Viswanathan, A.Nityananda Shetty, A.N.2026-02-042024Journal of Physics and Chemistry of Solids, 2024, 193, , pp. -223697https://doi.org/10.1016/j.jpcs.2024.112141https://idr.nitk.ac.in/handle/123456789/20904The effects of different aqueous acid electrolytes in imparting different features of energy storage to the nanocomposite of PANI50 %: CuO41.7 %: SnO<inf>2</inf>8.3 % (PCS) are studied with three different electrolytes 1 M H<inf>2</inf>SO<inf>4</inf> (SA), 1 M H<inf>2</inf>SO<inf>4</inf> + 1 M CH<inf>3</inf>SO<inf>3</inf>H (1:1) (SA + MSA) and acidified by-product (ABP). In the presence of SA, SA + MSA and ABP, the PCS produces, high energy density (E); high E & cyclic stability; and high E & rate capability, respectively. The maximum energy characters are achieved in the presence of SA + MSA. They are specific capacity (Q) of 301.6 C g−1, E of 50.26 W h kg−1 and power density (P) of 1.200 kW kg−1 at 1 A g−1. In the presence of SA + MSA the PCS nanocomposite exhibits 55.56 % retention of its initial Q up to 12500 cycles at 0.4 V s−1. This achieved high E is similar with E of Ni–Cd batteries. The use of by-product as electrolyte for supercapattery makes the process a green process. © 2024 Elsevier LtdElectrolytesNanocompositesAcid electrolytesAqueous acidsCyclic stabilityEnergyHigher energy densityMethanesulphonic acidRate capabilitiesSnO 2Stannic oxideSupercapatteryCopper oxides