Turning industrial waste-flax noil into regenerated cellulose fiber electrodes for eco-friendly supercapacitors

Sustainable conversion of wastes into eco-friendly wearable energy storage materials is of uppermost priority when facing the rapid development of human society. Although some attempts have successfully developed wastes into activated carbon electrodes, the high energy consumption of the production process and the powder form greatly restrict their application in eco-friendly wearable supercapacitors. Here, industrial waste-flax noil was conversed into fiber-shaped supercapacitors (FSSCs) via wet spinning and in situ deposition of polypyrrole (PPy). The regenerated cellulose fibers (RCFs) collected from the ethyl alcohol coagulation bath possessed excellent tensile behaviors and multi-groove surfaces, encouraging the subsequent textile processing and ions activities. After PPy deposition, the obtained fiber electrodes yielded high specific capacitance (510.7 F g-1 at 0.5 A g-1) and excellent coulombic efficiency (99.3% at 10 A g-1). More importantly, the assembled FSSCs delivered remarkable electrochemical performances and could power the LED. The green strategy proposed in this work provides a new consideration for converting wastes into practical eco-friendly wearable devices.