A majority of anion exchange membrane fuel cells (AEMFCs) reported in the literature have been unable to achieve high current or power. A recently proposed theory is that the achievable current is largely limited by poorly balanced water during cell operation. In this work, we present convincing experimental results – coupling operando electrochemical measurements and neutron imaging – supporting this theory and allowing the amount and distribution of water, and its impact on AEMFC performance, to be quantified for the first time. We also create new electrode compositions by systematically manipulating the ionomer and carbon content in the anode catalyst layer, which allowed us to alleviate the mass transport behavior limitations of H₂/O₂ AEMFCs and achieve a new record-setting peak power density of 1.9 W cm⁻² – a step-change to existing literature. Our efforts cast a new light on the design and optimization of AEMFCs – potentially changing the way that AEMFCs are constructed and operated.

中文翻译：

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除催化和膜之外：可视化并解决AEMFC中电极水积聚和溢流的挑战†

文献中报道的大多数阴离子交换膜燃料电池（AEMFC）无法实现高电流或高功率。最近提出的理论是，在电池运行期间，可达到的电流在很大程度上受到平衡水差的限制。在这项工作中，我们提出了令人信服的实验结果–耦合操作电化学测量和中子成像–支持这一理论，并首次量化了水的数量和分布及其对AEMFC性能的影响。我们还通过系统地控制阳极催化剂层中的离聚物和碳含量来创建新的电极组合物，这使我们能够减轻H ₂ / O ₂的传质行为限制。AEMFC达到了创纪录的1.9 W cm ^-2的峰值功率密度，这是对现有文献的一个逐步转变。我们的工作为AEMFC的设计和优化提供了新的思路-可能会改变AEMFC的构造和操作方式。