A tightly packed Co3O4/C&S composite for high-performance electrochemical supercapacitors from a cobalt(III) cluster-based coordination precursor

Single-material electrodes do not satisfy the demands of high-performance supercapacitors. Thus, to exploit the advantages of both oxides and carbon-based materials, a tightly packed Co3O4/C&S nanocomposite was fabricated by sintering a tightly packed cobalt(III) cluster-based coordination precursor at 400 ​°C. The coordination precursor, composites, and basic components were characterized, and the uniform nanocomposite was found to be composed of Co3O4 nanoparticles, incompletely carbonized C, and incompletely vulcanized S. When used as a supercapacitor electrode, the synthesized composite exhibited an exceptional electrochemical performance. More specifically, as the current density was increased from 0.5 to 10 Ag−1, 85.3% of the specific capacitance was retained. Moreover, >99.7% of the original specific capacitance was maintained after cycling for 20,000 cycles. This outstanding electrochemical performance was attributed to the highly stable electrode structure. These results indicate that a supercapacitor with electrodes composed of the as-prepared Co3O4/C&S composite show potential for use in commercial applications.