A comprehensive review on water management strategies and developments in anion exchange membrane fuel cells

Abstract

In spite of significant achievements in alkaline exchange membrane fuel cells (AEMFCs) in recent years, they are still lagging behind proton exchange membrane fuel cells (PEMFCs) due to performance instability. Among the relevant operational parameters of AEMFC, the researchers have found that poor water management within the cell was the main reason for failure of the system. In the past five years, numerous modeling and experimental works were reported proposing different strategies to improve water management of AEMFC. The achievable power output in AEMFCs is then comparable with that of PEMFCs or even more. Efforts have to be continued, but AEMFCs can become a strong competitor in the market place. This review paper discusses the strategies and developments impacting water management of AEMFCs providing knowledge source for upcoming studies.

Transition-Metal- and Nitrogen-Doped Carbide-Derived Carbon/Carbon Nanotube Composites as Cathode Catalysts for Anion-Exchange Membrane Fuel Cells

“…The spikes in the cell voltage are most likely due to periodic drying in the cell, as the average relative humidity remained constant at 73% for the duration of the experiment. We postulate that this could have been improved if the dew points were slightly adjusted to ensure that the cell was adequately humidified as explained by Hassan et al , 87 a thinner membrane was used to increase water back-diffusion from the anode to the cathode creating a more than desirable water gradient inside the fuel cell as supported by Veh et al , 88 and the cathode catalyst layer (CCL) was coated at a higher loading, making it thicker in order to better attract and retain more back-diffused water and in turn decreasing the overall cell resistance and providing adequate water for ORR and AEM hydration as explained by Gutru et al , 89 in their recent, comprehensive review on water management strategies in AEMFCs. The H 2 /air longevity data is some of the only data reported in the literature for precious-metal-free cathode catalysts in AEMFCs, as indicated by Table S4 .…”

Dimethylimidazolium-Functionalized Polybenzimidazole and Its Organic–Inorganic Hybrid Membranes for Anion Exchange Membrane Fuel Cells

“…Polymer electrolyte membrane fuel cells are one type of fuel cell suitable for portable and transportation applications, which feature quick start-up, low operation temperature, low cost, high efficiency, and so on [ 1 , 2 ]. Depending on the polymer electrolyte membrane, this type of fuel cell can be further divided into proton exchange membrane fuel cell (PEMFC) [ 3 , 4 ] and anion exchange membrane fuel cell (AEMFC) [ 5 , 6 ]. AEMFC has been attracted considerable attention in the recent decade due to several advantages over PEMFC, including (1) faster oxygen reduction reaction (ORR) under the basic condition that allows the catalyst at the cathode to employ platinum-free metal or low-platinum catalysts [ 7 , 8 , 9 ], (2) negligible fuel crossover owing to the hydroxide transport direction opposite to the direction of liquid fuel’s crossover (e.g., methanol) [ 10 , 11 ], as well as (3) minimized corrosion problems in alkaline environments [ 2 , 12 ].…”

Recent Insights on Catalyst Layers for Anion Exchange Membrane Fuel Cells

“…In addition to the development of new AEMs, other modifications improve water transport by (1) optimizing the hydrophilic/hydrophobicity of electrodes; 2) optimizing of Pt loading and ionomer in the catalyst layer; 3) employing thin and robust AEMs. [142]…”