Interface and energy band manipulation of Bi₂O₃-Bi₂S₃ electrode enabling advanced magnesium-ion storage

Rechargeable magnesium-ion (Mg-ion) batteries have attracted wide attention for energy storage. However, magnesium anode is still limited by the irreversible Mg plating/stripping procedure. Herein, a well-designed binary Bi₂O₃-Bi₂S₃ (BO-BS) heterostructure is fulfilled by virtue of the cooperative interface and energy band engineering targeted fast Mg-ion storage. The built-in electronic field resulting from the asymmetrical electron distribution at the interface of electron-rich S center at Bi₂S₃ side and electron-poor O center at Bi₂O₃ side effectively accelerates the electrochemical reaction kinetics in the Mg-ion battery system. Moreover, the as-designed heterogenous interface also benefits to maintaining the electrode integrity. With these advantages, the BO-BS electrode displays a remarkable capacity of 150.36 mAh g⁻¹ at 0.67 A g^–1 and a superior cycling stability. This investigation would offer novel insights into the rational design of functional heterogenous electrode materials targeted the fast reaction kinetics for energy storage systems.