Electro-grafting of polypyrrole onto functionalized carbon cloth for tuning high areal capacitance of flexible supercapacitors

The advancement of flexible energy storage device requires electrode materials that deliver both high electrochemical performance and mechanical durability. In this work, a Polypyrrole (PPy) is coated on pretreated carbon cloth (PCC) via electropolymerization of pyrrole (Py) by the electro-grafting approach. This facile, additive-free approach yields a uniform and adherent PPy layer with enhanced ion and electron transport pathways. The Polypyrrole-coated pretreated carbon cloth (PPy@PCC) electrode delivers an areal capacitance of 1212.5 mF/cm² in a three-electrode system, retaining 66% of its capacitance after 10,000 cycles at a current density of 10 mA/cm². In a symmetric two-electrode configuration, the device achieves 333 mF/cm² with 74% retention after 5000 cycles. The full cell exhibits excellent flexibility, maintaining stable performance under repeated multiple bending cycles at 0°, 90°, and 180°. Practical viability is demonstrated by powering an LED using a series connection of three devices, and further energy tuning is achieved through series and parallel configurations. This study presents a straightforward, eco-friendly, and scalable approach for developing high-performance, flexible supercapacitors suitable for next-generation wearable and portable electronics. • Fabrication of binder-free flexible PPy@PCC by electro-grafting approach. • The PPy@PCC electrode shows high areal capacitance, C A ≈1212 mF/cm² at 1 mA/cm 2 . • Symmetric device maintained 74% capacitance after 5000 cycles @10 mA/cm². • Symmetric device showed good stability with bending configurations (0°, 90° &180°) • Possibility of wearable, portable, and flexible supercapacitors.