PDF/月刊誌論文/code:pg_1103_03 マテリアル インテグレーション 2011年3月号
ELECTRONIC CERAMICS グリーンイノベーションを支える産総研の電子セラミックス研究

次世代型蓄電池のためのリチウムイオン伝導体の開発
■著者
独立行政法人　産業技術総合研究所　先進製造プロセス研究部門結晶制御プロセス研究グループ 秋本 順二

■要約
All solid-state lithium-ion batteries are expected to be a future battery technology because of their high energy density and high safety. Therefore, there has been an extensive effort to develop Li-ion-conducting inorganic materials for the use as solid electrolyte which is a key material of all solid-state lithium-ion batteries. In this article, we review the recent studies of garnet-related Li-ion conductors which are a new class of solid-state fast Li-ion conductors, and then report our structural studies on single-crystal X-ray diffraction analysis of cubic and tetragonal garnet-related Li7La3Zr2O12. Particularly, cubic Li7La3Zr2O12 is one of the good candidates for solid electrolyte, as this material has the good Li-ion conduction property, excellent thermal performance, and chemical stabilities against molten lithium, air, and moisture. It is revealed by our structural studies that the three-dimensional Li-ion conduction pathway of garnet-related Li-ion conductors is formed by the basic unit of loop structure. Structure analysis also identifies the Li atomic arrangement with occupational disordering and short Li-Li distance in the pathway for cubic Li7La3Zr2O12. A comparison of crystal structure of cubic Li7La3Zr2O12 with those of known Li-ion conducting oxide materials may provide clues to help improve the Li-ion conduction property.