香港科技大学Yoonseob Kim报道了锌空气电池用高效氢氧导电独立磷酸共价有机框架。相关研究成果发表在2024年11月18日出版的国际知名学术期刊《德国应用化学》。

由于其明确的晶体孔结构和沿骨架有序的功能离子基团，离子共价有机框架（iCOFs）表现出优异的性能，在储能和转换装置中具有巨大的应用潜力。

该文中，研究人员首次开发了即使在低离子交换容量（IEC）下也具有高氢氧化物导电性的阳离子鏻COFs。具体而言，研究人员合成了含有季鏻基团作为优异离子传输部分的COFs。然后，通过蒸汽辅助方法制备了独立的鏻膜，该膜在80°C下表现出126 mS cm^-1的高氢氧化物电导率，最低IEC为1.17 mmol g^-1。

所得薄膜成功应用于锌空气电池，能量密度为96.1 mW cm^-2，比容量为95.0 mAh cm^-2。运行时间超过2300分钟。总体而言，除了研究一种新型阳离子官能团外，研究人员还展示了COF基材料的独立成膜方法。

研究发现可以为将iCOFs领域推进到离子传输，和促进电化学应用提供坚实的基础。

附：英文原文

Title: Freestanding Phosphonium Covalent Organic Frameworks with Efficient Hydroxide Conduction for Zinc–Air Batteries

Author: Ye Tian, Xiaobin Hui, Kaiyu Wang, Yufei Yuan, Huanhuan Chen, Ki-Taek Bang, Ran Tao, Rui Wang, Dong-Myeong Shin, Yaozhong Lan, Zheng-Long Xu, Yoonseob Kim

Issue&Volume: 2024-11-18

Abstract: Owing to their well-defined crystalline pore structures and ordered functional ionic groups along the skeleton, ionic covalent organic frameworks (iCOFs) exhibit excellent performance and have significant potential for use in energy storage and conversion devices. Herein, we for the first time developed cationic phosphonium COFs with high hydroxide conduction even with low ion exchange capacity (IEC). Specifically, we synthesized COFs containing quaternary phosphonium groups as excellent ion transport moieties. Then, we fabricated freestanding phosphonium membranes through a vapor-assisted method, which exhibited high hydroxide conductivity of 126 mS cm–1 at 80 °C from a minimal IEC of 1.17 mmol g–1. The resulting film was successfully applied to zinc–air batteries, demonstrating energy density of 96.1 mW cm–2, specific capacity of 95.0 mAh cm–2, and stable operation over 2,300 min. Overall, in addition to investigating a novel cationic functional group, we demonstrated a freestanding film formation method of COF-based materials. The findings can provide a solid foundation for advancing the field of iCOFs to ion transport and promoting electrochemical applications.

DOI: 10.1002/anie.202419257

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202419257