Lasagne-like Bi₂O₃/Bi dual-carbon composites for high-capacity and long-life lithium storage

Bismuth, as an alloy-type anode material for lithium-ion batteries, demonstrates high specific capacity and volumetric energy density. Nonetheless, the substantial volume expansion and capacity fade arising from prolonged charge-discharge cycling have impeded its commercial implementation. In this study, we constructed graphene, amorphous carbon layer double-coated Bi₂O₃/Bi composites (Gr@Bi₂O₃/Bi@AC) with approximate lasagna structure as anode for lithium-ion batteries. The incorporation of Bi₂O₃not only facilitates lithium-ion adsorption but also mitigates volume fluctuations via conversion reactions. Multilayer graphene increases the specific surface area and enhances ion/electron transport, while its combination with amorphous carbon provides robust dual-layer protection and structural integrity. As a result, the Gr@Bi₂O₃/Bi@AC anode delivers a high initial coulombic efficiency (69.3 %), remarkable rate performance (466 mAh g⁻¹at 2000 mA g⁻¹), and outstanding long-term cycling stability (1012.1 mAh g⁻¹at 500 mA g⁻¹over 500 cycles). This work provides a novel design to cope with the capacity decay of Bi-based materials by optimizing the dual carbon layer structure and multi-component synergistic engineering. The obtained conclusion would provide an innovative approach to design anode materials with both high capacity and stability.