Single Cell Study of Water Transport in PEMFCs with Electrosprayed Catalyst Layers

Abstract

Water transport in proton exchange membrane fuel cells (PEMFCs) with electrosprayed catalyst layers is analyzed by means of water collection measurements. With this aim, single cells have been studied with different catalyst layers configuration: electrosprayed layer in cathode (EScat), in anode (ESan), and in both electrodes (ESboth). The electrosprayed catalyst layers show macroporous morphology and superhydrophobicity (water contact angle θ > 150°) . Initial polarization curves, taken after a few hours from cell start‐up, show above 20% higher maximum power density of EScat and ESan cells, compared with a conventional cell (with no electrosprayed layers). The performance improvement is due to lower internal resistance of the cell according to the polarization curves. Stability of the cells under the dry‐gas operation conditions used during water collection measurements, shows to be high only for EScat, whereas ESan, ESboth, and conventional cells suffer degradation and frequent membrane failure. Water collection experiments at variable temperature and current density reflect larger water flow towards the anode for EScat cell than for the other configurations. It is concluded that the high performance and stability of EScat is due to the enhanced water back diffusion from cathode to anode driven by the superhydrophobic electrosprayed catalyst layer in cathode. Favored back diffusion improves water balance in the cell, membrane humidification, decreases the internal resistance, and precludes anode drying and cathode flooding. The optimal cell configuration is obtained with an electrosprayed catalyst layer in the cathode and a standard hydrophilic catalyst layer in the anode.

Differences in the Electrochemical Performance of Pt-Based Catalysts Used for Polymer Electrolyte Membrane Fuel Cells in Liquid Half- and Full-Cells

“…They suggested that the optimal MEA will be obtained when prepared using the electrosprayed catalyst layer in the cathode and the hydrophilic catalyst layer in the anode. 349 In addition, the mass transport resistance of the electrosprayed and airbrushed catalyst layers were measured to investigate the effect of mass transport in the electrosprayed catalyst layer. The electrosprayed catalyst layer exhibited a smaller mass transport resistance.…”

“…346 Due to its macropores and superhydrophobicity, the electrosprayed catalyst layer enhanced the mass transport and cell performance. 346,349 4.1.1.3. Alternative Methods: Electrospinning.…”

“…The mass transfer phenomenon in the electrosprayed catalyst layer was also investigated. , Folgado et al showed that an MEA prepared with an electrosprayed catalyst layer applied in the cathode showed higher performance when compared to that in the anode and both electrodes. This was because the electrosprayed catalyst layer has a macroporous morphology and superhydrophobicity.…”

Passive Regulation of the Water Content at the Anode Chamber under Dead-Ended Conditions: Innovative Design of an Air-Breathing Proton Exchange Membrane Fuel Cell

“…A CIEMAT air-breathing PEM fuel cell (AB-PEMFC) round prototype based on WO2015025070A1 was used for the experiments [11,18]. The anode chamber consists of a circular PEEK plate with lateral gas fittings for fuel inlet and outlet.…”

Thermal neutron radiography of a passive proton exchange membrane fuel cell for portable hydrogen energy systems

“…For continuous passive operation, the flooding and drying-out of cathode and anode must be prevented, that depend on a delicate equilibrium between different operation parameters [13,14]. Incorporating passive water rejection means, like superhydrophobic layers that repeal the liquid water from porous electrodes [15], or a hydrophilic membrane to allow water permeation from the anode [16] help the passive PEMFC operation, where water management is more critical than for a conventional, flow-field based, PEMFC.…”