Co-sintering process of LiCoO2 cathodes and NASICON-type LATP solid electrolytes studied by X-ray diffraction and X-ray absorption near edge structure

Fumihiko Ichihara; Shogo Miyoshi; Takuya Masuda

doi:10.1039/d2cp01020h

Co-sintering process of LiCoO₂ cathodes and NASICON-type LATP solid electrolytes studied by X-ray diffraction and X-ray absorption near edge structure

Phys Chem Chem Phys. 2022 Nov 2;24(42):25878-25884. doi: 10.1039/d2cp01020h.

Authors

Fumihiko Ichihara¹, Shogo Miyoshi¹, Takuya Masuda^{1

2}

Affiliations

¹ Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan. MASUDA.Takuya@nims.go.jp.
² Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.

PMID: 36168846
DOI: 10.1039/d2cp01020h

Abstract

The composites of a high-capacity cathode material in lithium-ion batteries, LiCoO₂ (LCO) and an oxide-based solid electrolyte, Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP), were sintered at various temperatures and their reaction products were subsequently identified by X-ray diffraction (XRD) and X-ray absorption near edge structure (XANES). Rietveld analysis of XRD and the linear combination fitting of XANES showed that the reaction of LCO and LATP proceeds via three major steps; from 300 °C to 500 °C, LCO and LATP react with each other to form Co₃O₄, amorphous TiO₂ and Li₃PO₄; from 500 °C at which crystalline LCO is completely decomposed, LATP reacts not only with remaining amorphous/low crystalline LCO but also with Co₃O₄ to form LiCoPO₄ and TiO₂; from 700 °C to 750 °C, Co₃O₄ and TiO₂ react with each other to form CoTiO₃. The final products at 900 °C are LiCoPO₄, CoTiO₃, TiO₂, and Li₃PO₄.