MgFeSiO4 prepared via a molten salt method as a new cathode material for rechargeable magnesium batteries

Well-crystallized MgFeSiO₄ microparticles were synthesized at different temperatures by a simple molten salt method using KCl flux. As a new cathode for rechargeable magnesium batteries, the material shows a reversible Mg²⁺ intercalation-deintercalation process. In 0.25 mol/L Mg(AlCl₂EtBu)₂/THF electrolyte, MgFeSiO₄ synthesized at 900??C can deliver a 125.1 mAh/g initial discharge capacity and a 91.4% capacity retention on the 20th cycle at a rate of 0.1C (about 15.6 mA/g). The results show that MgFeSiO₄ could be a good host for Mg²⁺ intercalation, and a potential cathode material for high-energy rechargeable magnesium batteries.