Interfacial Coupling\ntoward Bismuth Sulfide/MXene\nHeterostructures Empowering Reversible Magnesium Storage

Bismuth-based compounds based on conversion-alloying\nreactions\nof multielectron transfer have attracted extensive attention as alternative\nanode candidates for rechargeable magnesium batteries (rMBs). However,\nthe inadequate magnesium storage capability induced by the sluggish\nkinetics, poor reversibility, and terrible structural stability impedes\ntheir practical utilization. Herein, monodispersed Bi<sub>2</sub>S<sub>3</sub> anchored on MXene has been prepared via a simple self-assembly\nstrategy to induce the interfacial bonding of Ti–S and Ti–O–Bi.\nUnique superiority, including good electrical conductivity, high mechanical\nstrength, and rapid charge transfer, is cleverly integrated together\nin the Bi<sub>2</sub>S<sub>3</sub>/MXene heterostructures, which endowed\nheterostructures with enhanced magnesium storage performance. Density\nfunctional theory calculations combined with kinetic behavior analyses\nconfirm the favorable charge transfer and low ion diffusion barrier\nin hybrids. Furthermore, a stepwise insertion-conversion-alloying\nreaction mechanism is revealed in depth by <i>ex situ</i> investigations, which may also account for promoting performance.\nThis work provides significant inspirations for constructing ingenious\nmulticompositional hybrids by strong interfacial coupling engineering\ntoward high-performance energy storage devices.