The Electrochemistry with Lithium versus Sodium of Selenium Confined To Slit Micropores in Carbon

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• 作者：Sen Xin ; Le Yu ; Ya You ; Huai-Ping Cong ; Ya-Xia Yin ; Xue-Li Du ; Yu-Guo Guo ; Shu-Hong Yu ; Yi Cui ; John B. Goodenough
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：July 13, 2016
• 年：2016
• 卷：16
• 期：7
• 页码：4560-4568
• 全文大小：786K
• 年卷期：0
• ISSN：1530-6992

文摘

Substitution of selenium for sulfur in the cathode of a rechargeable battery containing S_x molecules in microporous slits in carbon allows a better characterization of the electrochemical reactions that occur. Paired with a metallic lithium anode, the Se_x chains are converted to Li₂Se in a single-step reaction. With a sodium anode, a sequential chemical reaction is characterized by a continuous chain shortening of Se_x upon initial discharge before completing the reduction to Na₂Se; on charge, the reconstituted Se_x molecules retain a smaller x value than the original Se_x chain molecule. In both cases, the Se molecules remain almost completely confined to the micropore slits to give a long cycle life.