MEA for Anion Exchange Membrane Fuel Cells

It is still a problem to make MEAs for AEMFCs. The main obstacle is the lack of a binder which matches the anion exchange membrane. Varcoe et al. prepared catalyst layers on carbon cloth, for both anode and cathode, by using PTFE as the binder. They found that it is difficult to laminate the catalyst layer to a poly(ethylene-co-tetrafluoroethylene) membrane by hot press [118]. The electrodes and membrane are therefore simply assembled into the fuel cell fixture, non-laminated. 

As electrochemical reaction sites, CLs play an extremely important rote in the performance of fuel cell stacks. A CL mainly consists of catalyst, support and binder. The CL is usually coated on the surface of the GDL. Another method has the CL directly applied to the membrane (catalyst coated membrane, CCM). The selection of the components, the proper ratios of those components, the structure of the formed CL and the formation method of the CL are critical factors in the performance of a fuel cell. The stability of the fuel cell performance is directly related to the stabilities of the catalyst, binder and support in flie CL. Degradation of catalytic activity would be due to the agglomeration of the eatalyst particles and their detachment from the support, the degradation of the binder, and the oxidation and corrosion of the support, particularly at the cathode. Further improvement in CL performance is possible. The basic technical considerations include how to maximize the three-phase interface of the CL, how to stabilize the metal particles on the support, and how to reduce the degradation of the components in the CL. 

Rajalakshmi N, Dhathathreyan KS. Catalyst layer in PEMFC electrodes fabrication, characterization and analysis. Chem Eng J 2007 129 31-40. 

Wang CY. Fundamental models for fuel cell engineering. Chem Rev 2004 104 4727-66. 

Litster S, McLean G. PEM fuel cell electrodes. J Power Sources 2004 130 61-76. Gottesfeld S, Zawodzinski TA. Polymer electrolyte fuel cells. In Alkire RC, Kolb DM, editors. Advances in electrochemical science and engineering. New York Wiley-VCH 1997.5 195-301. 

---