Wang Xinyi, Liu Zhiqiang, Ma Heqi, Liu Yiwen, Sui Qing, Feng Jifei, Cai Guofa
Key for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Nanoscience and Materials Engineering, Henan University, Kaifeng, 475004, China.
Adv Sci (Weinh). 2024 Nov;11(44):e2407297. doi: 10.1002/advs.202407297. Epub 2024 Oct 1.
Metal-organic frameworks (MOFs) deliver potential applications in electrochromism and energy storage. However, the poor intrinsic conductivity of MOFs in electrolytes seriously hampers the development of the above-mentioned electrochemical applications, especially in one MOF electrode. Herein, a new Ni-based MOF (denoted Ni-DPNDI) is proposed with enhanced conductivity by π-delocalized DPNDI connectors. Predictably, the obtained Ni-DPNDI MOF achieves a conductivity of up to 4.63 S∙m at 300 K. Profiting from its unique electronic structure, the Ni-DPNDI MOF delivers excellent electrochromic and energy storage performance with a great optical modulation (60.8%), a fast switching speed (t = 7.9 s and t = 6.4 s), a moderate specific capacitance (25.3 mAh·g) and good cycle stability over 2000 times. Meanwhile, energy storage capacity is visual by the coloration states of Ni-DPNDI film. As a proof of the potential application, a large-area (100 cm) electrochromic energy storage smart window is further designed and displayed. The strategy provides an interesting alternative to porous multifunctional materials for the new generation of electronic devices with diverse applications.
金属有机框架材料（MOFs）在电致变色和能量存储方面具有潜在应用。然而，MOFs在电解质中的固有导电性较差，严重阻碍了上述电化学应用的发展，尤其是在单一MOF电极中。在此，通过π-离域的DPNDI连接体提出了一种具有增强导电性的新型镍基MOF（表示为Ni-DPNDI）。可以预见，所获得的Ni-DPNDI MOF在300 K时的电导率高达4.63 S∙m。得益于其独特的电子结构，Ni-DPNDI MOF具有出色的电致变色和能量存储性能，具有较大的光学调制率（60.8%）、快速的切换速度（t = 7.9 s和t = 6.4 s）、适中的比电容（25.3 mAh·g）以及超过2000次的良好循环稳定性。同时，能量存储容量可通过Ni-DPNDI薄膜的着色状态直观呈现。作为潜在应用的证明，进一步设计并展示了大面积（100 cm）的电致变色能量存储智能窗。该策略为新一代具有多种应用的电子设备的多孔多功能材料提供了一种有趣的替代方案。
