Optimization of Drying Process of Lithium Battery Pole Piece Based on Simulation Technology

Abstract

After electrode pulping and coating of lithium battery, it is necessary to dry the pole pieces, but there is a contradiction between drying efficiency and drying quality. In the process of rapid drying, the binder components are easy to migrate, which reduces the adhesion of the pole pieces, leading to the increase of internal resistance of the pole pieces and subsequent manufacturing defects. Therefore, this paper puts forward an optimization scheme of pole piece efficient drying process. Firstly, based on the analysis of the transfer process of heat and solvent quality in the drying process, the calculation method of drying curve is put forward, and the optimal design criteria of drying parameters are established. Furthermore, a multiphase flow and heat transfer model of drying process is constructed, and the oven structure and parameters are optimized based on multiphase flow simulation. The experimental results of drying process optimization of positive pole pieces show that the mass production speed of 51 Ah positive pole is increased by 25% after process optimization. The adhesion of the A surface of the pole piece is increased by 6.5%, and the difference between the A and B surfaces is decreased by 91%. The average resistance of the pole piece decreases by 12%, which meets the high requirements for the quality and efficiency of pole piece drying for automotive lithium-ion batteries.