Lithium battery oven heating plate

Abstract

The utility model relates to battery technical field discloses a lithium battery oven heating plate, including substrate, the one side surface of substrate is equipped with heating film, heating film includes mould body and is embedded in the heating element of mould body and is arranged in continuous circuit, the distribution density of heating element presents increasing setting along the central region of mould body to edge region, the one side of heating film away from substrate is equipped with heat conduction layer, and heat conduction layer includes multiple heat conduction parts that are arranged in interval, the utility model discloses through heating film can be pertinence compensation oven edge heat loss, and the temperature gradient is weakened from the heat source distribution level, and the heat conduction layer of interval arrangement further realizes the uniform conduction of heat, and the heating uniformity is greatly promoted, guarantees the battery capacity consistency and cycle life, the present application significantly improves temperature uniformity and reduces energy consumption, solves the problem that traditional heating plate thermal stress cracks and edge heat dissipation is too fast, is applicable to large -scale lithium battery drying process.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a heating plate for a lithium battery oven. Background Technology

[0002] In the lithium battery production process, the electrode drying stage requires strict temperature control within the range of 80~120℃. Temperature deviations or uneven distribution can easily lead to differences in residual solvent levels, coating carbonization and cracking, or substrate deformation, directly affecting cell capacity consistency and cycle life. Therefore, achieving precise, uniform, and safe heating of lithium batteries has become a key technological challenge for the industry. Early methods used in the industry included resistance heating and infrared heating, which, while meeting basic heating requirements, suffered from slow heating speeds, low temperature control accuracy, and poor energy efficiency. Furthermore, the linear distribution characteristics of heating elements could easily lead to excessive temperature gradients within the drying oven, further exacerbating the risk of performance fluctuations in lithium batteries. Traditional heating plates use unevenly distributed heating elements such as heating wires, making it difficult to eliminate the heat dissipation difference between the edge and center of the oven, and the temperature gradient problem has not been fundamentally solved. At the same time, due to the large difference in the coefficient of thermal expansion between the heating plate substrate and the insulation layer, delamination and deformation are prone to occur under long-term high-temperature conditions. This not only causes serious heat loss and soaring energy consumption, but may also lead to safety hazards such as insulation failure.

[0003] Although some solutions propose multi-zone independent temperature control to optimize uniformity, they require the addition of a large number of heating elements, sensors and control modules, resulting in complex structures and significantly increased costs. While carbon fiber heating films can achieve uniform surface heating, their long-term temperature resistance is generally below 200°C, making them unsuitable for abnormal electrode drying conditions or the high-temperature requirements of special electrodes, and thus failing to meet the reliability and economic requirements of industrial mass production. Utility Model Content

[0004] The purpose of this invention is to provide a heating plate for a lithium battery oven to solve the problems in the prior art, thereby improving the temperature uniformity of the heating plate and reducing energy consumption.

[0005] This utility model provides a heating plate for a lithium battery oven, comprising: substrate; A heating film is disposed on one side surface of the substrate. The heating film includes a mold body and heating elements embedded in the mold body in a continuous loop arrangement. The distribution density of the heating elements increases from the center region to the edge region of the mold body. A thermally conductive layer is disposed on the side of the heating film away from the substrate. The thermally conductive layer includes a plurality of thermally conductive portions arranged at intervals. The thermally conductive layer is used to uniformly conduct the heat generated by the heating film to the lithium battery to be heated. An insulating layer includes a first insulating layer and a second insulating layer. The first insulating layer is sandwiched between the heating film and the substrate, and the second insulating layer is sandwiched between the heating film and the heat-conducting part, respectively, to achieve electrical isolation between the heating film and the substrate and between the heating film and the heat-conducting layer.

[0006] In the lithium battery oven heating plate described above, preferably, the density of the heating element in the edge region of the mold body is 20%-30% higher than that in the central region.

[0007] In the lithium battery oven heating plate described above, preferably, the heating film is a serpentine electric heating nickel-chromium wire heating film.

[0008] In the lithium battery oven heating plate described above, preferably, a buffer layer is also sandwiched between the substrate and the first insulating layer.

[0009] In the lithium battery oven heating plate described above, preferably, a support frame for supporting lithium batteries is movably provided on the heat-conducting layer. The support frame has multiple storage slots, which correspond to the heat-conducting parts. The bottom of the storage slots has an open area for the battery to contact the heat-conducting parts. The bottom of the support frame has multiple connecting parts. When the support frame is mounted on the heat-conducting layer, the connecting parts are inserted into the gap between two adjacent heat-conducting parts.

[0010] In the lithium battery oven heating plate described above, preferably, a protective layer is provided on the side of the heat-conducting part facing the lithium battery, and the surface of the protective layer has a dot-matrix distributed heat-conducting hole.

[0011] In the lithium battery oven heating plate described above, preferably, a micro-motion sensor switch is provided on the side of the heating film.

[0012] In the lithium battery oven heating plate described above, preferably, the bottom of the substrate is provided with a plurality of positioning pins.

[0013] In the lithium battery oven heating plate described above, preferably, a temperature sensor is provided on the side of the heat-conducting layer.

[0014] Compared with the prior art, this utility model can specifically compensate for heat loss at the edge of the oven through the heating film, weaken the temperature gradient from the heat source distribution level, and further achieve uniform heat conduction through the spaced heat-conducting layers, greatly improving heating uniformity and avoiding problems such as uneven electrode solvent residue and coating carbonization cracking caused by temperature deviation, thus ensuring the consistency of cell capacity and cycle life. The first and second insulating layers respectively achieve reliable electrical isolation between the heating film and the substrate and the heat-conducting layer. At the same time, this layered structure can optimize the difference in thermal expansion coefficients between the substrate and the insulating layer by selecting appropriate materials, thereby reducing the risk of delamination deformation under long-term high-temperature conditions. This reduces heat loss and energy consumption, and avoids the safety hazards of insulation failure. In addition, this application significantly improves temperature uniformity and reduces energy consumption, and solves the problems of thermal stress cracking and excessive heat dissipation at the edges of traditional heating plates. It is suitable for large-scale lithium battery drying processes. Attached Figure Description

[0015] Figure 1 This is a layered schematic diagram of the heating plate of the lithium battery oven provided in an embodiment of this utility model; Figure 2 This is a side view of the heating plate of the lithium battery oven provided in an embodiment of this utility model; Figure 3 yes Figure 2 Enlarged view of point A in the image; Figure 4 This is a perspective view of the heat-conducting part provided in an embodiment of this utility model; Figure 5 This is a perspective view of the heating plate of the lithium battery oven provided in an embodiment of this utility model; Figure 6 This is a temperature rise curve of the heating plate of the lithium battery oven provided in an embodiment of this utility model; Figure 7 This is a temperature uniformity test report form provided by an embodiment of this utility model.

[0016] Explanation of reference numerals in the attached figures: 10. Substrate; 11. Positioning pin; 20. Heating film; 21. Mold body; 22. Heating element; 30. Thermally conductive layer; 31. Thermally conductive part; 310. Protective layer; 311. Thermally conductive hole; 40. First insulating layer; 41. Second insulating layer; 50. Buffer layer; 60. Support frame; 61. Storage slot; 62. Connecting part; 70. Micro-motion induction switch; 71. Temperature sensor. Detailed Implementation

[0017] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0018] See Figure 1-3 As shown, this embodiment provides a heating plate for a lithium battery oven, including a substrate 10, a heating film 20, a heat-conducting layer 30, and an insulating layer, wherein; A heating film 20 is disposed on one side surface of the substrate 10. The heating film 20 includes a mold 21 and heating elements 22 embedded in the mold 21 in a continuous loop arrangement. The distribution density of the heating elements 22 increases from the center region to the edge region of the mold 21. A heat-conducting layer 30 is disposed on the side of the heating film 20 away from the substrate 10. The heat-conducting layer 30 includes a plurality of heat-conducting portions 31 arranged at intervals. The heat-conducting layer 30 is used to uniformly conduct the heat generated by the heating film 20 to the lithium battery to be heated. An insulating layer includes a first insulating layer 40 and a second insulating layer 41. The first insulating layer 40 is sandwiched between the heating film 20 and the substrate 10, and the second insulating layer 41 is sandwiched between the heating film 20 and the heat-conducting portions 31, respectively, to achieve electrical isolation between the heating film 20 and the substrate 10 and between the heating film 20 and the heat-conducting layer 30. In the embodiments provided in this application, the heating film 20 adopts a design with increasing density from the center to the edge, which can specifically compensate for the problem of rapid heat loss in the edge area, making the edge heating elements more dense, generating more heat per unit area, improving temperature uniformity, and ensuring the heating consistency of the lithium battery. The heat-conducting layer 30 adopts spaced heat-conducting parts 31, which can concentrate heat transfer, reduce heat diffusion loss, and improve heat transfer efficiency through close contact between the heat-conducting parts 31 and the lithium battery, avoiding problems such as uneven drying of battery electrodes and performance differences caused by local temperature differences. In addition, the heat-conducting parts 31 can be adapted to the size of the lithium battery to meet the needs of different battery models. The first insulating layer 40 and the second insulating layer 41 respectively isolate the heating film 20 from the substrate 10 and the heating film 20 from the heat-conducting layer 30. They can be wrapped around the outside of the heating film 20 to achieve isolation from the substrate 10 and the heat-conducting layer 30 respectively. The first insulating layer 40 and the second insulating layer 41 are made of high-temperature resistant insulating materials, such as silicone and polyimide, to ensure electrical safety and effectively block the current conduction path, preventing the risk of leakage when the heating film 20 is working. This insulated and waterproof design eliminates the risk of open flames or high temperatures. Combined with over-temperature protection and circuit breaker protection, it reduces the risk of combustion and explosion and is easy to maintain.

[0019] In one feasible implementation, the density of the heating element 22 in the edge region of the mold 21 is 20%-30% higher than that in the central region. This density difference is a precisely matched value calculated based on heat dissipation characteristics. This quantitative design can avoid energy redundancy and improve energy efficiency while ensuring temperature uniformity. Within this range, it compensates for heat dissipation losses while achieving temperature uniformity within ±3℃, making it suitable for temperature-sensitive lithium battery materials. It features fast response, low thermal inertia, rapid heating rate, improved drying efficiency, and energy savings. Direct contact heat transfer results in low heat loss, achieving 20%-30% energy savings compared to hot air circulation. Figure 6 The image shows the heating plate's temperature rise curve. Figure 7 The table shown is a temperature uniformity test report after 1.5 hours of heating. The actual test results meet the temperature uniformity requirement of ±3°C. In this embodiment, the heating film 20 differs from traditional point-like resistance wires. The heating film 20 generates heat over a large area uniformly, directly conducting it to the interior of the oven or the surface of the material it contacts. The heating element 22 can be a resistance wire or a conductive material, such as nichrome wire, carbon fiber, or metal foil. When energized, the resistance generates Joule heat, converting electrical energy into heat energy. In this embodiment, the heating film 20 is a serpentine nichrome wire heating film 20. The serpentine nichrome wire is a continuous linear heating element, releasing heat continuously along its path. There are no gaps causing localized heatless areas. Combined with the heat-conducting layer 30, it achieves uniform surface heat conduction. Even in high-density areas at the edges, the narrow-spacing serpentine arrangement allows heat to cover the surface in a strip rather than concentrating at a single point, preventing localized overheating at the edges and further ensuring the uniformity of the heating plate surface temperature. Furthermore, the serpentine nichrome wire structure allows for flexible control of the heating element distribution density by adjusting the serpentine bending spacing. Density gradients can be achieved through serpentine path optimization, simplifying the manufacturing process and improving the continuity of heating density. It should be noted that nickel-chromium wire is a mature high-temperature heating material with high temperature resistance and oxidation resistance, which can extend the service life of the heating film by 20 years.

[0020] See Figure 1 and Figure 3 As shown, when the heating plate is working, the thermal expansion coefficients of the substrate 10, the first insulating layer 40, and the heating film 20 differ significantly. During temperature cycling, mutual tensile thermal stress is generated. If this stress cannot be released, it can easily lead to cracking of the insulating layer, peeling of the substrate 10 from the insulating layer, or even an open circuit in the heating film 20. To solve this problem, in this embodiment, a buffer layer 50 is also sandwiched between the substrate 10 and the first insulating layer 40. The buffer layer 50 is made of corrugated copper foil, which has a deformable elastic buffer space. When heated, the corrugated structure can expand to offset the difference in expansion between the layers. When cooled and contracted, the corrugations can absorb the contraction stress through contraction and rebound, avoiding stress concentration at the interface between the insulating layer and the substrate 10, fundamentally reducing the risk of cracking and peeling, and extending the service life of the heating plate. In addition, the buffer layer 50 can also compensate for any local gaps that may exist between the substrate 10 and the first insulating layer 40, improve the structural fit, and enhance long-term stability.

[0021] See Figure 1-3As shown, in this embodiment, a support frame 60 for supporting lithium batteries is movably provided on the heat-conducting layer 30. The support frame 60 is provided with a plurality of storage slots 61, which correspond to the heat-conducting parts 31. The bottom of the storage slots 61 has an open area for the battery to contact the heat-conducting parts 31. The bottom of the support frame 60 is provided with a plurality of connecting parts 62. When the support frame 60 is mounted on the heat-conducting layer 30, the connecting parts 62 are inserted into the gap between two adjacent heat-conducting parts 31. The gaps between the heat-conducting parts 31 can improve the heat conduction efficiency, while the connecting part 62 inserted into the gap between adjacent heat-conducting parts 31 can accurately position the support frame 60. During assembly, simply align the connecting part 62 with the gap and insert it to quickly achieve accurate alignment between the support frame 60 and the heat-conducting layer 30 without additional position adjustments, which greatly improves the efficiency of lithium battery loading. Multiple storage slots 61 correspond one-to-one with multiple heat-conducting parts 31, allowing each lithium battery to receive independent and uniform heat supply. Through the open area contacting the heat-conducting parts 31, the heat transfer efficiency and heating consistency are improved.

[0022] See Figure 4 As shown, in this embodiment, the heat-conducting part 31 can be made of aluminum plate. To avoid damage caused by direct contact between the heat-conducting part 31 and the lithium battery, a protective layer 310 is applied to the side of the heat-conducting part 31 facing the lithium battery. The surface of the protective layer 310 has dot-matrix distributed heat-conducting holes 311. The protective layer 310 can be made of high-temperature resistant insulating material, such as polytetrafluoroethylene film or polyimide film, to avoid physical damage to the lithium battery from the aluminum plate and eliminate the risk of electrochemical corrosion. The heat-conducting holes 311 directly connect the aluminum plate and the lithium battery casing, ensuring that the heat from the aluminum plate can be efficiently transferred to the battery and that the heat is evenly transferred to the battery surface, further improving the temperature uniformity of the lithium battery heating.

[0023] See Figure 5 As shown, in this embodiment, a micro-motion sensor switch 70 is provided on the side of the heating film 20. The micro-motion sensor switch 70 is used to determine whether the heating plate is installed in place. The setting and implementation of the micro-motion sensor switch 70 is prior art and will not be described in detail here.

[0024] See Figure 2-3 As shown, the bottom of the substrate 10 is provided with several positioning pins 11. The positioning pins 11 are precisely matched with the preset positioning holes in the oven to realize the installation and positioning of the heating plate in the oven. The positioning pins 11 can also provide guidance for the installation process of the substrate 10, reducing the time cost and operation difficulty of manual alignment, which is especially suitable for mass production scenarios.

[0025] See Figure 5As shown, in this embodiment, a temperature sensor 71 is provided on the side of the heat-conducting layer 30. The temperature sensor 71 is preferably located on the side of the heat-conducting layer 30 near the lithium battery. The lithium battery oven typically includes a PID temperature controller. The temperature sensor 71 collects the temperature signal near the lithium battery in real time, converts it into an electrical signal, and feeds it back to the PID temperature controller. The PID temperature controller receives the temperature signal from the temperature sensor 71, compares it with the target temperature, calculates an adjustment command using a PID algorithm, and controls the power of the heating film. The heating film receives the command from the PID temperature controller and converts electrical energy into heat energy to provide a stable heat source for the oven. These three components work together to achieve precise closed-loop temperature control, achieving an accuracy of ±1℃. The power output of the heating film 20 is adjusted in real time based on the temperature information fed back by the temperature sensor 71 to maintain the stability of the temperature inside the oven. This control system is existing technology and will not be described in detail here.

[0026] The above description, based on the embodiments shown in the drawings, details the structure, features, and effects of this utility model. The above description is only a preferred embodiment of this utility model, but the scope of implementation of this utility model is not limited to what is shown in the drawings. Any changes made in accordance with the concept of this utility model, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and drawings, shall be within the protection scope of this utility model.

Claims

1. A heating plate for a lithium battery oven, characterized in that, include: substrate; A heating film is disposed on one side surface of the substrate. The heating film includes a mold body and heating elements embedded in the mold body in a continuous loop arrangement. The distribution density of the heating elements increases from the center region to the edge region of the mold body. A thermally conductive layer is disposed on the side of the heating film away from the substrate. The thermally conductive layer includes a plurality of thermally conductive portions arranged at intervals. The thermally conductive layer is used to uniformly conduct the heat generated by the heating film to the lithium battery to be heated. An insulating layer includes a first insulating layer and a second insulating layer. The first insulating layer is sandwiched between the heating film and the substrate, and the second insulating layer is sandwiched between the heating film and the heat-conducting part, respectively, to achieve electrical isolation between the heating film and the substrate and between the heating film and the heat-conducting layer.

2. The heating plate for a lithium battery oven according to claim 1, characterized in that, The density of the heating element in the edge region of the mold is 20%-30% higher than that in the central region.

3. The heating plate for a lithium battery oven according to claim 1, characterized in that, The heating film is a serpentine electric heating nickel-chromium wire heating film.

4. The heating plate for a lithium battery oven according to claim 1, characterized in that, A buffer layer is also sandwiched between the substrate and the first insulating layer.

5. The heating plate for a lithium battery oven according to claim 1, characterized in that, The thermally conductive layer is movably provided with a support frame for supporting lithium batteries. The support frame is provided with multiple storage slots, which correspond to the thermally conductive parts. The bottom of the storage slots has an open area for the battery to contact the thermally conductive parts. The bottom of the support frame is provided with multiple connecting parts. When the support frame is mounted on the thermally conductive layer, the connecting parts are inserted into the gap between two adjacent thermally conductive parts.

6. The heating plate for a lithium battery oven according to claim 1, characterized in that, The side of the heat-conducting part facing the lithium battery is covered with a protective layer, and the surface of the protective layer has a dot-matrix distribution of heat-conducting holes.

7. The heating plate for a lithium battery oven according to claim 1, characterized in that, The heating film is equipped with a micro-motion sensor switch on its side.

8. The heating plate for a lithium battery oven according to claim 1, characterized in that, The bottom of the substrate is provided with several positioning pins.

9. The heating plate for a lithium battery oven according to claim 1, characterized in that, A temperature sensor is provided on the side of the thermally conductive layer.

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