In-situ controllable synthesis and performance investigation of carbon-coated monoclinic and hexagonal LiMnBO3 composites as cathode materials in lithium-ion batteries
In-situ controllable synthesis and performance investigation of carbon-coated monoclinic and hexagonal LiMnBO3 composites as cathode materials in lithium-ion batteries
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锂离子电池正极材料碳包覆单斜晶系和六方晶系LiMnBO3复合材料的原位可控合成及性能研究
DOI：
10.1016/j.jpowsour.2013.02.027
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发表时间：
2013-08-15
影响因子：
9.2
通讯作者：
Zhai, Yanjun
中科院分区：
文献类型：
--
作者：
Li, Shouli;Xu, Liqiang;Zhai, Yanjun
采用原位碳热固相合成方法，通过调节反应温度，实现了碳包覆单斜相LiMnBO 3（m-LiMnBO 3/C）和六方相LiMnBO 3（h-LiMnBO 3/C）复合材料的相控制合成。LiMnBO 3/C复合材料具有较高的循环稳定性，首次放电容量保持率为86.5（90.7 mAh g（-1）），在0.05 C下40次循环后（11 mA g（-1）），1.25-4.80 V范围内，而m-LiMnBO 3/C复合材料的首次放电容量为107 mAh g（-1），40次循环后容量留存率为80.8%。首次测试了m-LiMnBO_3/C的倍率性能，在0.1C（22 mA·g ~（-1））放电倍率下，m-LiMnBO_3/C的比容量为74.4mAh·g ~（-1）。电化学性能的提高可能主要归因于均匀包覆的碳层和所获得的产物的减小的颗粒尺寸。电化学阻抗谱（EIS）分析表明，55 ℃时LiMnBO 3/C复合材料的电荷转移电阻（R-ct）比25 ℃时的小，电导率比25 ℃时的高。所制备的LiMnBO 3/C复合材料具有相结构可控、性能优良等特点，有望成为锂离子二次电池正极材料。(c)2013爱思唯尔有限公司版权所有。
The phase controllable synthesis of carbon-coated monoclinic LiMnBO3 (m-LiMnBO3/C) and hexagonal LiMnBO3 (h-LiMnBO3/C) composites has been achieved via an in-situ carbothermal solid state synthesis approach only through the modulation of the reaction temperature. The h-LiMnBO3/C particles keep high cycle stability and retain 86.5% of the initial discharge capacity (90.7 mAh g(-1)) after 40 cycles at 0.05 C (11 mA g(-1)) within 1.25-4.80 V, while the m-LiMnBO3/C composites display a first discharge capacity of 107 mAh g(-1) and a capacity retention rate of 80.8% after 40 cycles. The rate performance of m-LiMnBO3/C has been tested for the first time, which has a capacity of 74.4 mAh g(-1) at the discharge rate of 0.1 C (22 mA g(-1)). The enhanced electrochemical performance might be largely attributed to the uniformly coated carbon layers and the reduced particle size of the as-obtained products. The electrochemical impedance spectroscopy (EIS) analysis reveals that the smaller charge transfer resistance (R-ct) and higher electronic conductivity of the LiMnBO3/C composites were obtained at 55 degrees C than those at 25 degrees C. The as-obtained LiMnBO3/C composites with controllable phases and high performances enable their promising applications as cathode materials for lithium-ion rechargeable batteries. (c) 2013 Elsevier B.V. All rights reserved.