Li-Si-Zr三元相图的实验研究与热力学优化.pdf

第25卷第5期
中国有色金属学报
2015年5
Volume 25 Number 5
The Chinese Journal of Nonferrous Metals
May 2015
文章编号:10040609(2015)-05-1227-09
ロ口
Li-Si-Zr三元相图的实验研究与热力学优化
龙朝辉123,梁思远3,尹付成,23,赵满秀,3,李智13,刘永雄,3
1.湘潭大学材料设计及制备技术湖南省重点实验室,湘潭41115
2.湘潭大学装备用关键薄膜材料及应用湖南省国防科技重点实验室,湘潭41105
湘潭大学材料科学与工程学院,湘潭4111050
摘要:采用平衡合金法,利用扫描电镜和X射线衍射等方法对LiSi-Zr三元系的470K等温截面的相关系进行
了实验测量。结果表明:该等温截面中存在(Si)+zrSi2+2 Zrlisi三相区;采用 CALPHAD方法对Li-Si-Zr三元系进
行了热力学优化。首先优化计算了LiZr二元系,其中熔体相( Liquid、BCC、FCC和HCP)采用替换溶液模型,过
剩自由能用 Redlich- Kister多项式展开;然后,结合文献中已有的LiSi和Si-zr体系的热力学参数,对Li-Si-Zxr
三元系进行了热力学优化。计算结果与实验数据符合得较好,获得了一套较为合理的热力学参数
关键词:Li-Si-r三元系:相平衡;平衡合金法:热力学优化
中图分类号:TG113.14
文献标志码:A
Experimental study and thermodynamic assessment of
Li-si-zr ternary system
ONG Zhao-hui, LIANG Si-yuan,YIN Fu-cheng 2.3, ZHAO Man-xiu LI Zhi, 2, LIU Yong-xiongl, 3
(1. Key Laboratory of Materials Design and Preparation Technology of Hunan Province
Xiangtan University, Xiangtan 411105, China;
2. Hunan Provincial National Defense Key Laboratory of Key Film Materials and Application for Equipment
Xiangtan University, Xiangtan 411105, China
3. School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China)
Abstract: The isothermal section of the -Zr emary system at470 Kwas studied through equilibrated alloy method
by scanning electron microscopy and X-ray diffractometry. The results show that there is(i)-#Zrsi t Zrlisi three-phase
equilibrium at this isothermal section. Based on the measured data obtained in this work and some information on
experimental phase diagram in literature, the thermodynamic assessment of the Li-si-zr ternary system was performed
with the CALPHAD method. Firstly, the Li-zr binary system was thermodynamically assessed. The solution phases
including liquid, BCC, FCC and HCP were described with a substitutional model, of which the excess Gibbs energies
were formulated with the Redlich-ister polynomial Then combind with he emod nami parameters of the Li-si
and Si-zr binary systems cited from literatures, the Li-si-zr erary system was thermodynamically assessed. The
calculated results agree well with the experimental data. A set of rational thermodynamic parameters for the ternary
system are obtained
Key words: Li-si-zr terary system; phase equilibrium; equilibrated alloy method; thermodynamic assessment
硅作为锂离子电池负极,其理论容量高达但在锂离子嵌入硅负极的过程中,硅的体积会产生较
4200mA-hg,是已知材料中理论容量最高的元素り。大膨胀,导致内应力过大,容易引起负极结构坍塌,
基金项目:教育部高等学校博士学科点专项科研基金资助项目(2012430120010;国家自然科学基金资助项目(5120146
收稿日期:2014-05-25:修订日期:2015-02-10
通信作者:龙朝辉,副教授,博士;电话:0731-58292209;传真:0731158292209:E-mai:zhaohuilong2004@126.com