Exploring the potential of CoAl2O4 nanoflakes in supercapacitor applications

Abstract

Spinel structured nanoparticles with binary and ternary metal oxide combinations have recently been identified as a viable material for use in supercapacitors. Two mixed-valence metal cations provide easy electron transport between various metal cations. High-performance CoAl<inf>2</inf>O<inf>4</inf> spinel nanoflakes were synthesized using a mixed-solvent solvothermal method, followed by calcination. First principles calculations revealed high density of states near the Fermi level indicating its potential for supercapacitor applications. These nanostructured materials were then experimentally explored as promising electrode candidates for supercapacitor applications, using a 2 M KOH aqueous electrolyte. The results were impressive: the material demonstrated a high specific capacitance of 851.9 F/g at a current density of 1 A/g and the fabricated supercapacitor exhibited a power density of 14940.0 W/kg at a current density of 12 A/g. Even under more demanding conditions, the electrode maintained strong durability, in terms of cyclic stability along with high energy and power density values making it a strong contender for next-generation energy storage devices. © 2025 Elsevier B.V.