Two-Dimensional Mesoporous Cobalt Sulfide Nanosheets as a Superior Anode for a Li-Ion Battery and a Bifunctional Electrocatalyst for the Li鈥揙2 System

详细信息    查看全文

• 作者：Palanichamy Sennu ; Maria Christy ; Vanchiappan Aravindan ; Young-Gi Lee ; Kee Suk Nahm ; Yun-Sung Lee
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：August 25, 2015
• 年：2015
• 卷：27
• 期：16
• 页码：5726-5735
• 全文大小：690K
• ISSN：1520-5002

文摘

We report the synthesis of two-dimensional (2D) Co₃S₄ in a nanothickness sheetlike morphology via simple hydrothermal process and its application to electrochemical energy-storage devices. The presence of unique mesopores with a combination of core/shell nanoparticles in the nanosheets showed superior electrochemical performances as a negative electrode for a Li-ion battery (LIB) and an electrocatalyst in Li鈥揙₂ battery applications. A high discharge capacity of 鈭?68 mAh g^鈥? is noted after 60 cycles with excellent cycling stability when evaluated as an anode for a LIB. On the other hand, the first discharge capacity of 鈭?917 mAh g^鈥? is observed with a high reversibility of 95.72% for the Li鈥揙₂ battery point of view. This exceptional electrochemical performance in both applications is mainly attributed to the presence of mesoporous with core/shell 2D nanostructure, which translates more catalytic bifunctional (oxygen reduction reaction/oxygen evolution reaction) active sites for Li鈥揙₂ and sustains the volume variations that occur in a three-dimensional manner upon the charge鈥揹ischarge process for LIB applications. Ex situ studies, such as transmission electron microscopy, X-ray photoelectron spectroscopy, and impedance spectroscopy studies, are also conducted to validate the reaction mechanisms.