Nanostructured porous polyaniline (PANI) coated carbon cloth (CC) as electrodes for flexible supercapacitor device

Nanostructured porous polyaniline (PANI) has been synthesized and coated simultaneously on a highly flexible and conductive carbon cloth (CC) substrate using a simple in-situ chemical oxidative polymerization technique. PANI coated CC (PANI−CC) based flexible electrodes were further used for the fabrication of flexible supercapacitor devices. For the comparison purpose, pure PANI has also been synthesized and tested for its electrochemical performance. The energy storage capacity of PANI and PANI–CC composite was investigated using electrochemical techniques like CV, GCD, and EIS in a potential range from 0 to 0.8 V in 1 M H2SO4 electrolyte. PANI−CC flexible electrodes exhibited the highest specific capacitance of 691 F/g; whereas, pure PANI could only achieve 575 F/g of specific capacitance at 1 A/g. Composite also exhibited outstanding cyclic stability by recollecting 94 % of its initial capacitance after 2000 GCD cycles. For actual implementation, a flexible supercapacitor device has been fabricated using stainless steel sheets and PANI−CC flexile electrodes. The energy storage performance of the PANI−CC flexible supercapacitor device was tested at several bending angles, which resulted in 72 % of capacitance retention at a maximum bending angle of 140° compared to the capacitance obtained at an angle 0° (flat state). PANI−CC exhibited improved electrochemical performance than pure PANI due to the synergistic effect between PANI and CC. Here, CC helped in enhancing the conductivity and stability; whereas, PANI boosted the capacitance owing to its excellent porosity and fast pseudocapacitive charge storage response.