Simultaneous Oxidation and Doping of Aniline to Polyaniline by Oxidative Template: Electrochemical Performance in Supercapacitor

Abstract

Polyaniline salts containing sulfuric acid and cetyltrimethylammonium sulfate dopants were prepared by aqueous (PANI-Aq), emulsion (PANI-Em), and interfacial (PANI-In) polymerization pathways using cetyltrimethylammonium peroxodisulfate as an oxidative template. Formation of polyaniline was confirmed from infrared and X-ray diffraction spectral results. Value of conductivity (15 S cm⁻¹) of the polyaniline salt prepared by emulsion polymerization pathway was higher with that of the conventional polyaniline salt. PANI-Aq, PANI-Em, and PANI-In showed layered, flower petals, and nanorod and flower petals morphologies, respectively. These polyaniline salts were used as electrode in supercapacitor. Specific capacitance of PANI-Em, PANI-Aq, and PANI-In were 520, 484, and 474 F g⁻¹, which were higher than the conventional PANI-H₂SO₄ salt (390). Energy density was 26, 24.2, and 23.6 Wh kg⁻¹, respectively at a power density of 120 W kg⁻¹. After 3000 charge-discharge cycles, retention in the specific capacitance values of polyaniline salts was 86% (PANI-Em), 85.4% (PANI-Aq) and 76.1% (PANI-In).

GRAPHICAL ABSTRACT

Keywords:

• Dual dopants
• energy storage
• oxidative template
• polyaniline
• supercapacitor

Acknowledgments

The authors thank Dr. Lakshmi Kantam, Director, IICT, for her support and encouragement. Authors also thank Dr. Vijayamohanan K. Pillai, Director, and Dr. S. Gopukumar, Senior Principal Scientist, CSIR-CECRI, Karaikudi, for their valuable suggestion.