Facile construction of MnCo2O4/CeO2 electrode with oxygen vacancies for asymmetric supercapacitor

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 (C_s) at 1 A/g. The energy density of asymmetric supercapacitors (ASCs) with rMnCo₂O₄/rCeO₂ as positive electrode and activated carbon (AC) as negative electrode is 40.27 Wh/kg at 800 W/kg. This study provides a positive reference for the design of other composite electrode materials with oxygen vacancies.