insulating substrate using at least one of the following metal oxide semiconductor materials: fluorine-doped tin dioxide, antimony-doped tin dioxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, vanadium pentoxide, indium zinc oxide, molybdenum-doped indium oxide, and indium tin oxide. The thickness of the electrothermal conversion layer is 15 nm to 50 nm.

[0009] In a preferred embodiment, the electrothermal conversion layer is one or more of graphene, carbon nanotubes, graphylene, metal alloys, or conductive polymers, formed on the surface of an insulating substrate by physical vapor deposition, screen printing, gravure printing, or coating processes.

[0010] In a preferred embodiment, the thickness of the first battery electrode and the second battery electrode is 0.05mm to 0.5mm, and the thickness of the planar heating element is 0.03mm to 0.8mm.

[0011] In a preferred embodiment, the edge dimensions of the first battery electrode and the second battery electrode are greater than or equal to the edge dimensions of the planar heating element, forming a wrap-around bonding structure; both the first battery electrode and the second battery electrode include electrode leads for electrical connection with battery cell tabs or external circuits.

[0012] In a preferred embodiment, the planar heating element is a flexible and bendable structure adapted to the elongated and thin electrode shape of the battery; the sheet resistance of the planar heating element is 5Ω / sq to 100Ω / sq, and it can be directly driven to generate heat by DC voltage.

[0013] In a preferred embodiment, the integrated heating electrode composite structure has a uniform overall thickness with a thickness deviation within ±0.02mm, and the uniformity error of the planar heating element in the power-on working state is within ±3℃.

[0014] In a preferred embodiment, the surfaces of the first battery electrode and the second battery electrode are provided with a roughening treatment layer to improve the adhesion to the planar heating element; the planar heating element is a continuous planar heating structure, and its heating area completely covers the relative contact area of ​​the first battery electrode and the second battery electrode.

[0015] One of the above technical solutions has the following advantages or beneficial effects: This invention integrates a planar heating element between two battery electrodes, forming an integrated composite heating electrode structure. The heating level extends directly from the traditional module or cell level to the electrode level inside the battery. The heat generated by the planar heating element can be directly conducted to the entire active reaction area of ​​the first and second battery electrodes with minimal interfacial thermal resistance. The heat conduction distance is shortened by at least an order of magnitude compared to existing solutions, significantly reducing heat loss during heat conduction and effectively improving heating energy efficiency. At the same time, this structure does not require additional space for heating components outside the battery module or cell, does not encroach on the effective space inside the battery system, and has minimal negative impact on battery energy density.

[0016] The planar heating element in this invention is a continuous planar heating structure. Its heating area completely covers the relative contact area of ​​the first battery electrode and the second battery electrode. Combined with the symmetrical heat-equalizing structure design of the two electrodes, it can ensure uniform contact between the heating surface and the heat-absorbing surface, realize uniform heat conduction between surfaces, and control the overall temperature difference of the battery electrode surface within ±3℃. This avoids the problem of uneven local thermal stress in the battery caused by uneven heating in the prior art, and improves the battery cycle life.

[0017] The composite structure of this invention places the planar heating element between two battery electrodes. Through the encapsulation design of the insulating sealing film and the electrode edges, the planar heating element is completely isolated from the electrochemical reaction area inside the battery. The heating area of ​​the planar heating element will not come into direct contact with the electrolyte or electrode active materials, avoiding the risk of performance degradation or short circuit caused by long-term contact between the heating element and the electrolyte or electrode materials. At the same time, the encapsulation structure of the planar heating element adopts a multi-layer composite encapsulation process, which further improves the insulation and sealing performance and avoids the safety hazards of built-in heating schemes from a structural perspective.

[0018] The planar heating element of this invention adopts a flexible and bendable structure, which can adapt to the internal assembly form of different types of batteries. It can be used in both the bending assembly of wound cells and the planar assembly of stacked cells. At the same time, the sheet resistance range of the planar heating element is compatible with conventional DC voltage levels, and can be directly powered by the power supply of the battery module itself or the low-voltage power supply inside the vehicle, without the need for additional boost or buck conversion circuits, thus simplifying the complexity of the battery thermal management system.

[0019] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0020] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in the invention and should not be construed as limiting the scope of the invention.

[0021] Figure 1 This is a cross-sectional schematic diagram of the battery electrode structure in this embodiment. Detailed Implementation

[0022] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0023] This embodiment provides a battery electrode structure with an integrated planar heating element. See [link / reference] Figure 1As shown, the battery electrode structure includes an insulated and sealed planar heating element 100 and a first battery electrode 200 and a second battery electrode 300 respectively attached and fixed to the two sides of the planar heating element; the planar heating element 100 includes an electrothermal conversion layer 102 made of conductive material, and the planar heating element 100 is used to perform electrothermal conversion when connected to an external power source. The first battery electrode 200 and the second battery electrode 300 are physically attached to the planar heating element 10 to form an integrated heating electrode composite structure.

[0024] In one specific embodiment, the first battery electrode 200 and the second battery electrode 300 both include a current collector 202 and an electrode active material 201; the first battery electrode 200, the second battery electrode 300 and the planar heating element 100 are fixedly and compositely connected by one of the following methods: hot pressing, bonding or ultrasonic composite.

[0025] In one specific embodiment, the planar heating element 100 includes a high-temperature resistant insulating substrate 101 selected from polyester polymer film, polyimide polymer film, and special high-temperature resistant engineering polymer film; an electrothermal conversion layer 102 disposed on the surface of the insulating substrate 101; at least one pair of conductive electrodes 103 disposed on both sides of the electrothermal conversion layer 102 and electrically connected to the electrothermal conversion layer 102; and an encapsulation film 104 encapsulating the insulating substrate 101, the electrothermal conversion layer 102, and the conductive electrodes 103 into an integral planar heating element. The conductive electrodes 103 are electrically connected to an external power source.

[0026] In one specific embodiment, the electrothermal conversion layer 102 is a conductive heating film formed by physical vapor deposition on the surface of an insulating substrate using at least one of the following metal oxide semiconductor materials: fluorine-doped tin dioxide, antimony-doped tin dioxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, vanadium pentoxide, indium zinc oxide, molybdenum-doped indium oxide, and indium tin oxide. The thickness of the electrothermal conversion layer is 15 nm to 50 nm.

[0027] In one specific embodiment, the electrothermal conversion layer 102 is a conductive heating film formed on the surface of an insulating substrate by physical vapor deposition, screen printing, gravure printing, or coating processes, consisting of one or more of graphene, carbon nanotubes, graphylene, metal alloys, or conductive polymers. The metal alloy can be a nickel-chromium alloy, an iron-chromium-aluminum alloy, or other high-resistance alloy materials; the conductive polymer can be an intrinsically conductive polymer material such as polypyrrole, polyaniline, or polythiophene, or a chemically modified or doped product of such materials.

[0028] In one specific embodiment, the thickness of the first battery electrode 200 and the second battery electrode 300 is 0.05mm to 0.5mm, and the thickness of the planar heating element 100 is 0.03mm to 0.8mm. Limiting the thickness range of each layer is to control the overall thickness of the composite structure within a reasonable range while ensuring structural strength, conductivity, and heating performance, thereby reducing its negative impact on battery energy density.

[0029] In one specific embodiment, the edge dimensions of the first battery electrode 200 and the second battery electrode 300 are greater than or equal to the edge dimensions of the planar heating element 100, forming a wrap-around bonding structure. Both the first battery electrode 200 and the second battery electrode 300 include electrode leads for electrical connection to the battery cell tabs or external circuitry. This arrangement ensures that the heating area of ​​the planar heating element is completely covered, concentrating heat within the effective reaction area of ​​the electrode, while also preventing misalignment between the electrode edge and the heating element edge or other battery cell components, reducing the risk of dimensional interference during assembly.

[0030] In one specific embodiment, the planar heating element 100 is a flexible and bendable structure, adapted to the elongated and thin electrode shape of the battery; the sheet resistance of the planar heating element 100 is 5Ω / sq to 100Ω / sq, and it can be directly driven to generate heat by DC voltage. Limiting the sheet resistance of the planar heating element 100 to the range of 5Ω / sq to 100Ω / sq is because the nominal voltage of automotive power batteries or energy storage batteries is mostly 12V, 24V, or 48V. This sheet resistance range can adapt to these conventional DC voltage levels, achieving a reasonable heating power density within a safe voltage range, avoiding excessive external power load due to excessive current, or insufficient heating rate to meet usage requirements due to insufficient current.

[0031] In one specific embodiment, the integrated heating electrode composite structure has a uniform overall thickness, with a thickness deviation within ±0.02mm. The planar heating element 100, under energized operation, exhibits a heating uniformity error within ±3°C. Limiting the thickness deviation of the composite structure to within ±0.02mm ensures the smooth progress of subsequent cell stacking or winding processes, preventing localized voids or excessive compaction within the cell after winding / stacking due to excessive thickness deviation. Limiting the heating uniformity error of the planar heating element to within ±3°C is significantly lower than the heating uniformity error requirements of conventional heating solutions in the industry, effectively preventing safety hazards caused by localized overheating of the battery electrode.

[0032] In one specific embodiment, the surfaces of the first battery electrode 200 and the second battery electrode 300 are provided with a roughening layer to improve the adhesion to the planar heating element 100. The planar heating element 100 is a continuous planar heating structure, and its heating area completely covers the relative contact area of ​​the first battery electrode 200 and the second battery electrode 300. The roughening layer can be obtained by conventional methods such as mechanical polishing, chemical etching, or corona treatment. The surface roughness needs to be controlled within a reasonable range to increase the contact area and improve the interlayer bonding force, without increasing the interface thermal resistance due to excessive roughness, which would affect the heat conduction efficiency. The planar heating element adopts a continuous planar heating structure, rather than a traditional serpentine or other linear / strip heating structure, which can uniformly distribute the current and avoid the risk of overheating caused by excessive local current. Example 1

[0033] This embodiment provides a battery electrode structure with an integrated planar heating element, the structure of which is as follows: Figure 1 As shown, the device includes a planar heating element 100, a first battery electrode 200, and a second battery electrode 300. The planar heating element 100 is an insulated and sealed structure. The first battery electrode 200 and the second battery electrode 300 are respectively attached and fixed to the two side surfaces of the planar heating element 100. The two side surfaces of the planar heating element 100 are physically attached to the first battery electrode 200 and the second battery electrode 300, forming an integrated heating electrode composite structure of "first battery electrode - planar heating element - second battery electrode".

[0034] like Figure 1 As shown, the planar heating element 100 includes an insulating substrate 101, an electrothermal conversion layer 102, a conductive electrode 103, and an encapsulation film 104. The insulating substrate 101 is a polyimide (PI) film with a thickness of 5 μm. The electrothermal conversion layer 102 is disposed on one side surface of the insulating substrate 101, is made of indium tin oxide (ITO), and is prepared by physical vapor deposition, with a thickness of 10 nm. The conductive electrode 103 is disposed at both edges of the electrothermal conversion layer 102, forming a reliable electrical connection with the electrothermal conversion layer 102. The encapsulation film 104 completely covers the insulating substrate 101, the electrothermal conversion layer 102, and the conductive electrode 103, forming an insulating and sealed structure. The conductive electrode 103 is a silver paste electrode printed on both edges of the electrothermal conversion layer 102, with a thickness of 10 μm and a width of 10 mm. The encapsulation film 104 is a polyimide (PI) film with a thickness of 5 μm, which is sealed and composited with the insulating substrate 101 into a single structure through a hot-pressing process.

[0035] In this embodiment, the first battery electrode 200 and the second battery electrode 300 have the same structure, both including a current collector 202 and an electrode active material 201. The current collector 202 is a metal foil commonly used in the lithium battery industry, and the electrode active material 201 is coated on both sides of the current collector 202. The first battery electrode 200, the second battery electrode 300, and the planar heating element 100 are fixedly bonded together as a single structure using a hot-pressing bonding process. Specifically, the hot-pressing bonding process is completed in a high-precision hot-pressing device to ensure that the bonding surfaces between each layer are free of gaps and air bubbles, forming a stable composite structure.

[0036] In this embodiment, the edge dimensions of both the first battery electrode 200 and the second battery electrode 300 are larger than the edge dimension of the planar heating element 100. Specifically, the edge dimensions of the first battery electrode 200 and the second battery electrode 300 exceed the edge dimension of the planar heating element 100 by 10mm, forming a wrap-around bonding structure. This structural design ensures that the heating area of ​​the planar heating element 100 is completely covered by the first battery electrode 200 and the second battery electrode 300, concentrating the heat within the effective reaction area of ​​the electrode and reducing the diffusion of heat to the non-reaction area. Both the first battery electrode 200 and the second battery electrode 300 include electrode leads, which are integrated with the current collector 202 and used to achieve electrical connection with the battery cell tab or external circuit.

[0037] In this embodiment, the planar heating element 100 is a flexible and bendable structure with a sheet resistance of 10Ω / sq, which can be directly driven to generate heat through a 4V DC voltage. When the power is on, the heating power density of the planar heating element 100 is uniform, with no local overheating or overcooling areas.

[0038] In this embodiment, the overall thickness of the integrated heating electrode composite structure is 50μm, and the thickness deviation is controlled within ±0.02mm; the heating uniformity error of the planar heating element under energized working conditions is within ±3℃. Example 2

[0039] This embodiment is basically the same in structure as Embodiment 1, with the only difference being: The insulating substrate 101 of the planar heating element 100 is a polyester polymer film (PET film) with a thickness of 20 μm; the electrothermal conversion layer 102 is made of aluminum-doped zinc oxide (AZO) and is prepared by physical vapor deposition process with a thickness of 20 nm; the conductive electrode 103 is a copper paste electrode with a thickness of 5 μm and a width of 10 mm; and the encapsulation film 104 is a PET film with a thickness of 20 μm.

[0040] The first battery electrode 200, the second battery electrode 300, and the planar heating element 100 are fixed and composited into a single structure by an adhesive bonding process. Specifically, modified acrylic adhesive is used as the adhesive layer, which is evenly coated on both sides of the bonding surface of the planar heating element 100. The adhesive layer thickness is 20μm. After bonding, the composite process is completed by curing at room temperature for 4 hours.

[0041] The planar heating element 100 has a sheet resistance of 20Ω / sq and can be directly driven to generate heat by a 4V DC voltage; the overall thickness of the integrated heating electrode composite structure is 60μm, and the thickness deviation is controlled within ±0.02mm; the heating uniformity error of the planar heating element 100 under the power-on working state is within ±3℃. Example 3

[0042] This embodiment is basically the same in structure as Embodiment 1, with the only difference being: The electrothermal conversion layer 102 of the planar heating element 100 is a graphene film, which is prepared by screen printing and has a thickness of 5nm; the conductive electrode 103 is a nickel paste electrode with a thickness of 10μm and a width of 20mm; the encapsulation film 104 is a special high-temperature resistant engineering polymer film with a thickness of 10μm.

[0043] The first battery electrode 200, the second battery electrode 300, and the planar heating element 100 are fixedly composited into a single structure by an ultrasonic composite process. Specifically, a high-frequency ultrasonic composite device is used to achieve stable composite between the layers under process parameters of 0.5 MPa pressure and 1 second composite time.

[0044] The sheet resistance of the planar heating element is 20Ω / sq, and it can be directly driven to generate heat by a 2V DC voltage; the overall thickness of the integrated heating electrode composite structure is 40μm, and the thickness deviation is controlled within ±0.02mm; the heating uniformity error of the planar heating element 100 under the power-on working state is within ±3℃. Example 4

[0045] This embodiment is basically the same in structure as Embodiment 1, with the only difference being: The insulating substrate 101 of the planar heating element 100 is a special high-temperature resistant engineering polymer film with a thickness of 20 μm; the electrothermal conversion layer 102 is a carbon nanotube film, prepared by gravure printing process, with a thickness of 50 nm; the conductive electrode 103 is a silver paste electrode with a thickness of 20 μm and a width of 5 mm; and the encapsulation film 104 is a polyimide polymer film with a thickness of 5 μm.

[0046] The first battery electrode 200, the second battery electrode 300, and the planar heating element 100 are fixed and composited into an integral structure by a hot-pressing bonding process; specifically, the hot-pressing temperature is 100℃, the pressure is 0.8MPa, and the holding time is 90 seconds, in order to adapt to the composite process requirements of carbon nanotube films.

[0047] The sheet resistance of the planar heating element is 100Ω / sq, and it can be directly driven to generate heat by an 8V DC voltage; the overall thickness of the integrated heating electrode composite structure is 50μm, and the thickness deviation is controlled within ±0.02mm; the heating uniformity error of the planar heating element 100 under the power-on working state is within ±3℃. Example 5

[0048] This embodiment is basically the same in structure as Embodiment 1, with the only difference being: The electrothermal conversion layer 102 of the planar heating element 100 is a nickel-chromium alloy thin film, which is prepared by physical vapor deposition and has a thickness of 5 nm; the conductive electrode 103 is an aluminum paste electrode with a thickness of 25 μm and a width of 5 mm; the encapsulation film 104 is a polyester polymer film with a thickness of 30 μm.

[0049] The first battery electrode 200, the second battery electrode 300, and the planar heating element 100 are fixedly composited into a single structure by an ultrasonic composite process. Specifically, a high-frequency ultrasonic composite device is used to achieve stable composite between the layers under process parameters of 0.8 MPa pressure and 1 second composite time.

[0050] The planar heating element 100 has a sheet resistance of 40Ω / sq and can be directly driven to generate heat by a 4V DC voltage; the overall thickness of the integrated heating electrode composite structure is 60μm, and the thickness deviation is controlled within ±0.02mm; the heating uniformity error of the planar heating element under power-on working conditions is within ±3℃. Example 6

[0051] This embodiment is basically the same in structure as Embodiment 1, with the only difference being: The insulating substrate 101 of the planar heating element 100 is a polyimide (PI) film with a thickness of 5 μm; the electrothermal conversion layer 102 is a polypyrrole conductive film, which is prepared by a coating process and has a thickness of 25 nm; the conductive electrode 103 is a carbon paste electrode with a thickness of 30 μm and a width of 6 mm; and the encapsulation film 104 is a polyimide-based polymer film with a thickness of 25 μm.

[0052] The first battery electrode 200, the second battery electrode 300, and the planar heating element 100 are fixed and composited into an integral structure by an adhesive bonding process. Specifically, a fluorine-modified hydrophobic pressure-sensitive adhesive is used as the adhesive layer, which is uniformly coated on both sides of the bonding surface of the planar heating element 100. The adhesive layer has a thickness of 8μm. After bonding, it is compacted by a hot pressing device with a pressure of 0.2MPa to complete the composite process.

[0053] The planar heating element 100 has a sheet resistance of 60Ω / sq and can be directly driven to generate heat by an 8V DC voltage; the overall thickness of the integrated heating electrode composite structure is 50μm, and the thickness deviation is controlled within ±0.02mm; the heating uniformity error of the planar heating element under power-on working conditions is within ±3℃.

[0054] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0056] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A battery electrode structure with an integrated planar heating element, characterized in that, The device includes an insulated and sealed planar heating element and a first battery electrode and a second battery electrode respectively attached and fixed to the two sides of the planar heating element; the planar heating element includes an electrothermal conversion layer made of conductive material, and the planar heating element is used to perform electrothermal conversion when connected to an external power source. The first battery electrode and the second battery electrode are physically attached to the planar heating element to form an integrated heating electrode composite structure.

2. The battery electrode structure according to claim 1, characterized in that, Both the first and second battery electrodes include current collectors and electrode active materials; the first and second battery electrodes are fixedly and compositely connected to the planar heating element by one of the following methods: hot pressing, bonding, or ultrasonic bonding.

3. The battery electrode structure according to claim 1, characterized in that, The planar heating element includes a high-temperature resistant insulating substrate selected from polyester polymer film, polyimide polymer film, and special high-temperature resistant engineering polymer film; an electrothermal conversion layer disposed on the surface of the insulating substrate; at least one pair of conductive electrodes disposed on both sides of the electrothermal conversion layer and electrically connected to the electrothermal conversion layer; and an encapsulation film that encapsulates the insulating substrate, the electrothermal conversion layer, and the conductive electrodes into an integral planar heating element. The conductive electrodes are electrically connected to an external power source.

4. The battery electrode structure according to claim 3, characterized in that, The electrothermal conversion layer is a conductive heating film formed by physical vapor deposition on the surface of an insulating substrate using at least one of the following metal oxide semiconductor materials: fluorine-doped tin dioxide, antimony-doped tin dioxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, vanadium pentoxide, indium zinc oxide, molybdenum-doped indium oxide, and indium tin oxide. The thickness of the electrothermal conversion layer is 15 nm to 50 nm.

5. The battery electrode structure according to claim 3, characterized in that, The electrothermal conversion layer is a conductive heating film formed on the surface of an insulating substrate by physical vapor deposition, screen printing, gravure printing, or coating processes, consisting of one or more of graphene, carbon nanotubes, graphylene, metal alloys, or conductive polymers.

6. The battery electrode structure according to claim 1, characterized in that, The thickness of the first battery electrode and the second battery electrode is 0.05mm~0.5mm, and the thickness of the planar heating element is 0.03mm~0.8mm.

7. The battery electrode structure according to claim 1, characterized in that, The edge dimensions of the first battery electrode and the second battery electrode are greater than or equal to the edge dimensions of the planar heating element, forming a wrap-around bonding structure; both the first battery electrode and the second battery electrode include electrode leads for electrical connection with the battery cell tabs or external circuits.

8. The battery electrode structure according to claim 1, characterized in that, The planar heating element is a flexible and bendable structure, adapted to the elongated and thin electrode shape of the battery; the sheet resistance of the planar heating element is 5Ω / sq to 100Ω / sq, and it can be directly driven to generate heat by DC voltage.

9. The battery electrode structure according to claim 1, characterized in that, The integrated heating electrode composite structure has a uniform overall thickness with a thickness deviation within ±0.02mm. The uniformity of heating of the planar heating element under energized operation is within ±3℃.

10. The battery electrode structure according to claim 1, characterized in that, The surfaces of the first and second battery electrodes are provided with a roughening treatment layer to improve the adhesion to the planar heating element; the planar heating element is a continuous planar heating structure, and its heating area completely covers the relative contact area of ​​the first and second battery electrodes.

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