Flexible and Durable Conducting Fabric Electrodes for Next-Generation Wearable Supercapacitors

This study presents the fabrication of highly conducting Au fabric electrodes using a layer-by-layer (LBL) approach and its application toward energy storage. Through the ligand-exchange mechanism, the alternating layers of tris(2-aminoethyl)amine (TREN) and gold nanoparticles (Au NPs) encapsulated with tetraoctylammonium bromide (TOABr) ligands (Au-TOABr) were deposited onto the fabric to achieve a highly conducting Au fabric (0.12 Ω/□) at room temperature in just two LBL cycles. In contrast to several existing techniques, the current study realizes highly conducting Au fabric (7-15 Ω/□) in a layer-by-layer coating. The obtained Au fabrics demonstrate excellent stability against various deformations and abrasions, and its sheet resistance remained unaltered even after multiple cycles of bending, twisting, scotch tape adhesions, and sandpaper abrasions. In addition, the prepared Au fabrics exhibit high robustness toward various chemical media, highlighting their anticorrosive properties. Although Au fabrics showed a slight increase in sheet resistance postwashing and ultrasonication tests, it was got ridden by coating a thin layer of a biocompatible polydimethylsiloxane (PDMS) polymer. Besides enhancing the adhesion of Au NPs, PDMS coating offered a hydrophobic surface to fabrics rendering their use toward self-cleaning applications. High-performing energy storage devices integrated with wearable technologies are in great demand. In this context, here, electropolymerized polyaniline (PANI)-coated Au fabrics were employed to develop supercapacitors with remarkable energy-storing capability. In a symmetric two-electrode configuration, the device offered a maximum areal capacitance of 660 mF/cm² with high areal energy and power densities of 58.64 μWh/cm² and 22.86 mW/cm², respectively. The solid-state supercapacitor device (SSD) fabricated using Au/PANI-30 electrodes exhibited an areal capacitance of 495 mF/cm² with energy and power densities of 33 μWh/cm² and 10,660 μW/cm², respectively. This LBL method offers a significant advantage over existing techniques by offering simple room-temperature fabrication with excellent conductivity and adaptability to various substrates and with ease of scalability.