Transparent, Self‐Adhesive, Conductive Organohydrogels with Fast Gelation from Lignin‐Based Self‐Catalytic System for Extreme Environment‐Resistant Triboelectric Nanogenerators

Conductive hydrogels have shown great promise in the field of sustainable power sources due to their unique features of sufficient flexibility, durability, and functional diversification. However, time- and energy-consuming polymerization process and poor adaptability in extreme environments severely impede their practical application in such an emerging field. Herein, a facile and universal self-catalytic system (AL-Cu2+) based on alkali lignin (AL) macromolecule has been designed to rapidly fabricate conductive and transparent organohydrogels in alkaline water–ethylene glycol (EG) binary solvent, which displays extreme environment applicability (‒40 to 60 °C), eligible stretchability (≈800% elongation), and robust self-adhesion (≈31.4 kPa). Interestingly, the introduced EG accelerates the polymerization, endows extreme freezing/drying resistance, and improves self-adhesion for the organohydrogels. The organohydrogel (water/EG = 2/3) that combines the above merits inspires the construction of triboelectric nanogenerator (O-TENG) for mechanical energy harvesting and converting regardless of low- or high-temperature environments. The generated electricity by the O-TENG can be used directly or stored to drive commercial electronics and installed on human joints for movement monitoring. This work sheds light on designing environment-resistant flexible TENGs based on multifunctional soft materials with fast gelation strategy, provoking more attention to sustainable high-value utilization of lignin for advanced applications.