锂锂电池基础科学问题(Ⅱ)----电池材料缺陷化学

doi:10.3969/j.issn.2095-4239.2013.02.010

摘要/Abstract

摘要： 在锂离子电池电极与电解质材料研究中,缺陷化学对于理解材料的物理化学性质,指导材料的理性设计与优化方面具有重要的意义.本文重点讨论了锂电池材料中缺陷形态的类型,热力学基础,缺陷的存在对材料性质的调制等方面的内容,讨论了小尺寸材料引起的电极电位偏离理想材料的问题.以锂离子电池中重要的正极材料LiFePO₄为例,结合第一性原理计算与原子级分辨的球差校正电镜技术,介绍了LiFePO₄中缺陷的生成与表征及对电子电导率的调制,对锂离子输运的影响,缺陷结构的可视化以及缺陷进一步演化导致的缺陷簇和超结构等方面的工作.

关键词: 缺陷化学, 电极材料, LiFePO4, 电化学, 锂电池

Abstract: Defect chemistry plays an important role in many aspects of electrode and electrolyte materials for Li-ion battery, particularly physical and chemical properties, rational design and optimization. In this article, the influence of defects on electrode materials properties and performance is mainly discussed. This includes defect formation, characterization, thermodynamics and electrochemistry. Taking olivine LiFePO₄ as an example, the impacts of defects are discussed based on the first-principles and spherical aberration-corrected scanning transmission electron microscopy (STEM) investigation. It is shown that element substitution/doping is able to enhance electronic conductivity and block the transport of Li ions due to its one-dimensional diffusion feature. It is also found that point defects could aggregate to form defect clusters or superstructures in a LiFePO₄structure. In addition, the voltage profile of nanostructured material could deviate from that of the bulk materials.

Key words: defect chemistry, electrode materials, LiFePO4, electrochemistry, Li-ion batteries

中图分类号:

O646.21

卢侠, 李泓. 锂锂电池基础科学问题(Ⅱ)----电池材料缺陷化学[J]. 储能科学与技术, 2013, 2(2): 157-164.

LU Xia, LI Hong. Fundamental scientific aspects of lithium batteries (Ⅱ)--Defect chemistry in battery materials[J]. Energy Storage Science and Technology, 2013, 2(2): 157-164.

参考文献

[1] Crawford J H,Slifkin L M. Point Defects in Solids[M]. New York:Plenan Press,1975.
[2] Huang Kun(黄昆),Han Ruqi(韩汝琦). 固体物理学[M]. Beijing:Higher Education Press,1988:529-552.
[3] Kittel C. Introduction to Solid State Physics [M]. 8th ed. New York:John Wiley&Sons,Inc.,2005:597-618.
[4] Kröger F A. Defect chemistry in crystalline solids[J]. Annu. Rev. Mater. Sci. ,1977,7:449-475.
[5] Kröger F A,Vink H J. Solid State Physics[M]. New York:Academic,1956,3:307.
[6] Zu C X,Li H. Thermodynamic analysis on energy densities of batteries[J]. Energy Environ. Sci. ,2011,4:2614-2624.
[7] Smyth D M. The Defect Chemistry of Metal Oxides[M]. USA:Oxford University Press,2000.
[8] Peng Jiayue(彭佳悦),Zu Chenxi(祖晨曦),Li Hong(李泓). Fundamental scientific aspects of lithium batteries(Ⅰ) Thermodynamic calculations of theoretical energy densities of chemical energy storage systems[J]. Energy Storage Science and Technology (储能科学与技术),2013,2(1):55-62.
[9] Liu Zhaojun(刘兆君). 锂离子电池电极材料中热力学和动力学问题的第一性原理研究[D]. Beijing:Institute of Physics,Chinese Academy of Sciences,2010.
[10] Delmer O,Balaya P,Kienle L,Maier J. Enhanced potential of amorphous electrode materials:Case study of RuO 2 [J] . Adv. Mater. ,2008,20:501.
[11] Zhong K F,Zhang B,Luo S H,Wen W,Li H,Huang X J,Chen L Q. Investigation on porous MnO microsphere anode for lithium ion batteries[J] . J. Power Sources ,2011,196:6802-6808.
[12] Balaya P,Maier J. Thermodynamics of nano- and macrocrystalline anatase using cell voltage measurements[J] . Phys. Chem. Chem. Phys. ,2010,12:215-219.
[13] Padhi A K,Nanjundawamy K S,Goodenough J B. Phospho-olivines as positive-electrode materials for rechargeable lithium batteries[J]. J. Electrochem. Soc. ,1997,144:1188.
[14] Ravet N,Goodenough J B,Besner S,Simoneau M,Hovington P,Armand M. Improved iron based cathode material[C] // 196th Meeting of the Electrochemical Society,Oct. 1999,Honolulu,Hawaї.
[15] Chung S Y,Bloking J T,Chiang Y M. Electronically conductive phospho-olivines as lithium storage electrodes[J] . Nat. Mater. ,2002,1:123-128.
[16] Herle P S,Ellis B,Coombs N,Nazar L F. Nano-network electronic conduction in iron and nickel olivine phosphates[J] . Nat. Mater. , 2004,3(3):147-152.
[17] Ravet N,Abouimrane A,Armand M. On the electronic conductivity of phospho-olivines as lithium storage electrodes[J] . Nat. Mater. ,2003,2(11):702-704.
[18] Shi S Q,Liu L J,Ouyang C Y,Wang D S,Wang Z X,Chen L Q,Huang X J. Enhancement of electronic conductivity of LiFePO 4 by Cr doping and its identification by first-principles calculations[J] . Phys. Rev. B ,2003,68:195108.
[19] Ouyang C Y,Shi S Q,Wang Z X,Huang X J,Chen L Q. First-principles study of Li ion diffusion in LiFePO 4 [J]. Phys. Rev. B ,2004,69:104303.
[20] Ouyang C Y,Shi S Q,Wang Z X,Li H,Huang X J,Chen L Q. The effect of Cr doping on Li ion diffusion in LiFePO 4 from first principles investigations and Monte Carlo simulations[J]. J. Phys. Cond. Mat. ,2004,16(13):2265-2672.
[21] Ouyang Chuying(欧阳楚英). 锂离子电池正极材料离子动力学性能研究[D]. Beijing:Institute of Physics,Chinese Academy of Sciences,2005.
[22] Maxisch T,Zhou F,Ceder G. Ab initio study of the migration of small polarons in olivine Li x FePO 4 and their association with lithium ions and vacancies[J] . Phys. Rev. B ,2006,73:104301.
[23] Li H,Wang Z X,Chen L Q,Huang X J. Research on advanced materials for Li-ion batteries[J] . Adv. Mater. ,2009,21:4593-4607.
[24] Axmann P,Stinner C,Wohlfahrt-Mehrens M,Mauger A,Gendron F,Julien C M. Nonstoichiometric LiFePO 4 :Defects and related properties[J] . Chem. Mater. ,2009,21:1636-1644.
[25] Islam M S,Driscoll D J,Fisher C A J,Slater P R. Atomic-scale investigation of defects,dopants,and lithium transport in the LiFePO 4 olivine-type battery material[J] . Chem. Mat. ,2005,17:5085-5092.
[26] Fisher C A J,Prieto V M H,Islam M S. Lithium battery materials LiMPO 4 (M = Mn,Fe,Co,and Ni):Insights into defect association,transport mechanisms,and doping behavior[J] . Chem. Mat. ,2008,20:5907-5915.
[27] Meethong N,Kao Y H,Speakman S A,Chiang Y M. Aliovalent substitutions in olivine lithium iron phosphate and impact on structure and properties[J] . Adv. Func. Mater. ,2009,19:1060-1070.
[28] Wagemaker M,Ellis B L,Luetzenkirchen-Hecht D,Mulder F M,Nazar L. Proof of supervalent doping in olivine LiFePO 4 [J] . Chem. Mater. ,2008,20:6313.
[29] Maier J,Amin R. Defect chemistry of LiFePO 4 [J] . J. Electrochem. Soc., 2008,155:A339-A344.
[30] Nishimura S,Kobayashi G,Ohoyama K,Kanno R,Yashima M,Yamada A. Experimental visualization of lithium diffusion in Li x FePO 4 [J]. Nature Mater. ,2008,7:707-711.
[31] Liu X S,et al. Phase transformation and lithiation effect on electronic structure of Li x FePO 4 :An in-depth study by soft X-ray and simulations[J]. J. Am. Chem. Soc. ,2012,134:13708-13715.
[32] He X Q,Gu L,Zhu C B,Yu Y,Li C L,Hu Y S,Li H,Tsukimoto S,Maier J,Ikuhara Y,Duan X F. Direct imaging of lithium ions using aberration-corrected annular-bright-field scanning transmission electron microscopy and associated contrast mechanisms[J] . Mater. Express ,2011,1(1):43-50.
[33] Chung S Y,Choi S Y,Yamamoto T,Ikuhara Y. Atomic-scale visualization of antisite defects in LiFePO 4 [J] . Phys. Rev. Lett. ,2008,100:125502.
[34] Gu L,Zhu C B,Li H,Yu Y,Li C L,Tsukimoto S,Maier J,Ikuhara Y. Direct observation of lithium staging in partially delithiated LiFePO 4 at atomic resolution[J] . J. Am. Chem. Soc. ,2011,133:4661-4663.
[35] Suo L,Han W,Lu X,Gu L,Hu Y S,Li H,Chen D,Chen L,Tsukimoto S,Ikuhara Y. Highly ordered staging structural interface between LiFePO 4 and FePO 4 [J]. Phys. Chem. Chem. Phys. ,2012,14:5363.
[36] Malik R,Zhou F,Ceder G. Kinetics of non-equilibrium lithium incorporation in LiFePO 4 [J]. Nat. Mater. ,2011,10:587.
[37] Sun Y,Lu X,Xiao R J,Li H,Huang X J. Kinetically controlled lithium-staging in delithiated LiFePO 4 driven by the Fe center mediated interlayer Li-Li interactions[J] . Chem. Mater. ,2013,dx.doi.org/10.1021/cm3028324.
[38] Wang L P,Li H,Huang X J,Baudrin E. A comparative study of F d-3m and P 4332 "LiNi 0.5 Mn 1.5 O 4 " [J] . Solid State Ionics ,2011,193:32-38.