Li Xiangyu, Feng Yangyang, Fu Shuai, Wu Tianrui, Liang Peng, Ma Xicheng, Iqbal Rashid, Qian Yuzhen, Ma Yandong, Bonn Mischa, Wang Hua, Dai Hongjie, Hao Jingcheng, Dong Renhao
Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
State Key Laboratory of Crystal Materials, School of Physics, Shandong University, Jinan, 250100, China.
Angew Chem Int Ed Engl. 2025 Jul;64(27):e202502988. doi: 10.1002/anie.202502988. Epub 2025 Jun 4.
As a unique class of framework electronic materials, 2D conjugated metal-organic frameworks (2D c-MOFs) exhibit intrinsic porosity, superior electrical conductivity, and abundant active sites. These properties endow them with great potential in electrochemical lithium-ion storage. However, the development of 2D c-MOF-based capacitors has encountered a bottleneck in enhancing Li-ion storage capacitance, and the design of high-capacitance MOF electrode materials has remained a challenge. Herein, we synthesize a Cu-OHDDQP (octahydroxy-dibenzo[a,c]dibenzo[5,6:7,8]quinoxalino[2,3-i]phenazine) 2D c-MOF with a quasi-honeycomb lattice by employing a nonplanar D-symmetric conjugated ligand embedding redox-active pyrazine moieties. The quasi-honeycomb lattice features a dual-porous tessellation of C-symmetric and C-symmetric pores. Notably, when utilized as active material for electrochemical lithium storage, Cu-OHDDQP achieves a record-high gravimetric specific capacitance among reported 2D c-MOFs of 452 F g in aqueous lithium electrolyte, along with a decent cycling stability of 90% after 1000 cycles. Such high capacitance is attributed to both the quasi-honeycomb lattice leading to higher surface area and the redox-active pyrazine moieties offering extra lithium-adsorption sites and associated pseudocapacitance. This work demonstrates that rational ligand design enables high-capacitance MOF electrodes materials, highlighting the potential of conductive MOFs for electrochemical energy technologies.
作为一类独特的骨架电子材料，二维共轭金属有机框架（2D c-MOFs）具有固有孔隙率、优异的导电性和丰富的活性位点。这些特性使其在电化学锂离子存储方面具有巨大潜力。然而，基于二维共轭金属有机框架的电容器的发展在提高锂离子存储电容方面遇到了瓶颈，高电容MOF电极材料的设计仍然是一个挑战。在此，我们通过采用嵌入氧化还原活性吡嗪基团的非平面D对称共轭配体，合成了具有准蜂窝晶格的Cu-OHDDQP（八羟基二苯并[a,c]二苯并[5,6:7,8]喹喔啉并[2,3-i]吩嗪）二维共轭金属有机框架。准蜂窝晶格具有C对称和C对称孔的双孔镶嵌结构。值得注意的是，当用作电化学锂存储的活性材料时，Cu-OHDDQP在水性锂电解质中实现了创纪录的高重量比电容，在报道的二维共轭金属有机框架中达到452 F/g，并且在1000次循环后具有90%的良好循环稳定性。如此高的电容归因于准蜂窝晶格导致更高的表面积以及氧化还原活性吡嗪基团提供额外的锂吸附位点和相关的赝电容。这项工作表明，合理的配体设计能够实现高电容MOF电极材料，突出了导电MOF在电化学能源技术中的潜力。
