以Fe2O3为原料合成FePO4及其在正极材料LiFePO4合成中的应用

doi:10.3724/SP.J.1077.2013.12178

摘要/Abstract

摘要：

以 Fe₂O₃、NH₄H₂PO₄和H₂NCONH₂为原料, 采用流变相法合成 FePO₄, 探究了温度对其合成过程的影响。以此 FePO₄为铁源, 再采用流变相法制备出正极材料 LiFePO₄。产物FePO₄和LiFePO₄的晶型、形貌分别通过XRD和SEM表征, XRD结果表明, FePO₄属三斜晶系, 具有α-石英结构, 而LiFePO₄属于斜方晶系, 具有橄榄石结构; SEM结果表明, FePO₄样品颗粒呈层状分布, LiFePO₄晶体形貌为类球形, 两者分散度良好, 平均粒径均为2 μm左右; 对所得正极材料 LiFePO₄进行恒电流充放电测试, 其初始放电容量达163.4 mAh/g。采用循环伏安、交流阻抗等对 LiFePO₄电化学性能表征, 结果均显示其电化学性能良好。表明以Fe₂O₃为原料采用流变相法所得磷酸铁是合成锂离子电池正极材料磷酸铁锂的较理想的铁源。

关键词: 锂离子电池, 正极材料, 磷酸铁, 磷酸铁锂, 流变相合成法

Abstract:

FePO₄ was synthesized by rheological phase method using Fe₂O₃, NH₄H₂PO₄ and H₂NCONH₂ as row materials. The influence of temperature on the synthesis process was investigated. Taking prepared FePO₄ as iron source, LiFePO₄was also synthesized by rheological phase method. The structure and morphology of as prepared FePO₄and LiFePO₄ were characterized by XRD and SEM, respectively. XRD results indicate that FePO₄ is belong to the triclinic system, with α-quartz structure and LiFePO₄ is belong to the orthorhombic system, with olivine structure. SEM results showed that the FePO₄ particles were layered distribution, while the LiFePO₄ particles seemed like spherical. Both of the particles were well dispersed, and the average particle sizes were about 2 μm. Electrochemical properties of the obtained LiFePO₄ cathode material were investigated by galvanostatic charge-discharge test, cyclic voltammetry(CV) and alternating current(AC) impedance methodes, the initial discharge capacity could reach 163.4 mAh/g, indicating excellent electrochemical performance. All the above results indicated that the prepared iron phosphate is an ideal iron source for the synthesis of lithium-ion battery cathode material LiFePO₄.

Key words: lithium-ion batteries, cathode material, FePO₄, LiFePO₄, rheological phase method

中图分类号:

TM912

王涛, 印野, 刘浩文. 以Fe₂O₃为原料合成FePO₄及其在正极材料LiFePO₄合成中的应用[J]. 无机材料学报, 2013, 28(2): 207-211.

WANG Tao, YIN Ye, LIU Hao-Wen. Synthesis of FePO₄ from Fe₂O₃ and Its Application in Synthesizing Cathode Material LiFePO₄[J]. Journal of Inorganic Materials, 2013, 28(2): 207-211.

图/表 11

图1 为不同温度下系列FePO4 样品及标准FePO4(PDF 29-0715)的XRD图谱。其中, 700℃所得产物的衍射峰强度较低, 峰形较宽, 与标准卡片的峰相比, 部分特征峰未出现, 说明该温度下煅烧所得的样品结晶度差, 晶体结构不完整。800℃和900℃所得产物的衍射峰均与标准样品FePO4 的特征峰完全吻合, 但800℃产物的衍射峰依然强度低, 峰形宽, 表明该温度下所得产物结晶不完全, 晶体结构不完整。而900℃产物的衍射峰峰形尖锐, 强度显著提高, 而且六方晶胞的一对特征双峰(206)/(302)也已经完全分裂开, 表明900℃所得FePO4 具有完整的晶体结构, 为最佳反应温度。在此条件下所得FePO4 属六方晶系, 晶胞参数a = 0.50330nm, b = 0.50330 nm, c = 1.12470 nm, 具有α-石英结构, 这种结构有利于Li+ 在碳热还原过程中向晶粒内部嵌入[13]。

图1 系列FePO4 (700、800、900℃)样品及标准FePO4(PDF 29-0715)的XRD图谱

Fig. 1 XRD patterns of FePO4 particles synthezised at different temperatures (700℃, 800℃, 900℃)

图2 900℃条件下制备的FePO4样品的SEM照片

Fig. 2 SEM images of FePO4 particles calcined at 900℃

图3 为LiFePO4 样品的XRD图谱。从图中可以看出, 以自制α-石英结构的FePO4 为铁源合成的LiFePO4 的衍射峰峰形尖锐, 强度高, 且与标准样品LiFePO4 (PDF卡片号: 40-1499)的特征峰完全一致。表明样品的结晶度高, 晶型完整, 具有橄榄石结构, 属于正交晶系。经计算, 其晶胞参数为: a = 0.6008 nm, b = 1.0334 nm, c = 0.4693 nm。

图3 LiFePO4 样品及标准LiFePO4 (PDF 40-1499)的XRD 图谱

Fig. 3 XRD pattern of LiFePO4 sample and standand LiFePO4 (PDF 40-1499)

图4 样品LiFePO4 的TG/DSC曲线

Fig. 4 TG/DSC curves of LiFePO4 particles

图5 为LiFePO4 样品的SEM照片。从图中可以看出所得的LiFePO4 为类球形, 颗粒大小均匀, 粒径约为1~2 μm, 这种类球形颗粒增加了颗粒的比表面积, 从而有利于缩短Li+在LiFePO4 体相中的扩散路程, 提高了材料的离子扩散速率[9], 对锂离子电池的电化学性能有显著的提高。

图5 LiFePO4 样品的SEM 照片

Fig. 5 SEM images of LiFePO4 sample

图6 LiFePO4 样品在电压2.0~3.8 V、充放电倍率0.2C时的初始充放电图

Fig. 6 Initial charge-discharge curve of LiFePO4 at 2.0-3.8 V, 0.1C

图7 LiFePO4 样品在电压2.0~4.8 V、扫速分别为0.1 V/s和0.01 V/s时的循环伏安曲线

Fig. 7 Cyclic voltammograms for LiFePO4 at 2.0-4.8 V, scaning rate of 0.1 and 0.01 V/s

图8 LiFePO4 样品的交流阻抗图

Fig. 8 EIS analysis of LiFePO4 sample

参考文献 18

[1]	Padhi A K, Nanjundaswamy K S, Masquelier C, et al. Effect of structure on the Fe3+/Fe2+ redox couple in iron phosphates. J. Electrochem. Soc., 1997, 144(5): 1609-1613.
[2]	Padhi A K, Najundaswamy K S, Goodenough J B. Phospho-olivines as positive-electrode materials for rechargeable lithium batteries. J. Electrochem. Soc., 1997, 144(4): 1188-1194.
[3]	Yang S, Song Y, Zavalij P Y, et al. Reactivity, stability and electrochemical behavior of lithium iron phosphates. Electrochemistry Communications, 2002, 4(3): 239-244.
[4]	吴宇平,袁翔云,董超,等. 锂离子电池—应用与实践, 2版. 北京化学工业出版社, 2012: 1-11.
[5]	TANG Chang-Ping, YING Jie-Rong, JIANG Chang-Yin, et al. Advanced in research on FePO4 of cathode materials for li - ion battery. The Chinese Journal of Nonferrous Metals, 2005, 15(Special 1): 25-29.
[6]	CHEN Yi-Ke, TONG Tian-Zhong-Ren, SHAN Mu-Bi-Yi. Preparation of ferri phosphate and its application to lithium battery. Journal of Huaqiao University (Natural Science), 2002, 23(4): 407-411.
[7]	Hyun Jin Yang, Hyun Jae Song, Hyun Joon Shin.A rapid synthesis 0f iron phosphate nanoparticles via surface -mediated spontaneous reaction for the growth of high-yield, single-walled carbon nanotubes. Langmuir, 2005, 21(20): 9098-9102.
[8]	GONG Fu-Zhong, YI Jun-Hui, ZHOU Li-Ya, et al. Preparation of two kinds of FePO4 powders with different morphologies and electrochemical properties of LiFePO4. Journal of Guangxi University (Natural Science), 2009, 34(6): 731-735.
[9]	HU Guo-Rong, ZHOU Yu-Lin, PENG Zhong-Dong, et al. Preparation and performance of FePO4 precursor for LiFePO4. Battery Bimonthly, 2007, 37(5): 339-341.
[10]	Yang S, Song Y, Peter Y Z, et al. Reactivity, stability and electrochemical behavior of lithium iron phosphates. Electrochemistry Communications, 2002, 4(3): 239-244.
[11]	Song Y, Yang S, Peter Y Z, et al. Temperature dependent properties of FePO4 cathode matcrials. Materials Research Bulletin, 2002, 37(7): 1249-1257.
[12]	Scaccia S, Carewska M, Prosini P P. Thermo analytical study of iron(Ⅲ) phosphate obtained by homogeneous precipitation from different media. Thermochimica Acta, 2004, 413(1/2): 81-86.
[13]	朱元保,张传福. 电化学数据手册. 长沙: 湖南科学技术出版社, 2001: 273-274.
[14]	SU Yuan-Zhi, XU Hui, CHEN Bai-Zhen, et al. Study of synthesis of LiFePO4 by microwave processing. Battery Bimonthly, 2006, 36(1): 43-44.
[15]	ZHENG Wei, YU Hong-Ming, CAO Gao-Shao, et al. Effect of synthesis temperature on electrochemical performances of LiFePO4/C composites. The Chinese Journal of Nonferrous Metals, 2010, 20(3): 572-577.
[16]	LI Tao, WEI Ming-Kun, WANG Xue-Fei, et al. Studies on performance of LiFePO4 materials prepared in charcoal-protected condition. Guangdong Chemical Industry, 2010, 37(212): 5-6, 34.
[17]	CHENG Nian-Fang, LI Tao. Study the performance of LiFePO4/C cathode material for lithium batteries. Guangzhou Chemical Industry, 2011, 39(8): 62-63, 78.
[18]	LIU Su-Qin, GONG Ben-Li, HUANG Ke-Long, et al. Synthesis of LiFePO4/C composite cathode materials by a novel carbothermal reduction method and its performance. Journal of Inorganic Materials, 2007, 22(2): 283-286.

以Fe₂O₃为原料合成FePO₄及其在正极材料LiFePO₄合成中的应用

Synthesis of FePO₄ from Fe₂O₃ and Its Application in Synthesizing Cathode Material LiFePO₄

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