Properties of manganese (III) oxide (Mn₂O₃) catalyst for use in Fe-air batteries

Materials Modelling Centre, University of Limpopo, Private Bag x1106, Sovenga 0727, South Africa

^* Corresponding author: matlouedwin49@gmail.com

Abstract

Fe-air batteries are promising energy storage devices with high energy density, excellent electrochemical performance, and affordability with low toxicity. However, challenges such as high over-potential, limited cycle life, and side reactions hinder its widespread applications. To address this, we performed density functional theory (DFT) calculations to investigate the structural, thermodynamic, and electronic properties of bulk Mn₂O₃. The calculated lattice parameters for Mn₂O₃ were in good agreement with experimental data with less than 2% difference. Mn2O3 is thermodynamically stable, shown by negative ΔH°f (-821.46 kJ/mol). The electronic band structures and the density of states (DOS) showed that the system has a direct band gap of 0.449 eV, displaying semiconducting behaviour. Thus, the partial density of states (PDOS) identified Mn-d states as the primary contributors to electronic states at Ef, with O-p orbitals participating through hybridization. These findings provide insights into Mn₂O₃’s potential as a catalyst in Fe-air batteries.