Poly(fluorene)‐Based Anion Exchange Membrane Demonstrating Excellent Durability at 1.5 A cm<sup>‒2</sup> for 2400 h in Water Electrolyzers
Haeryang Lim, Nam In Kim, Gi Won Shin, Jun Ho Lee, Sungryong Kim, Shin‐Woo Myeong, Chiho Kim, Sung Mook Choi, Taiho Park
Abstract
Abstract Anion exchange membrane water electrolyzer (AEMWE) is a cost‐effective alternative to proton exchange membrane water electrolyzer for green hydrogen production. However, AEMWE commercialization is hindered primarily by the lack of a reliable anion exchange membrane (AEM) for long‐term cell durability. In this study, a poly(fluorene)‐based PFAA‐QA AEM is developed with a simple structure, exhibiting satisfactory OH − conductivity (>174.6 mS cm −1 at 80 °C), good mechanical properties (tensile strength >35 MPa and elongation at break >51%), and excellent alkaline stability (>2000 h in 3 m KOH at 80 °C). These characteristics allow PFAA‐QA‐based AEMWEs to demonstrate a high cell performance (3.95 A cm −2 at 70 °C and 1.95 V) and long‐term durability at high current densities (1.5 A cm −2 for 2400 h at 70 °C). Therefore, the durability of these AEMWEs surpasses that of most AEMWEs with a low voltage decay rate (>29 mV kh −1 ).