Sponge-like porous manganese(II,III) oxide as a highly efficient cathode material for rechargeable magnesium ion batteries

Here, we are the first to report a spinel type Mn3O4 as cathode material for Mg-ion battery (MIB) with graphite foil (Gif) as current collector. High Coulombic efficiency and good cyclic stability of Mn3O4 are demonstrated, and the process is enhanced by using Mn3O4 nanoparticles with a sponge-like morphology. The powder exhibits a network of interconnected mesopores with well-dispersed nanoparticles (∼10 nm) and large specific surface area (102 m2 g−1 ). This structural configuration provides easy access for electrolyte penetration which markedly enhances the utilization of electroactive material, generates high ion flux across the electrode−electrolyte interface and provides more active sites for electrochemical reactions to occur. This study can possibly open the way for exploring other similar compounds with a spinel type structure for MIB.