Fabrication of NiCo2S4/carbon-filled nickel foam complex as an advanced binder-free electrode for supercapacitors

A novel strategy, composed of epoxy-resin filling, carbonization, and hydrothermal growing of NiCo2S4 nanorods, was developed to enlarge the surface area of nickel foam (NF) for loading electrochemically active materials and to successfully fabricate NiCo2S4/carbon-filled NF binder-free electrodes. Due to the certain electrical conductivity of the filled epoxy-resin-derived carbon and the enlarged loading surface area, the targeted electrode possesses outstanding electrochemical energy storage performance, with a maximum specific capacitance of 9.28 F cm-2 at a current density of 4 mA cm-2, more than 6 times the 1.46 F cm-2 of the NF-based electrode formed via directly growing NiCo2S4 on NF, and with a specific capacitance retention of about 60% after 2000 charge/discharge cycles. Our strategy provides a promising avenue for constructing a high-performance NF-based binder-free electrode and our resultant electrode presents great application potential in electrochemical energy storage.