One-Pot Super Critical Fluid Synthesis of Spinel MnFe₂O₄ Nanoparticles and its Application as Anode Material for Mg-ion Battery

In present study, the synthesis of spinel MnFe2O4 nanoparticles using a facile one-pot super critical fluid method and their application for Mg-ion battery application as anode materials is reported. The synthesized MnFe2O4 nanoparticles were well characterized for their structure and morphology using XRD, SEM, TEM and EDS analysis. The average particle size of materials was less than 50 nm with spinel structure. The main feature of magnesium ion battery is its high specific capacity and large volumetric energy density, which makes it a promising alternative to Li-ion batteries. The spinel MnFe2O4 material has been used as an anode material for Mg-ion batteries. At different C-rates (0.05C to 2C), electrochemical charge-discharge behaviour has been observed. In first cycle of the phase-pure spinel structured anode, an initial specific capacity of 195.82 mAh/g, 139.70 mAh/g, 25.04 mAh/g and 14.16 mAh/g were obtained at C rate of 0.05C, 0.1C, 1C and 2C, respectively. A possible phase conversion reaction of the anode resulted in a decrease in specific capacity with increasing C-rate.