A facile green synthesis of porous hexagonal cobalt pyrovanadate electrode for supercapacitors by deep eutectic solvent

Cobalt vanadate is a kind of promising electrode material for pseudo-supercapacitors because of their higher electrical conductivity, better electrochemical activity, and prominent specific capacitance than single metal oxides. In this paper, cobalt pyrovanadate (Co2V2O7) was primarily fabricated by a facile environment-friendly ionothermal method using a green deep eutectic solvent (DES) and followed the heat treatment in the air. The eutectic mixture discussed here was consisted of a hydrogen bond donor (urea) and acceptor (ChCl) in a 2:1 molar ratio. The as-prepared Co2V2O7 was porous hexagonal nanoplatelets, and its electrochemical performances were characterized by cycle voltammetry, galvanostatic charge/discharge and cycling stability tests in a three-electrode system with 2 M KOH electrolyte solution. The specific capacitance of the synthesized Co2V2O7 revealed 304 F g(-1) at the current density of 1 A g(-1). Surprisingly, it remained an excellent cycle performance with 103% in 100 charge/discharge cycles. Therefore, we have successfully presented a deep eutectic solvent derived routine to prepare porous hexagonal Co2V2O7 nanoplatelets electrode material. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, cobalt pyrovanadate was successfully fabricated using an ionothermal method and exhibited excellent electrochemical performance in the electrolyte solution. It showed a specific capacitance of 304 F g(-1) and maintained outstanding cycle performance, providing a new approach for the preparation of electrode materials for pseudo-supercapacitors.