Sulfonated graphene oxide‐doped proton conductive membranes based on polymer blends of highly sulfonated poly(ether ether ketone) and sulfonated polybenzimidazole

Abstract

Simultaneously improving the proton conductivity and mechanical properties of a polymer electrolyte membrane is a considerable challenge in commercializing proton exchange membrane fuel cells. In response, we prepared a new series of miscible polymer blends and thus the corresponding crosslinked membranes based on highly sulfonated poly(ether ether ketone) and sulfonated polybenzimidazole. The blended membranes showed more compact structures, due to the acid-base interactions between the two constituents, and improved mechanical and morphological properties. Further efforts by doping sulfonated graphene oxide (s-GO) forming composite membranes led to not only significantly elevated proton conductivity and electrochemical performance, but also better mechanical properties. Notably, the composite membrane with the filler content of 15 wt % exhibited a proton conductivity of 0.217 S cm 21 at 80 8C, and its maximum power density tested by the H 2 /air single PEMFC cell at room temperature reached 171 mW cm 22 , almost two and half folds compared with that of the native membrane. As a result, these polymeric membranes provided new options as proton exchange membranes for fuel-cell applications.

A novel proton exchange membrane derived from trisulfonated poly(arylene ether phosphine oxide) containing diphenyl ether moieties

“…5 For these reasons, other aromatic polymer membranes have being investigated to meet the requirements for PEMFC. 6–8…”

“…5 For these reasons, other aromatic polymer membranes have being investigated to meet the requirements for PEMFC. [6][7][8] As alternatives to Nafion, sulfonated poly (arylene ether)s and their derivatives have many desirable advantages such as excellent mechanical properties, good chemical stability, high glass transition temperatures and proton-conducting. [9][10][11][12] It is worth noting that high conductivity depends on high ion exchange capacity (IEC), but high IEC results in excessive water absorption, which would lead to loss of mechanical properties.…”

SPEEK‐Tin dioxide proton conducting membranes: Effect of modifying agent of tin dioxide particles surface

“…[ 9 ] The sulfonation degree (SD) of SPEEK must be moderated to promote proton conductivity without loss of chemical and dimensional stability, otherwise the polymer may solubilize in presence of hot water. [ 4,10–13 ] However, despite of presenting a smaller separation between hydrophilic and hydrophobic regions, proton conductivity values in hydrated SPEEK‐based membranes are lower than obtained in Nafion, due to the larger distance between sulfonic groups and lower connectivity between hydrophilic channels. [ 9 ]…”

Enhanced Proton Conductivity of Sulfonated Polysulfone Membranes under Low Humidity via the Incorporation of Multifunctional Graphene Oxide

“…The Nafion/GO hybrid membranes showed increased water uptake and enhanced proton conductivity under low humidity compared with the pure Nafion membrane. However, the proton conductivity of Nafion/GO hybrid membranes under 100% RH declined with increasing GO loading contents due to the lack of acidic proton-hopping sites (only a limited amount of carboxyl groups on the edges of GO). , To provide extra proton-hopping sites, the surface-functionalized GO such as sulfonated GO fillers have been extensively explored in PEMs, − even though these composite membranes doped with sulfonated GO do not exhibit significant enhancement on proton conductivity under low humidity.…”