正极材料LiFePO<sub>4</sub>液相法合成中反应液循环研究

摘要

以FeSO₄·7H₂O、NH₄H₂PO₄、H₂O₂和CH₃COOLi等为原料，采用液相法制备锂离子正极材料LiFePO₄。制备中反应液不经过处理直接用于制备FePO₄·xH₂O，溶剂乙醇蒸馏后循环使用制备LiFePO₄。通过X射线衍射、扫描电镜及恒流充放电对材料进行物性表征及性能测试。结果表明，制备FePO₄·xH₂O时反应液不经过任何处理直接使用5次，制得的样品纯度较高。并以制备的FePO₄·xH₂O为原料，蒸馏后的乙醇为溶剂，制备出具有良好电化学性能的LiFePO₄，在0.1 C倍率下，首次放电比容量为156.3 mAh·g^-1，循环30次后容量保持率99.49%。

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	马君君
	祖雪敏
	王兴尧

关键词： LiFePO₄；液相法；锂离子电池

Abstract：

LiFePO₄ cathode materials for lithium-ion batteries were synthesized by the liquid-state method using FeSO₄·7H₂O, NH₄H₂PO₄, H₂O₂, CH₃COOLi and so on. The aqueous can be directly used in the synthesis of FePO₄·xH₂O without any treatment and the ethanol should be distilled before the synthesis of LiFePO₄. The structure, morphology and electrochemical performance of the materials were analyzed by XRD, SEM and galvanostatic charge-discharge tests. The results showed that the high purity of FePO₄·xH₂O can be achieved and even prepared with the aqueous which was used for five times. LiFePO₄ cathode material prepared with the distilled ethanol exhibited the best initial discharge capacity of 156.3 mAh·g^-1 and the capacity retention ratio 99.49% after 30 cycles at 0.1 C rate.

Keywords： LiFePO₄； liquid-state method； lithium-ion batteries

Received 2015-04-02;

Fund:

国家自然科学基金（21276185）

Corresponding Authors: 王兴尧,E-mail:wxyghw@tju.edu.cn。 Email: wxyghw@tju.edu.cn

About author: 马君君(1987-),女,硕士研究生,从事锂离子电池材料制备与应用。

引用本文:

马君君, 祖雪敏, 王兴尧.正极材料LiFePO₄液相法合成中反应液循环研究[J]. 化学工业与工程, 2017,34(1): 60-64,83

Ma Junjun, Zu Xuemin, Wang Xinyao.Reaction Liquid Circulation in Liquid Phase Synthesis of LiFePO₄ as Cathode Material[J]. Chemcial Industry and Engineering, 2017,34(1): 60-64,83

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