Electrochemical Analyzing Method of the Charge Transfer Reaction at the Interface between Sulfide-based Solid Electrolyte and Positive Electrode Material with Microelectrode

Abstract

The charge transfer reaction at the LiNbO3-coated LiCoO2/sulfide-based solid electrolyte interface was investigated with a Ni microelectrode. A two-electrode cell was assembled and two electrochemical measurements were performed in order to evaluate exchange currents at various temperatures and activation energy for charge transfer reaction (ECT ) for positive electrode material. ECT at the LiNbO3-coated LiCoO2 /solid electrolyte interface was evaluated to be 48 kJ mol-1. This value was smaller than ECT at the LiCoO2/organic electrolyte interface. In case of Li metal negative electrode, it has already found that ECT at the Li metal/solid electrolyte interface is smaller than ECT at the Li metal/organic electrolyte interface due to the lack of a desolvation process. Similar to this, it was demonstrated that the charge transfer reaction at the LiCoO2/solid electrolyte didn’t contain the desolvation process.