Carbon-coated Bi5Nb3O15 as anode material in rechargeable batteries for enhanced lithium storage

Bismuth can alloy with lithium to generate Li3Bi with the volumetric capacity of about 3765 mAh cm−3 (386 mAh g−1), rendering bismuth-based materials as attractive alloying-type electrode materials for rechargeable batteries. In this work, bismuth-based material Bi5Nb3O15 @C is fabricated as anode material through a traditional solid-state reaction with glucose as carbon source. Bi5Nb3O15 @C composite is well dispersed, with small particle size of 0.5-2.0 µm. The electrochemical performance of Bi5Nb3O15 @C is reinforced by carbon-coated layer as desired. The Bi5Nb3O15 @C exhibits a high specific capacity of 338.56 mAh g−1 at a current density of 100 mA g−1. And it also presents an excellent cycling stability with a capacity of 212.06 mAh g−1 over 100 cycles at 100 mA g−1. As a comparison, bulk Bi5Nb3O15 without carbon-coating only remains 319.62 mAh g−1 at 100 mA g−1, revealing poor cycle and rate performances. Furthermore, in-situ X-ray diffraction experiments investigate the alloying/dealloying behavior of Bi5Nb3O15 @C. These insights will benefit the discovery of novel anode materials for lithium-ion batteries.