Atomic Layer Deposition of Al2O3–Ga2O3 Alloy Coatings for Li[Ni0.5Mn0.3Co0.2]O2 Cathode to Improve Rate Performance in Li-Ion Battery

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• 作者：Masihhur R. Laskar ; David H. K. Jackson ; Yingxin Guan ; Shenzhen Xu ; Shuyu Fang ; Mark Dreibelbis ; Mahesh K. Mahanthappa ; Dane Morgan ; Robert J. Hamers ; Thomas F. Kuech
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：April 27, 2016
• 年：2016
• 卷：8
• 期：16
• 页码：10572-10580
• 全文大小：662K
• 年卷期：0
• ISSN：1944-8252

文摘

Metal oxide coatings can improve the electrochemical stability of cathodes and hence, their cycle-life in rechargeable batteries. However, such coatings often impose an additional electrical and ionic transport resistance to cathode surfaces leading to poor charge–discharge capacity at high C-rates. Here, a mixed oxide (Al₂O₃)_1–x(Ga₂O₃)_x alloy coating, prepared via atomic layer deposition (ALD), on Li[Ni_0.5Mn_0.3Co_0.2]O₂ (NMC) cathodes is developed that has increased electron conductivity and demonstrated an improved rate performance in comparison to uncoated NMC. A “co-pulsing” ALD technique was used which allows intimate and controlled ternary mixing of deposited film to obtain nanometer-thick mixed oxide coatings. Co-pulsing allows for independent control over film composition and thickness in contrast to separate sequential pulsing of the metal sources. (Al₂O₃)_1–x(Ga₂O₃)_x alloy coatings were demonstrated to improve the cycle life of the battery. Cycle tests show that increasing Al-content in alloy coatings increases capacity retention; whereas a mixture of compositions near (Al₂O₃)_0.5(Ga₂O₃)_0.5 was found to produce the optimal rate performance.