Preparation and supercapacitor performances of spinel LiMn 2O4

LiMn2O4 was synthesized by high temperature solid-state reaction. Results of X-ray diffraction show that spinel LiMn 2O4 powder is obtained at 800°C. The supercapacitive performances of LiMn2O4 electrode materials were studied in terms of the charge-discharge curves, cyclic voltammetry and alternating current (AC) impedance in 2 mol·L-1(NH4) 2SO4 solution. The results of cyclic voltammetric curves show that LiMn2O4 represents rectangular shape performance in the potential range of 0-1 V. The charge-discharge curves are linear and represent regularly symmetrical triangle, the specific capacity reaches 141 F·g-1 at 5 mA·cm-2. The electrode exhibits excellent charge-discharge efficiency and stability. The results of AC impedance testing also show that LiMn2O4 electrode has typical capacitance impedance performance.