Wood-derived Flexible Supercapacitors for Anti-Freezing Green Power Sources

Abstract

Highly porous wood-derived electronics have attracted tremendous concern towards high-performance supercapacitors (SCs), owing to environmental benignity, natural abundance, renewability, and biodegradability. However, intrinsic rigidity and sluggish electrochemical reaction kinetics at low temperature remain great challenges for wood-based SCs. Herein, we demonstrate an anti-freezing flexible SC (AF-FSC) based on delignified wood electrodes with organohydrogen electrolyte. Chemical delignification process removes hemicellulose and lignin in natural wood, resulting into soft wood skeleton electrode. With assembling solid hydrogel electrolyte, AF-FSC exhibits high mechanical flexibility over 93% capacitance retention after 1000 bending/twisting cycles at -30°C. Besides, a high areal capacitance (285.2 mF cm-2) at -30°C is achieved, which is higher than most wood-derivatives operating at room temperature. The unique behaviors of anti-freezing flexible AF-FSC would perform as a green renewable power source for driving multi-functional electronic components in real-life scenarios.