Progress in research and development of electric vehicle battery pack thermal management system

The new energy automotive industry, represented by electric vehicles, is one of the strategic emerging industries that the country has focused on in the 13th Five-Year Plan period. As the main energy storage device of electric vehicles, the battery pack is a key equipment for electric vehicles. The temperature rise in the battery pack will seriously affect the operation of the electrochemical system of the battery pack, cycle life and charge acceptability, battery pack power, safety and Reliability; Temperature imbalance among the cells in the battery pack will eventually affect the consistency of the battery performance and the accuracy of the battery state of charge (SOC) estimation, affecting the system control and life of the electric vehicle. Therefore, thermal management of battery packs has become a bottleneck affecting the survival and development of the new energy automotive industry. In order to improve the performance of the entire vehicle and make the battery pack perform its best performance and life, it is necessary to optimize the structure of the battery pack and design an advanced battery pack thermal management system (BTMS).

Under the support of major projects of the Chinese Academy of Sciences Knowledge Innovation Project, scientists from the Research Institute of Heat and Mass Transfer at the Institute of Engineering Thermophysics, Chinese Academy of Sciences have successfully developed a 3mm ultra-thin integrated type battery cell for electric vehicles using the micro-groove group composite phase change heat dissipation technology. The thermal management unit uses the thermal management unit to construct a specific model of the micro-groove group composite phase change integrated thermal management electric vehicle battery pack prototype. The prototype achieves the technical specifications of the battery with an energy density ≥ 80Wh/kg, cycle life ≥ 1500 times, and a temperature difference between battery cells ≤ 3°C. The battery can be maintained at 25-40°C. Good operating temperature range. The research results solved the technical difficulty of maintaining uniform temperature among the high energy density battery grouping monomers existing in the electric vehicle industry.

Around the task of the project, the researchers published 6 papers in total, including 2 international authoritative heat transfer journals, 1 domestic core journal, 2 international conferences, 1 domestic conference, and 3 patent applications, among which invention patent 1 Items, utility models 2. At present, the project has passed acceptance, and the research results have aroused widespread concern in the domestic new energy automotive industry and local governments, and began to enter the stage of industrialization and application.