Hydrothermal growth of Cobalt germanate/reduced graphene oxide nanocomposite as superior anode materials for Lithium-ion batteries

Highlights: • The nanosized Co₂GeO₄ and Co₂GeO₄/RGO nanocomposites were prepared by a facile one pot hydrothermal route. • The Co₂GeO₄ and Co₂GeO₄/RGO nanocomposites could be used as novel high capacity anodes with both alloying and conversion reactions. • The RGO incorporation can improve the electrochemical performance of Co₂GeO₄ by buffering the volume changes and enhancing the conductivity of the electrodes. • The CGO/RGO nanocomposites exhibit a large reversible capacity of 1250 mAh g⁻¹ for the first cycle and a capacity retention of 1085 mAh g⁻¹ after 100 cycles. Remarkable rate performance was also recorded. - Abstract: Well dispersed Co₂GeO₄ (CGO) nanoplates and CGO/reduced graphene oxide (RGO) nanocomposites are prepared via hydrothermal method and characterized as novel lithium anode materials for the first time. Electrochemical measurements demonstrate that the CGO/RGO nanocomposites exhibit a large reversible capacity of 1250 mAh g⁻¹ for the first cycle and a capacity retention of 1085 mAh g⁻¹ after 100 cycles. Remarkable rate performance was also recorded. The superior electrochemical performance of the CGO/RGO nanocomposites electrode compared to the pure CGO electrode can be attributed to the well dispersed RGO which enhances the electronic conductivity and accommodate the volume change during the conversion reactions