Bulk-Type all-Solid-State lithium secondary batteries using highly ion-Conductive sulfide solid electrolyte thin films

Abstract

LiCoO2 particles were coated with 33Li4GeS 4·67Li3PS4 (mol%) solid electrolyte (SE) thin films by pulsed laser deposition (PLD). The all-solid-state cells using positive electrodes, composed of only LiCoO2 particles coated with SE thin films, were fabricated and their electrochemical performances were investigated. The cell was charged and discharged with a higher capacity of 67mAhg-1 than that using LiCoO2 particles without SE-coating. Moreover, the capacity of all-solid-state cell increased to 80mAhg-1 after enhancing the ionic conductivity of SE thin films by heat treatment at 200°C. The use of highly lithium-ion conductive thin films was effective in the formation of sufficient lithium-ion conduction paths in positive electrodes for bulk-type all-solid-state batteries. ©The Electrochemical Society of Japan, All rights reserved.