摘要
以聚乙烯吡咯烷酮(PVP)作为高分子聚合物配体,采用静电纺丝法制备了Si/C复合负极材料。利用PVP高温烧结形成的碳作为体积缓冲骨架,有效地解决了硅在循环过程中的体积膨胀和粉化问题。采用x射线衍射rXRD)、拉曼光谱(Raman)和扫描电子显微镜(SEM)对复合材料的晶体结构及微观形貌进行了研究。结果表明,材料整体呈纤维状分布,纤维直径300~400nm,Si粒子以“麦穗状”均匀地分布在由无定形碳构成的纤维上。电化学测试结果表明,复合材料首次充放电的不可逆容量为294.9mAh/g,是由于电极与电解液界面间固态电解质(SEI)膜的形成所致。另外,复合材料在低倍率(0.1c、0.2C和0.50和高倍率(1.0C和2.0℃)下均具有较高的库伦效率及较好的循环稳定性。
Si/C composite anode material was successfully fabricated by an electrospinning method using PVP as macromolecule polymer collocation. The carbon derived from sintering PVP at high temperature plays a role in buff- eting size skeleton of silicon, which can effectively improve the volume expansion and pulverization problem of sili- con at charge-discharge. The structure and morphology of the as-prepared samples were characterized by X-ray dif- fraction (XRD), Raman spectrum (Raman) and scanning electron microscope (SEM). The results show that the distri- bution of composite material is fibrous with diameter in the range of 300-400 nm. A "wheat like" structure is formed by Si particles distributed on the amorphous carbon fibers. The electrochemical test demonstrates that the irreversible capacity at first charge-discharge process is 294.9 mAh/g, which is due to the formation of solid electrolyte interface (SEI) film between the electrode and electrolyte. In addition, this composite material has very high columbic effi- ciency and excellent cycle stability, both at a low (0.1C, 0.2C and 0.5C) and high (1.0C and 2.0C) rates.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第2期197-202,共6页
Journal of Inorganic Materials
基金
吉林大学博士研究生交叉学科科研资助计划(2011J015)~~
关键词
锂离子电池
SI
C复合负极
静电纺丝
纳米纤维
lithium-ion battery
Si/C composite anode
electrostatic spinning
nanofibers