Green and Facile Synthesis of Zn₃V₂O₈−Ag@C Composite as an Efficient Electrode for Supercapacitor Application

The present study demonstrates the synthesis of ternary composites of zinc vanadate (Zn 3 V 2 O 8 ) with silver (Ag) and carbon matrix originated from the Bengal gram bean extract (BGBE) using a facile, economic, and environmentally sustainable rotational chemical bath deposition (R−CBD) method. From the electrochemical studies, it is found that the Zn 3 V 2 O 8 −Ag@C demonstrated improved electrochemical performance with the specific capacitance (Csp) of 380.1 F g −1 , energy density (ED) of 52.7 Wh kg −1 , with power density (PD) of 882.3 W kg −1 at 3 mA cm −2 current density and good capacitive retention of 89.8 % over 3000 charge–discharge (GCD) cycles, which is remarkably higher than the other electrode materials (Zn 3 V 2 O 8 , Zn 3 V 2 O 8 −Ag, Zn 3 V 2 O 8 @C). The combined merits of conductive silver (Ag) nanoparticle and carbonaceous material from BGBE assist in enhancing the overall electrochemical performance of Zn 3 V 2 O 8 −Ag@C. The Zn 3 V 2 O 8 −Ag@C nanocomposite was used as electrode material for the fabrication of a flexible symmetric solid–state supercapacitor device (SSC). The SSC device delivered a Csp of 69.17 F g −1 with an energy density (ED) of 13.8 Wh kg −1 at a 2 mA cm −2 current density. Moreover, the SSC shows a 90 % capacitive retention over the continuous GCD cycles.