High-rate properties of Li_1.95FeSiO₄/C/CNTs composite as cathode material for lithium-ion batteries

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• 作者：Xiaobing Huang ; Honghui Chen ; Haiyan Wang ; Shibiao Zhou ; Yu ; ao Chen ; Beiping Liu ; Jifeng Yang ; Guinan Zhou ; Qinglai Jiang ; Meizhen Qu ; Zhonglai Pan ; Zuolong Yu
• 关键词：Lithium ion battery ; Solid-state reaction ; Li1.95FeSiO4/C/CNTs composite ; Conductive network ; Li vacancies
• 刊名：Solid State Ionics
• 出版年：2012
• 出版时间：20 July, 2012
• 年：2012
• 卷：220
• 期：Complete
• 页码：18-22
• 全文大小：667 K

文摘

Li_1.95FeSiO₄/C/CNTs, Li₂FeSiO₄/C/CNTs and Li_1.95FeSiO₄/C composites were successfully prepared by the means of solid-state reaction in the present work. X-ray diffraction (XRD), scanning electron microscopy (SEM), charge-discharge test and electrochemical impedance spectra measurement were used to characterize the above samples and their differences were comparatively discussed. It was found that the Li_1.95FeSiO₄/C/CNTs composite delivered the best electrochemical performance in terms of the discharge capacity, cycling stability and rate capability among the above three samples. It exhibited a discharge capacity of 148 mAh g^? 1 at 0.2 C and 104 mAh g^? 1 at 5 C, respectively, and after 100 cycles at 1 C, 99.2 % of its initial capacity was retained. EIS result showed that electrochemical resistance of the Li_1.95FeSiO₄/C/CNTs electrode was obviously decreased, revealing much faster kinetics in comparison with the Li₂FeSiO₄/C/CNTs and Li_1.95FeSiO₄/C electrodes.