Enhanced Electrochemical Performance of Li1.2Mn0.54Ni0.13Co0.13O2 Cathode with an Ionic Conductive LiVO3 Coating Layer

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• 作者：Xiaoyu Liu ; Qili Su ; Congcong Zhang ; Tao Huang ; Aishui Yu
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2016
• 出版时间：January 4, 2016
• 年：2016
• 卷：4
• 期：1
• 页码：255-263
• 全文大小：683K
• ISSN：2168-0485

文摘

With the aim to enhance the Li⁺ ion conductivity, an ionic conductor, LiVO₃, has been successfully coated on the surface of lithium-rich layered Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ cathode materials for the first time. After combining with LiVO₃, significantly improved high-rate capability and cyclic stability of the Li-rich cathode have been achieved due to the enhanced lithium ion diffusion and stabilized electrode/electrolyte interface. Moreover, a stable three-dimensional spinel phase has been generated in the surface region during the coating process, which mitigates the structure deterioration and suppresses the voltage decay and energy density degradation. After optimization, 5 wt % LiVO₃-coated–Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ exhibits superior electrochemical performance with a higher reversible capacity of 272 mA h g^–1, increased initial Coulombic efficiency of 92.6%, and an excellent high-rate capability of 135 mA h g^–1 at 5 C, respectively. The coexistence of an ionic conductor coating layer and the locally transformed spinel structure generated in a one-step approach provides a novel design concept for surface modification on Li-rich Mn-based cathode materials toward high-performance lithium-ion batteries.