Enhanced transport properties of graphene-based, thin Nafion® membrane for polymer electrolyte membrane fuel cells

Abstract

Summary A polymer electrolyte membrane fuel cell (PEMFC) is one of the promising renewable energy conversion systems; however, its performance is considerably limited by the sluggish transport properties and/or reaction kinetics of the catalyst layers, especially at a high current density. In this study, graphene‐based, thin Nafion® membranes are prepared using 0 to 4 wt% of graphene nanoflakes, and the effects of the graphene are examined for enhanced transport properties. The electrical conductivity and dielectric constant are drastically enhanced to 0.4 mS/cm and 26 at 4 wt% of graphene nanoflakes, respectively, while the thermal conductivity linearly increases to 3 W/m‐K. The proton conductivity also significantly increases with the aid of graphene nanoflakes at >2 wt% of graphene nanoflakes, and the enhancement doubles compared with those of the carbon‐black (CB)‐based and carbon nanotube (CNT)‐based, thin Nafion® membranes, perhaps due to unique graphene structures. Additionally, the quasi‐steady‐state water contact angle increases from 113° to ~130° with the addition of graphene nanoflakes, showing that a hydrophobic‐like water wetting change may be related to the significant proton conductivity enhancement. This work provides an optimal material design guideline for the transport‐enhanced cathode catalyst layer using graphene‐based materials for polymer electrolyte membrane fuel cell applications.

Recent advances in additive‐enhanced polymer electrolyte membrane properties in fuel cell applications: An overview

“…The presence of glycerol also enhances the proton conductivity caused by the combination of proton movement by increasing the surface area of the small sphere of ZrP plus proton and jumps through both OH groups in the glycerol and ZrP dumping. Asmatulu et al has been fabricated the graphene‐based thin Nafion membrane for PEMFC. The proton conductivity with the graphene nanoflakes content at >2 wt% has significantly increased compared with the carbon black (CB)‐based and carbon nanotube (CNT)‐based, thin Nafion membranes which due to the unique graphene structures.…”

Carbon nanocomposites self‐assembly UiO‐66‐doped chitosan proton exchange membrane with enhanced proton conductivity

“…2,3 Although Nafion is widely used as a PEM due to its high proton conductivity and stability, 4 its applications are limited by unacceptable cost and poor methanol barrier. [5][6][7] Chitosan (CS) is explored as promising membrane-forming material for PEMs because of low cost and considerable methanol barrier properties. 8 However, a common problem of CS membrane is low proton conductivity, which has aroused more and more interest in extending proton transport channels to enhance conductivity of the PEMs.…”

Cross‐linked polymer electrolyte membrane based on a highly branched sulfonated polyimide with improved electrochemical properties for fuel cell applications

“…[1][2][3][4][5][6][7] Currently, state-of-the-art materials for PEMs are perfluorinated sulfonic acid membranes, such as Nafion. [8][9][10][11] The modification and researches are still ongoing. For example, Wu et al 11 used 2 to 5-nm quantum dots as a new smart filler for Nafion membrane to obtain high proton conductivity without scarifying mechanical stability.…”