Challenges in synthesizing carbon-coated LiFePO₄ nanoparticles from hydrous FePO₄ and their electrochemical properties

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• 作者：Seunghoon Nam ; Sungun Wi ; Changwoo Nahm ; Hongsik Choi ; Byungwoo Park
• 关键词：A. nanostructure ; A. inorganic compound ; B. chemical synthesis ; D. electrochemical properties
• 刊名：Materials Research Bulletin
• 出版年：2012
• 出版时间：November, 2012
• 年：2012
• 卷：47
• 期：11
• 页码：3495-3498
• 全文大小：775 K

文摘

Carbon-coated LiFePO₄ nanoparticles are obtained from a polymer-coated hydrous FePO₄ which is synthesized via the in situ polymerization of aniline. The difficulty in synthesizing a pure LiFePO₄ phase comes from achieving the exact stoichiometry between the added Li source and hydrous polyaniline-coated FePO₄. It is important to consider the amount of residual H₂O and polyaniline in FePO₄ to achieve the exact stoichiometry of Li vs. Fe. The phase impurities induced by inappropriate amount of Li severely deteriorate the electrochemical performance of C-coated LiFePO₄. On the other hand, the carbon-encapsulated LiFePO₄ nanoparticles with the exact amount of Li show a capacity of ¡«145 mAh g^?1 at 5 C, and exhibit a capacity of 170 mAh g^?1 for 250 cycles at 0.1 C which is nearly theoretical value.