Three-Dimension Hierarchical Al2O3 Nanosheets Wrapped LiMn2O4 with Enhanced Cycling Stability as Cathode Material for Lithium Ion Batteries

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• 作者：Feiyan Lai ; Xiaohui Zhang ; Hongqiang Wang ; Sijiang Hu ; Xianming Wu ; Qiang Wu ; Youguo Huang ; Zeqiang He ; Qingyu Li
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：August 24, 2016
• 年：2016
• 卷：8
• 期：33
• 页码：21656-21665
• 全文大小：8679K
• 年卷期：0
• ISSN：1944-8252

文摘

A three dimensional (3D) Al₂O₃ coating layer was synthesized by a facile approach including stripping and in situ self-assembly of γ-AlOOH. The uniform flower-like Al₂O₃ nanosheets with high specific area largely sequesters acidic species produced by side reaction between electrode and electrolyte. The inner coating layer wrapping spinel LiMn₂O₄ effectively inhibits the dissolution of Mn by suppressing directive contact with electrolyte to enhance cycling stability. The rate performance is improved because of the better electrolyte storage of the assembled hierarchical architecture of the 3D coating layer affording unimpeded Li⁺ diffusion from electrode to electrolyte. The electrochemical results reveal the as-prepared coated LiMn₂O₄ sample with the amount of Al₂O₃ at 1 wt % exhibits superior cycle stability under room temperature even at elevated temperature. The initial specific discharge capacity is 128.5 mAh g^–1 at 0.1 C and retains 89.8% of the initial capacity after 800 cycles at 1 C rate. When cycling at 55 °C, the composite shows 93.6% capacity retention after 500 cycles. This facile surface modification and effective structure of coating layer can be adopted to enhance the cycling performance and thermal stability of other electrode materials for which Al₂O₃ plays its role.