3D porous hydrated cobalt pyrovanadate microflowers with excellent cycling stability as cathode materials for asymmetric supercapacitor

摘要

Cobalt vanadates and their composites have drawn tremendous attention because of their outstanding cycling stability. Rational design of 3D microano-structures using a facile strategy has a promising potential for supercapacitor applications. Herein, we propose a 3D porous Co2V2O7-3 center dot 3H(2)O microflowers electrode as a cathode for pseudocapacitor via a simple co-precipitation technology. The resultant Co2V2O7-3 center dot 3H(2)O with microflowers structure exhibits a high specific capacitance of 351 F g(-1) at a current density of 1 A g(-1), and an ultralong cycle lifetime with 103% capacitance retention after 30,000 cycles. An asymmetric supercapacitor device is also successfully assembled consisting of Co2V2O7-3 center dot 3H(2)O cathode and rGO anode. The optimized ACS device with a potential window of 0-1.5 V delivers a high energy density and an excellent cycle lifetime. These superior electrochemical properties will render the 3D porous Co2V2O7-3 center dot 3H(2)O microflowers material as an attractive material for promising application in energy storage systems.