Reshetenko Tatyana V, Kulikovsky Andrei
Hawaii Natural Energy Institute, University of Hawaii, Honolulu, HI 96822, USA.
Theory and Computation of Energy Materials (IEK-13), Institute of Energy and Climate Research Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
Membranes (Basel). 2021 Dec 16;11(12):985. doi: 10.3390/membranes11120985.
The work presents a model for local impedance of low-Pt proton exchange membrane fuel cells (PEMFCs), including cathode pore size distribution and O transport along pores and through a thin ionomer film covering Pt/C agglomerates. The model was applied to fit the local impedance spectra of low-Pt fuel cells operated at current densities from 100 to 800 mA cm and recorded by a segmented cell system. Assuming an ionomer film thickness of 10 nm, the fitting returned the product of the dimensionless Henry's constant of oxygen dissolution in ionomer by the oxygen diffusivity in the ionomer (). This parameter allowed us to determine the fundamental O transport resistivity RN through the ionomer film in the working electrode under conditions relevant to the realistic operation of PEMFCs. The results show that variation of the operating current density does not affect RN, which remains nearly constant at ≃0.4 s cm.
该工作提出了一种低铂质子交换膜燃料电池（PEMFC）局部阻抗模型，包括阴极孔径分布以及氧气沿孔隙并通过覆盖在Pt/C团聚体上的薄离聚物膜的传输。该模型用于拟合由分段电池系统记录的、在100至800 mA/cm²电流密度下运行的低铂燃料电池的局部阻抗谱。假设离聚物膜厚度为10 nm，拟合得到了氧气在离聚物中溶解的无量纲亨利常数与氧气在离聚物中的扩散率（）的乘积。该参数使我们能够在与PEMFC实际运行相关的条件下，确定通过工作电极中离聚物膜的基本氧气传输电阻率RN。结果表明，工作电流密度的变化不会影响RN，其在≃0.4 s/cm时几乎保持恒定。
