Enhancement of the Rate Capability of LiFePO4 by a New Highly Graphitic Carbon-Coating Method

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• 作者：Jianjun Song ; Bing Sun ; Hao Liu ; Zhipeng Ma ; Zhouhao Chen ; Guangjie Shao ; Guoxiu Wang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：June 22, 2016
• 年：2016
• 卷：8
• 期：24
• 页码：15225-15231
• 全文大小：517K
• 年卷期：0
• ISSN：1944-8252

文摘

Low lithium ion diffusivity and poor electronic conductivity are two major drawbacks for the wide application of LiFePO₄ in high-power lithium ion batteries. In this work, we report a facile and efficient carbon-coating method to prepare LiFePO₄/graphitic carbon composites by in situ carbonization of perylene-3,4,9,10-tetracarboxylic dianhydride during calcination. Perylene-3,4,9,10-tetracarboxylic dianhydride containing naphthalene rings can be easily converted to highly graphitic carbon during thermal treatment. The ultrathin layer of highly graphitic carbon coating drastically increased the electronic conductivity of LiFePO₄. The short pathway along the [010] direction of LiFePO₄ nanoplates could decrease the Li⁺ ion diffusion path. In favor of the high electronic conductivity and short lithium ion diffusion distance, the LiFePO₄/graphitic carbon composites exhibit an excellent cycling stability at high current rates at room temperature and superior performance at low temperature (−20 °C).