Copper ferrites@reduced graphene oxide anode materials for advanced lithium storage applications

Copper ferrites are emerging transition metal oxides that have potential applications in energy storage devices. However, it still lacks in-depth designing of copper ferrites based anode architectures with enhanced electroactivity for lithium-ion batteries. Here, we report a facile synthesis technology of copper ferrites anchored on reduced graphene oxide (CuFeO₂@rGO and Cu/CuFe₂O₄@rGO) as the high-performance electrodes. In the resulting configuration, reduced graphene offers continuous conductive channels for electron/ion transfer and high specific surface area to accommodate the volume expansion of copper ferrites. Consequently, the sheet-on-sheet CuFeO₂@rGO electrode exhibits a high reversible capacity (587 mAh g^-1 after 100 cycles at 200 mA g^-1). In particular, Cu/CuFe₂O₄@rGO hybrid, which combines the advantages of nano-copper and reduced graphene, manifests a significant enhancement in lithium storage properties. It reveals superior rate capability (723 mAh g^-1 at 800 mA g^-1; 560 mAh g^-1 at 3200 mA g^-1) and robust cycling capability (1102 mAh g^-1 after 250 cycles at 800 mA g^-1). This unique structure design provides a strategy for the development of multivalent metal oxides in lithium storage device applications.