高电容性能MXene电极对插层修饰离子的选择性  

Selectivity for intercalated ions in MXene toward a high-performance capacitive electrode

作　　者：胡敏敏 代君 陈丽红 孟阿兰 王磊 李桂村 谢海姣 李镇江 Minmin Hu;Jun Dai;Lihong Chen;Alan Meng;Lei Wang;Guicun Li;Haijiao Xie;Zhenjiang Li(School of Materials Science and Engineering,Qingdao University of Science and Technology,Qingdao 266042,China;College of Electromechanical Engineering,Qingdao University of Science and Technology,Qingdao 266042,China;State Key Laboratory Base of Eco-chemical Engineering,College of Chemistry and Molecular Engineering,Qingdao University of Science and Technology,Qingdao 266042,China;Hangzhou Yanqu Information Technology Co.,Ltd.,Hangzhou 310003,China)

机构地区：[1]School of Materials Science and Engineering,Qingdao University of Science and Technology,Qingdao 266042,China [2]College of Electromechanical Engineering,Qingdao University of Science and Technology,Qingdao 266042,China [3]State Key Laboratory Base of Eco-chemical Engineering,College of Chemistry and Molecular Engineering,Qingdao University of Science and Technology,Qingdao 266042,China [4]Hangzhou Yanqu Information Technology Co.,Ltd.,Hangzhou 310003,China

出　　处：《Science China Materials》2023年第3期974-981,共8页中国科学（材料科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (52072196, 52002199, 52002200, and 52102106);the Major Basic Research Program of Natural Science Foundation of Shandong Province (ZR2020ZD09);the Natural Science Foundation of Shandong Province (ZR2019BEM042 and ZR2020QE063);the Innovation and Technology Program of Shandong Province (2020KJA004);the Open Project of Chemistry Department of Qingdao University of Science and Technology (QUSTHX201813);the Postdoctoral Innovation Project of Shandong Province (202101020);Taishan Scholars Program of Shandong Province (ts201511034)。

摘　　要：离子插层是提高Ti_(3)C_(2)TxMXene电化学性能的有效方法之一.然而,不同的插层离子对MXene的结构和电化学性能的影响是否相同这一问题尚不清楚.本文系统研究了Li+、Na+、K+、Cs+、Zn2+、Mg2+、SO_(4)2-和OH-等一系列离子插层后的MXene的结构特征和电化学性能.研究结果表明,插层离子的半径、电荷数和化学特性对插层效果都会产生影响.在所研究的插层剂中,由离子半径最大的一价阳离子Cs+和具有强碱性的阴离子OH-组成的插层剂CsOH对MXene具有较好的插层效果.插层后的MXene层间距增大,层间容纳了大量游离水,Ti的价态升高,片层表面有利于氧化还原反应的含O官能团增多,这都大大促进了电解液离子H+的扩散与存储.由此制备的电极的质量比电容大幅度提高,为原始MXene电极的7倍多,而且经过20,000次充放电循环后电容保持率未发生下降.本文为具有高电容性能的MXene和MXene基复合电极的合理设计和制备提供了指导.The intercalation of foreign ions has been demonstrated to be one of the effective methods to improve the electrochemical performance of Ti_(3)C_(2)TxMXene.However,whether different intercalated ions have diverse impacts on the MXene structure and electrochemical properties is not well understood.Herein,we comprehensively investigated the structural features and electrochemical performances of a series of ions,including Li+,Na+,K+,Cs+,Zn2+,Mg2+,SO_(4)2-,and OH-intercalated MXenes.Different ions are observed to exhibit variations in the intercalation effect because of the differences in their sizes,charge numbers,and chemical features.Among the investigated intercalation agents,CsOH composed of monovalent Gs+with a large size and strong base anion OH-exhibits a superior intercalation effect,where a large interlayer space accommodating a large amount of free water,a high oxidation state of Ti and a preferred surface with more O-containing functional groups for redox reaction is created,intensifying the pseudocapacitive H+intercalation.Therefore,CsOH-treated MXene exhibits a significant enhancement in gravimetric capacitance(i.e.,approximately725% of the original) and more than 100% capacitance retention over 20,000 cycles.This paper provides a guideline for the rational design and construction of high-capacitance MXene and MXene-based hybrid electrodes in aqueous electrolytes.

关 键 词：电容性能 充放电循环 质量比电容 电化学性能 氧化还原反应 离子半径 复合电极 电荷数 

分 类 号：O646.54[理学—物理化学] TM53[理学—化学]