▎ 摘　　要

NOVELTY - Supercapacitor comprises a first electrode that comprises a first current collector electrically coupled to a magnesium (Mg) rich material, a second electrode that comprises a second current collector electrically coupled to a carbonaceous material and a separator membrane treated with a magnesium salt positioned between the first electrode and the second electrode, where the first electrode, the second electrode, and the separator membrane are retained within a casing in a compact configuration. USE - Supercapacitor used in electrical circuits as energy-storage devices, and in low power electronics, stationary storage and E-mobility. ADVANTAGE - The supercapacitor has enhanced sspecific capacity of the order of twice or thrice the value reported so far in the state-of-the-art in the literature, excellent cyclability of about 2400 cycles, and is eco-friendly, easy to fabricate. Magnesium ion is common ion and enhances the specific capacity of the system. The bentonite clay acts as a good magnesium ion storage material at the electrical double layer.