Design and optimization of CdS-CeO₂ composite electrodes for enhanced electrochemical performance for asymmetric...

The advance of high-performance energy storage devices (ESD) is critical for modern semiconductor technology, rechargeable vehicles, and renewable energy integration. In this work, a CdS-CeO₂ composite was successfully synthesized via a hydrothermal method and investigated as an electrode material for an asymmetric supercapacitor (ASCs). The CdS-CeO₂ composite leverages the high redox activity and structural stability of CeO₂ along with the enhanced electrical conductivity and charge transport of CdS. Structural and morphological characterization using XRD, BET surface analysis, SEM, and EDX mapping confirmed the formation of a well-dispersed, hierarchical composite with abundant electro active sites. Electrochemical measurements revealed that the CdS-CeO₂ electrode delivers a specific capacitance of 476 F g^-1 at 1 A g^-1, along with good rate performance and outstanding long-term stability, retaining 95.83% of its initial capacitance after 15 000 charge-discharge cycles. The asymmetric supercapacitor ASC (CdS-CeO₂//AC) exhibited a highest energy density of 57.74 Wh kg^-1, and power density of 6298 W kg^-1, indicating the effectiveness of the CdS incorporation in enhancing the electrochemical performance. These results highlight the potential of oxide-sulfide composite engineering in designing next-generation electrodes for high-performance ASCs.