Interface Enhanced Formation System Design

Soft packing lithium battery formation has three main parts:the formation power supply cabinet, hot pressing mechanism, cold pressing mechanism. How will the combination of these three institutions reasonable together, improve the efficiency of formation process of lithium batteries, lithium battery was to improve the work efficiency and the capacity and stability is the urgent need to solve the problem in the production of lithium batteries.During the forming process of two factors play a decisive role, that is, the pressure and temperature. Solid Electrolyte Interface (SEI) film at high temperature, the corresponding loose more thick, SEI film at low temperature corresponding to dense more thin, high rate considering the high temperature, high capacity at low temperature is considered, mostly at room temperature. The pressure to ensure that the electrolyte and the pole piece full absorption and electrical core thickness uniform, pressure can protect the battery interface uniformity and smoothness, not the influence of the battery stability because gas during its formationPaper mainly relates to the soft packing lithium battery production process, design a new automation equipment for formation process to enhanced interface of battery. First proposed for lithium battery at constant temperature and constant pressure environment formation, this formation can be enhanced chemical interface of lithium battery. That is Interface enhanced formation (Interface Enhanced Formation referred to as IEF) system.This is a high current battery formation system, realize the constant temperature and constant pressure into the environment by using hot fixture in the soft packing lithium battery formation process, so that the battery interface has been strengthened and protection. And hot and cold fixture design near, the battery after hot pressing formation, in a short time within the limited cold pressure causes the battery was capable of fast setting.Hot fixture and cold fixture temperature adjusting, hot pressing fixture temperature by a thermostat thermostatic control, cold pressing fixture temperature by circulating cooling water control, adopts cooling water temperature controller and an electromagnetic valve control, in order to prevent the cooling water temperature is too low when the cold fixture dew, machine shutdown water closed. Selection of gas-liquid pressurized cylinder pressure, pressure size adjustable, in the formation process can be on the pressure cylinder for increasing and relief pressure control, so that the whole process, to keep the pressure constant.Through the analysis of research on the theory and practical debugging production situation, this system can meet the expected design effect. Pressure, temperature, repeated positioning accuracy of mechanism from the test data show that the system is a qualified system can meet the design requirements, and the system battery formation rate reaches above99%, the quality of battery was formation, whether it is the battery capacity, stability or appearance than before the forming methods have significantly improved.