A modified Al₂O₃ coating process to enhance the electrochemical performance of Li(Ni_1/3Co_1/3Mn_1/3)O₂ and its comparison with traditional Al₂O₃ coating process

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• 作者：Youyuan Huang ; Jitao Chen ; Fuquan Cheng ; Wang Wan ; Wen Liu ; Henghui Zhou ; Xinxiang Zhang
• 关键词：Lithium-ion batteries ; Lithium nickel cobalt manganese oxide ; Alumina coating ; Modification
• 刊名：Journal of Power Sources
• 出版年：2010
• 出版时间：15 December 2010
• 年：2010
• 卷：195
• 期：24
• 页码：8267-8274
• 全文大小：872 K

文摘

Al₂O₃-modified Li(Ni_1/3Co_1/3Mn_1/3)O₂ is synthesized by a modified Al₂O₃ coating process. The Al₂O₃ coating is carried out on an intermediate, (Ni_1/3Co_1/3Mn_1/3)(OH)₂, rather than on Li(Ni_1/3Co_1/3Mn_1/3)O₂. As a comparison, Al₂O₃-coated Li(Ni_1/3Co_1/3Mn_1/3)O₂ also is prepared by traditional Al₂O₃ coating process. The effects of Al₂O₃ coating and Al₂O₃ modification on structure and electrochemical performance are investigated and compared. Electrochemical tests indicate that cycle performance and rate capability of Li(Ni_1/3Co_1/3Mn_1/3)O₂ are enhanced by Al₂O₃ modification without capacity loss. Al₂O₃ coating can also enhance the cycle performance but cause evident capacity loss and decline of rate capability. The effect of Al₂O₃ coating and Al₂O₃ modification on kinetics of lithium-ion transfer reaction at the interface of electrode/electrolyte is investigated via electrochemical impedance spectra (EIS). The result support that the Al₂O₃ modification increase Li⁺ diffused coefficient and decrease the activation energy of Li⁺ transfer reaction but the traditional Al₂O₃ coating lead to depression of Li⁺ diffused coefficient and increase of activation energy.