Kinetic Study of Parasitic Reactions in Lithium-Ion Batteries: A Case Study on LiNi0.6Mn0.2Co0.2O2.

The side reactions between the electrode materials and the non-aqueous electrolytes have been the major contributor to the degradation of electrochemical performance of lithium-ion batteries. A home-built high-precision leakage current measuring system was deployed to investigate the reaction kinetics between the delithiated LiNi0.6Mn0.2Co0.2O2 and a conventional non-aqueous electrolyte. It was found that the rate of parasitic reaction had strong dependence on the upper cutoff potential of the cathode material. The kinetic data also indicated a change of reaction mode at about 4.5 V vs. Li+/Li.