Exploring PANI/CBTS Nanofiber Composites as Supercapacitor Electrodes: Structure–Performance Correlation

Abstract In this study, the electrochemical performance of supercapacitors is investigated using nanofiber Polyaniline (PANI) and PANI/Cu ₂ BaSnS ₄ (CBTS) composites with CBTS concentrations of 5%, 10%, and 20%. BET surface area and Horvath‐Kawazoe (HK) pore volume analyses show that nanofiber PANI has a higher surface area (35.3 m ² g ⁻¹ ) and pore volume (0.1391 cm ³ g ⁻¹ ) compared to CBTS (2.2 m ² g ⁻¹ and 0.0107 cm ³ g ⁻¹ ). Adding CBTS to PANI reduces these values, with composites ranging from 22.82 to 24.35 m ² g ⁻¹ and 0.1654 to 0.1845 cm ³ g ⁻¹ , respectively. HRTEM reveals evenly dispersed PANI nanofibers (40–60 nm diameter, several micrometers long), with CBTS crystalline regions (12–26 nm) on PANI/CBTS5, enhancing electrical conductivity. XPS confirms CBTS doping and significant electronic interactions between PANI and CBTS, detailing the chemical states of Cu, Ba, Sn, and S. Electrochemical tests over 10000 cycles demonstrate that PANI/CBTS composites outperform pure PANI, with PANI/CBTS5 achieving a specific capacitance of 374.2 F g ⁻¹ and an energy density of 5.20 Wh kg ⁻¹ . Higher CBTS concentrations slightly lower the specific capacitance. This pioneering study of CBTS's synergistic effects in supercapacitors highlights the potential of PANI/CBTS composites as promising materials for advanced energy storage applications.