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 %/V 2 O 5 46.15 % 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 H 2 SO 4 (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 s 1 , and specific capacity ( Q ) of 592.4 C g 1 , an E of 98.73 W h kg 1 (in the order of Li-ion batteries) and a P of 1.200 kW kg 1 at 1 A g 1 after 10,800 cycles in the presence of SA. A highest rate capability of 65.45 % up to 15 A g 1 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 g 1 , an E of 64.66 W h kg 1 and a P of 1.200 kW kg 1 were achieved at 1 A g 1 . The MSA+SLPV also features the energy enhancement with increase in number of days. • Achieved high energy supercapacitance of PANI/V 2 O 5 (PV) is in the range of Li-ion batteries. • Aqueous electrolytes are used get the energy density ( E ) comparable to E of Li-ion batteries. • The PV exhibited 65.45 % of retention of Q up to 15 A g 1 with a green electrolyte. • The achieved high E are 98.73 W h kg 1 at 1 A g 1 . • All these results are achieved in 2 EL – supercapattery cell set up.