Coaxial MWNTs@MnO₂ confined in conducting PPy for kinetically efficient and long-term lithium ion storage

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• 作者：Jiaxin Li ; Mingzhong Zou ; Yi Zhao ; Yingbin Lin ; Heng Lai ; Lunhui Guan ; Zhigao Huang
• 关键词：MWNTs@MnO2@PPy composites ; Rate performance ; Equivalent circuit ; Anode materials
• 刊名：Electrochimica Acta
• 出版年：30 November, 2013
• 年：2013
• 卷：111
• 期：Complete
• 页码：165-171
• 全文大小：2095 K

文摘

Coaxial MWNTs@MnO₂ confined in conducting polypyrrole (PPy) has been synthesized through an in situ polymerization of pyrrole monomers in the presence of prepared MWNTs@MnO₂. As an anode in lithium batteries (LIBs), the obtained MWNTs@MnO₂@PPy shows a high reversible capacity of 530 mA h g^鈭? tested at 1000 mA g^鈭? even after 300 cycles and an excellent rate performance. The superior electrochemical performance of the nanocable MWNTs@MnO₂@PPy is associated with a synergistic effect of the MWNT matrix and the highly conducting PPy coating layer. This nanocable configuration not only facilitates electron conduction but also maintains the structural integrity of active materials. In addition, an analysis of the AC impedance spectroscopy and the corresponding hypothesis for DC impedance confirm that such configuration can effectively enhance the charge-transfer efficiency and the lithium diffusion coefficient. Thus, PPy modification supplied a promising route to obtain manganese oxide based anode in order to achieve high-performance LIBs.