Enhancing the electrode performance of Co3O4 through Co3O4@a-TiO2 core–shell microcubes with controllable pore size

Abstract

Co₃O₄ is a potential high-capacity anode material for lithium ion batteries (LIBs), but it usually has poor cycling stability due to its enormous volume variation during the conversion reaction process. A protection strategy has been developed to enhance the electrode performance of Co₃O₄ through construction of Co₃O₄@amorphous-TiO₂ (Co₃O₄@a-TiO₂) core–shell nanostructures with controllable pore size, realized by precisely regulating the volume ratio of ethanol to water. To our knowledge, this is the first time to use core–shell Co₃O₄@a-TiO₂ as the anode material for the lithium-ion batteries. Noteworthy, electrochemical performances of the materials were found to be strongly correlated with their porous structures. With the excellent stability of TiO₂ sheath, high capacity of Co₃O₄ core, and the optimized porous size, these unique Co₃O₄@a-TiO₂ core–shell microcubes exhibit high capacity, long cycle life and good rate capability as advanced electrode materials for lithium-ion batteries. A high reversible capacity of ∼800 mA h g⁻¹ is obtained at 500 mA g⁻¹, keeping the value stable after 60 cycles. We anticipate that such a demonstration presents a versatile method toward synthesizing other high-performance and multifunctional metal oxides@a-TiO₂ nanocomposites for LIBs in near future.