Facile synthesis of MgCo₂O₄ 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.