摘要
用硫钨酸铵热分解制备出了WS2纳米纤维,采用TEM,HRTEM,XRD等对产物的形貌、结构、组成进行了检测,表明所制备出的灰黑色WS2纳米纤维平均直径为几十nm,最小只有几nm,长度为几十μm.通过XRD曲线与标准衍射谱比较,产物属六方晶系,a=0 3151nm,c=1 271nm,基本无杂质,较纯净.ED分析还表明纤维为单晶,晶化程度好,(002)和(100)等衍射斑点清晰,与XRD分析结果一致.电化学测试表明,当电池在0 1C倍率,0 05～2 5V电压范围内循环时,嵌/脱锂平台在0 11V和0 5V左右,首次可逆容量为730 1mA·h/g,WS2纳米纤维的储锂机理是片层间嵌锂,纳米级缝隙嵌锂和缺陷位置嵌锂.
Tungsten disulfide nanofibers were prepaired by the thermal decomposition of ammonium tetrathiotungstate. TEM, HRTEM and XRD were employed to investigate the shape, the structure and the composition of the product whose average diameter is less than 100 nm with the thinnest of only several nanometers and length is longer than 10 um. The XRD reveals the product was dark-gray crystals of pure tungsten disulfide with hexagonal lattice, a=0.3151 nm, c=1.271 nm, The ED pattern reveals that the nanofibers was mono-crystal with high crystallization degree, and the electron diffraction spots such as (100) and (002) were very clear. This is in good consistent with the resalts from XRD. Electrochemical tests show that the plateaus of lithium ion insertion and extraction were at about 0.11 V and 0.5 V respectively when the battery was cycling at 0.1 C and 0.05～2.5 V. It's frist reversible capacity is 730.1 mA·h/g. The charge-discharge mechanism of WS_2 nanofibers is that lithium can be stored between it's crystal layers, in the nano-scale interstices and other defect structures.
出处
《材料与冶金学报》
CAS
2004年第1期39-42,共4页
Journal of Materials and Metallurgy
基金
沈阳市科技基金资助项目(030241)
关键词
WS2纳米纤维
热分解
表征
电化学性能
可逆容量
储锂机理
tungsten disulfide nanofibers
thermal decomposition
characterization
electrochemical properties
reversible capacity
charge-discharge mechanism
