Bulk-type All-solid-state Lithium Secondary Batteries Using Highly Ion-conductive Sulfide Solid Electrolyte Thin Films

LiCoO2 particles were coated with 33Li(4)GeS(4).67Li(3)PS(4) (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 67 mAh g(-1) than that using LiCoO2 particles without SE-coating. Moreover, the capacity of all-solid-state cell increased to 80 mAh g(-1) after enhancing the ionic conductivity of SE thin films by heat treatment at 200 degrees 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. (C) The Electrochemical Society of Japan, All rights reserved.