Carbonate-assisted hydrothermal synthesis of porous hierarchical Co3O4/CuO composites as high capacity anodes for lithium-ion batteries

Abstract Through thermal decomposition of hybrid carbonate (Cu, Co) 2 (OH) 2 CO 3 precursors synthesized by a simple carbonate-assisted hydrothermal method, porous hierarchical Co 3 O 4 /CuO composites with different ratios of Co to Cu were successfully fabricated. A cooperative self-assembly effect of different carbonates has been proposed to explain the formation of nanosheets assembled hierarchical (Cu, Co) 2 (OH) 2 CO 3 precursor. Electrochemical lithium storage properties of all the composites are evaluated as anode materials for lithium-ion batteries. It is found that the ratio of Co to Cu plays a vital role in affecting the morphology, structure and subsequent electrochemical performance of the Co 3 O 4 /CuO composites. Owing to the superior porous hierarchical structure and synergistic lithium storage effect of both active electrode materials, the Co 3 O 4 /CuO composites demonstrate higher capacities and enhanced cycling stability compared to pure Co 3 O 4 or CuO electrodes. The Co 3 O 4 /CuO composite (Co: Cu = 6: 1) electrode delivers a high reversible capacity of 1056 mAh g −1  at a current density of 200 mA g −1 for 500 cycles. With the superior electrochemical performance and easy preparation, the porous hierarchical Co 3 O 4 /CuO composites demonstrate promising application potential as anode materials for next generation high performance LIBs.