Ultra-Stable, Highly Proton Conductive, and Self-Healing Proton Exchange Membranes Based On Molecule Intercalation Technique and Noncovalent Assembly Nanostructure

摘要

Proton exchange membranes (PEMs) that can heal mechanical damage torestore original functions are imperative for fabricating reliable and durableproton exchange membrane fuel cells (PEMFCs). Here, an ultra-stable, highlyproton conductive self-healing PEM via hydrogen-bonding complexationbetween Nafion and poly(vinyl alcohol) (PVA) followed by incorporation ofsodium lignosulfonate (SLS) intercalation-modified graphene oxide (GO) andpost-modification with 4-formylbenzoic acid (FBA) is presented. Notably, theintroduction of GO complexes and post-modification of FBA molecules effectivelyimproves the stability of composite membranes and also participatein the establishment of proton-conducting nanochannels. Compared withrecast Nafion, the FBA-Nafion/PVA@SLS/GO composite membranes exhibitenhanced mechanical properties (36.2 MPa at 104.8% strain) and higherproton conductivity (0.219 S cm~(?1) at 80 ℃-100% RH and 23.861 mS cm~(?1) at80 ℃-33% RH, respectively). More importantly, the incorporated PVA givesthe FBA-Nafion/PVA@SLS/GO composite membranes superior self-healingcapabilities that can heal mechanical damage of several tens of micrometersin size and restore their original proton conductivity under the operating conditionsof the PEMFCs. This study opens an avenue toward the developmentof reliable and durable PEM for PEMFCs.