Zhang Jing, Luo Derong, Xiao Hong, Zhao Huizi, Ding Bing, Dou Hui, Zhang Xiaogang
Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies, College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China.
ACS Appl Mater Interfaces. 2023 Jul 26;15(29):34704-34710. doi: 10.1021/acsami.3c03643. Epub 2023 Jul 18.
As a new class of crystalline materials, covalent organic frameworks (COFs) have long-range ordered channels and feasibility to functionalize. The well-arranged pores make it possible to contain and transport ions. Here, we designed a novel functionalized anionic COF-SS-Li by a post-synthetic method utilizing the Povarov reaction of BDTA-COF, anchoring -SO groups to the COF backbone and converting the imine linkage to a more stable quinoline unit. The grafted -SO groups and directional channels can promote the lithium-ion transport through a hopping mechanism. As a solid-state lithium-ion electrolyte, COF-SS-Li exhibits the conductivities of 9.63 × 10 S cm at 20 °C and 1.28 × 10 S cm at 40 °C and a wide electrochemical window of 4.85 V. The assembled Li|COF-SS-Li|Li symmetric cell can cycle stably for 600 h at 0.1 mA cm. Also, the Li|COF-SS-Li|LiFePO cell delivers an initial capacity of 117 mAh g at 0.1 A g and retains a capacity rate of 56.7% after 500 cycles. The research enriches the solid-state electrolytes for lithium-ion batteries.
作为一类新型晶体材料，共价有机框架（COFs）具有长程有序通道且具备功能化的可行性。排列规整的孔道使得其能够容纳和传输离子。在此，我们通过一种后合成方法，利用BDTA-COF的Povarov反应设计了一种新型功能化阴离子COF-SS-Li，将-SO基团锚定到COF主链上，并将亚胺键转化为更稳定的喹啉单元。接枝的-SO基团和定向通道能够通过跳跃机制促进锂离子传输。作为一种固态锂离子电解质，COF-SS-Li在20℃时的电导率为9.63×10 S cm，在40℃时为1.28×10 S cm，并且具有4.85 V的宽电化学窗口。组装的Li|COF-SS-Li|Li对称电池在0.1 mA cm下能够稳定循环600 h。此外，Li|COF-SS-Li|LiFePO电池在0.1 A g下的初始容量为117 mAh g，在500次循环后容量保持率为56.7%。该研究丰富了用于锂离子电池的固态电解质。
