Synthesis of highly crystalline polyaniline with the use of (Cyclohexylamino)-1-propanesulfonic acid for supercapacitor

Abstract

Polyaniline (PANI) salt was prepared with 3-(Cyclohexylamino)-1-propanesulfonic acid (CAPS) as a novel dopant by aqueous polymerization pathway. Effects of sodium lauryl sulfate surfactant, mineral acid (H2SO4), and a combination of surfactant with mineral acid during the polymerization reaction were also determined. PANI-CAPS showed semicrystalline with flake-like morphology. The use of the sodium lauryl sulfate along with CAPS resulted in the formation of highly crystalline nanospheres with flake-like morphology. In order to find out the effect of surfactant, sodium lauryl sulfate was used in the reaction. The combination of sodium lauryl sulfate, CAPS, and H2SO4 brings about an extended nanosphere morphology. These polyaniline salts were used as electrode materials in the supercapacitor application, in a symmetric two-electrode cell configuration. The values of specific capacitance, energy, and power densities of PANI-CAPS-DHS-H2SO4 material at 2 mA cm−2 were 495 F g−1, 90 kJ kg−1, and 120 J Kg−1 s−1, respectively. Moreover, 85 % of the original capacitance was retained after 3,000 galvanostatic charge–discharge cycles with a coulombic efficiency of 96–99 %. The value of phase angle is close to 90 at low frequencies, indicating a good capacitive behavior.