High energy and rate capable supercapacitor of polyaniline / vanadium pentoxide nanocomposite and its green electrolyte

The concept of hybrid supercapacitors of combining the high energy density (E) of batteries and high power densities (P) of supercapacitors is better achieved with the PANI53.84 %/V₂O₅46.15 % nanocomposite (PV). As it exhibited a supercapacitor performance on par with that of Li – ion batteries. This high energy features of PV are achieved by the green approach of using the by-product obtained in the synthesis of electrode material as its electrolyte with and without modification. The energy storage parameters of PV in the presence of 1 M H₂SO₄ (SA) as electrolyte, are very unique as they increased in quantity with increase in No. of energy storage/delivery cycles. The PV displayed an exceptional durability up to 20,500 cycles at 0.4 V s¹, and specific capacity (Q) of 592.4 C g¹, an E of 98.73 W h kg ¹ (in the order of Li-ion batteries) and a P of 1.200 kW kg¹ at 1 A g¹ after 10,800 cycles in the presence of SA. A highest rate capability of 65.45 % up to 15 A g¹ is achieved when the by-product of PANI (SL of PANI) is used as the electrolyte for PV. When the by-product of PV is used as its electrolyte after its acidification with conc. methane sulphonic acid (MSA+SLPV), the Q of 388.0 C g¹, an E of 64.66 W h kg¹ and a P of 1.200 kW kg¹ were achieved at 1 A g¹. The MSA+SLPV also features the energy enhancement with increase in number of days.