Efficient supercapattery behavior of mesoporous hydrous and anhydrous cobalt molybdate nanostructures

Hydrous forms of cobalt molybdate binary metal oxide nanoaggregates were synthesized via a simple chemical co-precipitation technique. The subsequent heat treatment at 400 ^°C converted the sample into anhydrous cobalt molybdate (CoMoO₄) with mesoporous nanostructure. The anhydrous cobalt molybdate possess surface area and pore volume of 63.92 m²g^-1 and 0.1802 cm³g^-1 which is much higher than the hydrous cobalt molybdate (1.215 m²g^-1 and 0.0072 cm³ g⁻¹). The electrodes designed using these materials exhibited a battery-like behavior with maximum specific capacity of 97 Cg^-1 and 177 Cg^-1 for hydrous and anhydrous cobalt molybdate samples respectively. In addition, a supercapattery was fabricated utilizing anhydrous cobalt molybdate//activated carbon electrodes, which showed maximum specific capacity value of 64 Cg^-1 at 1 Ag^-1 discharge specific current and showed better specific energy ∼18.89 Whkg⁻¹ for a specific power of 1.06 kWkg⁻¹. Moreover, the supercapattery exhibited good capacity retention ∼93% after 5000 charge/discharge cycles.