Natural Jute Fibre‐Based Supercapacitors and Sensors for Eco‐Friendly Energy Autonomous Systems

Abstract Environmentally friendly energy devices and systems are of increasing interest for the circular economy and sustainable information and communications technology. To this end, an energy‐autonomous system comprised of natural jute fiber‐based supercapacitor (SC) and sensors (temperature and humidity) is presented. This material is coated with poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)/single‐walled carbon nanotubes as the electrode and cellulose‐based material as a separator. Further, a newly prepared hydroxyethyl cellulose‐potassium chloride based gel is used as the electrolyte. The observed capacitance is nearly twice the value reported for similar SCs. The energy and power densities of the presented SC are 0.712 μWh cm⁻¹ and 3.85 µW cm⁻¹, respectively at a capacitance of 8.65 mF cm⁻¹ and an applied current of 0.1 mA. The fabricated temperature sensor shows a relative change in response of 0.23% °C⁻¹ from 24 to 35 °C and the humidity sensor exhibits a sensitivity of 1.5 Ω/%RH (relative change of 0.20%) up to 50%RH. Developed using sustainable and biocompatible materials, the presented SC can power the jute‐fiber based sensors, thus demonstrating an attractive eco‐friendly solution for applications such as wearables, grain sacks, and bags.