Evaluation of Diaphragms and Membranes as Separators for Alkaline Water Electrolysis
Evaluation of Diaphragms and Membranes as Separators for Alkaline Water Electrolysis
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DOI：
10.1149/1945-7111/abda57
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发表时间：
2021-01-01
影响因子：
3.9
通讯作者：
Turek, Thomas
中科院分区：
文献类型：
--
作者：
Brauns, Joern;Schoenebeck, Jonas;Turek, Thomas
分离器是碱性电解性能的关键部件，因为它确保电极之间的离子接触并防止产物气体混合。分离器的离子电导率影响电池电压，溶解产物气体的渗透性影响产物气体杂质。目前，隔膜被用作隔膜分离器，隔膜的孔系统中充满电解质溶液，以实现离子的交换。气相的突破可以在一个特定的压差之前被阻止。隔膜的缺点是需要高度浓缩的电解质溶液来保持高离子电导率。阴离子交换膜的使用可以解决这个问题。然而，这些材料的长期稳定性仍未得到证实。本研究比较了两种预商用隔膜，一种是阴离子交换膜，一种是离子溶剂化膜，最先进的隔膜是锆石（TM） Perl UTP 500。除了物理表征外，还对材料样品进行了电化学评价，以确定欧姆电阻和产品气体杂质。结果表明，较薄的膜片性能优于标准材料，聚合物膜的性能可与标准材料相媲美。
The separator is a critical component for the performance of alkaline water electrolysis as it ensures the ionic contact between the electrodes and prevents the product gases from mixing. While the ionic conductivity of the separator affects the cell voltage, the permeability of the dissolved product gases influences the product gas impurity. Currently, diaphragms are used as separators, the pore system of which is filled with the electrolyte solution to enable the exchange of ions. The breakthrough of the gas phase can be prevented up to a specific differential pressure. A drawback of diaphragms is the requirement of a highly concentrated electrolyte solution to maintain a high ionic conductivity. The usage of anion-exchange membranes could solve this problem. However, the long-term stability of such materials remains unproven. This study compares two pre-commercial diaphragms, an anion-exchange membrane, and an ion-solvating membrane with the state-of-the-art diaphragm Zirfon(TM) Perl UTP 500. Besides physical characterization, the material samples were evaluated electrochemically to determine the ohmic resistance and the product gas impurities. The results show that the thinner diaphragm outperforms the reference material and that polymer membranes can compete with the performance of the reference material.