Visualization of the reaction distribution in a composite cathode for an all-solid-state lithium-ion battery

In this work, we directly observed the reaction distribution formed in a composite cathode of the all-solid-state lithium-ion battery (ASSLIB) LiCoO2/Li2.2C0.8B0.2O3|Li2.2C0.8B0.2O3|PEO|Li during charging by using the two-dimensional X-ray absorption spectroscopy (2D-XAS) at Co K-edge. The two-dimensional mapping of the state of charge in a composite cathode indicated that the reaction distribution was formed during charging process in the in-plane direction due to the disconnection in electron pathway at cracks. It was experimentally confirmed that the 2D-XAS technique was a useful tool for evaluating the reaction distribution in a composite cathode of an ASSLIB and investigating the influence factors for the formation of the reaction distribution. (C) 2017 The Ceramic Society of Japan. All rights reserved.