无机材料学报 ›› 2017, Vol. 32 ›› Issue (5): 476-482.DOI: 10.15541/jim20160408

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锂离子电池正极材料LiMn0.6Fe0.4PO4/C的制备及电化学性能

李 威, 张远杰, 王选朋, 牛朝江, 安琴友, 麦立强   

  1. (武汉理工大学 材料复合新技术国家重点实验室, 材料科学与工程国际化示范学院, 武汉 430070)
  • 收稿日期:2016-07-05 修回日期:2016-08-31 出版日期:2017-05-20 网络出版日期:2017-05-02
  • 作者简介:李 威(1990–), 男, 硕士研究生. E-mail: whlglw90@163.com
  • 基金资助:
    国家重大科学研究计划课题(2013CB934103);国家自然科学基金创新研究群体(51521001);国家自然科学基金杰出青年基金(51425204);武汉理工大学自主创新研究基金(WUT: 2016-Ⅲ-013);National Basic Research Program of China (2013CB934103);Innovative Research Groups of the National Natural Science Foundation of China (51521001);The National Science Foundation for Distinguished Young Scholars of China (51425204);The Fundamental Research Funds for the Central Universities (WUT: 2016-Ⅲ-013)

Synthesis and Electrochemical Performance of LiMn0.6Fe0.4PO4/C Cathode for Lithium-ion Batteries

LI Wei, ZHANG Yuan-Jie, WANG Xuan-Peng, NIU Chao-Jiang, AN Qin-You, MAI Li-Qiang   

  1. (State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China)
  • Received:2016-07-05 Revised:2016-08-31 Published:2017-05-20 Online:2017-05-02
  • About author:LI Wei. E-mail: whlglw90@163.com

摘要:

以蔗糖为碳源, 以草酸为抗氧化剂, 采用溶剂热、球磨和固相烧结相结合的方法制备了LiMn0.6Fe0.4PO4/C正极材料, 并通过改变烧结温度得到了不同形貌结构的目标产物。以金属锂片为对电极, 组装成锂离子半电池, 探究其电化学性能。研究结果表明, 当烧结温度为650℃时, 该材料表现出优异的电化学性能, 在0.2C(1C=170 mA/g)的电流密度下, 起始容量为119.1 mAh/g, 循环80次之后, 容量上升到148.8 mAh/g, 并且该材料在大电流密度下也表现出优异的循环稳定性。

关键词: 锂离子电池, LiMn0.6Fe0.4PO4/C, 正极材料, 电化学性能

Abstract:

The LiMn0.6Fe0.4PO4/C cathode for lithium-ion batteries (LIBs) was synthesized by solvothermal, ball-milling combined with solid phase calcination method using sucrose as a carbon source and oxalic acid as an antioxidant. The final products with different morphologies were obtained by changing sintering temperatures. The structure and morphology of the target products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Cyclic voltammetry and galvanostatic charge and discharge tests were employed to characterize the electrochemical properties of the samples. The results manifest that well-crystallized olivine structure LiMn0.6Fe0.4PO4/C nano-rods and nano-spindles with no obvious impurity phase are obtained. The spindle-like LiMn0.6Fe0.4PO4/C sample S-650 (which was sintered at 650℃) shows a highly monodisperse and homogeneous morphology. Electrochemical analysis results demonstrate that S-650 exhibits the best electrochemical performance with an initial discharge capacity of 119.1 mAh/g at the current density of 0.2 C (1 C=170 mA/g), and a capacity of 148.8 mAh/g is achieved after 80 charge-discharge cycles, in comparison with S-600 (which was sintered at 600℃) and S-700 (which was sintered at 700℃). Meanwhile, S-650 also demonstrates excellent cycling stability even at a high current density of 2C.

Key words: lithium-ion batteries, LiMn0.6Fe0.4PO4/C, cathode material, electrochemical performance

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