Membrane-electrode assemblies output performance

Based on the Model 3, a 10-cell stack of microfuel cells was assembled. It was reported that an output of near 10 W was achieved, as shown in Fig. 8.23 [47]. Recently, through membrane electrode assembly (MEA) improvement, a power density 290 mW cm of the cell with an air cathode has been achieved. A 5-cell stack with effective area of 67 cm demonstrated that the power reached IlOW when the operating temperature reached 60 °C, though the stack started at room temperature without humidification. The performances of single ceU and 5-ceU stacks are shown in Fig. 8.24. 

Recent intensive studies have, however, been reported to lead to AEMs with high ionic conductivities, reportedly comparable to Nalion . These promising AEMs [11, 45-51] are still to be evaluated in AMFCs. Most hydrocarbon AEMs are soluble in various solvents, which is potentially useful for the formulation of alkaline ionomers required for the preparation of high-performance membrane electrode assemblies (MEAs). If the conductive properties reported can be translated into high power outputs, then AMEC performances comparable to those of PEMFCs can be expected in the near future. 

Table 13.2 summarizes the fuel cell performances of different composite PBI membranes with silica- or titania-based fillers. A direct compaiismi between the outputs is not recommended due to the different membrane-electrode-assembly preparation procedure, cell size, etc. 

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