Energy crises have prompted researchers to develop new electrode materials for efficient energy storage, leading to the creation of effective energy storage devices. Therefore, this study introduces Ni-doped ZnSe/rGO-based materials fabricated through a hydrothermal synthesis method, which demonstrated enhanced electrical and electrochemical performance. X-ray diffraction (XRD) analysis revealed an increase in the crystallite size from 49.72 nm to 96.74 nm, accompanied by a corresponding growth in the particle size, which can be attributed to the incorporation of Ni and rGO as substituents. The electrochemical characterization of all fabricated electrodes indicated that the best-performing Zn0.90Ni0.10Se/rGO composite achieved a high specific capacitance of 1920.20 F g-1 at 5 mV s-1, significantly surpassing that of pure ZnSe (346.8 F g-1), as determined from CV measurements. Additionally, the Zn0.90Ni0.10Se/rGO electrode demonstrated excellent cycling stability (90.85% capacitance retention after 10 000 cycles), a high power density of 3500 W kg-1 at a current density of 7 A g-1, and an energy density of 83.81 Wh kg-1 at a current density of 1 A g-1, with a storage capability of 1058.75 F g-1. The combined effect of Ni and rGO doping in the composites resulted in a notable reduction in series and charge transfer resistances. Under optimal conditions, it exhibited excellent electrochemical performance, as indicated by good ionic conductivity (0.037 S cm-1), the highest transference number for cations (0.90), and a rate constant of 1.42 × 10-8 cm s-1 at an exchange current density of 0.00137 A g-1, as well as a diffusion coefficient of 8.03 × 10-13 m2 s-1, suggesting enhanced ion transport characteristics. These promising attributes of Zn0.90Ni0.10Se/rGO strongly demonstrate it as an ideal electrode material for advanced energy storage applications.
Asif et al. (Thu,) studied this question.