Structural Analysis of Electrode-Electrolyte Interface in Lithium Batteries

Abstract

Batteries are a key technology in todays society. Since the lithium-ion configuration has been widely accepted, significant efforts have been devoted to attain high energy and power densities to produce an excellent energy storage system without any safety issue. To improve the reliability and power characteristics of batteries, deep insights into the reactions at the electrodeelectrolyte interface are necessary. It is rather difficult to detect the reaction at the electrochemical interface using polycrystalline electrode materials, which are used for practical battery systems. The model systems with epitaxial thin-film electrodes might be suitable for understanding these reactions, because the film electrodes provide flat surface, which makes easier to detect the reactions by in situ scattering techniques. The in situ techniques for directly observing surface structural changes of the electrodes have been developed for surface X-ray scattering and neutron reflectivity techniques. These techniques are reviewed and future studies on the interfacial reaction in batteries will be discussed.