Fabrication of coral like carbon black/MnO2 nano composites from commercial carbon black and their application in supercapacitors

Abstract

A carbon black/MnO₂ nano-composite (CB/MnO₂) of coral-like architecture was synthesized from a commercially available conductive carbon black (CB) using an in situ method. The morphology and structural analysis of the synthesized CB/MnO₂ revealed 10 nm thick MnO₂ nano-sheets grown on the CB. The MnO₂ nano-sheets of poorly crystalline δ-MnO₂ birnessite structure assembled into a coral-like architecture. Energy dispersive X-ray (EDX) microanalysis showed high Mn content in the composite. Electrochemical tests using the synthesized CB/MnO₂ showed a specific capacitance of 946 F g⁻¹ at a current density of 0.3 A g⁻¹, which was much higher than that of the composites reported in the literature. Under a current density of 30 A g⁻¹, the CB/MnO₂ electrode was shown to retain a high specific capacitance after 5000 charge/discharge cycles. The results from this study demonstrate that the CB/MnO₂ nano composite materials of coral-like architecture fabricated with commercially available CB and MnO₂ achieved a good electrochemical performance, exhibiting promising application prospects.