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2010 , Vol. 25 >Issue 3: 327 - 331

DOI: https://doi.org/10.3724/SP.J.1077.2009.09472

研究快报

热处理温度对多元醇合成Li2MnSiO4/C电化学性能的影响

  • 刘文刚 ,
  • 许云华 ,
  • 杨 蓉 ,
  • HOJAMBERDIEV Mirabbos ,
  • 周志斌
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  • 1．西安建筑科技大学 材料科学与工程学院, 西安710055；2.西安理工大学 理学院, 西安710048

收稿日期: 2009-07-08

  修回日期: 2009-10-26

  网络出版日期: 2010-03-20

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Effect of Heattreatment Temperature on the Electrochemical Performances of the Li2MnSiO4/C Composite Prepared through Polyol Process

  • LIU Wen-Gang ,
  • XU Yun-Hua ,
  • YANG Rong ,
  • HOJAMBERDIEV Mirabbos ,
  • ZHOU Zhi-Bin
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  • 1．School of Material Science and Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China；2.School of Science, Xi’an University of Technology, Xi’an 710048, China

Received date: 2009-07-08

  Revised date: 2009-10-26

  Online published: 2010-03-20

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摘要

采用多元醇法合成Li2MnSiO4/C复合材料:将Si(OC2H5)4、LiAc·2H2O、Mn(Ac)2·4H2O在乙二醇中196℃回流16h，沉淀物过滤、干燥以后与蔗糖混合并在500、600和700℃分别加热10h,自然冷却到室温.利用X射线衍射、元素分析、场发射扫描电镜、高分辨透射电镜等手段对合成样品进行表征.Rietveld精修表明，合成样品中存在两种Li2MnSiO4相，空间群分别为Pmn21和P121/n1，还有Li2SiO3杂相.FESEM观察显示当热处理温度从500℃升高至700℃时，样品的颗粒粒径从5~20nm提高到20~40nm.Li2MnSiO4/C复合材料中的碳分布是均匀的.HRTEM分析表明在Li2MnSiO4颗粒上包覆有一层无定型的碳薄膜.电化学性能测试表明，在600℃保温10h得到的样品具有最佳的电化学性能，首次放电容量达到132.4mAh/g，10次循环后容量保持率为80%.

关键词： 硅酸锰锂; 正极材料; 多元醇法; 热处理温度; 电化学性能

本文引用格式

刘文刚 , 许云华 , 杨 蓉 , HOJAMBERDIEV Mirabbos , 周志斌 . 热处理温度对多元醇合成Li2MnSiO4/C电化学性能的影响[J]. 无机材料学报, 2010 , 25(3) : 327 -331 . DOI: 10.3724/SP.J.1077.2009.09472

Abstract

The Li2MnSiO4/C composite was synthesized through a polyol process following by heattreatment at intermediate temperatures. The precursors were precipitated from Si(OC2H5)4, LiAc·2H2O and Mn(Ac)2·4H2O in ethylene glycol by refluxing at 196℃ for 16h, the dried powders were milled, pressed and heat-treated at 500℃, 600℃ and 700℃ for 10h. The obtained samples were characterized by X-ray diffraction, automatic elemental analyzer, field emission scanning electron microscope (FESEM), energy dispersive spectroscope (EDS), and high resolution transmission electron microscope (HRTEM). As a result of the Rietveld refinement, two possible Li2MnSiO4 forms crystallizing in Pmn21 and P121/n1 space groups, respectively, are considered as the major phases, and Li2SiO3 is identified as the impurity phase. According to the FESEM observation, the mean particle size increases from 5-20nm to 20-40nm as the heattreatment temperature increasing from 500℃ to 700℃. Carbon is homogenously distributed on the prepared Li2MnSiO4/C composites. The HRTEM examination confirms that the Li2MnSiO4 particles are surrounded by a very thin amorphous carbon layer. The electrochemical experiments reveal that the Li2MnSiO4/C composite heat-treated at 600℃ for 10h has the higher electrochemical performance with an initial discharge capacity of 132.4mAh/g and a capacity retention ratio of 80% at the tenth cycle.

Key words： lithium manganese silicate; cathode material; polyol process; electrochemical performance

参考文献

［1］Padhi A K, Nanjundaswamy K S, Goodenough J B. Phospho-olivines as positive-electrode materials for rechargeable lithium batteries. J. Electrochem. Soc., 1997, 144(4):1188-1194.

［2］Nakamura T, Miwa Y, Tabuchi M, et al. Structural and surface modifications of LiFePO4 olivine particles and their electrochemical properties. J. Electrochem. Soc., 2006, 153(6):A1108-1114.

［3］Gu Y J, Zeng C S, Wu H K, et al. Enhanced cycling performance and high energy density of LiFePO4 based lithium ion batteries. Mater. Lett., 2007, 61(25):4700-4702.

［4］Nytén A, Abouimrane A, Armand M, et al. Electrochemical performance of Li2FeSiO4 as a new Li-battery cathode material. Electro. Chem. Commun., 2005,7(2):156-160.

［5］Dominko R, Bele M, Gabercek M, et al. Structure and electrochemical performance of Li2MnSiO4 and Li2FeSiO4 as potential Li-battery cathode materials. Electrochem. Commun., 2006, 8(2):217-222.

［6］Dominko R, Bele M, Kokalj A, et al. Li2MnSiO4 as a potential Li-battery cathode material. J. Power Sources, 2007,174(2):457-461.

［7］Dominko R. Li2MSiO4 (M = Fe and/or Mn) cathode materials. J. Power Sources, 2008, 184(2):462-468.

［8］Gong Z L, Li Y X, Yang Y. Synthesis and characterization of Li2MnxFe1-xSiO4 as a cathode material for lithium-ion batteries. Electrochem. Solid State Lett., 2006, 9(12):A542-A544.

［9］Yang Y, Li Y X, Gong Z L. Synthesis and Characterization of High Capacity Silicate/C Cathode Materials for Lithium Ion Batteries. IMLB2006, Biarritz, France, 2006, Abstract 210.

［10］Li Y X, Gong Z L, Yang Y. Synthesis and characterization of Li2MnSiO4/C nanocomposite cathode material for lithium ion batteries. J. Power Sources, 2007, 174(2):528-532.

［11］Liu W G, Xu Y H, Yang R. Synthesis, characterization and electrochemical performance of Li2MnSiO4/C cathode material by solid-state reaction. J. Alloys Compd. 2009, 480(2):L1-L4.

［12］BregadoGutiérrez J, SaldivarGarcía A J, Lopez H F. Synthesis of Co-50Ni nanocrystals obtained by a modified polyol method. Mater. Lett., 2008, 62(6/7):939-942.

［13］Yan S Y, Sun G Q, Tian J, et al. Polyol synthesis of highly active PtRu/C catalyst with high metal loading. Electrochem. Acta, 2006, 52(4):1692-1696.

［14］Lim P Y, Liu R S, She P L, et al. Synthesis of Ag nanospheres particles in ethylene glycol by electrochemical-assisted polyol process. Chem. Phys. Lett., 2006, 420(4/5/6):304-308.

［15］Kim T R, Kim D H, Ryu H W, et al. Synthesis of lithium manganese phosphate nanoparticle and its properties. J. Phys. Chem. Solids, 2007, 68(5/6):1203-1206.

［16］Kim D H, Kim J K. Synthesis of LiFePO4 nanoparticles and their electrochemical properties. J. Phys. Chem. Solids, 2007, 68(5/6):734-737.

［17］Politaev V V, Petrenko A A, Nalbandyan V B, et al. Crystal structure, phase relations and electrochemical properties of monoclinic Li2MnSiO4. J. Solid State Chem., 2007, 180(3):1045-1050.

［18］Arroyo-deDompablo M E, Dominko R, Gallardo-Amores J M, et al. On the energetic stability and electrochemistry of Li2MnSiO4 polymorphs. Chem. Mater., 2008, 20(17):5574-5584.

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