Formation of an integrated catalyst-coated membrane using electrohydrodynamic atomization Layer-by-Layer deposition for direct methanol fuel cells

In this work, an integrated catalyst-coated membrane (CCM) is prepared by successively spray deposit Pt/C nano-suspension, Nafion solution and Pt-Ru/C nano-suspension on a cathode gas diffusion layer using electrohydrodynamic atomization (EHDA) Layer-by-Layer (LbL) deposition. Porous cathode and anode catalyst layers and dense Nafion membrane are deposited using the EHDA LbL deposition technique. It is also found that the EHDA LbL deposited CCM presents close packed structure. An 85 h life test shows that the EHDA LbL deposited cathode electrode side of the integrated CCM still presents well compact feature. Whereas, the delamination of the anode electrode side formed by direct pressing method is evident. The performance of the cell with different methanol concentrations is also examined. It is found that the 3 M methanol concentration gives the highest cell performance. Moreover, the polarization behaviour, methanol crossover and impedance response of the cell at different working temperatures are analysed. The cell performance demonstrates faster increase between 20 degrees C and 50 degrees C than between 50 degrees C and 70 degrees C. The methanol crossover test shows that the cell presents higher increase level of methanol crossover between 40 degrees C and 50 degrees C than other 10 degrees C temperature increase steps. (c) 2012 Elsevier B.V. All rights reserved