Importance of Hydroxide Ion Conductivity Measurement for Alkaline Water Electrolysis Membranes

Membranes

Jaehong Chun¹  Rae Duk Lee¹  Jian Hou²  Chang Hyun Lee²  Jun Hyun Lim²  Jaehan Yun²  Jinwoo Jung² 

[1] AES Tech Co., Ltd., Daejeon 34052, Korea;Department of Energy Engineering, Dankook University, Cheonan 31116, Korea;

关键词: hydroxide ion transport;    ion conductivity;    polymer electrolyte membrane;    alkaline water electrolysis;    hydrogen generation;    impedance measurement;   

DOI  :  10.3390/membranes12060556

来源: DOAJ

【 摘 要 】

Alkaline water electrolysis (AWE) refers to a representative water electrolysis technology that applies electricity to synthesize hydrogen gas without the production of carbon dioxide. The ideal polymer electrolyte membranes for AWE should be capable of transporting hydroxide ions (OH⁻) quickly in harsh alkaline environments at increased temperatures. However, there has not yet been any desirable impedance measurement method for estimating hydroxide ions’ conduction behavior across the membranes, since their impedance spectra are significantly affected by connection modes between electrodes and membranes in the test cells and the impedance evaluation environments. Accordingly, the measurement method suitable for obtaining precise hydroxide ion conductivity values through the membranes should be determined. For this purpose, Zirfon^®, a state-of-the-art AWE membrane, was adopted as the standard membrane sample to perform the impedance measurement. The impedance spectra were acquired using homemade test cells with different electrode configurations in alkaline environments, and the corresponding hydroxide ion conductivity values were determined based on the electrochemical spectra. Furthermore, a modified four-probe method was found as an optimal measurement method by comparing the conductivity obtained under alkaline conditions.

【 授权许可】

Unknown