Joseph Vellaichamy, Nagai Atsushi
Ensemble3 - Centre of Excellence Wólczyńska 133 01-919 Warszawa Poland
RSC Adv. 2023 Oct 16;13(43):30401-30419. doi: 10.1039/d3ra04855a. eCollection 2023 Oct 11.
Recent electrochemical energy conversion devices require more advanced proton conductors for their broad applications, especially, proton exchange membrane fuel cell (PEMFC) construction. Covalent organic frameworks (COFs) are an emerging class of organic porous crystalline materials that are composed of organic linkers and connected by strong covalent bonds. The unique characteristics including well-ordered and tailorable pore channels, permanent porosity, high degree of crystallinity, excellent chemical and thermal stability, enable COFs to be the potential proton conductors in fuel cell devices. Generally, proton conduction of COFs is dependent on the amount of water (extent of humidity). So, the constructed fuel cells accompanied complex water management system which requires large radiators and airflow for their operation at around 80 °C to avoid overheating and efficiency roll-off. To overcome such limitations, heavy-duty fuel cells require robust proton exchange membranes with stable proton conduction at elevated temperatures. Thus, proton conducting COFs under anhydrous conditions are in high demand. This review summarizes the recent progress in emerging COFs that exhibit proton conduction under anhydrous conditions, which may be prospective candidates for solid electrolytes in fuel cells.
近期的电化学能量转换装置在广泛应用中需要更先进的质子导体，尤其是在质子交换膜燃料电池（PEMFC）的构建方面。共价有机框架（COFs）是一类新兴的有机多孔晶体材料，由有机连接体组成并通过强共价键相连。其独特的特性包括有序且可定制的孔道、永久孔隙率、高结晶度、出色的化学和热稳定性，使COFs成为燃料电池装置中潜在的质子导体。一般来说，COFs的质子传导取决于水量（湿度程度）。因此，构建的燃料电池伴随着复杂的水管理系统，该系统在约80°C下运行时需要大型散热器和气流，以避免过热和效率下降。为克服此类限制，重型燃料电池需要在高温下具有稳定质子传导的坚固质子交换膜。因此，对无水条件下质子传导的COFs需求很高。本综述总结了在无水条件下表现出质子传导的新兴COFs的最新进展，这些COFs可能是燃料电池中固体电解质的潜在候选材料。
