Solving the Structure of Li Ion Battery Materials with Precession Electron Diffraction: Application to Li₂CoPO₄F

Abstract

The crystal structure of the Li 2 CoPO 4 F high-voltage cathode for Li ion rechargeable batteries has been completely solved from precession electron diffraction (PED) data, including the location of the Li atoms. The crystal structure consists of infinite chains of CoO 4 F 2 octahedra sharing common edges and linked into a 3D framework by PO 4 tetrahedra. The chains and phosphate anions together delimit tunnels filled with the Li atoms. This investigation demonstrates that PED can be successfully applied for obtaining structural information on a variety of Li-containing electrode materials even from single micrometer-sized crystallites.