淬冷法合成锂离子电池正极材料LiFePO_4的研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
提高锂离子电池性能和降低电极材料的成本一直是锂离子电池领域的主要研究方向。本文基于这种趋势在详细考查了锂离子电池正极材料研究发展的基础上,选取了橄榄石型LiFePO_4材料作为研究对象,并运用水淬冷法对其合成和改性工作进行了较为深入和系统的研究。
     研究对比了随炉冷却方式和水淬冷方式对合成纯相LiFePO_4微观结构和电化学性能的影响。研究发现水淬冷方式较随炉冷却方式制备的LiFePO_4具有更精细的颗粒尺寸,通过Rietveld法结构精修分析发现采用淬冷法制备的样品晶格内存在一定的缺陷,并造成晶胞体积发生收缩;从化学热力学、动力学和晶体学角度对淬冷法制备的LiFePO_4的作用机理进行分析,提出了淬冷法制备的样品中可能存在离子扩散的空位和通道,这些空位和通道可能为锂离子的扩散提供路径,有利于固相法制备LiFePO_4电化学性能的改进;通过正交实验优化了淬冷固相法制备LiFePO_4的工艺条件。在最优条件下制备的纯相LiFePO_4在0.1C倍率下可逆放电容量达151.1 mAh·g~(-1),0.5C倍率下达132.0 mAh·g~(-1),明显优于常规固相法制备的LiFePO_4。
     采用水淬冷法合成了碳包覆的LiFePO_4/C化合物,并借助拉曼(Raman)光谱手段研究了碳在制备LiFePO_4/C中的作用机理,研究表明碳有效改进LiFePO_4的电化学性能需要以下三个条件:(ⅰ).磷酸铁锂颗粒多为sp~2型的碳所包覆;(ⅱ).包覆碳能形成良好的导电网络;(ⅲ).碳包覆均匀。采用淬冷固相法通过正交实验优化了低碳高活性LiFePO_4/C的合成条件,经过优化后合成的LiFePO_4/C复合材料0.1C放电容量达163.8 mAh·g~(-1),在1C和2C倍率下的放电容量分别达143.4和124.7 mAh·g~(-1),循环性能优良。而复合材料中的原位碳包覆量仅为0.98%,比表面积为8.9 m~2·g~(-1),极大地改善了材料的物理性能。
     采用水淬冷法合成了铁位掺杂和锂位掺杂的LiFePO_4化合物,并借助四探针法测电导率、粉末微电极循环伏安法和交流阻抗法探讨了铁位掺杂和锂位掺杂对LiFePO_4电导率的改善机理。研究表明:(ⅰ).通过铁位掺杂Mg~(2+)和Ni~(2+)不但将样品的电导率提高了2-3个数量级,而且掺杂还降低了O对Li的束缚,从而有利于Li~+的快速传输。(ⅱ).锂位掺杂Ti~(4+)和Nb~(5+)不但可以将LiFePO_4的电导率提高近100倍,而且锂位掺杂在一定程度上还可以抑制脱锂.嵌锂过程中LiFePO_4的相变,从而有利于Li~+扩散。但是,锂位引入过多的杂原子会导致材料电化学性能的下降。
     为了进一步提高磷酸铁锂的电导率并优化LiFePO_4/C的性能,本文研究了水淬冷法制备低碳掺杂型LiFePO_4的合成与性质。研究发现经过低碳量包覆和金属离子掺杂方法可以将LiFePO_4的电导率提高到10~(-2)S·cm~(-1)数量级,材料的电化学性能尤其是倍率性能得到明显的改善。样品LiFe_(0.99)Mg_(0.01)PO_4/C在2C倍率下首次放电容量达到133.9mAh·g~(-1),经过50次循环几乎无衰减,而样品中的原位碳含量仅为1.05%。Li_(1-x)FePO_4和Li_(1-x)Fe_(0.99)Mg_(0.01)PO_4/C(x=0~0.8)的交换电流密度数值分别介于0.04-0.10和0.1-0.42 mA·cm~(-2)之间,并且交换电流密度随着锂含量的变化而变化,并在x=0.4~0.5附近出现最大值。
     研究了喷雾干燥法制备球形高密度LiFePO_4的工艺参数,结果表明,在较低固体含量(20%)和高离心转速(18000r·min~(-1))下可制得实心球形粒子前驱体。以实心粒子前驱体所合成的产物仍为实心,振实密度达到1.51g·cm~(-3),所制备的实心多孔样品在0.2C、1C和2C倍率下的可逆比容量分别为150.2、144.0和129.8 mAh·g~(-1),而且材料循环性能良好。
Intensive research and development work is being conducted to further improve the performance of lithium ion batteries and reduce the cost of electrode materials.Based on this trend and reviewing the development of cathode materials for lithium ion batteries,this dissertation focusing on olivine LiFePO_4 cathode materials.The synthesis and modification of LiFePO_4 cathode materials were studied by water quenching treatment in details.
     The effect of common cooling mode and water quenching(WQ) mode on the microstructure and electrochemical performance of LiFePO_4 were studied.In contrast to the common cooling mode,LiFePO_4 synthesized by water quenching treatment had more fine grain size. Crystal defect existence of the sample prepared by water quenching treatment was found by Rietveld refinement,which produced the crystal volume contraction.The working mechanism of water quenching treatment was discussed from chemical thermodynamics,chemical dynamics and crystallography.And the existences of vacancy and diffusion channel were brought on in the sample by water quenching method.These vacancies were helpful to improve the electrochemical performance of LiFePO_4 for offering the diffusion path of lithium ion in the electrode process.The synthetic conditions of pure LiFePO_4 were optimized by orthonormal experiment.The pure LiFePO_4 prepared under optimum condition had the highest reversible discharge specific capacity of 151.1 mAh·g~(-1) at 0.1C rate and 132.0 mAh·g~(-1) at 0.5C rate.
     LiFePO_4/C composite was prepared by water quenching treatment and the working mechanism of carbon in the LiFePO_4/C composite was studied by Raman spectrum method.The results showed that three necessary conditions determine the improvement of LiFePO_4/C.(ⅰ).The particles of LiFePO_4 need be coated by sp~2 type carbon;(ⅱ).The good electronic conductive network among particles need be formed;(ⅲ).The uniformity of carbon on the surface of LiFePO_4 particle is also necessary. The synthesis of LiFePO_4/C with low carbon content and good activity by water quenching treatment was optimized by orthonormal experiment. The optimum sample with good cyclic capability displayed the highest reversible discharge specific capacity of 163.8 mAh·g~(-1) at 0.1C rate and 143.4 mAh·g~(-1) at 1C rate and 124.7 mAh·g~(-1) at 2C rate.And the in situ carbon content of the sample was only 0.98%.The specific surface area was 8.9 m~2·g~(-1).Hence the physical property of the sample was improved greatly.
     The Fe sites(M2) doping and Li sites(M1) doping LiFePO_4 compound were synthesized by WQ method and the mechanism of the improvement of electronic conductivity was also discussed by four-probe method,powder microelectrode cyclic voltammetry and electrochemical impedance spectroscopy measurements.The study indicated:(ⅰ) the Fe sites doping Mg~(2+) and Ni~(2+) did not only improve the electronic conducivity by 2~3 order of magnitude but also weakened the bound of oxygen to lithium,which is propitious to the transport of Li ions;(ⅱ) the electronic conducivity of doping samples in Li sites by Ti~(4+) and Nb~(5+) was improved by 100 times.Meanwhile,structure change due to phase transformation was inhibited to some extent.But electrochemical performance was poor with doping excess atoms in Li sites.
     The synthesis and capability of doping type sample with low carbon content were investigated in order to further improve the electronic conductivity of LiFePO_4 and optimize the performance of LiFePO_4/C. The electronic conductivity was enhanced to 10~(-2) S·cm~(-1) by this method. The electrochemical property especially the rate capability was improved greatly.The sample LiFe_(0.99)Mg_(0.01)PO_4/C showed 133.9 mAh·g~(-1) at 2C discharge rate and almost no loss after 50~(th) cycles.And the in situ carbon in the sample was only 1.05%.The ranges of exchange current density(i_0) in Li_(1-x)FePO_4 and Li_(1-x)Fe_(0.99)Mg_(0.01)PO_4/C(x=0~0.8) were 0.04~0.10 and 0.1~0.42 mA·cm~(-2),respectively.The exchange current density were changed with lithium content in the electrode,and the max value was obtained near at x=0.4~0.5.
     The synthetic conditions of spherical LiFePO_4 with high tap density were studied by spray drying(SD) method.The results showed dense spherical precursor was prepared at the low solid content(20%) and high speed of centrifugal atomizer for 18000 r·min~(-1).The product with dense particle was synthesized by using dense precursor.And the tap density was 1.51 g·cm~(-3).The sample with good cycle capability could reach 150.2, 144.0 and 129.8 mAh·g~(-1) at the discharge rate of 0.2C、1C and 2C, respectively.
引文
[1]郭炳焜,徐徽,王先友.锂离子电池。中南大学出版社.2002.
    [2]吴宇平,万春荣,姜长印.锂离子二次电池[M],北京:化学工业出版社,2002:12.
    [3]T Nagaura,K Tozawak.Lithium ion rechargeable battery[J].Pro.batts.Sol.Cell,1990:209-210.
    [4]陈立泉.锂离子正极材料的研究发展[J].电池.2002,32(6):6-8。
    [5]M Yoshio,H Tanaka,K Tominaya.Synthesis of LiCoO_2 from cobalt-organic acid complex and its electrode behavior in a lithium secondary battery[J].J Power Sources,1992,40(1):347-353.
    [6]M M Thackeray.Structural considerations of layered and spinel lithiated oxides for lithium ion battery[J].J Electrochem Soc,1995,142(8):2558-2563.
    [7]K Mizushima,P C Jones,P J Wiseman,et al.Li_xCoO_2(0    [8]R Koksbang,J Barker,H Shi,M Y Saidi.Cathode materials for lithium rocking chair batteries[J].Solid State Ionics,1996,84:1-21.
    [9]P N Kumta,D Gallet,A Waghray,et al.Synthesis of LiCoO_2 powders for lithium-ion batteries from precursors derived by rotary evaporation[J].J Power sources,1998,72:91-98.
    [10]R Alcantara,P Lavela,J L Yirado.Structure and electrochemical Properties of Boron-Doped LiCoO_2[J].Journal of Solid State Chemistry,1997,134(2):265-273.
    [11]J Akimoto,Y Gotoh,Y Oosawa.Synthesis and structure refinement of LiCoO_2single crystals[J].J Solid State Chemistry,1998,141(1):298-302.
    [12]R Stoyanova,E Zhecheva,L Zarkova.Effect of Mn-substitution for Co on the crystal structure and acid delithiation of LiMn_yCo_(1-y_O_2 solid solutions[J].Solid State Ionics.1994,73(1-2):233-240.
    [13]M holzapfel,R schreiner,A ott.Lithium-ion conductors of the system LiCo_(1-x)Fe_x O_2:a first electrochemical investigation[J].Electrochemical Acta,2001,46(7):1063-1070.
    [14]S Madhavia,G.V Subba Raob,B V R Chowdari,et al.Effect of Cr dopant on the cathodic behavior of LiCoO_2[J].Electrochimica Acta,2002,48(3):219-226.
    [15]S Madhavi,G V Subba Raob,B V R Chowdari,et al.Synthesis and cathodic properties of LiCo_(1-y)Rh_yO_2(0≤y≤0.2) and LiRhO_2[J].J Electrochem Soc,2001,148(4):A1279-A1286.
    [16]Jin K Hong,Jong H,Lee seung M.Effect of carbon additive on electrochemical performance of LiCoO_2 composite cathodes[J].J Power sources,2002,111(1):90-96.
    [17]Imach,Kodama,Yasunobu Yoshida,et al.Non-aqueous electrolyte cell having a positive electrode with Ti-attached LiCoO_2[p].United states:6395426,2002.
    [18]Huang Weiwei,Roger Frech.Vibrational spectroscopic and electrochemical studies of the low and high temperation phases of LiCo_(1-x)M_xO_2(M=Ni or Ti)[J].Solid State Ionics,1996,86-88:395-400.
    [19]M Mladenov,R Stoyanova,E Zhecheva,et al.Effect of Mg Doping and MgO-surface modification on the cycling Stability of LiCoO_2 electrodes[J].Electrochemistry Communications,2001,3:410-416.
    [20]S Levasseur,M Menetrier,C Delmas.On the LixCo_(1-y)Mg_yO_2 system upon deintercalation:electrochemical,electronic properties and 7Li MAS NMR studies[J].J Power Sources,2002,112(2):1-9.
    [21]Woo-Sub Yoon,Kyung-Keun Lee,Kwang-Bum Kim.Synthesis of LiAl_yCo_(1-y)O_2using acrylic acid and its electrochemical properties for Li rechargeable batteries[J].J Power Sources,2001,97-98(2):303-307.
    [22]Y I Jang,Biying Huang,Haifeng Wang,et al.Synthesis and characterization of LiAl_yCo_(1-y)O_2 and LiAl_yNi_(1-y)O_2[J].J Power sources,1999,81-82(1-4):589-593.
    [23]Jung-Jin Kim,Kwang Hyun Ryu,Kiyoshi Sakaue,et al.Strutural characterization for the chemically Li~+ ion extracted LiyCoO_2,LiyCo_(0.95)Ga_(0.05)O_2,and LiyCo_(0.9)Ga_(0.1)O_2 compounds[J].J Physics and Chemistry of Solids.2002,63(11):2037-2045.
    [24]N Imanishi,M Fujii,A Hirano,et al.Structure and electrochemical behaviors of Li_xCoO_2(x>1) treated under high oxygen pressure[J].Solid state ionics.2001,140(1-2):45-53.
    [25]C Delmas.On the behavior of the LiNi_xO_2 system of electrochemical and structural overview[J].J Power Sources,1997,(68):120-124.
    [26]高虹,翟秀静,翟玉春等.锂离子电池正极材料LiNiO_2的制备和研究[J]。电源技术,1997,23:53-55.
    [27]刘汉三.锂离子电池正极材料锂镍氧系列化合物的合成、结构和性能研究[D],厦门大学,2003。
    [28]A Rougier,P Gravereau,C Delmas.Optimization of composition of the Li_(1-z)Ni_(1+z)O_2 electrode material:Structural,magnetic and electrochemical studies [J].J Electrochem Soc,1996,143(4):1168-1175.
    [29]Wang G X,Zhong S,Bradhurst D H,et al.Synthesis and characterization of LiNiO_2 compounds as cathodes for rechargeable lithium batteries[J].J Power Sources,1998,76(2):141 - 146.
    [30]J Dahn,E Rossen,C D Joners,et al.Electrochemical poperties of LiNi_(1-y)Fe_yO_2[J].Solid state ionics,1993(61):355-340.
    [31]Y Gao,MYakovleva,W Ebner,et al.Synthesis and charge-discharge properties of LiNi_(1-x)Ti_(x/2)Mg_(x/2)O_2 compounds[J].Solid state Letters,1998,(1):117-120.
    [32]M M Thackeray.Structural considerations of layered and spinel lithiated oxides for lithium ion batteries[J].J Electrochem Soc,1995,142(8):2558-2563.
    [33]D L Siapkas,C Mitsas,I Samaras,et al.,Synthesis and characterization of LiMn_2O_4 for use in Li-ion batteries[J].J Power Sources,1998,72(1):459-465.
    [34]Y Y Xia,H Takeshige,N Hideyake,et al.Synthesis and electrochemical behavior of LixMn2_O_4[J].J Power.Sources,1995,56(1 ):61-67.
    [35]Y K Sun,I H Oh,K Y Kim,et al.Synthesis of spinel LiMn_2O_4 by the sol-gel method for a cathode active material in lithium secondary batteries[J].Ind Eng Chem Res,1997,36:4839-4846.
    [36]S T Myung,S Komaba,N Kumaqai.Enhanced structure stability and cycle ability of Al-doped LiMn_2O_4 spinel synthesized by the Emulsion drying method[J].J Electrochem Soc,2001,148(5):A482-A489.
    [37]唐致远,阮艳莉,锂离子电池容量衰减机理的研究进展[J].化学进展,2005.17(1):1-8.
    [38]N V Kosova,E T Devyatkina,S G Kozlova.Mechanochemical way for preparation of disordered lithium managanese spinel compounds[J].J Power Sources,2001,97:406-411.
    [39]Liu Z L,Wang H B,Fang L,et al.Improving the high-temperature performance of LiMn_2O_4 spinel by micro-emulsion coating of LiCoO_2[J].J Power Sources,2002,104(1):101-107.
    [40]S Komaba,T Sasaki,Y Miki,et al.Electrochemical characteristics and managanese dissolution of spinel Li_(1.05)M_(0.2)Mn_(1.75)O_4(M=Al,Co,and Cr) cathode for rechargeable lithium ion batteries[J].Electrochemistry,2003,71(12):1236-1239.
    [41]A K Padhi,K S Naanjundaswamy,C Masquelier,et al.Phospho- olivines as positive-eclectrode materials for rechargeable lithium Batteries[J].J Electrochem -ical Soc,1997,144(4):1188-1194.
    [42]A K Padhi,K S Naanjundaswamy,C Masquelier.Mapping of transition-metal redox energies in phosphates with NASICON structure by lithium intercalation [J],J Electrochem Soc,1997,144:2581-2586.
    [43]A D Wadsley.Crystal chemistry of nonstoichiometric quinquevalent vanadium oxides:crystal structure of Li_(1+x)V_3O_8[J].Acta Crystallogram,1957,10:261-267.
    [44]L A De Picciotto,K T Adendorff,D C Liles,et al.Structural characterization of Li_(1+x)V_3O_8 insertion electrodes by single-crystal X-ray diffraction[J].Solid State Ionics,1993,62(3-4):297-307.
    [45]J Barker,M Y Saidhi,J L Swoyer.Electrochemical propertied of bet-Li_3V_2(PO_4)_3prepared by carbothermal reduction[J].J Electrochem Soc,2004,151(6):A796-A800.
    [46]M Y Saidi,J Barker,H Huang,et al.Performance characteristics of lithium vanadium phosphate as a cathode materials for lithium-ion batteries[J].J Power Sources,2003,119-121:266-272.
    [47]B Ramesh Babu.Solid-state synthesis and characterization of LiNi_yCo_(1-y)O_2(0.0≤y≤0.4)[J].International Journal of Inorganic Materials,2001,3(4-5):401-407.
    [48]G T K Fey,J G Chen,V Subramanian,et al.Preparation andelectrochemi-cal properties of Zn-doped LiNi_(0.8)Co_(0.2)O_2[J].J Power Sources,2002,11(2):384-394.
    [49]A D Epifanio,F Croce,F Ronci,et al.Thermal,electrochemical and structural properties of stabilized LiNi_yCo_(1-y-z)M_2O_2 Lithium-ion cathode Material prepared by a chemical route[J].J Chem Phys,2001,67(3):4399-4403.
    [50]G Ting-Kuo Fey,V Subra,V Subramanian,et al.Electrochemical performance of Sr~(2+)-doped LiNi_(0.8)Co_(0.2)O_2 as a cathode material for lithium batteries synthesized via a wet chemistry route using oxalic acid[J].Materials letters.2002,52(3):197-202.
    [51]张爱波,刘建睿,黄卫东等.锂离子蓄电池正极材料LiNi_xCo_(1-x)O_2的研究进展[J].电源技术,2003,27(5):484-487.
    [52]E Rossen,C Jones,J R Dahn.Preparation and characterizationg of Li_xNi_(1-y)Mn_yO_2(0≤y≤0.6)[J].Solid State Ionics,1992(57):311-316.
    [53]C Delmas,C Pouillerie,L Croguennec,et al.Effect of synthesis conditions on electrochemical properties of LiNi_(1-y)Mg_yO_2 cathode for lithium rechargeable batteries[J]. Solid state Ionics, 2000(132): 15-23.
    [54] A G Ritchie. Recent developments and likely advances in lithium rechargeable batteries[J]. J Power Sources, 2004,136: 285-289.
    [55] Y D Zhong, X B Zhao, G S Cao. Characterization of solid-state synthesized pure and doped lithium nickel cobalt oxides[J]. Materials Science and Engineering B, 2005,121:248-254.
    [56] N Yabuuchi, T Ohzuku. Novel lithium insertion material of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 for advanced lithium-ion batteries[J]. J Power Sources, 2003,119-121:171-174.
    [57] Y Koyama, I Tanaka, H Adachi, et al. Crystal and electronic structures of superstructural Li_(1-x)[Ni_(1/3)Co_(1/3)Mn_(1/3)]O_2[J]. J Power Sources, 2003, 119-121: 644-648.
    [58] B J Hwang, Y W Tsai, D Carlier, et al. A combined computational experimental study on LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2[J]. Chem Mater, 2003,15: 3676-3682.
    [59] A K Padhi, K S Najundaswamy, C Masquelier C, et al. Effect of structure on the Fe~(3+)/Fe~(2+) redox couple in iron phosphates[J], J Electrochem Soc,1997, 144: 1609-1613.
    [60] N Takimi, A Satoh, M hara, et al. Structural and kinetic characterization of lithium intercalation into carbon anodes for secondary lithium batteries[J]. J Electrochem Soc, 1995,142(2): 371-379.
    [61] A A Andriiko, P V Rudenok, L I Nyrkova. Diffusion coefficient of Li~+ in solid-state rechargeable battery materials[J]. J Power Source, 1998, 72 (2): 146-149.
    [62] Atsuo Yamada, Mamoru Hosoya, Sai-Cheong Chung, et al. Olivine-type cathodes Achievements and problems[J]. J Power Source, 2003,119-121(1-2): 232-238.
    [63] D Morgan, A Van der Ven, G Ceder. Li conductivity in Li_xFePO_4 (M=Mn, Fe, Co, Ni) olivine materials [J]. Electrochemical and Solid Letters, 2004, 7(2): A30-A32.
    [64] M Saiful Islam, Daniel J. Driscoll, A J Crag, et al. Atomin-Scale Investigation of Defects, Dopants, and Lithium Transport in the LiFePO_4 Olivine-type Battery Material[J]. Chem Mater, 2005,17(20): 5085-5092.
    [65] P P Prosini, Marida Lisi, Daniela Zane, et al. Determination of the chemical diffusion coefficent of lithium in LiFePO_4[J]. Solid State Ionics, 2002, 148: 45-51.
    [66] Masaya Takahashi, Shin-ichi Tobishima, Kcji Takei, et al. Reaction behavior of LiFePO_4 as a cathode material for rechargeable lithium batteries[J]. Solid State Ionics, 2002, 148: 283-289.
    [67] M Takahashi, S Tobishima, K Takei, et al. Characterization of LiFePO_4 as the cathode material for rechargeable lithium batteries[J], J Power Sources, 2001, 97-98: 508-501.
    [68] S Yang, Y Song, P Y Zavalij, et al. Reactivity, Stability and electrochemical behavior of lithium iron phosphates[J], Electrochem Comm, 2002, 4: 239-244.
    [69] A S Andersson, J O Thomas. The source of first-cycle capacity loss in LiFePO_4[J]. J Power Sources, 2001, 97-98: 498-502.
    [70] A S Andersson, B Kalska, L Haggstrom, et al. Lithium extraction/insertion in LiFePO_4: an X-ray diffraction and Mossbauer spectroscopy study[J]. Solid State Ionics, 2000,130: 41-52.
    [71] N Ravet, Y Chouinard, J F Magnan, et al. Electroactivity of natural and synthetic triphylite[J]. J Power Sources, 2001, 97-98(1-2): 503-507.
    [72]A S Andersson, J O Thomas, B Kalska, et al. Thermal Stability of LiFePO_4-Based Cathodes[J]. Electrochemical and Solid State Letters, 2000,3(2):66-68.
    [73] G Li, H Azuma, M Tohda. Optimized LiMn_yFe_(1-y)PO_4 as the cathode for lithium batteries[J]. J Electrochem Soc, 2002,149(6): A743-A747.
    [74] Z Zhang, D Fouchard, J R Rea. Differential scanning calorimetry material studies: implications for the safety of lithium-ion cells[J]. J Power Source, 1998, 70:16-20.
    [75] D D MacNeil, Zhonghua Lu, Zhaohui Chen, et al. A comparison of the electrode/electrolyte reaction at elecated temperatures for various Li-ion battery cathodes[J]. J Power Source, 2002, 108: 8-14.
    [76] Robert Dominko, Miran Gaberscek, Jernej Drofenik, et al. The role of carbon black distribution in cathodes for Li ion batteries[J]. J Power Sources, 2003, 119-121:770-773.
    [77] Jae-KwangKim, Jae-WonChoi, GouriCheruvally, et al. A modified mechanical activation synthesis for carbon-coated LiFePO_4 cathode in lithium batteries[J]. Materials Letters, 2007, 61(18): 3822-3825.
    [78] J Barker, M Y Saidi, J L Swoyer. Lithium Iron (Ⅱ) Phospho-olivines Prepared by a Novel Carbothermal Reduction Method[J]. Electrochem Solid-State Lett, 2003, 6(3): A53-A55.
    [79] H Huang, S C Yin, L F Nazar. Approaching theoretical capacity of LiFePO_4 at room temperature at high rates[J]. Electrochem Solid State Lett, 2001, 4: A170-A172.
    [80] Zhaohui Chen, J R Dahn. Reducing carbon in LiFePCVC composite electrodes to maximize specific energy, volumetric energy, and tap density[J]. J Electrochem Soc, 2002,149(9): A1184-1189.
    [81] P P Prosini, D Zane, M Pasquali. Improved electrochemical performance of a LiFePO_4-based composite cathode[J]. Electrochim Acta, 2001, 46: 3517- 3523.
    [82] H T Chung, S K Jang, H W Ryu, et al. Effects of nano-carbon webs on the electrochemical properties in LiFePO_4/C composite[J]. Solid State Commun, 2004,131(8): 549-554.
    [83] M M Doeff, Y Hu, F Mclarnon, et al. Effect of surface carbon structure on the electrochemical performance of LiFePO_4[J]. Electrochem Solid-state Lett. 2003, 6(10):A207-A209.
    [84]Y Sundarayya, K C Kumara Swamy, C S Sunandana. Oxalate based non- aqueous sol-gel synthesis of phase pure sub-micron LiFePO_4[J]. Materials Research Bulletin, 2007,42 : 1942-1948.
    [85] K S Park, J T Son, H T Chung, et al. Surface modification by silver coating for improving electrochemical properties of LiFePO_4[J]. Solid State Communicatio -ns, 2004,129(5): 311-314.
    [86] F Croce, A D Epifanio, J Hassoun, et al. A novel concept for the synthesis of an improved LiFePO_4 lithium battery carhode[J]. Electrochem Solid State Lett, 2002,5(3): A47-A50.
    [87] PARK Jong Suk, LEE Kyung Tae, LEE Kyung Sub. Effect of Fe_2P in LiFePO_4/Fe_2P composite on the electrochemical properties synthesized by MA and control of heat condition[J]. Rare Materials 25(SPEC), 2006, 179-183.
    [88] Chunsheng Li, Shaoyan Zhang, Fangyi Cheng, et al. Porous LiFePO_4/NiP Composite Nanospheres as the Cathode Materials in Rechargeable Lithium Ion Batteries[J]. Nano Res,2008,1: 242-248.
    [89] J Wolfenstine. Electrical conductivity of doped LiCoPO_4[J]. J Power Sources , 2006,158: 1431-1435.
    [90] Nonglak Meethong, Hsiao-Ying Shadow Huang, et al. Strain Accommodation during Phase Transformations in Olivine-Based Cathodes as a Materials Selection Criterion for High-Power Rechargeable Batteries[J]. Advanced Functional Materials, 2007,17: 1115-1123.
    [91] S Y Chung, J T Bloking, Y M Chiang. Electronically conductive phospho- olivines as lithium storage eletrodes[J]. Nature Material, 2002,1(2): 123-128.
    [92] P S Herle, B Ellis, N Coombs, et al. Nano-network electronic conduction in iron and nickel olivine phosphates[J]. Nature Materials, 2004, 3 (3): 147-152.
    [93] C Y Ouyang, S Q Shi, Z X Wang, et al. The effect of Cr doping on Li ion diffusion in LiFePO_4 from first principles investigations and Monte Carlo simulations[J]. Journal of Physics Condensed Matter, 2004,16: 2265-2272.
    [94] Fei Zhou, Matteo Cococcioni, Kisuk Kang, et al. The Li intercalation potential of LiMPO_4 and LiMSiO_4 olivines with M=Fe, Mn, Co, Ni[J]. Electrochemistry Communications, 2004, 6(11): 1144-1148.
    [95] S Anandhakumar, M Sundar, S Selladurai. Synthesis and performance study of cobalt-substituted lithium iron phosphate[J]. Ionics, 2007,13:19-23
    [96] A Yamada, Y Kudo, K Y Liu. Phase diagram of Li_x(Mn_yFe_(1-y))PO_4 (0    [97] G Li, Y Ku do, K Y Liu, et al. X-ray absorption study of Li_x(Mn_yFe_(1-y))PO_4 (0    [98] J Molenda, W Ojczyk, J Marzec. Electrical conductivity and reaction with lithium of LiFe_(1-y)Mn_yPO_4 olivine-type cathode materials[J]. Journal of Power Sources, 2007,174(2): 689-694.
    [99] D Shanmukaraj, G X Wang, R Murugan, et al. Electrochemical studies on LiFe_(1-x)Co_xPO_4/carbon composite cathode materials synthesized by citrate gel technique for lithium-ion batteries[J]. Materials Science and Engineering, 2008, 149(1): 93-98.
    [100] A Yamada, S C Chung, K Hinokuma. Optimized LiFePO_4 for lithium battery cathodes[J]. J Electrochem Soc, 2001,148: A224-A229.
    [101] S B Lee, S H Cho, S J Cho, et al. Synthesis of LiFePO_4 material with improved cycling performance under harsh conditions [J]. Electrochemistry Communicat ions, 2008, 10:1219-1221.
    [102] S Franger, F L Cras, C Bourbon, et al. Comparison between different LiFePO_4 synthesis routes and their influence on its physicochemical properties [J]. J Power Sources, 2003,119-121: 252-257.
    [103] Jiajun Chen, Shijun Wang, M.Stanley Whittingham. Hydrothermal synthesis of cathode materials[J]. J Power Sources, 2007,174: 442-448.
    [104] Keisuke Shiraishi, Kaoru Dokko, Kiyoshi Kanamura. Formation of impurities on phospho-olivine LiFePO_4 during hydrothermal synthesis[J]. J Power Sources, 2005,146: 555-558.
    [105] Masashi Higuchi, Keiichi Katayama, Yasuo Azuma, etc. Synthesis of LiFePO_4 cathode material by microwave processing [J]. J Power Sources, 2003, 119-121: 258-261.
    [106] K S Park. Synthesis LiFePO_4 by coprecipitation and microwave heating[J]. Electrochemistry Comunications, 2003, 5(10): 839-842.
    [107] Lei Wang, Yudai Huang, Rongrong Jiang, et al. Nano-LiFePO_4 / MWCNT Cathode Materials Prepared by Room-Temperature Solid-State Reaction and Microwave Heating[J]. J Electrochem Soc, 2007,154(11): A1015-A1019.
    [108] P Afanasiev, C Geantet. Sysnthesis of solid materials in molten nitrates[J]. Coordination Chemistry Reviews. 1998,178-180: 1725-1752.
    [109] C Han, Y Hong, C M Park, et al. Synthesis and electrochemical properties of lithium cobalt oxides prepared by molten-salt synthesis using the eutectic mixture of LiCl-Li_2CO_3[J]. J Power Sources, 2001, 92: 95-101.
    [110] H Liang, X Qiu, S Zhang, et al. High performance lithium cobalt oxides prepared in molten KC1 for rechargeable lithium-ion batteries[J]. Electrochemistry Communications, 2004, 6: 505-509.
    [111] Jiang-Feng Ni, Heng-Hui Zhou, Ji-Tao Chen, et al. Molten salt synthesis and electrochemical properties of spherical LiFePO_4 particles[J]. Materials Letters, 2007,61:1260-1264.
    [112] Mu-Rong Yang, Tsung-HsienTeng, She-HungWu. LiFePO_4 /carbon cathode materials prepared by ultrasonic spray pyrolysis[J]. J Power Sources, 2006, 159: 307-311.
    [113] M M Doeff, R Finones, Hu Yaoqin. Electrochemical performance of Sol-Gel synthesized LiFePO_4 in lithium battery [J]. 11th International Meeting on Lithium Battery (IMLB), 2002, Monterey, CA, USA.
    [114] P P Prosini, M Carewska, S Scaccia, et al. A New Synthetic Route for Preparing LiFePO_4 with Enhanced Electrochemical Performance [J]. J Electrochem Soc, 2002,149(7):A886-A890.
    [115] F Crose, A D Epifanio, J Hassoun, et al. A novel concept for the synthesis of an improved LiFePO_4 lithium battery cathode[J].Electrochemical and solide-states Letters,2002,5(3):47-50.
    [116]S Franger,F LeCras,C Bourbon,et al.LiFePO_4 Synthesis Routes for Enhanced Electrochemical Performance[J].Electrochemical and Solid-state,2002,5(10)A231-A233.
    [117]G Arnold,J Garche,R Hemmer,et al.Fine-particle lithium iron phosphate LiFePO_4 synthesized by a new low-cost aqueous precipitation technique[J].Journal of Power Sources,2003,119-121:247-251.
    [118]K S Park,K T Kang,S B Lee,et al.Synthesis of LiFePO_4 with fine particle by co-precipitation method[J].Materials Research Bulletin,2004,39(12):1803-1810.
    [119]Sung Woo Oh,HyunJ oo Bang,Seung-Taek Myung,et al.The Effect of Morphological Properties on the Electrochemical Behavior of High Tap Density C-LiFePO_4 Prepared via Co-precipitation[J].Journal of The Electrochemical Society,2008,1556:A414-A420.
    [120]王秋娟,李全安,陈云贵.快淬对储氢合金组织和电化学性能的影响[J].洛阳工学院学报,2001,22(2):8-11.
    [121]V Shrikant,Joshi,Qibin Liang,et al.Effect of quenching conditions on particle formation and growth in thermal plasma synthesis of fine powders[J].Plasma Chemistry and Plasma Processing,2005,10(2):339-358
    [122]肖劲,曾雷英,彭忠东等.锂离子电池正极材料LiNi_(0.5)Mn_(0.5)O_2的循环性能[J].中国有色金属学报,2006,16(8):1439-1444。
    [123]C W Park,S H Kim,K S Nahm,et al.Structural and electrochemical study of Li[Cr_xLi_(1-x)/3Mn_(2(1-x)/3)]O_2(0≤x≤0.328) cathode materials[J].Journal of Alloys and Compounds,2008,449(1-2):343-348.
    [124]李树棠.晶体X射线衍射学基础。北京,冶金工业出版社,1990
    [125]周伟舫主编.电化学测量.上海:上海科学技术出版社,1985
    [126]周仲柏,陈永言编著。电极过程动力学基础教程.武汉:武汉大学出版社,1989
    [127]田昭武著.电化学研究方法.北京:科学出版社,1984
    [128]Haefliger,W William.Water treatment using fine particle super magnets[P].United States Patent 4836932.
    [129]A K Dwarapureddy.Study of particle growth and breakdown in single size gamma prime distribution and high temperature greep in in7381c nickel superalloy[G].B Tech,Nagarjuna University,2006
    [130]黄琼,赵珊茸.Di-An-Ab体系快速冷却结晶的枝晶研究[J]。人工晶体学报,2003,32(3):228-232.
    [131]魏智强,巩纪军,乔宏霞等.等离子体制备铁纳米粉末的性能表征[J].兰州交通大学学报(自然科学版),2004,23(4):107-110.
    [132]P Jozwiak,J E Garbarczyk,M Wasiucionek,et al.DTA,FTIR and impedance spectroscopy studies on lithium iron phosphate glasses with olivine-like local structure[J].Solid State Ionics,2008,179:46-50.
    [133]M S Whittingham.Lithium Batteries and Cathode Materials[J].Chem Rev,2004,104:4271-4301.
    [134]C D Wagner,W M Riggs,L E Davis.Handbook of X-ray Photoelectron Spectroscopy[M].Perkin-Elmer Corporation Physical Electronics Division.1979,USA.
    [135]Aniruddha Deb,Uwe B ergmann,Elton J Cairns,et al.Structural Investigations of LiFePO_4 Electrodes by Fe X-ray Absorption Spectroscopy[J].J.Phys.Chem.B 2004,108:7046-7051.
    [136]W C ocran。晶体原子动力学[M]。1983,北京高教出版社。
    [137]钱逸泰.结晶化学导论[M].1993,中国科技大学出版社。
    [138]B Henderson。晶体缺陷[M]。1983,高等教育出版社.
    [139]廖立兵.晶体化学及晶体物理学[M].2000,地质出版社.
    [140]B K伐因斯坦.现代晶体学[M].1990,中国科技大学出版社。
    [141]黄昆。固体物理学[M].1998,高等教育出版社.
    [142]F Tuinstra,J L Koenig.Raman spectrum of graphite[J].J Chem Phys,1970,53:1126-1130.
    [143]Denis Y.W.Yu,Christopher Fietzek,Wolfgang Weydanz,et al.Study of LiFePO_4 by cyclic voltammetry.Journal of The Electrochemical Society,2007,154(4):A253-A257
    [144]D Wang,H Li,S Shi,et al.Improving the Rate Performance of LiFePO_4 by Fe-site Doping[J].Electrochimica Acta,2005,50(14):2955-2958.
    [145]C Delacourt,C Wurm,L Laffont,et al.Electrochemical and electrical properties of Nb and/or C-containing LiFePO_4 composites[J].Solid State Ionics,2006,177(3-4):333-341.
    [146]许芳伟,薛卫东,苏荣等.LiFePO_4掺杂Mg前后导电性能的理论研究[J].四川师范大学学报,2008,31(2):224-228.
    [147]Hui Liu,Jingying Xie,Ke Wang.Synthesis and characterization of LiFePO_4/(C+Fe_2P) composite cathodes[J].Solid State Ionics,2008,179(27-32):1768-1771.
    [148]王德宇 锂离子电池磷酸盐正极材料的制备与改性研究[D].北京:中国科院物理研究所,2005.
    [149]A J Bard,L R Faulkner.Electrochemical Methods[M].Wiley,New York,1980.
    [150]杨书延,刘玉霞,尹艳红等.镁离子掺杂对LiFePO_4/C电化学性能和结构的影响.无机材料学报,2007,22(4):627-630
    [151]Xu Guang Gao,Guo Rong Hu,Zhong Dong Peng,et al.Pure LiFePO_4 with high energy density prepared by water quenching treatment[J].Chinese Chemical Letters,2007,18(10):1256-1260.
    [152]Feng Yu,Jingjie Zhang,Yanfeng Yang,et al.Preparation and characterization of mesoporous LiFePO_4/C microsphere by spray drying assisted template method[J].J Power Sources,In Press,2008.
    [153]Fei Gao,Zhiyuan Tang,Jianjun Xue.Preparation and characterization of nano-particle LiFePO_4 and LiFePO_4/C by spray-drying and post-annealing method[J].Electrochimica Acta,2007,53(4):1939-1944.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700