Microwave-Assisted synthesis of interconnected holey nanosheets of zinc vanadate for High-Performance supercapacitor

Abstract

Developing electrode materials with high energy density and cyclic stability is crucial for advanced supercapacitor (SC) devices in the field of green energy technologies. However, the choice of electrode material and its synthesis approaches significantly impact the electrochemical performance of these devices. In this study, the effect of microwave power on the synthesis process, physicochemical properties and electrochemical performance of zinc vanadate (ZVO) is investigated. The interconnected “holey” ZVO nanosheets are synthesized using a microwave-assisted chemical synthesis process with different microwave powers with shorter reaction time (3 min). X-ray diffraction confirmed that the synthesized ZVO has an orthorhombic crystal structure. At lower microwave power (450 W), interconnected holey nanosheets are observed. When the power is increased above 450 W, the nanosheets disintegrated into an interconnected network of nanopebbles. The ZVO nanosheet electrode showed a specific capacity of 145.16 mAh/g and a specific capacitance of 871.01 F/g at 5 A/g, with a capacity retention of 96% after 5000 cycles. Furthermore, an aqueous asymmetric hybrid supercapacitor (AHSC) device with ZVO-1//AC configuration achieved a specific energy density of 32.77 W/kg at a power density of 400 W/kg with a capacity retention of 82.8% after 2000 cycles. These findings strongly indicate that the developed ZVO holey nanosheets can be used as a potential electrode material for high-performance SC devices.