以FePO4·xH2O、V2O5、NH4H2PO
和Li2CO3为原料，以乙二酸为还原剂，在常温常压下经机械活化并还原嵌锂，形成无定形的5LiFePO4·Li3V2(PO4)3前驱体混合物，然后低温热处理合成出晶态的复合正极材料5LiFePO4·Li3V2(PO4)3.分别研究了复合材料的物相结构、形貌、电化学性能.SEM图像表明合成的材料粒径小、分布均匀，一次粒径为100～200nm.充放电测试结果表明，650℃烧结12h制得的复合正极材料5LiFePO4·Li3V2(PO4)3电化学性能优良，1C放电比容量高达158mAh/g，达到该复合材料的理论比容量（156.8mAh/g）.复合材料具有良好的倍率性能和循环性能，在10C放电比容量高达114mAh/g，100次循环后容量几乎无衰减.循环伏安测试表明，复合材料的脱嵌锂性能优良，且明显优于单一的LiFePO4和Li3V2(PO4)3.
郑俊超
,
李新海
,
王志兴
,
覃东棉
,
郭华军
,
彭文杰
. 锂离子电池复合正极材料xLiFePO4·yLi3V2(PO4)3的制备与性能研究[J]. 无机材料学报, 2009
, 24(1)
: 143
-146
.
DOI: 10.3724/SP.J.1077.2009.00143
5LiFePO4·Li3V2(PO4)3 was synthesized via calcining amorphous 5LiFePO4·Li3V2(PO4)3 obtained through lithiation of FePO4·xH2O and V2O5 by using oxalic acid as a novel reducing agent at room temperature. The crystal structure, morphology and electrochemical properties of the products were investigated. The results show that the sample synthesized at 650℃ for 12h has fine particle sizes of 100-200nm with homogenous sizes distribution. Electrochemical measurement results indicate that the material exhibites high rate characteristic and high discharge capacity of 158mAh/g (theoretic capacity 156.8mAh/g) and 114mAh/g at 1C and 10C rate, respectively. There is no obvious capacity fade observed after 100 cycles at 10C rate. The electrochemical performance of composite cathode material 5LiFePO4·Li3V2(PO4)3 is better than that of individual cathode material, such as LiFePO4 and Li3V2(PO4)3.
［1］Padhi A K, Nanjund Aswamy K S, Goodenough J B. J. Electrochem. Soc., 1997, 144(4):1188-1194.
［2］吴宇平,万春荣,姜长印. 锂离子二次电池.北京: 化学工业出版社, 2002: 56-58.
［3］Padhi A K, Nanjund Aswamy K S, Masquelier C, et al. J. Electrochem. Soc., 1997, 144(5):1609-1613.
［4］Morgan D, Ceder G, Saidi M Y. Chem. Mater., 2002, 14(3): 4 684-4 693.
［5］Huang H, Yin S C, Kerr T. Adv. Mater.，2002, 14（21）:1525-1528.
［6］Liu H, Fu L J, Zhang H P, et al. Electrochem. Solid-State Lett., 2006, 9(12): A529 - A533.
［7］Liu H, Fu L J, Li C, et al. Electrochem. Commun.,2006, 8(10):1553-1557.
［8］Zheng J C, Li X H, Wang Z X, et al. J.Power Sources,2008,184(2):574-577.
［9］Yang M R, Wu K, Wu S H. J. Power Sources,2007, 165(2):646-650.
［10］Wang L N, Li Z C, Xu H J, et al. J. Phys. Chem.C, doi: 10.1021/jp0758014.
［11］Chung S Y, Bloking J T, Chiang Y M. Nat. Mater.,2002, 1(2): 123-128.
［12］Hu G R, Gao X G, Peng Z D, et al. Trans. Nonferrous Met. Soc. China,2007, 17(2): 296-300.
［13］Hu Y, Doeff M M, Kostecki, et al. J. Electrochem. Soc.,2004, 151(8): A1279-A1285.
［14］Sun Y H, Liu X Q. Chinese Chem. Lett., 2006, 17(8): 1093-1096.
［15］Wang G X, Bewlay S, Needham S A, et al. J. Electrochem. Soc., 2006, 153(1): A25-A31.
［16］Zhong S K, Yin Z L, Wang Z X, et al. Trans. Nonferrous Met. Soc. China,200, 16(2):s708-s710.
