New Insight into the Reaction Mechanism for Exceptional Capacity of Ordered Mesoporous SnO2 Electrodes via Synchrotron-Based X-ray Analysis

详细信息    查看全文

• 作者：Hyunchul Kim ; Gwi Ok Park ; Yunok Kim ; Shoaib Muhammad ; Jaeseung Yoo ; Mahalingam Balasubramanian ; Yong-Hun Cho ; Min-Gyu Kim ; Byungju Lee ; Kisuk Kang ; Hansu Kim ; Ji Man Kim ; Won-Sub Yoon
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：November 25, 2014
• 年：2014
• 卷：26
• 期：22
• 页码：6361-6370
• 全文大小：938K
• ISSN：1520-5002

文摘

Tin oxide-based materials, operating via irreversible conversion and reversible alloying reaction, are promising lithium storage materials due to their higher capacity. Recent studies reported that nanostructured SnO₂ anode provides higher capacity beyond theoretical capacity based on the alloying reaction mechanism; however, their exact mechanism remains still unclear. Here, we report the detailed lithium storage mechanism of an ordered mesoporous SnO₂ electrode material. Synchrotron X-ray diffraction and absorption spectroscopy reveal that some portion of Li₂O decomposes upon delithiation and the resulting oxygen reacts with Sn to form the SnO_x phase along with dealloying of Li_xSn, which are the main reasons for unexpected high capacity of an ordered mesoporous SnO₂ material. This finding will not only be helpful in a more complete understanding of the reaction mechanism of Sn-based oxide anode materials but also will offer valuable guidance for developing new anode materials with abnormal high capacity for next generation rechargeable batteries.