Sulfurization of Ni-foam as a binder-free supercapacitor electrode

This paper is dedicated to the fabrication and characterization of NiSx supercapacitor electrodes prepared from Ni-foam by means of a one-zone sulfurization process. The successful preparation of NiSx (x= 1 and 2) was confirmed by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). A specific capacitance of 105 mF/cm
²
and 510 mF/cm
²
was achieved on electrodes prepared at 400°C and 250 °C, respectively. Anodic and cathodic peaks indicate the pseudo-capacitive character of the charge storage mechanism for both samples prepared at different sulfurization temperature. It is proposed that the 4.9 times higher capacitance of sample prepared at 250°C is associated with a higher density of nickel sulfide nanoflakes in the structure.