Effects of phase assemblage and microstructure-type for Sn/intermetallic ‘composite’ films on stress developments and cyclic stability upon lithiation/delithiation

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• 作者：Ravi Kali ; Yaadhav Krishnan ; Amartya Mukhopadhyay ; ^{amartya_mukhopadhyay@iitb.ac.in}
• 关键词：Intermetallic ; Microstructure ; In-situ stress measurement ; Mechanical integrity ; Electrochemical behavior
• 刊名：Scripta Materialia
• 出版年：2017
• 出版时间：15 March 2017
• 年：2017
• 卷：130
• 期：Complete
• 页码：105-109
• 全文大小：1570 K
• 卷排序：130

文摘

Annealing treatment of as-deposited β-Sn film on Cu resulted in the development of ‘composite’ film comprised of Sn-Cu intermetallic phases (Cu3Sn and Cu6Sn5) surrounding ‘percolating’ network of β-Sn, all underneath a thin continuous β-Sn layer. Such phase assemblage and microstructure-type resulted in significantly improved mechanical integrity upon lithiation/delithiation; and accordingly very stable Li-capacity retention with continued electrochemical cycling. In-situ monitoring of the stress developments during lithiation/delithiation indicated that the presence of intermetallic ‘buffer’ phase(s) results in ~ 3 times lower stress magnitudes compared to ‘pure’ Sn upon ‘full’ lithiation, along with absence of signature for mechanical degradation in the stress-time profiles.