Facile synthesis of MgCo 2 O 4 hexagonal nanostructure via co‐precipitation approach and its supercapacitive properties

Magnesium cobalt oxide (MgCo2O4) hexagonal nanoplates were prepared via a fast and simple co-precipitation process. The electrochemical properties of MgCo2O4 nanostructures were characterized by various techniques. Furthermore, the MgCo2O4 hexagonal nanoplate material was used for supercapacitors. In three-electrode scheme, MgCo2O4 hexagonal nanoplate electrode demonstrated a good specific capacity of 164 mAh g−1 at 3 A g−1. Furthermore, an aqueous asymmetric supercapacitor (ASC) using MgCo2O4//activated carbon (AC) was also fabricated. The MgCo2O4//AC delivered 39 mAh g−1 of specific capacity at 1 A g−1. It revealed the high energy density of 28.34 W h kg−1 with the power density of 363 W kg−1 with the current density of 0.5 A g−1. The impressive electrochemical performance is mainly associated to high surface area of 55 m2 g−1 resulted from voids/gaps in-between hexagonal nanoplates of MgCo2O4. Also, a toy motor fan, 11 light-emitting diodes (LEDs), and a kitchen timer were functionalized by series linked two ASCs for practical applications.