Porous CuCo₂O₄ nanocubes wrapped by reduced graphene oxide as high-performance lithium-ion battery anodes

A composite of porous CuCo₂O₄ nanocubes well wrapped by reduced graphene oxide (rGO) sheets has been synthesized by a facile microwave-assisted solvothermal reaction and applied as anode in lithium ion batteries (LIBs). The porous structure of the CuCo₂O₄ nanocubes not only provides a high surface area for contact with the electrolyte, but also assists by accommodating volume change upon charging-discharging. Impedance measurements and transmission electron microscopy show that incorporation of rGO further decreases the charge transfer resistance and improves the structural stability of the composite. As an anode material for a LIB, the composite exhibits a high stable capacity of ∼570 mA h g^-1 at a current density of 1000 mA g^-1 after 350 cycles. With a high specific surface area and a low charge transfer resistance, the composite anode shows impressive performance especially at high current density. The LIB shows a high capacity of ∼450 mA h g^-1 even at a high current density of 5000 mA g^-1, demonstrating the composite's potential for applications in LIBs with long cycling life and high power density. © The Royal Society of Chemistry 2014.