High electrochemical performance asymmetric supercapacitor based on La2O3//Co3O4 electrodes

The Co3O4 and La2O3 electrodes are prepared using chemical bath deposition method. The electrochemical properties of Co3O4 and La2O3 electrodes show maximum specific capacitance of 415 and 288 Fg(-1) in potential window of 0.0 to -0.6 and -0.2 to 0.5 V/SCE, respectively in 1 M KOH electrolyte at scan rate of 5 mV s(-1). The solid state asymmetric supercapacitor device (ASC) is fabricated using Co3O4 as an anode and La2O3 as a cathode with PVA-KOH gel as a solid electrolyte and separator. Co3O4//La2O3 asymmetric supercapacitor shows good performance with specific capacitance of 15 F g(-1) and 92% capacitance retention after 2000 cycles. The energy and power densities are 42.9 Wh kg(-1) and 108.2 W kg(-1), respectively. Two assembled Co3O4/P2O3 ASCs devices in series lights up red LED after charging for 45 s. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.