Study On Membrane Electrodes Assemblies Of Micro PEMFC

Membrane Electrodes Assemblies (MEA) of micro Proton Exchange Membrane Fuel Cell is studied in this paper, including the following three issues:(i) Fabrication and optimization of MEA; (ii) Investigation influence of micro PEMFC operation condition on the performance of MEA; (iii) Application of MEA in micro PEMFC based on PCB technology.First, Fabrication and optimization of MEA are studied in many aspects, for example hot press parameters, components of catalyst layer and diffusion layer, PEM thickness, etc. The specified technique parameters are as follows: hot press parameters of MEA: hot press operation parameters should be controlled within the range of 135℃ ~150℃ for hot press temperature, t1=3Os t2=90s for hot press time, 4MPa~6MPa for hot press pressure. For catalyst layer parameters control, Nation PTFE and Pt loadings are optimized ,which are 1.0mg/cm2, 10% and 0.4mg/cm2 respectively. Diffusion layer parameters control: it seemed that MEA fabricated with the carbon paper has the best performance. This can be explained by its properties of good gas permeation, high conductivity, moderate hydrophobicity characteristic. PEM thickness control: Nation membrane 1135 is well fit for μPEMFC, because of its decent thickness and robustness. The maximum power density and limit current density attain 115 mW/cm2 and 440mA/cm2 respectively.Second, influence of micro PEMFC running conditions on the performance of MEA is studied. The result showed that: Effects of the cell placement orientations and H2 rate on the performance of the MEA are very little and O.OlmL/min flow rate of hydrogen is reasonable. Effect of air convection environmental condition and flowfield size on the performance of the cell are very obvious, performance of the cell is the best with 4# size flowfield. After running for 618 hours, Performance of the MEA is still very stable.Finally, application research of MEA in micro PEMFC based on PCB technology was carried out. The result showed that: micro PEMFC manufactured by PCB technology is feasible. The cell stack with pseudo-bipolar structure showed that the MEAS have uniform performance and the maximum power density of every cell is about 115mW/cm2.