Facile Synthesis and Characterization of SnO2/Bi5Nb3O15/Polyaniline Nanocomposite for Supercapacitor Application

Abstract

This Ph.D. dissertation investigates the ternary SnO2/Bi5Nb3O15/PANI nanocomposites, which were developed and evaluated for their potential as advanced electrode materials for superca pacitor applications. SnO2 and Bi5Nb3O15 (BNO) nanoparticles were synthesized using an en vironmentally friendly method, while polyaniline (PANI) was synthesized through chemical poly merization. The fabrication of both binary and ternary composites were carried out using ultra sonication with optimized mass proportions. SnO2-based composites suffer from poor ion trans port, volume changes, and low conductivity. To overcome these issues, a novel SnO2/BNO/PANI ternary nanocomposite was developed via a simple and eco-friendly synthesis by integrating BNO and the conducting polymer PANI to SnO2. XRD analysis confirmed the formation of tetragonal SnO2 and orthorhombic BNO phases, and also presence of PANI in the binary, and ternary nanocomposites did not alter their crystal structures. FTIR analysis confirmed the bind ing of PANI to the synthesized pristine nanoparticle and nanocomposites surfaces, while TEM imaging displayed well-integrated nanostructures. Electrochemical performance was investi gated in 1 M H2SO4 electrolyte using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy, revealed a significant enhancement in performance due to the incorporation of PANI. The SnO2/BNO/PANI electrode achieved an impressive spe cific capacitance of 424 F.g−1 at a scan rate of 5 mV.s−1, outperforming as compared to SnO2, BNO, SnO2/BNO, and SnO2/PANI electrodes. Asymmetric supercapacitors (ASCs), utilizing activated carbon (AC) as the negative electrode, demonstrated exceptional device-level per formance. The AC//SnO2/BNO/PANI, AC//SnO2/PANI-30%, and AC//BNO/PANI-30% devices provided specific capacitances of 247.52 F.g−1 at 0.2 A.g−1, 237.38 F.g−1 at 0.3 A.g−1, and 475.44 F.g−1 at 0.1 A.g−1, respectively. The corresponding long-term cycling tests of these de vices were confirmed remarkable stability with average Coulombic efficiencies of 98.76% at 2 A.g−1, 99.85% at 1 A.g−1 and 100% at 1 A.g−1, after 5000, 2000, and 5000 cycles, respectively. Additionally, the ternary nanocomposite exhibited capacitance retention of up to 73.03% after 5000 cycles. Overall, this dissertation demonstrates that the synergistic integration of SnO2, BNO, and PANI enhances specific capacitance, energy, and power density, confirming that the facile-synthesized SnO2/BNO/PANI ternary nanocomposite is a promising and durable electrode material for high-performance supercapacitors