Fuel cell catalyst layers containing short-side-chain perfluorosulfonic acid ionomers

Abstract

Porous catalyst layers (CLs) containing short-side-chain (SSC) perfluorosulfonic acid (PFSA) ionomers of different ion exchange capacity (IEC: 1.3, 1.4 and 1.5 meq g −1 ) were deposited onto Nafion 211 to form catalyst-coated membranes. The porosity of SSC-PFSA-based CLs is larger than Nafion-CL analogues. CLs incorporating SSC ionomer extend the current density of fuel cell polarization curves at elevated temperature and lower relative humidity compared to those based on long-side chain PFSA (e.g., Nafion)-based CLs. Fuel cell polarization performance was greatly improved at 110• C and 30% relative humidity (RH) when SSC PFSI was incorporated into the catalyst layer.Crown

Effects of short-side-chain perfluorosulfonic acid ionomers as binders on the performance of low Pt loading fuel cell cathodes

“…These observations can be ascribed to an increase of the O 2 diffusion resistance from the gas phase to the catalyst sites as a result of excess water uptake in the cathode CLs. This type of effect seems to be a unique property for the SSC ionomers, reflecting their high IEC levels and thereby increased swelling, as can be seen in previous reports by Peron et al [23] and Lei et al [24]; increased polarization was found at 100% RH in the former work, and large Tafel slopes were found in the latter work. Such performance reductions were also reported for the hydrocarbon ionomers in our previous studies, caused by the high degree of swelling of the ionomers and/or insufficient mass (O 2 and proton) transport [9,10,31].…”

Polymer electrolyte membrane water electrolyser with Aquivion® short side chain perfluorosulfonic acid ionomer binder in catalyst layers

“…The current/power density performances and thermal stability of PEMFC using Aquivion Ò were found to be slightly better than those with Nafion Ò binders [7,12]. With incorporation of the SSC-PFSA ionomer only in CLs, the polarization performance of a Nafion Ò membrane PEMFC was greatly improved at 110 C and at 30% relative humidity (RH) [13]. Due to the adoption of SSC-PFSA, the operational temperature range of PEMFC could be extended up to 130 C, which is considered promising to overcome main challenges of PEMFCs for automotive applications [5e13].…”

Low equivalent weight short-side-chain perfluorosulfonic acid ionomers in fuel cell cathode catalyst layers

“…Xu et al have recently reported their results on improved PEMFC performance using low EW PFSA in the CCL; however, the study did not fully explore the microstructure-performance relationship from the perspective of electrode design [15]. Peron et al studied the influence of different EW SSC ionomers on the cell performance at high temperatures, and found that fuel cell performance was greatly improved at 110 • C and 30% relative humidity (RH) [16]. Despite the above-mentioned findings reported in the literature, the role of SSC PFSA ionomers in CCLs is still not sufficiently understood.…”