Finite Thickness Effects on Nafion Water Uptake and Ionic Conductivity at Hydrophilic Substrate Interfaces, and Implications for PEMFC Performance

Published

September 28, 2017

Author(s)

Steven C. DeCaluwe, Joseph Dura

Abstract

The effect of film thickness on water uptake in ultra-thin Nafion films is probed via in situ neutron reflectometry for a series of 10 samples with thicknesses ranging from 7 - 103 nm, and the resulting effects on ionic conductivity. The water uptake in the lamellae and the bulk-like layer varies non-monotonically, decreasing as the equivalent Nafion thickness increases from 7 nm to 12 nm, increasing with increasing film thickness for equivalent Nafion thicknesses ranging from 12 nm-60 nm, and then constant for films with equivalent thickness ≥. Composition depth profiles are used to predict the anisotropic ionic conductivities, which are used in a flooded-agglomerate model of PEMFC catalyst layers to predict the effect of lamellar structure transport properties on PEMFC performance.

Citation

Electrochemical Society Transactions

Volume

80

Issue

8

Pub Type

Journals

Download Paper

Local Download

Keywords

Thin film ionomer, Nafion, Lamellae, confinement, PEM fuel cell, neutron eflectometry, ionic conductivity

Citation

DeCaluwe, S. and Dura, J. (2017), Finite Thickness Effects on Nafion Water Uptake and Ionic Conductivity at Hydrophilic Substrate Interfaces, and Implications for PEMFC Performance, Electrochemical Society Transactions, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=923923 (Accessed April 18, 2024)