Nickel cobalt sulfide composite nanosheet anchored on rGO as effective electrode for quasi-solid supercapacitor

A solid supercapacitor based on inorganic/organic composite electrolyte has great promise as a fresh wave of energy storage structure in building engineering owning to its inherent mechanical robustness. Unfortunately, the limited capacity and energy density of these supercapacitors are still challenging. Here, rGO/Ni x Co y S electrodes were fabricated by in-situ growth on nickel foam (NF). The edge sulfur-enriched Ni x Co y S nanosheets were equally anchored on rGO surface, increasing the number of electrochemical active sites, accelerating ion diffusion and improving the electrical conductivity . The morphology and electrochemical behavior of the rGO/Ni x Co y S composite are remarkably affected by the Ni to Co molar ratio . It turned out that the rGO/Ni x Co y S composite with a Ni to Co molar ratio of 1:1 (rGO/Ni 1 Co 1 S) exhibited a high capacitance of 4.55 F cm −2 at 1 mA cm −2 . Subsequently, a novel quasi-solid supercapacitor was assembled using rGO/Ni 1 Co 1 S cathode, rGO/Fe 2 O 3 anode as well as inorganic/organic composite solid electrolyte. The device achieved a high energy density of 3.6 μWh cm −2 at a power density of 163.2 μW cm −2 , and moderate self-discharge (SDC) process, outperforming those of earlier reported structural devices. The practical application demonstration proves the feasibility of ternary rGO/Ni 1 Co 1 S electrode combined with inorganic/organic composite solid electrolyte in building energy storage field.