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Item Durable and high energy yielding PANI/Ni(OH)2 nanocomposites and its supporting electrolyte improved supercapacitance(Elsevier Ltd, 2024) Viswanathan, A.; Nityananda Shetty, A.N.The driving force behind supercapacitor research is to enhance the energy density (E) to the level of Li-ion batteries, and achieving high power density (P). This task is accomplished by using nanocomposites of polyaniline (PANI) and Ni(OH)2 (PN) as the electrode material for supercapacitors. These nanocomposites were synthesized using acetic acid (PN - AA) (PANI 75% and Ni(OH)2 25%) and methane sulphonic acid (PN - MSA) (PANI 83.33% and Ni(OH)2 16.67%) as dopants for PANI through an in-situ single-step method. The PN – MSA exhibited higher energy storage characters than PN – AA with 1 M H2SO4 (SA) as electrolyte. PN - MSA exhibited high-energy characteristics, including a specific capacitance (Cs) of 735.29 F g‒1, an energy density (E) of 147.05 W h kg‒1 (comparable to Li-ion batteries), and a power density (P) of 2.3466 kW kg‒1 at 1 A g‒1. In addition, it also exhibited an exceptional cyclic stability up to 58,800 cycles at 0.4 V s‒1. The energy characters of PN-AA are also substantially high and are a Cs of 641.02 F g‒1, an E of 128.20 W h kg‒1 (in the same order of Li-ion batteries), a P of 2.0385 kW kg‒1 at 1 A g‒1 and a cyclic stability up to 18,400 cycles was also obtained at 0.4 V s‒1. Both PN - AA and PN - MSA demonstrated an impressive feature of an increase in energy storage with an increase in the number of charge/discharge cycles. PN - MSA exhibited an improvement in energy storage characteristics of up to 44% when a mixture of sulphuric acid and methane sulphonic acid with concentrations of 1 M and 0.33 M, respectively, was used as an electrolyte. © 2024 Elsevier LtdItem High energy supercapacitance of magnetic PANI/Ni2O3 nanocomposite and its magnetic structural repair(Elsevier Ltd, 2024) Viswanathan, A.; Nityananda Shetty, A.N.A magnetically auto healable and robust supercapacitor from a nanocomposite of PANI68.1 %: Ni2O331.9 % (PNi) synthesized in an in situ single step method, is achieved. PNi provided an exceptional character of healing the structural damage of PANI by the magneticity of Ni2O3 nanoparticles and showed a feature of increase in energy storage with increase in No. of charge/discharge cycles. The PNi exhibited a cyclic stability up to 16,800 cycles without significant reduction in initial Cs. The energy storage parameters achieved after 10,000 cycles are specific capacitance (Cs) of 347.6 F g−1, specific energy (E) of 69.52 W h kg−1, which is in the regime of E of Ni-metal hydride batteries of 0.9–1.3 V potential range, and specific power (P) of 8.571 kW kg−1 at 3 A g−1. Therefore, the PNi would be of a potential electrode material for the fabrication of long withstanding, robust and self - magnetically healable supercapacitor that delivers high energy. © 2024 Elsevier LtdItem High energy supercapattery of polyaniline/cupric oxide/stannic oxide nanocomposite(Elsevier Ltd, 2024) Viswanathan, A.; Nityananda Shetty, A.N.The effects of different aqueous acid electrolytes in imparting different features of energy storage to the nanocomposite of PANI50 %: CuO41.7 %: SnO28.3 % (PCS) are studied with three different electrolytes 1 M H2SO4 (SA), 1 M H2SO4 + 1 M CH3SO3H (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 LtdItem A green approach to energy storage properties of polyaniline(Springer, 2024) Viswanathan, A.; Nityananda Shetty, A.N.The green energy storage of polyaniline, without major wastages excreted into the environment is effectively demonstrated by using the polyaniline as supercapacitor electrode and the by-product obtained during the synthesis of polyaniline as its electrolyte. This green approach to the energy storage properties of sulphuric acid doped polyaniline (H-PANI) exhibited a substantial improvement in its energy storage, compared to the conventional approach of using an ionically conducting liquid as electrolyte like 1 M H2SO4 (SA), separately. The amelioration of 40.44% was achieved when the by-product obtained as supernatant liquid (SL) was used as electrolyte compared to SA. The H-PANI provided a specific capacity (Q) of 146.4 C g?1, a specific energy (E) of 24.40 W h kg?1 and a specific power (P) of 1.200 kW kg?1 at 1 A g?1 in the presence of SA. The Q of 205.6 C g?1, E of 34.26 W h kg?1 (similar range of E of Pb-acid batteries), P of 1.200 kW kg?1 were achieved in the presence of SL at 1 A g?1 and a high rate capability of 29.18% retention of initial Q up to 25 A g?1 was also achieved. This approach is useful to harvest high energy characters from PANI. © Indian Academy of Sciences 2024.Item Reduced graphene oxide/polyaniline/vanadium pentoxide/stannic oxide quaternary nanocomposite, its high energy supercapacitance and green electrolyte(Springer, 2024) Viswanathan, A.; Nityananda Shetty, A.N.Challenge of achieving high energy density (E) comparable with Li-ion batteries in supercapacitors, with low potential window offering aqueous electrolytes (1.2 V) has been overcome by using the electrode material composed of rGO 3.70%:PANI 51.86%:V2O5 33.33%:SnO2 11.11% (GPVS). The GPVS exhibited different extents of energy storage in the presence of 1 M sulphuric acid (H2SO4) and acidified supernatant liquid (ASL), a green electrolyte. Here, the ASL is the by-product, which is obtained as supernatant liquid after the synthesis of GPVS composites in an in situ synthetic method, and acidified using conc. H2SO4. The energy storage obtained in the presence of ASL is 38% higher than the energy storage obtained in the presence of H2SO4. The GPVS exhibited a remarkable feature of amelioration of energy storage with increase in CV cycles in the presence of H2SO4. The GPVS exhibited an extraordinary cyclic stability up to 41,300 cycles. The energy storage parameters achieved in the presence of H2SO4 after 33,800 cycles are, a specific capacitance (Cs) of 694.44 F g?1, an E of 138.88 W h kg?1 (comparable with E of Li-ion batteries) and a power density (P) of 2.1020 kW kg?1 at 1 A g?1. The energy storage parameters achieved in the presence of ASL are, a Cs of 212.31 F g?1, an E of 42.46 W h kg?1 (comparable with E of Ni–Cd batteries) and a P of 3.1583 kW kg?1 at 2 A g?1. It is satisfying that all these high energy characters are achieved with the real two electrodes–supercapacitor cell step up. The green supercapacitors are made by using the by-product, which is obtained as supernatant liquid after the synthesis of GPVS as its electrolytes. © Indian Academy of Sciences 2024.