CN-122025928-A - Battery thermal management system

CN122025928ACN 122025928 ACN122025928 ACN 122025928ACN-122025928-A

Abstract

The application discloses a battery thermal management system, and relates to the field of battery thermal management. The battery thermal management system comprises a battery module, a silica gel heat conduction interface layer, an electric heating layer, a variable thermal resistance layer and a liquid cooling plate, wherein the silica gel heat conduction interface layer, the electric heating layer and the variable thermal resistance layer are sequentially arranged on the battery module, and the liquid cooling plate is arranged above the variable thermal resistance layer in a vertically movable mode. When the temperature of the battery module reaches a preset threshold value, the liquid cooling plate is controlled to move towards the direction of the variable thermal resistance layer so as to compress the variable thermal resistance layer or move away from the direction of the variable thermal resistance layer, so that the thermal resistance value of the variable thermal resistance layer is adjusted. By adjusting the variable thermal resistance layer to be in a compressed state or to be kept in a free state, the thermal resistance value of the variable thermal resistance layer is flexibly adjusted, high-efficiency heat conduction or heat insulation is realized, the heating and heat dissipation modes are caused to operate independently and effectively instead of being interfered with each other, and high-efficiency heating or high-efficiency heat dissipation is realized.

Inventors

HUANG ZICHAO
WANG HUATAO
Du fangzheng
SONG XIAOYUN
SONG TAO
LIU SHUIGUO
YING HAIFENG

Assignees

常州宏巨电子科技有限公司
哈尔滨工业大学（威海）

Dates

Publication Date: 20260512
Application Date: 20260309

Claims (10)

1. A battery thermal management system, comprising: A battery module; The silica gel heat conduction interface layer covers the upper surface of the battery module; The electric heating layer is covered on the upper surface of the silica gel heat conduction interface layer and comprises a heating element and a heat conduction insulating packaging piece for wrapping the heating element; a variable thermal resistance layer covering the upper surface of the electric heating layer; A liquid cooling plate disposed above the variable thermal resistance layer in a vertically movable manner, and The control device comprises a temperature sensor, a controller and a driving mechanism, wherein the temperature sensor is connected with the battery module and is in communication connection with the controller, and is used for detecting the temperature of the battery module and transmitting the detected temperature to the controller, the controller is used for comparing the received temperature with a preset temperature and generating a control instruction, the driving mechanism is in communication connection with the controller and is connected with the liquid cooling plate, and the driving mechanism is used for receiving the control instruction and controlling the liquid cooling plate to move towards the direction of the variable thermal resistance layer according to the received control instruction so as to compress the variable thermal resistance layer or controlling the liquid cooling plate to move away from the direction of the variable thermal resistance layer so as to realize adjustment of the thermal resistance value of the variable thermal resistance layer.
2. The battery thermal management system of claim 1, wherein the variable thermal resistance layer comprises, by weight, 100 parts of polyether polyol, 35-55 parts of toluene diisocyanate, 2.0-4.5 parts of water, 0.5-2.5 parts of silicone oil foam stabilizer, 0.1-0.5 parts of amine catalyst, 0.1-0.4 parts of tin catalyst and 30-40 parts of diamond powder, wherein the average particle size of the diamond powder is 5-50 μm.
3. The battery thermal management system of claim 2, wherein the diamond powder is a silane modified diamond powder, the method of making the silane modified diamond powder comprising the steps of: (1) Mixing diamond powder and nitric acid, stirring at 70-90 ℃, and cooling to obtain diamond acid liquor; (2) Mixing a silane coupling agent with an ethanol solution, and regulating the pH to 4-5 to obtain a modified liquid; (3) Dripping the modified liquid obtained in the step (2) into the diamond acid liquid obtained in the step (1), stirring and dispersing, stirring and reacting, cooling, filtering to remove the solvent, washing and drying to obtain the silane modified diamond powder; in the step (1), the weight ratio of diamond powder to nitric acid is 50 (110-160); In the step (2), the weight ratio of the silane coupling agent to the ethanol solution is 5 (17-22), and the ethanol solution is obtained by mixing absolute ethanol and water.
4. The battery thermal management system according to claim 2, wherein the diamond powder includes diamond powder having an average particle diameter of 30 to 50 μm and diamond powder having an average particle diameter of 5 to 10 μm, and a weight ratio of the diamond powder having an average particle diameter of 30 to 50 μm to the diamond powder having an average particle diameter of 5 to 10 μm is (35 to 40): (10 to 15).
5. The battery thermal management system of claim 2, wherein the method of preparing the variable thermal resistance layer comprises the steps of: step one, mixing polyether polyol, water, silicone oil foam stabilizer, amine catalyst, tin catalyst and diamond powder, mechanically stirring, ultrasonically dispersing and vacuum defoaming to obtain a mixture; Step two, mixing the mixture obtained in the step one with toluene diisocyanate, controlling the temperature to be 25-40 ℃, and stirring at a stirring rate of 1000-3000 rpm to obtain a reaction solution; Pouring the reaction liquid obtained in the step two into a mould, foaming freely to obtain a foam block, and curing the foam block at room temperature to obtain the variable thermal resistance layer; In the second step, the toluene diisocyanate comprises toluene-2, 4-diisocyanate and toluene-2, 6-diisocyanate, and the weight ratio of the toluene-2, 4-diisocyanate to the toluene-2, 6-diisocyanate is (3.5-4.5): 1.
6. The battery thermal management system of claim 1, wherein the variable thermal resistance layer has a thickness of 300-800 μm.
7. The battery thermal management system of claim 1, wherein the thickness of the electrical heating layer is 0.2-2.0 mm.
8. The battery thermal management system of claim 7, wherein the preparation raw materials of the heat-conducting insulating package comprise a polyimide precursor solution and a first heat-conducting filler, and the weight ratio of the polyimide precursor solution to the first heat-conducting filler is (40-60): 40-60; wherein the first heat conductive filler is at least one selected from the group consisting of aluminum oxide, aluminum nitride and boron nitride, The average particle size of the first heat conducting filler is 0.1-18 mu m.
9. The battery thermal management system according to claim 1, wherein the preparation raw materials of the silica gel heat conduction interface layer comprise addition type liquid silicone rubber and a second heat conduction filler, and the weight ratio of the addition type liquid silicone rubber to the second heat conduction filler is (15-20): (80-85); The second heat conducting filler is zinc oxide or aluminum oxide, and the average particle size of the second heat conducting filler is 1-190 mu m.
10. The battery thermal management system of claim 1, further comprising a housing and a cover plate, wherein the battery module is disposed in the housing, the cover plate is disposed at an open end of the housing, the silica gel heat conducting interface layer, the electrical heating layer, the variable thermal resistance layer and the liquid cooling plate are disposed in the housing, the driving mechanism is disposed on the cover plate, and a driving end of the driving mechanism penetrates through the cover plate and is connected with the liquid cooling plate.

Description

Battery thermal management system Technical Field The application relates to the field of battery thermal management, in particular to a battery thermal management system. Background The battery cells include lithium ion batteries, sodium ion batteries, magnesium ion batteries, and the like, and comprise cylindrical battery cells, square battery cells and blade-shaped battery cells in a packaging mode. The battery cell comprises a shell, an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive plate, a negative plate and a separation membrane. A number of battery cells are connected together to form a battery module. A battery refers to a final state of a battery system incorporated in an electric vehicle, and generally includes one or more battery modules, and a case for fixing the one or more battery modules. Electrochemical cycling performance and safety performance of the battery are closely related to the working temperature. The optimal temperature working range and allowable temperature range of the battery are generally 20-30 ℃. In the process of charging and discharging, or influenced by external environment, the battery can be overheated or overcooled, and the performance and the service life of the battery can be directly influenced by the overheating or overcooling of the battery, so that the battery needs to be subjected to heat management to ensure that the battery is in a proper temperature range. At present, a heating-radiating assembly is generally arranged at the bottom, the side wall or the upper part of the battery module, and a heating piece or a radiating piece is started according to the detected temperature of the battery, so that the thermal management of the battery is realized. Existing heat-dissipating components often include an electrical heating plate in contact with the battery and a liquid cooling plate in contact with the electrical heating plate. The electric heating plate comprises an electric heating element and an insulating layer for packaging the electric heating element, wherein a runner is arranged in the liquid cooling plate, and cooling liquid can circulate in the runner. When the battery temperature is too low, the electric heating plate needs to be started for heating, however, the liquid cooling plate and the cooling liquid in the liquid cooling plate inevitably form a heat leakage path, and the heating efficiency is reduced. When the temperature of the battery is too high, the liquid cooling plate needs to be started to radiate heat, and at the moment, the electric heating plate becomes extra heat resistance to interfere with radiating efficiency. Therefore, at present, one of the two heat dissipation and heating is inevitably interfered during the operation of the other, which affects the heating efficiency or the heat dissipation efficiency. Disclosure of Invention The application mainly aims to provide a battery thermal management system, which aims to solve the problem that one of a heating unit and a radiating unit in the prior art is interfered when the other one works, so that the heating efficiency or the radiating efficiency is influenced. The application provides a battery thermal management system, comprising: A battery module; The silica gel heat conduction interface layer covers the upper surface of the battery module; The electric heating layer is covered on the upper surface of the silica gel heat conduction interface layer and comprises a heating element and a heat conduction insulating packaging piece for wrapping the heating element; a variable thermal resistance layer covering the upper surface of the electric heating layer; A liquid cooling plate disposed above the variable thermal resistance layer in a vertically movable manner, and The control device comprises a temperature sensor, a controller and a driving mechanism, wherein the temperature sensor is connected with the battery module and is in communication connection with the controller, and is used for detecting the temperature of the battery module and transmitting the detected temperature to the controller, the controller is used for comparing the received temperature with a preset temperature and generating a control instruction, the driving mechanism is in communication connection with the controller and is connected with the liquid cooling plate, and the driving mechanism is used for receiving the control instruction and controlling the liquid cooling plate to move towards the direction of the variable thermal resistance layer according to the received control instruction so as to compress the variable thermal resistance layer or move away from the direction of the variable thermal resistance layer so as to realize adjustment of the thermal resistance value of the variable thermal resistance layer. Through adopting above-mentioned technical scheme, set up variable thermal resistance layer between liquid cooling board and electrical heating layer,