Stable functionalized graphene oxide–cellulose nanofiber solid electrolytes with long-range 1D/2D ionic nanochannels

Abstract

Solid electrolytes which could transport cations are widely used in energy-related and environmental applications. Herein, functionalized graphene oxide–cellulose nanofiber solid proton electrolytes (NPGOM-CNF) are successfully prepared. Based on 1D CNF and 2D dopamine-functionalized GO (NPGO), long-range 1D and 2D ionic nanochannels are constructed in the membranes with perfluorinated sulfonic acid resin (PFSA). The proton conductivity of NPGOM-10-CNF is as high as 0.4 S cm⁻¹ at 80 °C and 95% RH, two times higher than that of commercialized Nafion117. The single-cell performance of the NPGOM-10-CNF-based MEA is 31% higher than that of the Nafion117-based MEA at 60 °C and 100% RH on account of higher proton conductivities and better H₂ impedance ability. Besides, NPGOM-CNF membranes also possess outstanding stability in water and high methanol barrier performance, demonstrating great practical application potential.