J. Mater. Sci. Technol. ›› 2022, Vol. 96: 332-344.DOI: 10.1016/j.jmst.2021.05.025

• Research Article • Previous Articles    

Urea-assisted hydrothermal synthesis of MnMoO4/MnCO3 hybrid electrochemical electrode and fabrication of high-performance asymmetric supercapacitor

Mohan Reddy Pallavolu, Arghya Narayan Banerjee*(), Ramesh Reddy Nallapureddy, Sang W. Joo*()   

  1. School of Mechanical Engineering and Center for Research Facilities, Yeungnam University, Gyeongsan 38541, South Korea
  • Received:2021-02-26 Revised:2021-04-19 Accepted:2021-05-13 Published:2022-01-10 Online:2022-01-05
  • Contact: Arghya Narayan Banerjee,Sang W. Joo
  • About author:swjoo@yu.ac.kr (S.W. Joo).
    *E-mail addresses: arghya@ynu.ac.kr (A.N. Banerjee),

Abstract:

Transition metal molybdates/carbonates and hybrid nanomaterials have attracted great attention in energy storage applications because of their enriched redox activity, good electronic conductivity, and stable crystallinity. We synthesize a multicomponent MnMoO4/MnCO3 hybrid by a one-step hydrothermal method with urea as the reaction fuel. By controlling only the urea concentration in the initial precursor solution, the MnMoO4/MnCO3 molecular ratio is controlled effectively, which is found to have a profound effect on the electrochemical properties of the hybrid electrodes. The electrochemical measurements show that the specific capacitance of MnMoO4/MnCO3 hybrid is 1311 F/g, the energy density of 116.8 Wh/kg, and power density of 383 W/kg at a current density of 1 A/g with 79% capacitance retention over 5000 cycles. The fabricated asymmetric supercapacitor device exhibits good energy storage performance, including the specific capacitance of 97 F/g along with the energy density of 26.5 Wh/kg and the power density of 657 W/kg at a current density of 1 A/g and good reversibility with capacitance retention of 85% after 2000 cycles and 70% over 5000 cycles. The increase in the energy density of 900% with a mere 60% decrement in the energy density indicates its potential superior applications in high-power devices.

Key words: Asymmetric supercapacitors, Hydrothermal synthesis, MnMoO4/MnCO3 hybrid, Energy storage applications