Facile synthesis of spinel MgCo₂O₄ nanosheets for high-performance asymmetric supercapacitors

Two dimensional (2D) spinel cobaltite has great potential in electrochemical energy storage due to its unique structure and remarkable performance. Herein, we reported for a successful synthesis of MgCo2O4 nanosheets through direct hydrothermal decomposition of a mixed aqueous solution of MgCl2 and CoCl2 and formic acid (HCOOH, FA) at 200 degrees C for 6 h. The MgCo2O4 nanosheets yield a specific capacitance of 1431.2 F.g(-1) at 1.0 A.g(-1) in a three-electrode system and a high energy density of 32 Wh.kg(-1) at a power density of 800 W.kg(-1) in an aqueous asymmetric supercapacitor (MgCo2O4 thin sheets (+)//active carbon (AC) (-)). The MgCo2O4 nanosheets display potential applications in electrochemical energy storage. (C) 2020 Elsevier B.V. All rights reserved.