Low-temperature coprecipitation synthesis of amorphous nickel cobalt sulfide nanoparticles for high-performance supercapacitors

Amorphous nickel cobalt sulfide nanoparticles have been successfully synthesized by a facile low-temperature coprecipitation method and used as an electrode material for supercapacitors. The electron microscope (EM) results reveal that the amorphous nickel cobalt sulfide is composed of numerous nano-sized particles with a diameter mainly between 25 and 50 nm. And the pore size analysis shows that the material is mesoporous with a primary pore diameter of about 30.0 nm. Benefiting from the amorphous and mesoporous structure characteristics, the amorphous nickel cobalt sulfide nanoparticles modified Ni foam electrode possesses a high specific capacitance of 1549 F g⁻¹ at a current density of 1 A g⁻¹, good long-term cycling stability over 2000 cycles at 10 A g⁻¹ with 91% capacitance retention.