共价有机骨架在高性能锂离子电池负极材料中的应用  

Application of Covalent Organic Frameworks in High-performance Lithium-ion Battery Anode Materials

作　　者：张晋恺 李佳莉 刘晓明[1] 母瀛[1] ZHANG Jinkai;LI Jiali;LIU Xiaoming;MU Ying(College of Chemistry,Jilin University,Changchun 130012,China)

机构地区：[1]吉林大学化学学院,长春130012

出　　处：《高等学校化学学报》2024年第3期114-124,共11页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:51673078)资助.

摘　　要：通过缩合聚合反应制备了两种热稳定性高、结晶性好和比表面积大的共价有机骨架(COF-1,COF-2)材料.将它们作为锂离子电池(LIBs)负极材料时,均表现出较高的可逆容量(经过150次循环后,COF-1和COF-2的充电比容量分别为484和327 mA·h/g)、出色的倍率性能(2和10 A/g电流密度下,COF-1和COF-2的可逆容量分别为296,180 mA·h/g和265,166 mA·h/g)、超大电流密度下的工作能力(5 A/g电流密度下循环2000次,COF-1和COF-2的充电比容量分别为572和332 mA·h/g)以及极端温度下的运行性能(50和‒15℃环境中循环40次后,COF-1和COF-2的充电比容量分别为2101,218 mA·h/g和1760,172 mA·h/g).两种COF均具有随着充放电的持续进行,电化学活性基团被激活的能力,COF-1和COF-2在不添加导电剂的情况下循环400次,充电比容量分别从23和16mA·h/g增长到45和31mA·h/g;通过对实验数据的分析,证明了在大电流密度以及高温环境等能使离子扩散速率加快的条件下,更有利于这种激活效应的发生.通过对比两种COF材料,发现含有三嗪环结构的COF-1的储锂性能及电化学反应动力学性质优于全部为苯环结构的COF-2,表明芳香环中的C=N可能是一种具有较高电化学活性的基团.In this work,two covalent organic frameworks(COF-1,COF-2)with high thermal stability,good crystal-linity,and large specific surface area were prepared through polycondensation.When used as anode materials for lithium-ion batteries(LIBs),they exhibited high reversible capacities(charging specific capacities after 150 cycles,COF-1:484 mA·h/g and COF-2:327 mA·h/g,respectively),excellent rate performance(reversible capacities at 2 and 10 A/g current densities,COF-1:296,180 mA·h/g,and COF-2:265,166 mA·h/g,respectively),working capacity under extremely high current density(charging specific capacities for 2000 cycles of 5 A/g current density,COF-1:572 mA·h/g,COF-2:332 mA·h/g)and operating performance under extreme temperatures(charging specific capacities after 40 cycles in 50 and‒15℃environments,COF-1:2101,218 mA·h/g,COF-2:1760,172 mA·h/g).In addition,both types of COFs have the ability to activate electrochemical active groups as charging and discharging continue.COF-1 and COF-2 were cycled 400 times without adding conductive agents,and the charging specific capacity increases from 23 and 16 mA·h/g to 45 and 31 mA·h/g,respectively.And through the analysis of Chem.J.Chinese Universities,2024,45(3),20230523 experimental data,we prove that under the conditions of high current density or high temperature environment,which can accelerate the ion diffusion rate,the activation effect is more favorable.By comparing these two types of COF materials,we also found that COF-1 with triazine ring structures has better lithium storage performance and electrochemical reaction kinetics than COF-2 with all benzene ring structures,indicating that C=N in the aromatic ring may be a group with high electrochemical activity.

关 键 词：共价有机骨架 锂离子电池 负极材料 比容量上升 电化学活性 

分 类 号：O646[理学—物理化学]