Effect on physiochemical assets of Dy added spinel ZnSm₂O₄ for energy storage applications

Supercapacitors are considered a potential source of energy conversion systems due to their advantages like high energy density, extensive cycle life, and quick charging and discharging. However, because of excessive voltage drops, they exhibit low energy density and durability. In this work, high content heteratom with various concentrations in a spinel system fabricated by hydrothermal technique. The materials were then analysed by different physical characterization methods including X-ray diffraction spectroscopy (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Using these techniques, the impact of dysprosium ions on ZnSm₂O₄ structure and morphology was studied. Moreover, the samples were subjected to various electrochemical tests including a polarization curve (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). Among all high content heteroatom samples, 20% Dy-added ZnSm₂O₄ displayed the highest electrochemical activity. The sample shows 1908 F g⁻¹ specific capacitance and 1.85 Wh g⁻¹ specific energy at 0.03 A g⁻¹ current density. The fabricated sample also showed long term stability and shows up to 95% capacitance retention after 2000 cycles. The Dy⁺ doping improves compound integrity that enhances electrochemical performance. These results open a new path for the enhanced electrochemical performance in the application of supercapacitor.