Wearable Supercapacitors Printed on Garments

Abstract

Electronic garments have garnered considerable attention as a core technology for the upcoming wearable electronics era. To enable ubiquitous operation of electronic garments, they must be monolithically integrated with rechargeable power sources. Here, inspired by printing-assisted aesthetic clothing designs, a new class of wearable supercapacitors (SCs) is demonstrated that can be directly printed on T-shirts, which look like letters (or symbols) commonly printed on T-shirts. The printed SCs consist of activated carbon/multiwalled carbon nanotube/ionic liquid-based electrodes and ionic liquid/thiol-ene polymer network skeleton/SiO2 nanoparticle-based gel electrolytes. The rheological properties of the electrode/electrolyte pastes are fine-tuned by varying the colloidal network structure, which affects the printing processability and formation of the nanoscale ion/electron conduction channels. To ensure the seamless unitization and design versatility of the printed SCs, the T-shirt is sewn with electroconductive stainless steel (SS) threads prior to the printing process. Onto the SS threads acting as shape-directing current collectors, the electrode/electrolyte pastes are sequentially stencil-printed and sealed with water-proof packaging films. The printed SCs exhibit exceptional form factors, flexibility, and thermal stability. Notably, the SC-printed T-shirts maintain their electrochemical activity upon exposure to laundering, wringing, ironing, and folding, demonstrating their potential and practical applicability as a promising electronic garment technology.