Nickel-mixed chromium sulfide nanoparticle synthesis, characterization, and supercapacitor applications

Researchers are always encouraged to develop new electrode materials to design efficient, safe, and eco-friendly energy storage systems. Doping or mixing is an effective way to improve the electrochemical performance of supercapacitors. In this study, Ni-mixed Cr2S3 (Ni-Cr2S3) nanoparticles were synthesized through a hydrothermal technique with varying molar ratios of Ni and Cr. As prepared different Ni-Cr2S3 nanoparticles were characterized using XRD, XPS, FESEM, TEM, and EDX techniques. The results displayed that the structure and activity of the Ni-Cr2S3 were significantly influenced by the dopant quantity of Ni in Cr2S3. Among a series of Ni-Cr2S3 with various Ni:Cr ratios, the Ni-Cr2S3 (2:1) electrode exhibited a higher specific capacitance of 187.53 F g-1 at 0.5 A g-1 and good operational stability with 93.31 % retention over 5000 charge-discharge cycles. Moreover, the assembled sandwich -type symmetric supercapacitor (Ni-Cr2S3 (2:1)//Ni-Cr2S3 (2:1)) delivered the highest capacitance of 48.0 F g-1 at a current density of 1 A g-1 with excellent cycling performance of 91.26 % and Coulombic efficiency of 99.74 % after 5000 cycles at 5 A g-1. The Ni-Cr2S3 (2:1)//Ni-Cr2S3 (2:1) device possessed the energy/power density of 6.66 Wh kg -1/499.5 W kg -1, when increasing the current density it retained the energy/power density of 1.66 Wh kg -1/2988 W kg -1.