An efficiency aqueous hybrid supercapacitor with high working voltage based on porous PbO2/WO3·H2O positive electrode

Abstract

The PbO2/WO3·H2O composite is prepared by embedding the suspending WO3·H2O nanosheets into the PbO2 matrix during the galvanostatic deposition. The PbO2 matrix provides a metal-like conductive platform for WO3·H2O nanosheets, and the doping of WO3·H2O nanosheets improves the utilization rate and specific capacitance of the PbO2 electrode material. At the same time, the sulfate effect of PbO2 is reduced and its cycle life is prolonged. Therefore, the PbO2/WO3·H2O composite has a high specific capacitance (∼515 F/g), a large electrochemical active area, a large electrochemical window (∼2 V), and a long life. The PbO2/WO3·H2O//AC AHS based on the PbO2/WO3·H2O positive electrode presents high working voltage of 2.25 V, high specific capacitance of 114.5 F/g, high energy density of ∼49.8 Wh/kg, high power density of ∼358.6 W/kg, and long lifespan over traditional aqueous hybrid supercapacitor (at 10 mA/cm2).