Fabrication of Mn3O4-WO3 nanoparticles based nanocomposites symmetric supercapacitor device for enhanced energy storage performance under neutral electrolyte

Abstract

Development of pseudocapacitive electrode materials with wide potential windows is the major challenge for supercapacitor application to overcome the critical energy crisis. In this consequence, we have prepared Mn3O4-WO3 nanoparticles based nanocomposite with the variable stoichiometric amount of Mn sources via the one-pot solvothermal method. Among all the synthesized nanocomposite and bare samples, Mn3O4-WO3 (10:1) nanoparticles nanocomposite pursue excellent specific capacitance in three and two-electrode systems. In a three-electrode system the synthesized Mn3O4-WO3 (10:1) nanoparticles nanocomposite displays maximum specific capacitance 358 F g−1 using a neutral electrolyte with a wide working potential window. The electrokinetic analysis of the synthesized Mn3O4-WO3 (10:1) nanoparticles nanocomposite has been predominant capacitive contribution over the charge storage. Further the fabricated symmetric supercapacitor device (SSD) using Mn3O4-WO3 (10:1) nanocomposite pursues the maximum specific capacitance 101 F g−1 along with the energy density of 56.11 Wh kg−1 and power density 5 kW kg−1. Moreover the fabricated device of the synthesized Mn3O4-WO3 (10:1) nanocomposite demonstrates outstanding durability which has 95.5% specific capacitance retention upto 5000 continuous charge-discharge cycles. The improved stability and higher electrochemical activity are due to the nanocomposite effect, high pore volume and surface area, and low charge transfer resistance of the synthesized Mn3O4-WO3 (10:1) nanocomposite.