基于电纺聚丙烯腈(PAN)前驱体制备三维氮掺杂炭纳米纤维(NCFs)自支撑集流体,以Li_2S_6溶液为活性物质,研究了不同热处理温度下制备的NCFs理化性能及其在锂硫电池中的电化学行为。结果表明,热处理温度为900℃时,制备的NCFs(NCFs-900)表现出优异的电化学性能。当载硫量为4.19 mg·cm~(-2)时,NCFs-900@Li_2S_6电极在0.2C下,初始放电容量为875 mAh·g~(-1),经250周循环后仍有707 mAh·g~(-1),库伦效率为98.55%。同时在高倍率1 C下循环150周后容量保持率为81.53%。A 3 D assembly of nitrogen-doped carbon nanofibers(NCFs)derived from polyacrylonitrile was synthesized by a combined electrospinning/carbonization technique and was used as the positive current collector in lithium sulfur(Li-S)batteries containing a Li2 S6 catholyte solution.The physical and electrochemical behavior of the NCFs were investigated and it was found that their electrochemical performances depended on the pyrolysis temperature.Of the samples carbonized at 800,900 and 1000℃,those carbonized at 900℃performed best,and delivered a reversible capacity of 875 mAh·g-1 at a high sulfur loading of 4.19 mg·cm2 and retained at 707 mAh·g-1 after 250 cycles at 0.2 C.The coulombic efficiency of the NCF-900@Li2 S6 electrode was almost 98.55%over the entire cycle life.In addition,the capacity retention of the electrode reached 81.53%even at a high current density of 1 C for over150 cycles.It was found that the NCFs carbonized at 900℃had the highest electrical conductivity,which might be the dominant factor that determined its performance for use as a positive current collector.
机构地区江苏大学新材料研究院 长沙矿冶研究院有限责任公司
出处《新型炭材料》 SCIE EI CAS CSCD 北大核心 2021年第3期606-615,共10页New Carbon Materials
基金国家自然科学基金项目(51874146) 中国博士后科学基金特别资助项目(2018T110551) 中国博士后科学基金项目(2017M621640) 江苏省“六大人才高峰”高层次人才项目(XCL-125) 江苏大学人才启动基金项目(15JDG014).
关键词聚丙烯腈 氮掺杂炭纳米纤维 热解温度 电化学行为Polyacrylonitrile NCFs Pyrolysis temperatures Electrochemical behaviors
分类号TQ127.11 [化学工程—无机化工]
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