Background on Fuel Cell Membranes

Direct methanol fuel cells are being considered as the power supply for a number of applications such as automotive, portable electronics including cellular phones and laptop computers, auxiliary power for instmmentation, and as a battery replacement for combat personnel and other military needs. 

2 BACKGROUND ON FUEL CELL MEMBRANES 29.2.1 General Requirements 

For PEMFC operation under high relative humidity (RH) conditions at T 80°C, perfluorosulfonic acid (PFSA) proton conductors (e.g.. Nation , whose chemical structure is shown in Fig. 29.4) are the membrane material of choice due to their high conductivity 

There are two major challenges for membrane scientists with regard to proton exchange membrane fuel cells (1) PEMEC membranes that conduct protons under high-temperature and low-humidity conditions and (2) DMFC membranes that are highly conductive but act as barriers to methanol. 

For a DMFC, the membrane properties of utmost interest are the proton conductivity and methanol crossover. Ideally, the membrane should be a good proton conductor (with a 

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