Designed nano architectonics of rare earth sesquioxides Gd2O3-Y2O3 bimetallic nanocomposite as a potential electrode material for asymmetric supercapacitor application

Due to their superior electrochemical properties , bimetallic nanocomposites (NCs) have attracted greater attention than monometallic nanoparticles . This study focuses on enhancing the specific capacitance and cycling stability of the Gd₂O₃-Y₂O₃ nanocomposites (NCs) for supercapacitor applications. The binary Gd₂O₃-Y₂O₃ NC electrode demonstrated a significantly higher specific capacitance of 823 F/g at a scan rate of 10 mV/s, compared to the monometallic oxides Gd₂O₃ (396 F/g) and Y₂O₃ (217 F/g). Additionally, the binary nanocomposites (NCs) electrode exhibited capacitive and diffusion contributions of 63.99 % and 36.01 %, respectively, and achieved outer, total, and inner specific capacitances of 740.74 F/g, 724.63 F/g, and 970.87 F/g, as determined through Trasatti analysis. A Gd₂O₃-Y₂O₃//AC asymmetric supercapacitor device was constructed, demonstrating an energy density of 31.5 Wh/kg and a power density of 697.40 W/kg. Furthermore, the device exhibited remarkable durability, with 90.92 % capacitance retention and 92 % coulombic efficiency after 10,000 charge/discharge cycles. These findings highlight the potential of the Gd₂O₃-Y₂O₃ NCs as a promising electrode material for high-energy storage supercapacitor applications.