Electrochemical insights into CdS-polyaniline nanocomposites for high-energy supercapacitors

In this study, a series of CdS-incorporated polyaniline (CdS-PANI) nanocomposites were synthesized with different weight ratios (5 %, 10 %, and 15 %) via in situ chemical oxidative polymerization to explore their potential for high-performance supercapacitor applications. The systematic incorporation of CdS significantly influenced the crystal structure, morphology, porosity, and electrochemical characteristics of the composites. The optimized 15 % CdS-PANI nanocomposite exhibited a high surface area of 36 m 2 g −1 and mesoporosity with an average pore diameter of 47 nm. It delivered a specific capacitance of 940 F g −1 at 0.1 A g −1 in a three-electrode system. In an asymmetric configuration (15 % CdS-PANI || AC) operated at a potential window of 0–1.2 V, the electrode achieved 244 F g −1 at 1 A g −1 with an energy density of 98.8 Wh kg −1 at a power density of 1486 W kg −1 . When extended to a wider potential window from negative to positive polarity, the device exhibited a specific capacitance of 275 F g −1 at 2 A g −1 and an energy density of 93.2 Wh kg −1 at a power density of 1532 W kg −1 . Unlike conventional PANI-based systems, this work establishes a direct correlation between CdS loading, and pseudocapacitive performance, providing new insight into charge storage mechanisms in hybrid polymer-semiconductor systems. This study therefore offers a distinctive design strategy for developing high-capacitance and stable hybrid electrodes suitable for next-generation energy storage devices.