Modification of Interface Between LiCoO[sub 2] Electrode and Li[sub 2]S–P[sub 2]S[sub 5] Solid Electrolyte Using Li[sub 2]O–SiO[sub 2] Glassy Layers

Abstract

Effects of modification of the electrode/electrolyte interface with thin films on impedance profiles and rate capabilities of all-solid-state glass ceramic/ cells were investigated. Large resistance was observed at the –electrode/sulfide–electrolyte interface in all-solid-state cells. The interfacial resistance was decreased by oxide coatings on ; the effective coatings were a lithium-ion conductive glassy film and an insulative film. The coating film decreased the interfacial resistance more effectively when the coating amounts increased from (film thickness was ca. ). However, of coating exhibited higher interfacial resistance than noncoating because the thick coating film acted as a high-resistance layer. Temperature dependence of the interfacial resistance suggests that the resistance decrease was achieved mainly by an increase of pre-exponential factor rather than by a decrease of activation energy for ion conduction at the interface. At room temperature, all-solid-state cells with -coated were discharged even under the high current density, .