摘要
采用交流阻抗法、EDS与XPS成分分析对锂离子电池高容量硅负极在首次嵌锂过程中的表面成膜行为进行了研究,并对膜组分进行了详细测试与分析．交流阻抗分析发现硅负极的表面成膜现象出现在较低的嵌锂电位下,膜厚随着嵌锂过程的进行而增加,其组分以LiF和Li2CO3为主．通过Ar离子流对硅负极表面的深度刻蚀的XPS分析发现,其表面的膜层为非均质层,暴露于电解液中一侧的膜层组分中碳酸盐含量较高,而随着深度的增加, LiF的相对含量增加,靠近电极一侧的膜层可能存在着少量硅的氧化物及其与电解液的反应产物．少量Si由于不可逆反应形成的化合物也存在于SEI膜的膜层中．
The solid electrolyte interface and its formed-behavior on silicon anode, which mainly occur during the first lithium ion insertion, were detected and analyzed by EIS, EDS and XPS. The results show that the SEI film on silicon electrode surface forms under a low lithium-inserting voltage. The thickness of SEI film increases with the depth of the state of discharge. The depth XPS analysis of the electrode surface demonstrates the inhomogeneous characteristic of SEI film. LiF and Li2CO3 are the major lithiated components including in SEI film, whereas Li2CO3 more approaches to the surface exposed to the electrolyte and LiF is more close to the side of silicon electrode. Some trace of siliconcontaining compound, which might be the reacting product of electrolyte and silicon electrode, exists in SEI film.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第3期437-441,共5页
Journal of Inorganic Materials
基金
国家自然科学基金(50502009)
辽宁省科技基金(20051056)
关键词
锂离子电池
硅负极
固体电解质膜
lithium ion batteries
silicon anode
solid electrolyte interface film
