Biomass Hydrogel Electrolytes toward Green and Durable Supercapacitors: Enhancing Flame Retardancy, Low-Temperature Self-Healing, Self-Adhesion, and Long-Term Cycling Stability.

Hydrogels have shown promise as quasi-solid-state electrolytes for flexible supercapacitors but face challenges such as poor self-repair, unstable electrode adhesion, limited temperature range, and flammability. Herein, an all-round green hydrogel electrolyte (silk nanofibers (SNFs)/peach gum polysaccharide (PGP)/borax/glycerol (SPBG)-ZnSO) addresses these issues through dynamic cross-linking of peach gum polysaccharide and silk nanofibers with borax, integrating varieties of key property including high water retention, broad temperature tolerance (-20 to 90 °C), excellent self-adhesion (60.7 kPa for carbon cloth electrodes), satisfactory flame retardancy (limited oxygen index of 51%), low-temperature self-healing (-20 °C), and good ionic conductivity (7.

Fire-resistant and low-temperature self-healing bio-based hydrogel electrolytes based on peach gum polysaccharide/sisal nanofibers for flexible supercapacitors.

The introduction of flame retardancy and low-temperature self-healing capacities in hydrogel electrolytes are crucial for promoting the cycle stability and durability of the flexible supercapacitors in extreme environments. Herein, biomass-based dual-network hydrogel electrolyte (named PSBGL), was synthesized with borax crosslinked peach gum polysaccharide/sisal nanofibers composite, and its application in flexible supercapacitors was also investigated in detail. The dynamic cross-linking of the dual-network endows the PSBGL with excellent self-healing performance, enabling ultrafast self-healing within seconds at both room temperature and extreme low temperatures.