Trimethylsilyl Chloride-Modified Li Anode for Enhanced Performance of Li–S Cells

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• 作者：Meifen Wu ; Zhaoyin Wen ; Jun Jin ; Bobba V. R. Chowdari
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：June 29, 2016
• 年：2016
• 卷：8
• 期：25
• 页码：16386-16395
• 全文大小：821K
• 年卷期：0
• ISSN：1944-8252

文摘

A facile and effective method to modify Li anode for Li–S cells by exposing Li foils to tetrahydrofuran (THF) solvent, oxygen atmosphere and trimethylsilyl chloride ((CH₃)₃SiCl) liquid in sequence is proposed. The results of SEM and XPS show the formation of a homogeneous and dense film with a thickness of 84 nm on Li metal surface. AC impedance and polarization test results show the improved interfacial stability. The interfacial resistances as well as polarization potential difference have obviously decreased as compared with that of a pristine Li anode. CV and charge–discharge test results demonstrate that more reversible discharge capacity and higher Coulombic efficiency can be achieved. Specific capacity of 760 mAh g^–1 and an average Coulombic efficiency of 98% are retained after 100 cycles at 0.5C without LiNO₃ additive. Additionally, the Li–S cell with a modified Li anode displays a greatly improved rate performance with ∼425 mAh g^–1 at 5C, making it more attractive and competitive in the applications of high-power supply.