WATER MANAGEMENT IN PEMFC WITH ULTRA-THIN CATALYST-LAYERS

摘要

A two-dimensional non-isothermal multi-physics proton-exchange-membrane fuel-cell (PEMFC) modeling has been undertaken to investigate the interplay between the platinum (Pt) loading, water-capacity, water transport and cell performance at low operating temperatures (＜ 40 ℃). Two ultra-thin catalyst layers (CLs), traditional Pt/C with extremely low Pt loading and nano-structured thin-film (NSTF), have been the main focus in the present model. Modeling data are compared with experimental polarization curves for both NSTF and traditional Pt/C CLs. Using the model, the interplay between the inherent CL water-capacity versus its removal rate through either the anode or cathode side of the PEMFC is explored. The controlling parameters for the water removal and accumulation (e.g., thickness of catalyst layer, existence of microporous layer, etc.) are also analyzed and the tradeoff between these parameters elucidated with a path towards efficient water management for ultra-thin CLs.