Gao Ye, Han Wang-Kang, Zhu Ruo-Meng, Fu Jia-Xing, Feng Jing-Dong, Gu Zhi-Guo
Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, P. R. China.
Small. 2024 Dec;20(49):e2406251. doi: 10.1002/smll.202406251. Epub 2024 Sep 17.
Rational construction of high-performance ionic conductors is a critical challenge in the field of energy storage. In this study, a series of 1D anionic titanium-based covalent organic frameworks (COFs) containing abundant alkali metal ion migration sites, namely, COF-M-R (M = Li, Na, K; R = H, Me, Et), is constructed. The integration of negative TiO sites on 1D anionic COFs allows alkali metal cations to migrate directly through the channels. Meanwhile, the π-π stacking of 1D chain-to-chain allows the distribution of ion-migration sites in 2D planes. In view of this, multidimensional ionic transport in COFs is realized to achieve high ionic conductivity. COF-M-Rs exhibit an increased ionic conductivity as the counterions change from Li to Na to K. Notably, COF-Na-Et has an impressive ionic conductivity as high as 0.81 × 10 S cm. The different decorated groups (H, Me, and Et) on the skeleton influence the dissociation of the cation from the polyanion. This study offers deep insights into the design of COF-based solid-state electrolytes to achieve high ionic conductivity by increasing the ionic transport dimensions.
高性能离子导体的合理构建是储能领域的一项关键挑战。在本研究中，构建了一系列含有丰富碱金属离子迁移位点的一维阴离子钛基共价有机框架（COF），即COF-M-R（M = Li、Na、K；R = H、Me、Et）。一维阴离子COF上负性TiO位点的整合使碱金属阳离子能够直接通过通道迁移。同时，一维链与链之间的π-π堆积使离子迁移位点在二维平面上分布。鉴于此，实现了COF中的多维离子传输以实现高离子电导率。随着抗衡离子从Li变为Na再变为K，COF-M-R的离子电导率增加。值得注意的是，COF-Na-Et具有高达0.81×10 S cm的令人印象深刻的离子电导率。骨架上不同的修饰基团（H、Me和Et）影响阳离子从聚阴离子上的解离。本研究为通过增加离子传输维度来设计基于COF的固态电解质以实现高离子电导率提供了深刻见解。
