High Energy Density, Super-Deformable, Garment-Integrated Microsupercapacitors for Powering Wearable Electronics.

Lightweight energy storage technologies are integral for powering emerging wearable health monitors and smart garments. In-plane, interdigitated microsupercapacitors (MSCs) hold the greatest promise to be integrated into wearable electronics because of their miniaturized footprint, as compared to conventional, multilayered supercapacitors and batteries. Constructing MSCs directly on textiles, while retaining the fabric's pliability and tactile quality, will provide uniquely wearable energy storage systems. However, relative to plastic-backed or paper-based MSCs, garment-integrated MSCs are underreported. The challenge lies in creating electrochemically active fiber electrodes that can be turned into MSCs. We report a facile vapor deposition and sewing sequence to create rugged textile MSCs. Conductive threads are vapor-coated with a stably p-doped conducting polymer film and then sewn onto a stretchy textile to form three-dimensional, compactly aligned electrodes with the electrode dimensions defined by the knit structure of the textile backing. The resulting solid-state device has an especially high areal capacitance and energy density of 80 mF/cm2 and 11 μW h/cm2 with a polymer gel electrolyte, and an energy density of 34 μW h/cm2 with an ionic liquid electrolyte, sufficient to power contemporary iterations of wearable biosensors. These textile MSCs are also super deformable, displaying unchanging electrochemical performance after fully rolling-up the device.