Self-assembled and highly faceted growth of Mo and V doped ZnO nanoflowers for high-performance supercapacitors

The rational design of metal ion-doped transition metal oxides has been considered as a novel electrode material for the development of high-performance asymmetric supercapacitors (ASCs). Herein, we facilely synthesized molybdenum and vanadium doped zinc oxide (Mo- and V-doped ZnO) lotus flower-like hierarchical structures using the co-precipitation method for use as a high capacity cathode material for ASCs. The formation mechanism during the self-assembly growth and highly faceted Mo- and V-doped ZnO lotus flowers were examined. Utilizing the beneficial properties of high electrochemical conductivity and excellent electroactive area, Mo-and V-doped ZnO lotus flowers demonstrated maximum specific capacities of 336 C g(-1) and 362 C g(-1) with good cycling stability. Furthermore, the ASC has been fabricated with V doped ZnO as a cathode and activated carbon as a negative electrode, which shows a high specific capacitance of 111 F g(-1), an energy density of 32.4 Wh kg(-1), and a power density of 5.16 kW kg(-1), respectively. The fabricated device also demonstrated excellent electrochemical capacitance retention of 85% and Coulombic efficiency of 98% after 2000 cycles. These superior characteristics indicate the promising potentiality of the new materials reporting for low-cost and high-performance supercapacitors. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Metal ion-doped transition metal oxides, particularly Mo- and V-doped ZnO lotus flower-like hierarchical structures, have been synthesized and shown promising potential as high-performance electrode materials for ASCs. The ASC fabricated with V-doped ZnO as a cathode and activated carbon as a negative electrode exhibits high specific capacitance, energy density, power density, capacitance retention, and Coulombic efficiency after 2000 cycles. These results highlight the potential of the new materials for low-cost, high-performance supercapacitors.