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

Abstract

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.