<p>Although surfactant concentration is a critical factor in the efficacy of RGO/PANI composite electrodes, it has never been the subject of a systematic study. The structure, morphology, and electrochemical performance of RGO/PANI-CTAB synthesized by in-situ polymerization were examined in this study in relation to the impact of variable CTAB concentrations (0.04–0.1 M). The results indicated that the optimal concentration of CTAB was 0.08 M. At this concentration, CTAB functioned as a soft template, resulting in the production of PANI nanofibers with a diameter of 50–80 nm that were uniformly distributed on the RGO surface. These nanofibers exhibited the highest specific surface area, degree of doping, and number of active sites. In contrast, the excessive CTAB concentration degraded the material quality by an inordinate amount of micelle aggregation at a concentration of 0.1 M. The RGO/PANI-CTAB composite (0.08 M CTAB) exhibited excellent performance in a three-electrode cell configuration, achieving the highest specific capacitance (704 F g⁻¹ at 1 A g⁻¹), the lowest series resistance (Rs = 0.45 Ω), and good cycling stability with 96% retention after 1000 cycles and 86% after 5000 cycles. The asymmetric supercapacitor cell (ASC) assembled with this composite offers a voltage window of up to 1.7 V, a specific capacitance of 58 F g⁻¹, and a rate capability of 11% when the current density increases from 1 A g-¹ to 5 A g⁻¹. It also delivers an energy density of 23.3 Wh kg⁻¹ and a power density of 850 Wh kg⁻¹. The chemical structure and morphology of the PANI nanofibers remained largely unaltered following the cycling process. The results of this study reveal that RGO/PANI-CTAB with 0.08 M CTAB is a highly prospective, high-performance, and cost-effective supercapacitor electrode material for the development of next-generation energy storage devices.</p>