关键词: 燃料电池, 模型, 分布, 膜, 催化剂

Abstract:

During the aging process of fuel cell, the migration of catalyst in the catalytic layer and the increase of the particle size will deteriorate the performance of fuel cell. This paper proposed a new agglomerate layered distribution model, in which the layered interface can change linearly along the thickness of the film. Through the coupling of the macro-electrode model and the aggregate sub-scale model, the influence of the uneven distribution of aggregates on the performance of the proton exchange membrane fuel cell was analyzed by the finite element method. The results showed that the loss of catalyst near the outside of the aggregate had great influence on the battery performance. When the outer region without catalyst reached 10% of the radius, the current density decreased by 89.8% when the output voltage was 0.2V. When the inner region without catalyst reached 10% of the radius, the current density at the output voltage of 0.2V decreased by about 25%. Compared with the catalyst migration toward the proton exchange membrane, the catalyst migration toward the gas diffusion layer had greater impact on fuel cell performance. The fuel cell current densities from the layered and incrementally distributed agglomerate model and the layered decreasing distributions model were about 60% and 10% of those given by the uniformly distributed agglomerate model respectively. In addition, the performance of the cell could be improved by doubling the platinum loading.

Key words: fuel cells, model, distribution, membrane, catalyst