Reaction at Interface of LiCoO2 Layer and Li2O-B2O3-P2O5 Electrolyte Fabricated by Aerosol Flame Deposition

Abstract

The thin film battery has been fabricated by CVD, sputtering, pulse laser deposition and Sol-gel method. Among these methods RF magnetron sputtering and pulse laser deposition methods have demonstrated the successful thin film battery. However these processes using the plasma under high vacuum, it needs long time to deposit the electrolyte layer and the cathode layer of a few micrometers due to low deposition speed. The Li2O-P2O5-B2O3 glass soot which is synthesized by Aerosol Flame Deposition was densified by heat treatment at 400~600°C for 2h [1]. In this work the average conductivity and activation energy of glass electrolyte were investigated from 10mHz to 10MHz with an ac signal amplitude of 5mV by AC impedance measurement. The conductivity of electrolyte prepared at conditions of 20sccm flow rate of BCl3 and 80sccm flow rate of POCl3 was about 10-6 S/cm at room temperature. And the reaction at interface LiCoO2 layer and electrolyte fabricated by the Aerosol Flame Deposition method was investigated by various heat treatments conditions. The electrochemical characteristic of thin film battery was investigated by using cell, which consisted of a Li metal as anode. Thin film battery was performed charge capacities between 4.4 and 3.2V at the rate of 0.2mA/cm2. Cyclic voltammograms of thin film battery were collected at a sweep rate of 0.1mV/s.