淬冷法制备LiNi_(0.5)Co_(0.5)O_2正极材料及其性能表征
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摘要
采用1 000℃煅烧并在液氮中淬冷的方法制备LiNi_(0.5)Co_(0.5)O_2正极材料,在2.50～4.50 V范围内,以0.1 C (28m A/g)放电,其初始比容量可达到255.0 m Ah/g,为理论值的93%,并且具有高放电容量循环性能;在大倍率条件下,仍有175.6 m Ah/g (5 C)和145.4 m Ah/g (10 C)的初始放电比容量。采用循环伏安(CV)、交流阻抗谱(EIS)、X射线衍射(XRD)等测试技术进行测试,结果表明高温淬冷处理方法有利于提高LiNi_(0.5)Co_(0.5)O_2正极材料的晶胞体积与晶体的层间距,降低材料接触与迁移电阻,改善其电化学性能。
LiNi_(0.5)Co_(0.5)O_2 cathode material was synthesized by calcinating at 1 000 ℃ and quenching in liquid nitrogen.The initial discharge specific capacity is 255.0 m Ah/g, which is 93% of the theoretical value. The cathode material has high capacity cycle performance at 0.1 C(28 m A/g) at the range of 2.50-4.50 V. The initial discharge specific capacities are respectively 175.6 and 145.4 m Ah/g at 5 C and 10 C. The testing results of cyclic voltammograms(CV) and AC impedance spectroscopy(EIS) and X-ray diffraction(XRD) show that with quenching method at high temperature, the cell volume and the layer distance between crystals increase, the contact and migration resistance of materials reduce, and the electrochemical performance is improved.
LiNi_(0.5)Co_(0.5)O_2 cathode material was synthesized by calcinating at 1 000 ℃ and quenching in liquid nitrogen.The initial discharge specific capacity is 255.0 m Ah/g, which is 93% of the theoretical value. The cathode material has high capacity cycle performance at 0.1 C(28 m A/g) at the range of 2.50-4.50 V. The initial discharge specific capacities are respectively 175.6 and 145.4 m Ah/g at 5 C and 10 C. The testing results of cyclic voltammograms(CV) and AC impedance spectroscopy(EIS) and X-ray diffraction(XRD) show that with quenching method at high temperature, the cell volume and the layer distance between crystals increase, the contact and migration resistance of materials reduce, and the electrochemical performance is improved.
引文
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[3]彭文杰,李新海,王云燕,等.LiNi0.5Co0.5O2的制备及其电化学性能[J].中南大学学报(自然科学版),2004,35(3):390-395.
[4]蔡振平,刘人敏,吴国良,等.锂离子电池正极材料LiNi0.5Co0.5O2的制备及性能[J].电池,2002,32:58-60.
[5] SUBRAMANIAN V, KISHOR K, RAMBABU B. Synthesis and electrochemical properties of submicron LiNi0.5Co0.5O2[J]. Solid State Ionics, 2004, 175(1/4):315-318.
[6]卢华权,吴锋苏,岳锋,等.草酸盐共沉淀法制备锂离子电池正极材料LiNi0.5Mn0.5O2及其电化学性能[J].物理化学学报,2010, 26(1):51-56.
[7] ZHONG Y D, ZHAO X B, CAO G S. Characterization of solid state synthesized pure and doped lithium nickel cobalt oxides[J]. Material Science and Engineering B, 2005, 121(1):248-254.
[8]林和成,杨勇.AlF3包覆Li Ni0.45Mn0.45Co0.10O2锂离子电池正极材料的结构表征和电化学性能研究[J].化学学报,2009,67(2):104-108.
[9] LIN H C, ZHENG J M, YANG Y. The effects of quenching treatment and AlF3coating on LiNi0.5Mn0.5O2cathode materials for lithium-ion battery[J]. Materials Chemistry and Physics, 2010, 119:519-523.
[10] NOBILI F, CROCE F, SCROSATI B, et al. Electronic and electrochemical properties of LixNi1-yCoyO2cathodes studied by impedance spectroscopy[J]. Chem Mater, 2001, 13:1642-1646.
[2]杨书廷,岳红云,尹艳红,等.微波-固相复合加热技术合成LiNi0.5Co0.5O2及其性能研究[J].高等学校化学学报,2006,27(11):2017-2021.
[3]彭文杰,李新海,王云燕,等.LiNi0.5Co0.5O2的制备及其电化学性能[J].中南大学学报(自然科学版),2004,35(3):390-395.
[4]蔡振平,刘人敏,吴国良,等.锂离子电池正极材料LiNi0.5Co0.5O2的制备及性能[J].电池,2002,32:58-60.
[5] SUBRAMANIAN V, KISHOR K, RAMBABU B. Synthesis and electrochemical properties of submicron LiNi0.5Co0.5O2[J]. Solid State Ionics, 2004, 175(1/4):315-318.
[6]卢华权,吴锋苏,岳锋,等.草酸盐共沉淀法制备锂离子电池正极材料LiNi0.5Mn0.5O2及其电化学性能[J].物理化学学报,2010, 26(1):51-56.
[7] ZHONG Y D, ZHAO X B, CAO G S. Characterization of solid state synthesized pure and doped lithium nickel cobalt oxides[J]. Material Science and Engineering B, 2005, 121(1):248-254.
[8]林和成,杨勇.AlF3包覆Li Ni0.45Mn0.45Co0.10O2锂离子电池正极材料的结构表征和电化学性能研究[J].化学学报,2009,67(2):104-108.
[9] LIN H C, ZHENG J M, YANG Y. The effects of quenching treatment and AlF3coating on LiNi0.5Mn0.5O2cathode materials for lithium-ion battery[J]. Materials Chemistry and Physics, 2010, 119:519-523.
[10] NOBILI F, CROCE F, SCROSATI B, et al. Electronic and electrochemical properties of LixNi1-yCoyO2cathodes studied by impedance spectroscopy[J]. Chem Mater, 2001, 13:1642-1646.