Interfacial Reconstruction Toward Reversible Mg Anode in Conventional Electrolytes

Rechargeable magnesium batteries are considered with great potential as sustainable, economic-friendly, safe energy storage techniques. Whereas, the Mg metal anode exhibits limited plating/stripping behavior in the conventional electrolytes due to the severe passivation. Herein, a facile LiI solution treatment is reported to reconstruct the interphase between Mg metal anode and electrolytes, converting the original passivation film to I-riched solid electrolyte interphase with the ability of rapid Mg²⁺ migration, which can reduce the overpotential for Mg anode plating/stripping from 2 to 0.4 V at 0.1 mA cm^-2. In addition, Li⁺ from the LiI precursor can be released and shuttles to the Mo₆S₈ cathode side, promoting cointercalation of Mg²⁺. With the simultaneous improvement of the anode and cathode, the Mg//Mo₆S₈ full cell delivers a decreasing voltage hysteresis (0.1 V) and much enhanced specific capacity (80.8 mAh g^-1). This work provides a maneuverable anode treatment for constructing a passivation-against interphase between Mg metal anode and the conventional electrolytes, contributing an insight for the development toward high-performance Mg batteries.