<p>Composite electrode materials combining conductive polymers with carbon-based frameworks have shown great potential in advanced energy storage applications. In this work, polyaniline (PANI)-coated polyimide carbon microsphere (PI-C) composites (PANI/PI-C) with optimizing feed ratios were synthesized by in situ polymerization. PI-C serves as an excellent support for PANI, creating a synergistic effect that significantly, achieves superior electrochemical performance. The results show that 50% is the most appropriate addition amount of PI-C, the composite demonstrated an impressive specific capacitance of 540 F g⁻¹ at 0.5 A g⁻¹, and under a higher current density of 10 A g⁻¹, it maintained a significant capacitance of 412.9 F g⁻¹. After 5000 charge–discharge cycles, it preserved 90.4% of its original capacitance. Furthermore, when assembled as a symmetric supercapacitor, it achieved an energy density of 12.7 Wh kg⁻¹ at a power density of 249.9 W kg⁻¹, retaining 83.1% of its capacitance after 5000 cycles at a current density of 5 A g⁻¹. These results demonstrate the excellent electrochemical performance and structural stability of PANI/PI-C composites, highlighting their application prospects in high-performance supercapacitors and broader energy storage technologies.</p> Graphical abstract <p></p>