Investigating the influence of the side-chain pendants of perfluorosulfonic acid membranes in a PEMFC by molecular dynamics simulations
Investigating the influence of the side-chain pendants of perfluorosulfonic acid membranes in a PEMFC by molecular dynamics simulations
复制标题
DOI：
10.1016/j.mtcomm.2019.100625
复制
发表时间：
2019-12-01
影响因子：
3.8
通讯作者：
Lee, Seung Geol
中科院分区：
文献类型：
--
作者：
Kwon, Sung Hyun;Kang, Haisu;Lee, Seung Geol
在这项研究中，我们使用全原子分子动力学（MD）模拟来评估PFSA聚合物侧链垂坠对Nafion或aquvion离子组成的膜的影响。尽管Aquivion离聚体的当量重量较低，但Nafion和Aquivion离聚体在室温（298.15 K）和工作温度（353.15 K）下均表现出相似的密度，这导致Aquivion膜中磺酸基/磺酸基以及磺酸基/水分子的相关性较高。我们还发现aquvion膜对水、水合氢离子和氧分子的扩散系数比Nafion膜高。这些结果与体积分析结果一致，表明aquvion膜中的溶剂体积比Nafion膜中的溶剂体积大，这有利于水通道的形成和小分子扩散的改善。该研究为改善PEMFC性能提供了PFSA膜设计的见解。
In this study, we used full atomistic molecular dynamics (MD) simulations to evaluate the influence of the side-chain pendants of the PFSA polymer in membranes composed of Nafion or Aquivion ionomers. Despite the lower equivalent weight of the Aquivion ionomer, the Nafion and Aquivion ionomers exhibit similar densities at both room (298.15 K) and operating (353.15 K) temperatures, which leads to higher sulfonic-group/sulfonic-group and sulfonic-group/water-molecule correlations in the Aquivion membrane. We also found that the Aquivion membrane exhibits higher diffusion coefficients for water, hydronium ions, and oxygen molecules than the Nafion membrane. These results are in good agreement with the volume-analysis results, which reveal that the solvent volume is higher in the Aquivion membrane than in the Nafion membrane, which leads to favorable water channels and improved small-molecule diffusion. This study provides PFSA membrane-design insight that can improve PEMFC performance.