High-Performance Flexible Zinc-Air Batteries Enabled by a Sodium Polyacrylate-Based Gel Electrolyte Containing Graphene Oxide and Cellulose Nanofibers

Flexible zinc-air batteries (ZABs) have attracted considerable attention due to their high energy density, low cost, and eco-friendliness. However, the poor cycle life and aqueous electrolyte evaporation considerably hinder their practical applications, and the key challenge lies in the development of a robust electrolyte with high conductivity and good stability. Herein, we fabricate a novel gel polymer-based electrolyte (GPE) strengthened by graphene oxide (GO) and cellulose nanofibers (CNFs). Particularly, the incorporation of rigid GO and CNFs into a sodium polyacrylate (PANa)-bonded network could significantly improve the conductivity and mechanical properties of the GPE. Impressively, the conductivity of the composite electrolyte is tested to be 178.6 mS cm-1 and the elongation capability is over 13.8 times of its initial length, making it a promising candidate for flexible energy storage. With such a designed GPE, the sandwich-structured flexible ZABs exhibit an extended cycle life of over 214 h at 2 mA cm-2 and are capable of working normally even under bending, implying their superiority for high-performance flexible ZABs.