Porous Co3O4 Nanosheets with Extraordinarily High Discharge Capacity for Lithium Batteries

Abstract

Cobalt and battery charge: Porous Co₃O₄ with a hexagonal sheetlike structure has been synthesized through precursor Co(OH)₂ hexagonal nanosheets (see figure). The as-prepared nanosheets exhibit excellent Li-battery performance with a good cycle life and high capacity (1450 mAh g⁻¹). In this work, we report the simple solid-state formation of porous Co₃O₄ with a hexagonal sheetlike structure. The synthesis is based on controlled thermal oxidative decomposition and recrystallization of precursor Co(OH)₂ hexagonal nanosheets. After thermal treatment, the hexagonal sheetlike morphology can be completely preserved, despite the fact that there is a volume contraction accompanying the process: Co(OH)₂→Co₃O₄. Because of the intrinsic crystal contraction, a highly porous structure of the product is simultaneously created. Importantly, when evaluated as electrode materials for lithium-ion batteries, the as-prepared porous Co₃O₄ nanosheets exhibit superior Li-battery performance with good cycle life and high capacity (1450 mAh g⁻¹) due to their porous sheetlike structure and small size. As far as we know, the performance of the Co₃O₄-based anode materials for lithium batteries presented here is the best up to now. Considering the improved performance and cost-effective synthesis, the as-prepared porous Co₃O₄ nanosheets might be suitable as anode electrodes for next-generation lithium-ion batteries.