Supercapacitor performance of a nanocomposite of dilithium and β-NiS

Abstract

Abstract Binary nanocomposites of Li2 incorporated β-NiS have been synthesized via hydrothermal technique. XRD results indicate the formation of nanocomposite of Li2 and rhombohedral β-NiS. A spongy layered morphology could be identified through SEM analysis. The presence of Ni, S and Li2 could be identified through energy-dispersive X-ray analysis. The charge storage capabilities of Li2: β-NiS nanocomposites were examined using electroanalytical methods such as cyclic voltammetry, galvanic charge-discharge, and ac impedance analysis. In the three-electrode configuration, the electrodes could provide a specific capacitance of 860 F g− 1 (CV at 10 mV s− 1) and 700 F g− 1 (GCD at 2 mA cm− 2). The Li2: β-NiS electrode reveals pseudocapacitive behaviour. The Li2: β-NiS electrode could provide 90% capacity retention after 3000 continuous charge-discharge cycles at 10 mA cm− 2. A symmetric device has been fabricated using Li2: β-NiS as the working electrodes, and its performance has been studied in a window of 1 V with the lower end at 0.5 V. The energy and power density exhibited by the symmetric device is 12 W h kg− 1 and 500 W kg− 1. The symmetric device could yield 94% capacity retention even after 5,000 continuous charge-discharge cycles.