Preparation and electrochemical properties of MnO₂/PANI-CNTs composites materials

ABSTRACT

In this article, carbon nanotubes (CNTs) was modified with conducting polymer polyaniline (PANI) to produce composite supporters (PANI-CNTs), and then the MnO₂/PANI-CNTs composite material was prepared by hydrothermal route through the oxidation of manganese sulfate using ammonium persulphate (APS) as oxidizing agent. XRD, FT-IR, SEM and laser Raman spectroscopy were used to characterize the composition and structure of materials, meanwhile the electrochemical properties of the material were also investigated. In addition, a series of materials such as MnO₂, MnO₂-CNTs, MnO₂-PANI with different supporters were also prepared to investigated the support effects on the structure and electrochemical properties of composite materials. The characterization results show that the dispersion of MnO₂ in composites was greatly affected by the constitution of supports. In comparison with poor MnO₂ dispersion on MnO₂/CNTs, as for the composite materials including PANI, the anchoring of Mn²⁺ through covalent bond between PANI and Mn²⁺, which would help to disperse the MnO₂, and then uniform ‘starfish-type’ MnO₂ was achieved on MnO₂/PANI-CNTs composite. Moreover, the addition of PANI would improve the conductivity of composite materials. In conclusion, high electrical conductivity and MnO₂ dispersion on MnO₂/PANI-CNTs composite results in higher specific capacitance (391F/g), which was triple value of specific capacitance for pure MnO₂ (132 F/g). Moreover, high specific capacitance retention (90%) for MnO₂/PANI-CNTs composite displays good electrochemical stability in comparison with other composites.

Graphical Abstract

KEYWORDS:

• Supercapacitor
• manganese dioxide
• carbon nanotubes (CNTs)
• polyaniline (PANI)
• composite materials

Acknowledgments

This work is supported by Henan province university key scientific research project [16B150013]; the high-level talent scientific research foundation project of Pingdingshan university [PXY-BSQD-2015008].

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Key Scientific Research Project of Colleges and University in Henan Province (16B150013), Scientific Research Start-up Foundation for the High-level Talent of Pingdingshan University (PXY-BSQD-2015008).