安全性是制约锂离子电池向电动汽车领域应用拓展的主要障碍之一.本工作提出了一种能够有效改善锂离子电池安全性的电解液添加剂3,4-乙烯二氧噻吩单体(EDOT),研究了EDOT在有机电解液中的电氧化聚合行为及其对Li Co O2电极高温热行为和电...安全性是制约锂离子电池向电动汽车领域应用拓展的主要障碍之一.本工作提出了一种能够有效改善锂离子电池安全性的电解液添加剂3,4-乙烯二氧噻吩单体(EDOT),研究了EDOT在有机电解液中的电氧化聚合行为及其对Li Co O2电极高温热行为和电池安全性、电化学性能的影响.循环伏安(CV)和透射电镜(TEM)表征结果表明,单体添加剂能够在电池充电过程发生电氧化聚合,在正极表面形成一层聚(3,4-乙烯二氧噻吩)(PEDOT)导电聚合物膜.差示扫描量热(DSC)分析结果显示,PEDOT隔离了电解液与正极表面的直接接触,减少了过热条件下电解液在正极表面的分解放热.安全性测试结果表明,在电解液中仅添加0.1%的EDOT单体,即可将电池在150oC高温热冲击下发生热失控的时间推迟13.8 min.电化学性能测试结果表明,聚合产物良好的电子导电性能有效改善正极的电子传导能力,在一定程度上提高电池的倍率性能和循环稳定性,而容量、低温性能等基本不受影响,展示出良好的应用前景.展开更多
Electrocatalytic CO_(2) reduction has attracted growing attention as a promising route to realize artificial carbon recycling.Proton transfer plays an essential role in CO_(2) reduction and dramatically impacts produc...Electrocatalytic CO_(2) reduction has attracted growing attention as a promising route to realize artificial carbon recycling.Proton transfer plays an essential role in CO_(2) reduction and dramatically impacts product distribution.However,the precise control of proton transfer during CO_(2) reduction remains challenging.In this study,we present a well-controlled proton transfer through the modification of several purines with similar molecular structures,and reveal a direct correlation between surface proton transfer capability and CO_(2) reduction selectivity over Cu electrode.With a moderate proton transfer capability,the guanine modification can remarkably boost CH_(4) production and suppress C2 products formation.In-situ ATR-SEIRAS suggests a weakened^(*)CO intermediate adsorption and a relatively low local pH environment after the guanine modification,which facilitates the^(*)CO protonation and detachment for CH_(4) generation.展开更多
文摘安全性是制约锂离子电池向电动汽车领域应用拓展的主要障碍之一.本工作提出了一种能够有效改善锂离子电池安全性的电解液添加剂3,4-乙烯二氧噻吩单体(EDOT),研究了EDOT在有机电解液中的电氧化聚合行为及其对Li Co O2电极高温热行为和电池安全性、电化学性能的影响.循环伏安(CV)和透射电镜(TEM)表征结果表明,单体添加剂能够在电池充电过程发生电氧化聚合,在正极表面形成一层聚(3,4-乙烯二氧噻吩)(PEDOT)导电聚合物膜.差示扫描量热(DSC)分析结果显示,PEDOT隔离了电解液与正极表面的直接接触,减少了过热条件下电解液在正极表面的分解放热.安全性测试结果表明,在电解液中仅添加0.1%的EDOT单体,即可将电池在150oC高温热冲击下发生热失控的时间推迟13.8 min.电化学性能测试结果表明,聚合产物良好的电子导电性能有效改善正极的电子传导能力,在一定程度上提高电池的倍率性能和循环稳定性,而容量、低温性能等基本不受影响,展示出良好的应用前景.
基金supported by the National Key Basic Research Program of China(973)(2012CB932800,2012CB215500)National Natural Science Foundation of China(21125312,21203142,21573167)+1 种基金Doctoral Fund of Ministry of Education of China(20110141130002)Fundamental Research Funds for the Central Universities,China(2014203020207)
基金supported by the National Key Research and Development Program of China(2016YFB0101203)the National Natural Science Foundation of China(91545205,21633008)~~
文摘Electrocatalytic CO_(2) reduction has attracted growing attention as a promising route to realize artificial carbon recycling.Proton transfer plays an essential role in CO_(2) reduction and dramatically impacts product distribution.However,the precise control of proton transfer during CO_(2) reduction remains challenging.In this study,we present a well-controlled proton transfer through the modification of several purines with similar molecular structures,and reveal a direct correlation between surface proton transfer capability and CO_(2) reduction selectivity over Cu electrode.With a moderate proton transfer capability,the guanine modification can remarkably boost CH_(4) production and suppress C2 products formation.In-situ ATR-SEIRAS suggests a weakened^(*)CO intermediate adsorption and a relatively low local pH environment after the guanine modification,which facilitates the^(*)CO protonation and detachment for CH_(4) generation.
