All‐Printed Green Micro‐Supercapacitors Based on a Natural‐derived Ionic Liquid for Flexible Transient Electronics

The fabrication and characterization of green, flexible, ultra-thin supercapacitors that are able to operate above 1.5 V is reported, using an all-printed process. devices produced by aqueous spray casting a natural-derived electrolyte ionogel composed 2-hydroxyethyl cellulose the ionic liquid choline lactate, while electrodes highly porous nanostructured carbon films deposited supersonic cluster beam deposition (SCBD). obtained (device thickness < 10 μm) stable bending they possess power values up 120 kW kg–1. combination SCBD constitutes versatile, scalable, eco-friendly process directly print interconnected elements suitable for transient electronic systems.