Facile Synthesis of Hierarchical MgCo <sub>2</sub> O <sub>4</sub> @MnO <sub>2</sub> Core-Shell Nanosheet Arrays on Nickel Foam as an Advanced Electrode for Asymmetric Supercapacitors
Yifei Teng, Deyang Yu, Yingdi Li, Yanan Meng, Yunpeng Wu, Yi Feng, Yingjie Hua, Chongtai Wang, Xudong Zhao, Xiaoyang Liu
Abstract
Ternary transition metal oxides (TTMOs) material has recently drawn significant interests to researchers, as a potential electrode material to advance the energy storage technology. In this paper, the hierarchical MgCo 2 O 4 @MnO 2 core-shell nanosheet arrays (CNAs) were resoundingly fabricated on nickel foam using a simple solvothermal reaction and a calcination afterwards. The assembled MgCo 2 O 4 @MnO 2 electrode had a specific capacity of 968.98 C g −1 under 1 mA cm −2 in a 1 M KOH solution. Additionally, two asymmetric supercapacitors (ASCs) were assembled, one with PVA-KOH gel (PKG) as electrolyte and the other with KOH solution as electrolyte. Both of the ASCs were made with MgCo 2 O 4 @MnO 2 CNAs/Ni foam as the positive electrode and the activated carbon (AC) as the negative electrode, and both exhibited extraordinary electrochemical properties. The remarkable electrochemical performance revealed that the MgCo 2 O 4 @MnO 2 nanomaterial was a prospective electrode material and can be applied potentially in energy storage field.