Microwave-assisted hydrothermal synthesis of electrochemically active nano-sized Li₂MnO₃ dispersed on carbon nanotube network for lithium ion batteries

详细信息    查看全文

• 作者：Arum Choi ; Kowsalya Palanisamy ; Yunok Kim ; Jaegu Yoon ; Jin-Hwan Park ; Suk Woo Lee ; Won-Sub Yoon ; Kwang-Bum Kim
• 关键词：Lithium manganese oxide ; Carbon nanotube ; Nanocomposite ; Microwave-assisted hydrothermal process ; Lithium ion batteries
• 刊名：Journal of Alloys and Compounds
• 出版年：5 April, 2014
• 年：2014
• 卷：591
• 期：Complete
• 页码：356-361
• 全文大小：2545 K

文摘

Electrochemically active Li₂MnO₃ nanoparticle dispersed on carbon nanotube (CNT) network has been successfully synthesized by microwave-assisted hydrothermal (MAH) process. To the best of our knowledge, this is the first report showing the formation of Li₂MnO₃ nanoparticle on CNT network using MnO₂-coated CNT composite. Appearance of superlattice peak in X-ray diffraction (XRD) pattern and Raman-active modes near the lower wavelength region of Raman spectra reveals the structure transition from spinel LiMn₂O₄ to layered-type Li₂MnO₃ phase. The X-ray absorption near edge spectra (XANES) shows increase in average oxidation state of Mn ion from 3.5+ to 4+, and Mn-O and Mn-Mn peak intensity variations observed from extended X-ray absorption fine structure (EXAFS) are well evidenced for the formation of ordered Li₂MnO₃ structure. Electrochemical performance of Li₂MnO₃ nanocomposite electrode material prepared from higher LiOH concentration shows much higher capacity than spinel component alone. This synthetic strategy opens a new way for effective synthesis of electrochemically active Li₂MnO₃ on CNT network, making it suitable for advanced lithium ion battery.