Core–Shell Structured o-LiMnO2@Li2CO3 Nanosheet Array Cathode for High-Performance, Wide-Temperature-Tolerance Lithium-Ion Batteries

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• 作者：Junling Guo ; Yingjun Cai ; Suojiang Zhang ; Shimou Chen ; Fengxiang Zhang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：June 29, 2016
• 年：2016
• 卷：8
• 期：25
• 页码：16116-16124
• 全文大小：656K
• 年卷期：0
• ISSN：1944-8252

文摘

To develop a high-capacity, high-rate, cycle-stable cathode material has long been the focus for lithium-ion battery (LIB) research. Recently, layer-structured orthorhombic-LiMnO₂ (o-LMO) has attracted extensive interest owing to its large discharge capacities. However, poor cycle performance greatly hinders its practical application, especially at high temperatures. Conventional strategies to address this issue often lead to sacrificed rate performance and mostly work at low temperatures. Herein, we report a novel core–shell structured, o-LiMnO₂@Li₂CO₃ (o-LMO@Li₂CO₃) nanosheet array cathode, where the Li₂CO₃ shell improves cycle performance by preventing o-LMO dissolution in the electrolyte (even at an elevated temperature), the o-LMO core provides high capacities and the nanosheet array architecture ensures rate performance (to the best of our knowledge, this o-LMO nanosheet array architecture is reported for the first time). The above features work synergistically to give well-balanced cycle performance (79% capacity retention at 60 °C, 400 cycles), capacity (207 mAh gp>–1p> at 0.5C) and rate performance (128 mAh gp>–1p> at 5C) of the o-LMO@ Li₂CO₃ cathode as well as remarkable full-cell performance (∼67% capacity retention for 400 cycles at ∼2C, 60 °C). Our work demonstrates that the synergistic effect between the o-LMO core, Li₂CO₃ coating and the nanoarray structure is an effective strategy for developing high-energy/power density, high-stability LIB cathodes.