Mesoporous LiFePO4 microspheres for rechargeable lithium-ion batteries
Mesoporous LiFePO4 microspheres for rechargeable lithium-ion batteries
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DOI：
10.1016/j.electacta.2013.02.124
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发表时间：
2013-05
影响因子：
6.6
通讯作者：
Juan Du;Lifang Jiao;Qiong Wu;Yong-chang Liu;Zhan Qi;Lijing Guo;Yijing Wang;H. Yuan
中科院分区：
文献类型：
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作者：
Juan Du;Lifang Jiao;Qiong Wu;Yong-chang Liu;Zhan Qi;Lijing Guo;Yijing Wang;H. Yuan
以柠檬酸为络合剂和还原剂，采用水热法制备了一系列介孔LiFePO4/C微球。在时间相关实验的基础上，系统地研究了前驱体的生长演化过程。得到了直径为∼2μm的纯介孔LiFePO4微球，该微球由大量致密的纳米颗粒(∼200 nm)组成。这些微球LiFePO4具有较高的敲击密度(1.35gcm−_3)和较大的Brunauer-Emmett-Teller比表面积(20.992m2g−_1)，这有利于提高材料的电化学性质。在0.1C倍率下，LiFePO4/C微球的首次放电容量为163.8mAhg−1，相当于LiFePO4理论容量(170mAhg−1)的96.4%。该材料还表现出优异的高倍率性能(120.3mAhg−1，10C)和循环稳定性(200次循环后0.5C倍率下容量保持率为98.1%)。
A series of mesoporous LiFePO4/C microspheres have been successfully synthesized via a hydrothermal process using citric acid as chelating agent and reductant. The growth evolution process of the precursor is systematically investigated based on the time-dependent experiments. Pure mesoporous LiFePO4microspheres are obtained with a diameter of ∼2μm, which are composed of numerous compact nanoparticles (∼200nm). These microspheric LiFePO4shows high tap density (1.35gcm−3) and large Brunauer–Emmett–Teller (BET) surface area (20.992m2g−1), which favor the electrochemical properties. The initial discharge capacity of LiFePO4/C microspheres is 163.8mAhg−1at 0.1C rate, corresponding to 96.4% of the theoretical capacity of LiFePO4(170mAhg−1). The material also shows excellent high rate capability (120.3mAhg−1, 10C), and cycling stability (a capacity retention of 98.1% at 0.5C rate after 200 cycles).