Lithium-ion conductive glass-ceramics with composition ratio control and their electrochemical characteristics

Abstract

We have developed the high ionic conducting glass-ceramics with the crystalline phase of Li_1+x+yAl_x(Ti_2−yGe_y)P_3−zSi_zO₁₂ with the NASICON type structure. This type of glass-ceramics exhibits high lithium-ion conductivity of 10⁻⁴ S cm⁻¹ or more at room temperature. Although this glass-ceramics reacts with Li metal gradually with the passage of time, we have improved the thermal and electrochemical properties by controlling constitution of Ti and Ge in the Li-ion conducting glass-ceramics with the NASICON type structure. Those glass-ceramics worked well as electrolyte of a lithium-ion secondary battery by the charge–discharge test using a half cell with LiFePO₄ cathode at room temperature.