Facile fabrication of hollow CuO nanocubes for enhanced lithium/sodium storage performance

Abstract

Hollow nanomaterials provide abundant reaction sites and facilitate tolerance for volume changes during the charging–discharging process, and are potential candidates for alkaline ion storage. In this work, hollow CuO nanocubes are synthesized via solvothermal reaction and subsequent annealing, which serve as alkali-ion battery anode materials. Based on Ostwald ripening, the precursor Cu₂O nanocubes with vacancies are initially fabricated during the solvothermal process. Subsequently, after thermal annealing, the Cu₂O nanocubes are converted into hollow CuO nanocubes, which could enhance lithium/sodium storage performances. As anodes for lithium-ion batteries, hollow CuO nanocubes exhibit a high capacity of 865 mAh g⁻¹ at 0.1 A g⁻¹ after 100 cycles. Meanwhile, SIBs with the CuO nanocube anode also exhibit excellent electrochemical performance.