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.