Synthesis of Multiphase Cu₃Ge/GeO_<i>x</i>/CuGeO₃ Nanowires for Use as Lithium‐Ion Battery Anodes

Abstract

Abstract Multiphase nanowires composed of Cu 3 Ge, GeO x , and CuGeO 3 , obtained through the thermochemical reduction of CuGeO 3 , are investigated as anode materials for lithium‐ion batteries. Initially, CuGeO 3 nanowires are prepared by using a facile hydrothermal process without the use of any templates or surfactants. The as‐prepared CuGeO 3 nanowires are demonstrated to be single‐crystalline with a diameter of around 70 nm and a length of 0.5–2 μm. Subsequently, multiphase Cu 3 Ge/GeO x /CuGeO 3 nanowires are prepared through the controlled thermochemical reduction of the as‐prepared CuGeO 3 nanowires under a H 2 atmosphere at 250 °C. Upon thermochemical reduction, the wire‐shaped morphology is retained, but the phase partially transforms to a mixture of crystalline Cu 3 Ge nano‐domains (&lt;10 nm) with high electronic conductivity and amorphous GeO x . The newly generated multiphase nanowires exhibit enhanced cycle stability with high lithium‐storage capability compared to that of the as‐prepared CuGeO 3 nanowires.