Enhanced electrochemical performances of 5?V spinel LiMn_1.58Ni_0.42O₄ cathode materials by coating with LiAlO₂

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• 作者：Fuquan Cheng ; Yuelong Xin ; Youyuan Huang ; Jitao Chen ; Henghui Zhou ; ^{hhzhou@pku.edu.cn} ; Xinxiang Zhang
• 关键词：Lithium ion batteries ; Spinel cathode oxides ; Lithium aluminate coating ; Surface modification
• 刊名：Journal of Power Sources
• 出版年：2013
• 出版时间：1 October, 2013
• 年：2013
• 卷：239
• 期：Complete
• 页码：181-188
• 全文大小：2033 K

文摘

LiAlO₂-surface modified LiMn_1.58Ni_0.42O₄ spinel cathode materials have been prepared by coating Al₂O₃ on Mn_0.79Ni_0.21CO₃ precursors, followed by post-sintering with Li₂CO₃ at 900?¡ãC. X-ray diffraction and FT-IR analyses indicate that during the calcination process aluminum ions not only react with Li₂CO₃ to form a strengthened LiAlO₂ coating layer but also migrate from the surface into the spherical particles. The LiAlO₂-surface modified LiMn_1.58Ni_0.42O₄ samples exhibit excellent electrochemical performance compared to that of the bare one in terms of rate capability and cyclability. In particular, the 1?mol. % LiAlO₂-surface modified sample can deliver a discharge capacity of 100.6?m?Ah?g^?1 even at a high current density of 4?C-rate, while the bare one only has a discharge capacity of 49.5?m?Ah?g^?1. At 55?¡ãC, the 1?mol. % LiAlO₂-surface modified LiMn_1.58Ni_0.42O₄ sample shows outstanding cyclability with less than 5 % capacity fade after 150 cycles. Based on these results, coating on the precursors to prepare a strengthened LiAlO₂ coating layer would be a promising method to enhance the electrochemical performance of 5?V spinel cathode materials.