Anion exchange membrane fuel cells can potentially revolutionize energy storage and delivery; however, their commercial development is hampered by a significant technological impedance: the chemical decomposition of the anion exchange membranes during operation. The hydroxide anions, while transported from the cathode to the anode, attack the positively charged functional groups in the polymer membrane, neutralizing it and suppressing its anion-conducting capability. In recent years, several new quaternary ammonium salts have been proposed to address this challenge, but while they perform well in ex-situ chemical studies, their performance is very limited in real fuel cell studies. Here, we use experimental work, corroborated by molecular dynamics modeling to show that water concentration in the environment of the hydroxide anion, as well as temperature, significantly impact its reactivity. We compare different quaternary ammonium salts that have been previously studied and test their stabilities in the presence of relatively low hydroxide concentration in the presence of different amounts of solvating water molecules, as well as different temperatures. Remarkably, with the right amount of water and at low enough temperatures, even quaternary ammonium salts which are considered “unstable”, present significantly improved lifetime.

阴离子交换膜燃料电池可能会彻底改变能量的存储和输送方式。但是，它们的商业发展受到了重大技术阻抗的阻碍：运行过程中阴离子交换膜的化学分解。氢氧根阴离子从阴极传输到阳极时，会侵蚀聚合物膜中带正电荷的官能团，从而中和它并抑制其阴离子传导能力。近年来，已提出了几种新的季铵盐来应对这一挑战，但它们在非原位表现良好化学研究中，它们的性能在实际的燃料电池研究中非常有限。在这里，我们使用实验工作，并通过分子动力学模型进行了验证，结果表明，氢氧根阴离子环境中的水浓度以及温度会显着影响其反应性。我们比较了先前已研究过的不同季铵盐，并在存在不同量的溶剂化水分子以及不同温度的情况下，在相对较低的氢氧化物浓度下测试了它们的稳定性。值得注意的是，使用适量的水并在足够低的温度下，即使被认为是“不稳定”的季铵盐也可以显着提高使用寿命。