LIG-based flexible interdigitated micro-supercapacitor cell with PANI-p-TS electrosynthesized in acetonitrile: influence of perchlorate-based electrolytes

The present work reports the first use of p-toluene sulfonate-doped polyaniline (PANI-p-TS) as the active electrode material in the Laser-Induced Graphene (LIG)-based flexible interdigitated micro-supercapacitor cell. First, PANI-p-TS is electrochemically synthesized on a graphite surface using the intermittent cyclic voltammetry technique in aniline and p-TSA/p-TS buffered acetonitrile solution. The capacitive properties of the obtained coating are investigated by CV, GCD, and EIS tests in LiClO₄, Mg(ClO₄)₂, Mn(ClO₄)₂, Zn(ClO₄)₂, and NaClO₄ solutions and after adjusting the pH of these solutions to 1 with HClO₄ due to the proton sensitivity of PANI to determine the most efficient electrolyte for the micro-supercapacitor cell. LiClO₄:HClO₄ medium among electrolytes achieves the highest capacity of 431 F.g⁻¹ at 1.0 A.g⁻¹ and a low internal resistance of 1.9 ohm.cm². Dunn’s method reveals Li-ion enhances the faradaic contribution because of its chaotropic nature. Second, PANI-p-TS is coated on LIG produced from polyimide for cell studies and characterized. XPS, XRD, HR-TEM, and FESEM analyses confirm the formation of homogeneous, porous PANI-p-TS in its emeraldine form on LIG. A symmetric micro-supercapacitor with flexible LIG//PANI-p-TS electrodes in a PVA/LiClO₄:HClO₄ gel electrolyte delivers 98 µWh.cm⁻² and 5 mW.cm⁻² at 15.6 µA.cm⁻² and 100% capacity retention after 5000 cycles.