文献类型：期刊文献

英文题名：Heteroatomic SenS8-n Molecules Confined in Nitrogen-Doped Mesoporous Carbons as Reversible Cathode Materials for High-Performance Lithium Batteries

作者：Sun, Fugen[1];Cheng, Hongye[2];Chen, Jianzhuang[1];Zheng, Nan[1];Li, Yongsheng[1];Shi, Jianlin[1,3]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Key Lab Ultrafine Mat, Lab Low Dimens Mat Chem,Minist Educ, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[3]Chinese Acad Sci, Shanghai Inst Ceram, State Key Lab High Performance Ceram & Superfine, Shanghai 200050, Peoples R China

年份：2016

卷号：10

期号：9

起止页码：8289

外文期刊名：ACS NANO

收录：;EI(收录号：20164002874512);WOS:【SCI-EXPANDED(收录号:WOS:000384399300020)】；

基金：This work was financially supported by National Science Foundation of China (No. 51502090), China Postdoctoral Science Foundation (Nos. 2014M560306 and 2015T80407), and grants from the Science and Technology Commission of Shanghai Municipality (No. 15YF1402800) and Fundamental Research Funds for the Central Universities (No. 222201414033).

语种：英文

外文关键词：heteroatomic SenS8-n molecules; nitrogen-doped mesoporous carbons; selenium-sulfur-carbon composites; mixed chalcogen cathodes; lithium batteries

摘要：A reversible cathode material in an ether-based electrolyte for high-energy lithium batteries was successfully fabricated by homogeneously confining heteroatomic SenS8-n molecules into nitrogen-doped mesoporous carbons (NMCs) via a facile melt impregnation route. The resultant SenS8-n/NMC composites exhibit highly reversible electrochemical behavior, where selenium sulfides are recovered through the reversible conversion of polysulfoselenide intermediates during discharge charge cycles. The recovery of selenium sulfide molecules endows the SenS8-n/NMC cathodes with the rational integration of S and Se cathodes. Density functional theory calculations further reveal that heteroatomic selenium sulfide molecules with higher polarizability could bind more strongly with NMCs than homoatomic sulfur molecules, which provides more efficient suppression of the shuttling phenomenon. Therefore, with further assistance of mesopore confinement of the nitrogen-doped carbons, the Se2S6/NMC composite with an optimal Se/S mole ratio of 2/6 presents excellent cycle stability with a high initial Coulombic efficiency of 96.5% and a high reversible capacity of 883 mAh g(-1) after 100 cycles and 780 mAh g(-1) after 200 cycles at 250 mA g(-1). These encouraging results suggest that the heteroatomization of chalcogen (such as S, Se, or Te) molecules in mesostructured carbon hosts is a promising strategy in enhancing the electrochemical performances of chalcogen/carbon-based cathodes for Li batteries.