Supercapacitor performance of a nanocomposite of dilithium and β-NiS

In this report, binary nanocomposite of Li2-incorporated beta-NiS has been successfully synthesized via the hydrothermal technique. The formation of Li2 and rhombohedral beta-NiS nanocomposite, spongy layered flakes morphology, and elemental analysis was characterised by performing XRD, SEM, and energy-dispersive X-ray analysis, respectively. The charge storage capability of the Li2: beta-NiS nanocomposite was examined in the three-electrode configuration. The voltammetric curve from cyclic voltammetry and charge-discharge plateaus from Galvanostatic charge/discharge measurements shows the Li2: beta-NiS exhibits pseudocapacitive behaviour. The Li2: beta-NiS electrode delivers exceptional specific capacitance of 800 F g-1 at 10 mV s-1 and remarkable cyclic stability of 90% after 3000 continuous charge-discharge cycles at 10 mA cm-2. In addition, a symmetric device has been assembled with Li2: beta-NiS nanocomposite electrode. The performance of a symmetric device has been studied in a window of 1 V with a lower end at 0.5 V. (0.5 to 1.5 V). It is examined that the device exhibits good energy density and power density of 12 Wh Kg-1 and 500 W Kg-1, respectively. The symmetric device could yield 94% capacity retention after 5000 continuous charge-discharge cycles at a current density of 15 mA cm-2. From this report, the electrochemical performance of Li2: beta-NiS electrode suggests it can be a promising electrode for high-performance supercapacitors.