title: Internal potential mapping of charged solid-state-lithium ion batteries using in situ Kelvin probe force microscopy.
abstract: Solid-state-lithium ion batteries (SS-LIBs) are a promising candidate for next-generation energy storage devices. Novel methods for characterizing electrochemical reactions occurring during battery operation at the nanoscale are highly required for understanding the fundamental working principle and improving the performance of the devices. In this work, we combined Ar ion milling under non-atmospheric conditions with in situ cross-sectional Kelvin probe force microscopy (KPFM) for direct imaging of the internal electrical potential distribution of the SS-LIBs. We succeeded in the direct visualization of the change in the potential distribution of a cathode composite electrode (a mixture of the active materials, solid electrolytes, and conductive additives) arising from battery charging (electrochemical reaction). The observed results provided several insights into battery operation, such as the behavior of Li ions and inhomogeneity of electrochemical reactions in the electrode. Our method paves the way to characterize the fundamental aspects of SS-LIBs for the improvement of device performance, including the evaluation of the distribution of the Li ion depleted regions, visualization of the conductive paths, and analysis of the cause of degradation.
authors.affiliation: National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan. masuda.hideki@nims.go.jp.
authors.forename: Hideki
authors.initials: H
authors.lastname: Masuda
authors.affiliation: National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan. masuda.hideki@nims.go.jp and Global Research Center for Environment and Energy Based on Nanomaterials Science (GREEN), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ishida
authors.affiliation: TAIYO YUDEN CO., LTD., 5607-2 Nakamuroda, Takasaki, Gunma 370-3347, Japan.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ogata
authors.affiliation: TAIYO YUDEN CO., LTD., 5607-2 Nakamuroda, Takasaki, Gunma 370-3347, Japan.
authors.forename: Daigo
authors.initials: D
authors.lastname: Ito
authors.affiliation: National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan. masuda.hideki@nims.go.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fujita