Jung-Yi Yu

Improved Cycle Life and Storage Performance in High-Voltage Operated Li2MnO3-LiMO2(M=Ni, Co, Mn)/Graphite Cell System by Fluorine Compounds as Main Electrolyte Solvent

Li2MnO3-LiMO2(M=Ni, Co, Mn) nano-composite is a promising cathode material for xEV application due to its high theoretic capacity. However high voltage operating system of Li2MnO3-LiMO2(M=Ni, Co, Mn) has worked as a hurdle in its application because of the inherent demerits, such as cycle life degradation and gas evolution. In order to enhance cell performance of Li2MnO3-LiMO2(M=Ni, Co, Mn)/graphite cell, we examined electrolyte mainly composed of FEC, fluroalkyl ether and LiPF6 (F-based EL). F-based EL showed much better discharging retention ratio than 1.3 M LiPF6 EC/EMC/DMC (3/4/3, v/v/v) (STD). Furthermore gas evolution, especially CO and CO2 during 60 o C storage for 30 days was dramatically