High Rate Capability and Excellent Thermal Stability of Li+-Conductive Li2ZrO3-Coated LiNi1/3Co1/3Mn1/3O2 via a Synchronous

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• 作者：Jicheng Zhang ; Zhengyao Li ; Rui Gao ; Zhongbo Hu ; Xiangfeng Liu
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：September 3, 2015
• 年：2015
• 卷：119
• 期：35
• 页码：20350-20356
• 全文大小：506K
• ISSN：1932-7455

文摘

A novel synchronous lithiation route has been successfully used to coat Li⁺-conductive Li₂ZrO₃ on the surface of LiNi_1/3Co_1/3Mn_1/3O₂ (Li₂ZrO₃@LNCMO). In this strategy, Li₂ZrO₃ layer and LiNi_1/3Co_1/3Mn_1/3O₂ host simultaneously form from ZrO₂@Ni_1/3Co_1/3Mn_1/3C₂O₄路xH₂O precursor. In compared to bare LNCMO, the reversible capacity, cycling performance, thermal stability, rate capability, and polarization of Li₂ZrO₃@LNCMO have all been greatly improved. At 0.1 and 10 C, the specific capacity of Li₂ZrO₃@LNCMO is 192 and 106 mAh g^鈥?, respectively, while they are 178 and 46 mAh g^鈥? for bare LNCMO. At a current density of 5 C, the capacity retention of Li₂ZrO₃@LNCMO at 25 and 55 掳C after 400 cycles is enhanced to 93.8% and 85.1%, respectively, compared to 69.2% and 37.4% of bare LNCMO. The largely enhanced electrochemical performances of Li₂ZrO₃@LNCMO cathode can be attributed to the high Li-ion conductivity as well as the proctection of Li₂ZrO₃ coating. Li⁺ conductivity of Li₂ZrO₃@LNCMO is about 20 times higher than that of bare LNCMO. Moreover, the migration of partial Zr⁴⁺ to the host LNCMO phase not only benefits Li-ion or electron conductivity but also alleviates the Li鈥揘i cation mixing and improves the structure stability. The cations migration, doping effect, and the reduced cation mixing further contribute to the electrochemical performance enhancement.