Synergistic design of hollow CuO nanocubes supported on graphene for high-performance lithium-ion battery anodes

Improving the performance and lifespan of lithium-ion battery anodes has long been hindered by challenges such as volume changes, capacity degradation, and increased electrical resistance during charge–discharge cycles. In this study, we propose a synergistic design strategy to overcome these limitations by synthesizing hollow CuO nanocubes supported on graphene (H-CuO/G) as a high-performance anode material. This approach combines the structural benefits of hollow nanomaterials, which accommodate volume changes and provide abundant active sites, with the excellent electrical conductivity and mechanical stability of graphene. The synthesis involves a simple polyol method to create uniform Cu₂O nanocubes supported on graphene, followed by a continuous high-temperature oxidation process utilizing the Kirkendall effect to form hollow CuO structures. The resulting H-CuO/G anode achieved a remarkably high discharge capacity of 1,366 mAh·g⁻¹ at a current density of 0.1 A·g⁻¹ and maintained stable cycling performance over 1,000 cycles, even at a high current density of 5.0 A·g⁻¹. This outstanding performance is attributed to the synergistic effects between the hollow CuO nanocubes, which offer a high specific surface area, and the graphene support, which enhances electronic conductivity and structural stability.