Improved thermal stability of graphite electrodes in lithium-ion batteries using 4-isopropyl phenyl diphenyl phosphate as an additive

To enhance the thermal stability of graphite electrodes for lithium-ion batteries, 4-isopropyl phenyl diphenyl phosphate (IPPP) was investigated as an additive in the electrolyte of 1.0 M LiPF6 in ethylene carbonate and diethyl carbonate (1: 1 in weight). The electrochemical performance of Li/IPPP-electrolyte/C half cells was evaluated. The thermal behavior of LixC6 and LixC6-IPPP-electrolytes were examined using a C80 micro-calorimeter. Electrolytes with 5 and 10% IPPP improve the thermal stability of the graphite electrode in the tests. The electrochemical performance of Li/IPPP-electrolyte/C cells is not degraded by the addition of this amount of IPPP to the electrolyte.