Influence of formation process on gas generation and electrochemical performance of Li-rich/Si@C Li-ion batteries

Abstract

According to the unique characteristics of Li-rich manganese-based cathode materials during the first cycle charge, a pulse formation process was designed to reduce the gas production during the formation process and improve the electrochemical performance of the Li-rich/Si@C batteries. The GC-MS, SEM, XPS and electrochemical test results show that, compared with the traditional formation process by optimizing the formation process, the gas production of the batteries under the pulse formation is reduced by about 37%. After pulse formation, a dense film structure can be formed on the surface of the positive and negative active materials, the stress of the cells during the formation process can be relieved. The pulse formation process can also effectively save the formation time, shorten the time from 102.6 h to 81.5 h. In addition, the electrochemical stability during cycle is improved, after 500 cycles, both the capacity retention rate and the median voltage have been significantly improved.

Keywords

• lithium-rich manganese-based cathode material
• formation process
• gas generation
• electro-chemical performance
• lithium-ion battery