文献类型：期刊文献

英文题名：Enhanced electrochemical performances of mesoporous carbon microsphere/selenium composites by controlling the pore structure and nitrogen doping

作者：Liu, Lei[1];Wei, Yanju[1];Zhang, Chuanfang[1];Zhang, Chuan[1];Li, Xu[1];Wang, Jitong[1];Ling, Licheng[1,2];Qiao, Wenming[1,2];Long, Donghui[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Key Lab Specially Funct Polymer Mat & Related Tec, Shanghai 200237, Peoples R China

年份：2015

卷号：153

起止页码：140

外文期刊名：ELECTROCHIMICA ACTA

收录：;EI(收录号：20145100352259);WOS:【SCI-EXPANDED(收录号:WOS:000348450000019)】；

基金：This work was partly supported by MOST (2014CB239702) and National Science Foundation of China (No. 51302083, No. 51172071, No. 51272077), and Fundamental Research Funds for the Central Universities and Program of Shanghai Subject Chief Scientist (No 13XD1424900).

语种：英文

外文关键词：Lithium-selenium batteries; Mesoporous carbon microsphere; Electrochemical performance; Pore size effect; Nitrogen-doping effect

摘要：Mesoporous carbon microspheres (MCMs) with tunable pore sizes have been prepared via a high-throughput spray drying-assisted hard template method and used as the hosts to load selenium (Se) for lithium-selenium (Li-Se) batteries. The pore size control of the MCMs (3.8, 5, 6.5, 9.5 nm) was achieved by in-situ polymerized colloid silica templates with different sizes, thus prompting us to focus on tracing the effects of mesopore size on electrochemical performance of MCMs/Se cathodes. The results reveal that relative higher capacity and better cycling performance are presented in MCMs with smaller pores size due to the more effective confinement effect. At an optimal pore size of 3.8 nm, the MCMs/Se with 50% Se loading delivers an initial capacity of 513mAhg(-1) and capacity retention of 300mAhg(-1) after 100 cycles at 0.5 C. Furthermore, it is concluded that nitrogen doping could assist MCMs to retard the diffusion of polyselenide species possibly via an enhanced surface adsorption. The composites thus increase the reversible capacity by 30% after 100 cycles compared with the nitrogen-free composite. These results indicate that controlling pore structure and surface chemistry are good strategies to optimize the electrochemical performance of C/Se based cathodes for Li-Se batteries. (C) 2014 Elsevier Ltd. All rights reserved.