Facile Construction of Mnco2o4/Ceo2  Electrode with Oxygen Vacancies For Asymmetric Supercapacitor

Abstract

A MnCo2O4/CeO2 electrode with oxygen vacancies (rMnCo2O4/rCeO2) was prepared by water bath synthesis, annealing, and NaBH4 reduction procedure. The improved electrochemical performance of the rMnCo2O4/rCeO2 electrode is attributed to the diversified atomic valence states, the presence of oxygen vacancies, and the synergistic interaction between the two components. The rMnCo2O4/rCeO2 electrode can provide more electroactive sites, accelerate the dynamic reaction, improve the diffusion rate of ions and conductivity, and thus improve the electrochemical performance. The rMnCo2O4/rCeO2 electrode has 1062 F/g specific capacitance (Cs) at 1 A/g. Asymmetric supercapacitors (ASCs) with positive electrodes of rMnCo2O4/rCeO2 and negative electrodes of activated carbon (AC) provide an energy density of 40.27 Wh/kg at 800 W/kg. This study is a favorable reference for designing the other composite electrode materials with oxygen vacancies.

Keywords: Supercapacitor, Oxygen vacancy, MnCo2O4/CeO2