质子交换膜（PEM）燃料电池的效率取决于质子在PEM中的迁移率，其由膜的水合作用和温度决定。虽然光学技术或中子或X射线散射技术可用于研究PEM中的水合和温度的不均匀性，但这些技术不能在测量分层PEM中提供三维空间分辨率。由于其提供非侵入性3D图像的能力，PEM中质子的自旋-晶格弛豫时间（T1）和自旋-自旋弛豫时间（T2）对比度磁共振成像（MRI）已被建议作为绘制燃料电池中水合的方法。我们表明，虽然T1和T2成像可用于映射质子交换膜在等温条件下的水化，质子T1和T2也是温度的函数。对于PEM燃料电池，其中电流密度大并且预期有热梯度，T1和T2弛豫时间不能用于映射水合。然而，移动质子的化学位移是水合作用的强函数，而不是温度。因此，化学位移成像（CSI）可以用来映射水合。可移动质子的扩散常数，这可以通过脉冲场梯度NMR确定，增加与温度和水合。因此，CSI之后通过脉冲场梯度的扩散成像可用于PEM中的水合和温度的单独映射。在这里，我们展示了Nafion PEM中水合作用和温度的16 x 16像素MRI映射，空间分辨率为1 mm x 1 mm，总扫描时间为3分钟，温度分辨率为6 K，水合作用的不确定性在15%以内。所展示的映射可以推广用于成像任何燃料电池或液流电池的交换膜。
英文摘要：
The efficiency of a proton exchange membrane (PEM) fuel cell depends on the mobility of protons in the PEM, which is determined by the hydration and temperature of the membrane. While optical techniques or neutron or x-ray scattering techniques may be used to study the inhomogeneities in hydration and temperature in PEMs, these techniques cannot provide 3 dimensional spatial resolution in measuring layered PEMs. Due to their ability to provide non-invasive 3D images, spin-lattice relaxation time (T1) and spin-spin relaxation time (T2) contrast magnetic resonance imaging (MRI) of protons in PEMs have been suggested as methods to map hydration in the fuel cells. We show that while T1 and T2 imaging may be used to map hydration in PEMs under isothermal conditions, proton T1 and T2 are also a function of temperature. For PEM fuel cells, where current densities are large and thermal gradients are expected, T1 and T2 relaxation times cannot be used for mapping hydration. The chemical shift of the mobile proton is, however, a strong function of hydration but not temperature. Therefore, chemical shift imaging (CSI) can be used to map hydration. The diffusion constant of the mobile proton, which can be determined by pulsed field gradient NMR, increases with both temperature and hydration. Therefore, CSI followed by imaging of diffusion via pulsed field gradients can be used for separate mappings of hydration and temperature in PEMs. Here, we demonstrate a 16 x 16 pixel MRI mapping of hydration and temperature in Nafion PEMs with a spatial resolution of 1 mm x 1 mm, a total scan time of 3 minutes, a temperature resolution of 6 K, and an uncertainty in hydration within 15%. The demonstrated mapping can be generalized for imaging exchange membranes of any fuel cells or flow batteries.
Bipolar plates for the next generation of proton exchange membrane fuel cells (PEMFCs): A review of the latest processing methods for unconventional flow channels
Doped graphene/carbon black hybrid catalyst giving enhanced oxygen reduction reaction activity with high resistance to corrosion in proton exchange membrane fuel cells
碳的氮掺杂是通过铂-氮和碳-氮键改善质子交换膜燃料电池催化剂性能和耐久性的重要方法。该研究表明，连接铂和石墨烯/炭黑（石墨烯/炭黑的比例= 2/3）杂化载体材料的对苯基和石墨N作用桥实现了铂纳米颗粒的平均尺寸为（4.88 +/-1.79）nm。在0.60 V时，它使低温氢燃料电池的性能提高到0.934 W cm-2，是商用Pt/C的1.55倍。掺杂还增强了Pt与载体材料之间的相互作用和抗腐蚀性，从而提高了低温氢燃料电池的耐久性，在30k循环的原位加速应力降解试验中，Pt/C的催化剂降解衰减为92 mV，在0.80 A cm-2处的衰减为10 mV，远低于能源部的目标（<30 mV）。同时，Pt/NrEGO2-CB3在1.5A cm-2的碳腐蚀原位加速应力试验中，经过5k次循环后，仍保持初始功率密度的78%，比商业Pt/C的功率密度稳定，加速应力试验后仅保持54%。
Nanoscale study of reactive transport in catalyst layer of proton exchange membrane fuel cells with precious and non-precious catalysts using lattice Boltzmann method
Computational Insights into PEMFC Durability: Degradation Mechanisms, Interfacial Chemistry, and the Emerging Role of Machine Learning Potentials
Organization for Research and Development of Innovative Science and Technology, Kansai University（关西大学创新科学技术研发组织）；Department of Chemistry and Materials Engineering, Faculty of Chemistry, Materials and Bioengineering, Kansai University（关西大学化学·材料·生物工程学院化学与材料工程系）
