Construction of Hierarchical Mn₂O₃@MnO₂ Core–Shell Nanofibers for Enhanced Performance Supercapacitor Electrodes

Manganese oxide (MnOx) is a considerable candidate for supercapacitor electrode materials owing to its large theoretical capacitance and low price, but its performance is generally limited by unsatisfactory cycle performance and poor conductivity. Herein, Mn2O3@MnO2 composite nanofibers have been prepared via electrospinning and hydrothermal methods. Adjusting the KMnO4 precursor concentration during the hydrothermal process, Mn2O3@MnO2 core–shell nanofibers with variable compositional ratios of MnO2 to Mn2O3 have been obtained. The hierarchically core–shell structure and the synergistic effect between the two oxides enable the as-prepared Mn2O3@MnO2 nanocomposite electrode to achieve a desirable electrical conductivity and cycle stability. Consequently, Mn2O3@MnO2-0.3 nanofiber electrodes display an enhanced specific capacitance of 225.0 F g–1 (0.2 A g–1) along with a pretty cycling stability (86.5% after 5000 cycles) at 5 A g–1. These results demonstrate the substantial prospects of the as-prepared Mn2O3@MnO2 nanofibers for enhanced performance supercapacitors.