Koichi Kajihara

Evaluation of Electrochemical Characteristics of Li7La3Zr2O12 Solid Electrolyte

Introduction Rechargeable lithium ion batteries have been used as energy sources for many mobile devices because of their high energy density. However, they have suffered from safety problems at high temperatures due to use of flammable organic electrolytes. Therefore, all-solid-state lithium ion batteries with solid electrolytes have been intensively investigated. Li0.35La0.55TiO3(LLT) has been investigated as a solid electrolyte for all-solid-state lithium ion batteries. LLT has a perovskite-type structure and high lithium ion conductivity. However, the redox reaction of titanium in LLT occurs at 1.8V vs. Li / Li, which limits its practical application. Li7La3Zr2O12 (LLZ) has also been paid much attention as a solid electrolyte due to its chemical stability and high lithium ion conductivity. [2] In this study, we minutely examined the electrical characteristics of LLZ to reveal its availability as a solid electrolyte in allsolid-state lithium ion batteries.