Electrochemical performance of symmetric supercapacitor based on Li4Mn5O12 electrode in Li2SO4 electrolyte

In this paper, spinel Li4Mn5O12 electrode material was prepared by a citric-acid-assisted combustion method. The structure and morphology of Li4Mn5O12 were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDAX), scanning electron microscopy (SEM) and electron tunneling electron microscopy (TEM). The results showed that the Li4Mn5O12 powders were nano-sized particles. XRD Rietveld refinement gives the crystal structure of prepared sample. Electrochemical performance of Li4Mn5O12 electrode was studied by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements. Li4Mn5O12/Li4Mn5O12 symmetric supercapacitor was fabricated at the first time. The maximum specific capacitance was 69 F g−1 in the potential range of 0–1.4 V in 1 mol L−1 Li2SO4 electrolyte. The energy density was 67.6 W h kg−1 at a power density of 493.8 W kg−1 based on the total weight of the active electrode materials.