Preparation and Electrochemical Performance of CoS2/carbon nanofibers as electrode materials for supercapacitors

Electrode materials are one of the core components of supercapacitors, and cobalt-sulfur compounds have the following advantages: insoluble in alkaline solutions, long service lives, high conductivities and abundant valence states. The addition of a sulfur source by the hydrothermal method can decrease the discharge of harmful gases. Influencing factors can be adjusted to prepare a composite with excellent electrochemical properties. The structural and morphological properties of CoS2/CNFs are characterized through X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. CoS2/CNFs reaches 380.4 F·g−1; thus, over 81.2% of the initial capacitance is retained as the current density was increased from 1 to 10 A·g−1. CoS2/CNFs also exhibits excellent cycling performance with 90.5% capacitance retention after 2000 charge/discharge cycles. The combination of CoS2 and carbon nanofibers can not only reduce volume expansion but also improve cycling stability.