Dynamic Networks of Cellulose Nanofibrils Enable Highly Conductive and Strong Polymer Gel Electrolytes for Lithium‐Ion Batteries

Tunable dynamic networks of cellulose nanofibrils (CNFs) are utilized to prepare high-performance polymer gel electrolytes. By swelling an anisotropically dewatered, but never dried, CNF in acidic salt solutions, a highly sparse network is constructed with fraction CNFs as low 0.9%, taking advantage the very high aspect ratio and ultra-thin thickness (micrometers long 2–4 nm thick). These expose interfacial areas can accommodate massive amounts ionic conductive liquid polyethylene glycol-based electrolyte into strong homogeneous In addition reinforced mechanical properties, presence simultaneously enhances conductivity due their excellent water-binding capacity according computational simulations. This strategy renders room-temperature 0.61 ± 0.12 mS cm−1 which one highest among The shows superior performances separator for lithium iron phosphate half-cells specific (161 mAh g−1 at 0.1C), rate capability (5C), cycling stability (94% retention after 300 cycles 1C) 60 °C, well stable room temperature performance considerably improved safety compared commercial systems.