Fabrication of Cu2V2O7 nanoparticles and Cu2V2O7/MXene composite as high-performance electrode for aqueous asymmetric supercapacitors: Role of electrolyte environment

초록

Bimetallic vanadium oxides are found to be extremely suitable candidate for supercapacitors owing to their rich redox active sites, high theoretical capacitance, elevated energy density, impressive power output, and excellent cycling durability. So, in the present work, Cu2V2O7 nanoparticles are synthesized using adoptable hydrothermal method and their supercapacitive properties are performed in three different electrolytes (LiOH, NaOH and KOH). The capacitance of Cu2V2O7 in 2 M KOH is found to be 557 F g- 1, which is higher than 2 M LiOH (305 F g- 1) and 2 M NaOH (431 F g- 1). Further, specific capacitance of sole Cu2V2O7 is improved by adding small amount of MXene (Ti3C2) and improved capacitance of 782 F g- 1 is obtained from Cu2V2O7/MXene in 2 M KOH electrolyte. Furthermore, aqueous asymmetric supercapacitor (ASC) is assembled by Cu2V2O7/MXene (positive electrode), activated carbon (AC) (negative electrode) and 2M KOH (electrolyte). Cu2V2O7/MXene//AC delivers the maximum energy density of 38.04 Wh kg- 1 at 800 W kg- 1. Additionally, four light-emitting diodes (LEDs), thermometer/humidometer, toy motor fan and kitchen timer are functionalized separately by seriesconnected two Cu2V2O7/MXene//AC devices.

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