欢迎访问《电化学(中英文)》期刊官方网站,今天是
研究论文

高倍率性能正极材料LiFe_(0.9)Mg_(0.1)PO_4的结构

  • 胡林 ,
  • 李征 ,
  • 曾照强
展开
  • 清华大学材料科学与工程系,新型陶瓷与精细工艺国家重点实验室;

收稿日期: 2009-08-28

  修回日期: 2009-08-28

  网络出版日期: 2009-08-28

Structural Basis for High-rate Capability of Cathode Material Li_(0.1)Fe_(0.9)Mg_(0.1)PO_4

  • HU Lin ,
  • LI Zheng ,
  • ZENG Zhao-qiang
Expand
  • (State Key Laboratory of New Ceramics and Fine Processing,Department of Materials Science and Engineering,Tsinghua University,Beijing 100084,China

Received date: 2009-08-28

  Revised date: 2009-08-28

  Online published: 2009-08-28

摘要

应用高温固相反应合成锂离子电池正极材料LiFePO4和LiFe0.9Mg0.1PO4.不同浓度的K2S2O8水溶液氧化LiFe0.9Mg0.1PO4制备部分脱锂两相混合物Li0.4Fe0.9Mg0.1PO4及完全脱锂单相化合物Li0.1Fe0.9Mg0.1PO4.X射线衍射物相分析(XRD),选区电子衍射(SAED)和高分辨原子图像(HRTEM)测试表明,脱锂相Li0.1Fe0.9Mg0.1PO4是单相化合物,没有发生相分离.点阵参数计算表明,LiFe0.9Mg0.1PO4体系嵌锂相和脱锂相的晶格错配度与LiFePO4体系相比有所降低,这正是锂离子电池正极材料LiFe0.9Mg0.1PO4具有高倍率循环充放电比容量的结构基础.

本文引用格式

胡林 , 李征 , 曾照强 . 高倍率性能正极材料LiFe_(0.9)Mg_(0.1)PO_4的结构[J]. 电化学, 2009 , 15(3) : 250 -254 . DOI: 10.61558/2993-074X.1989

Abstract

Cathode materials LiFePO4 and LiFe0.9Mg0.1PO4 for lithium ion batteries were synthesized by a solid state reaction. Chemical oxidation to obtain Li0.4Fe0.9Mg0.1PO4 and Li0.1Fe0.9Mg0.1PO4 was carried out by reacting LiFe0.9Mg0.1PO4 with K2S2O8 solution of different concentration. Li0.1Fe0.9Mg0.1PO4 was confirmed to be a single phase compound with no impure phases,investigated by X-ray diffraction (XRD),selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM) techniques. Calculated lattice parameter results showed decreased lattice misfit between lithiated LiFe0.9Mg0.1PO4 and delithiated Li0.1Fe0.9Mg0.1PO4,compared lattice misfit between LiFePO4 and FePO4. It was considered the decreased lattice misfit as the structural basis for optimized high-rate capability of cathode material LiFe0.9Mg0.1PO4 for lithium ion batteries.

参考文献

[1]Wang De-yu,Li Hong,Shi Si-qi,et al.Improving the rate performance of LiFePO4by Fe-site doping[J].Electrochim Acta,2005,50:2955-2958. [2]Delacourt C,Laffont L,Masquelier C,et al.Toward understanding of electrical limitations(electronic,ion-ic)in LiMPO4(M=Fe,Mn)electrode materials[J].J Electrochem Soc,2005,152(5):A913-A921. [3]Huang H,Yin S,Nazar L.Approaching theoretical ca-pacity of LiFePO4at room temperature at high rates[J].Electrochem Solid State Lett,2001,4(10):A170-A172. [4]Chung S,Bloking J,Chiang Y.Electronically conduc-tive phosphor-olivines as lithium storage electrodes[J].Nat Mater,2002,1:123-128. [5]Herle P,Ellis B,Nazar L,et al.Nano-network elec-tronic conduction in iron and nickel olivine phosphates[J].Nat Mater,2004,3:147-152. [6]Ouyang Chu-ying,Shi Si-qi,Chen Li-quan,et al.First-principles study of Li ion diffusion in LiFePO4[J].Phys Rev B,2004,69(10):104303-1-5. [7]Wang Chun-sheng,Hong Jian.Ionic/electronic conduc-ting characteristics of LiFePO4cathode materials:the determining factors for high rate performance[J].Elec-trochem Solid State Lett,2007,10(3):A65-A69. [8]Meethong N,Carter W,Chiang Y,et al.Size-depend-ent lithium miscibility gap in nanoscale Li1-xFePO4[J].Electrochem Solid State Lett,2007,10(5):A134-A138. [9]Meethong N,Carter W,Chiang Y,et al.Strain accom-modation during phase transformations in olivine-based cathodes as a materials selection criterion for high-power rechargeable batteries[J].Adv Funct Mater,2007,17:1115-1123. [10]Islam M,Driscoll D,Slater P,et al.Atomic-scale in-vestigation of defects,dopants,and lithium transport in the LiFePO4olivine-type battery material[J].Chem Mater,2005,17(20):5085-5092. [11]Padhi A,Nanjundaswamy K,Goodenough J.Phospho-olivines as positive-electrode materials for rechargeablelithium batteries[J].J Electrochm Soc,1997,144(4):1188-1194. [12]Yamada A,Koizumi H,Nishimura S,et al.Room-tem-perature miscibility gap in LixFePO4[J].Nat Mater,2006,5:357-360. [13]WangDe-yu,WuXiao-dong,ChenLi-quan,etal.Cracking causing cyclic instability of cathode material[J].J Power Sources,2005,140:125-128. [14]Hong Jian,Wang Chun-sheng,Kasavajjula Uday.Ki-netic behavior of LiFe0.9Mg0.1PO4cathode material for Li-ion batteries[J].J Power Sources,2006,162:1289-1296.
文章导航

/