Electrospun deposited Mn₂O₃/GO nanofiber composite electrode for hybrid coin cell supercapacitor devices

In this study, the nanocomposite of manganese oxide (Mn₂O₃)/graphene oxide (GO) is deposited on a current collector using the single-nozzle electrospinning method. The effects of the GO concentration (volume %) of the Mn₂O₃ nanofibers (NFs) on the structural, morphological, and electrochemical properties are investigated systematically. The presence of GO in the Mn₂O₃ NF samples is confirmed using X-ray diffraction patterns, Raman spectroscopy, and X-ray photoelectron spectroscopy, where sp² hybridization can be observed. The influence of the GO (volume %) in the Mn₂O₃ NF samples on the contribution of the capacitive and diffusion-controlled process has been calculated mathematically. GO at 5 vol% in the Mn₂O₃ sample exhibited a high specific capacitance of 588 Fg⁻¹ at a current density of 0.5 mAcm⁻² (2.5 Ag⁻¹) in 1 M aqueous electrolyte with 98% cyclic stability up to 1000 cycles. Furthermore, a coin cell hybrid device was assembled using Mn₂O₃/GO and a Li-chip as an electrode, 1 M LiPF₆ as an electrolyte, and a polypropylene sheet as a separator. This device exhibited a capacitance, an energy density, and a power density of 0.33 F (specific capacitance of 740 Fg⁻¹), 925 Whkg⁻¹, and 3.3 kWkg⁻¹, respectively at a current density of 1 mAcm⁻² (2.5 Ag⁻¹) along with 90% retention in capacitance measured till 5000 cycles.