Enhanced energy storage performance of Y2O3-MoS2 nanocomposites based aqueous psuedocapacitor

Abstract

Development of high-performance electrode materials with enhanced charge transport and electrochemical stability is crucial for the next-generation energy storage devices. In this work, we synthesized Y 2 O 3 -MoS 2 nanocomposites with varying Y 2 O 3 content to investigate the influence of systematic Y 2 O 3 addition on structural and electrochemical properties of MoS 2 -based electrodes. Structural and morphological analyses confirmed the successful formation of Y 2 O 3 -MoS 2 composites, revealing composition-dependent changes in their microstructure. These nanocomposites demonstrated enhanced electrochemical performance. One of the nanocomposites showed a maximum specific capacitance of 589 F/g at 1 A/g. Dunn's model analysis revealed a mixed charge storage mechanism involving both capacitive and diffusion-controlled contributions with a dominant capacitive contribution. The nanocomposite demonstrated excellent reversibility with a coulombic efficiency of 99.9% at 10 A/g. Furthermore, a high energy density of 81.8 Wh/kg was achieved at a power density of 500 W/kg, indicating efficient energy storage capability. Electrochemical impedance spectroscopy revealed low charge transfer resistance and showed non-ideal capacitive behavior. The present study demonstrates that controlled incorporation of Y₂O₃ can effectively improve the electrochemical performance of MoS₂-based electrodes and provides insights into the relationship between composition, structure, and electrochemical behavior for supercapacitor applications.