Tailoring of an ultralow temperature adaptive cellulose nanofiber-based flexible zinc-air battery with long cycle life

Abstract

Flexible zinc-air batteries are competitive energy storage equipment for wearable electronic devices, but the generation of zinc dendrites reduces their cycle life, and the formation of ice crystals limits their application at ultralow temperatures. Herein, a novel low-temperature adaptive cellulose nanofiber (CNF)-based sandwich-structured flexible zinc-air battery (CNF-FZAB-PF) was well constructed using a CNF-based flexible hydrogel electrolyte containing lithium chloride, an air cathode with a FeCo nanosheet catalyst and carbon cloth, and a zinc anode. The rigid-flexible cocrosslinked double network skeleton supported by CNF and lithium chloride of CNF-FZAB-PF endowed it with excellent mechanical properties and an energy efficiency of 58%. Interestingly, zinc dendrites on the zinc anode and ice crystals at low temperatures were effectively inhibited by enhancing the interface ionic conduction between the zinc anode and hydrogel electrolyte with lithium chloride. Thus, CNF-FZAB-PF exhibited a stable open circuit voltage of 1.49 V, a specific capacity of 663 mA h g⁻¹, an energy density of 981.24 W h kg⁻¹, a long cycle time of 80 h, and operational stability under room and ultralow temperatures (−60 °C).