Synthesis and Charge–Discharge Properties of Ultrafine YMnO₃ Particles by Stearic Acid Sol–Gel Method

Yttrium manganite (YMnO₃), a novel kind of perovskite oxide, was synthesized by stearic acid sol–gel method using stearic acid, Y₂O₃, and Mn(NO₃)₂ as raw materials. Structure and morphology of YMnO₃ were characterized using X-ray diffraction and transmission electron microscopy. Results show that ultrafine YMnO₃ particles were fabricated at 700 within 8 h. Electrochemical performance of YMnO₃ was investigated by constant current charge–discharge technique. The as-prepared YMnO₃ electrode has excellent electrochemical performance, and the specific capacitance as a single electrode is up to 164.19 F/g in 6 mol/L KOH electrolyte solution. At 5 mA/g current density, different potentials were applied to obtain the optimum cell voltage from 0.1 V to 0.3 V. Under this condition, the supercapacitor exhibits good charge–discharge capacities and equivalent series resistance is only 1.0 Ω. After 50 charge–discharge cycles, specific capacitance of YMnO₃ composite is reduced within 10%, indicating that YMnO₃ composite has excellent and steady electrochemical performance and is a promising electrode material for supercapacitors.