多孔微纳结构富锂正极材料0.6Li2MnO3·0.4LiNi0.5Mn0.5O2的制备及其电化学性能 |
Preparation and Electrochemical Performance of Porous Micro-Nano Structure Layered Li-Rich 0.6Li2MnO3·0.4LiNi0.5Mn0.5O2 Cathode for Lithium-Ion Batteries |
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摘要: 采用碳酸盐共沉淀与燃烧法相结合的方法制备得到了多孔微纳球形结构的富锂正极材料0.6Li2MnO3·0.4LiNi0.5Mn0.5O2。借助X射线衍射(XRD)分析、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)、N2吸附-脱附和恒电流充放电测试研究了其晶体结构、微观形貌和电化学性能。结果表明该方法制备出的材料是由一次颗粒径约300 nm的小颗粒组成的多孔微纳球形结构,比表面积为13 m2·g-1,具有完善的α-NaFeO2层状结构(空间群为R3m)。电化学性能测试结果证实该材料具有优异的高容量、高循环稳定性和高倍率性能。在2.0~4.8 V,电流密度为0.1C、0.2C、0.5C、1C、3C、5C和10C时的放电比容量分别为:266、254、235、205、186、149和107 mAh·g-1;在0.5C下循环100次后,放电比容量仍为217 mAh·g-1(容量保持率为94%)。 |
关键词: 微纳结构 碳酸盐共沉淀法 富锂正极材料 电化学性能 锂离子电池 |
基金项目: 国家自然科学基金(No.21506133)和四川省科技支撑计划(No.2014GZ0077)资助项目。 |
Abstract: A Li-rich 0.6Li2MnO3·0.4LiNi0.5Mn0.5O2 cathode material with porous micro-nano spherical structure is prepared using a combination of carbonate co-precipitation and combustion method. Powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorpation-desorpation and galvanostatic charge-discharge tests are employed to analyze the crystal structure, micro morphology and electrochemical properties of the as-prepared material. Results indicate that this cathode has a porous micro-nano spherical structure, which is composed of primary particles with a small size about 300 nm. Moreover, this cathode has a well-ordered layered α-NaFeO2 structure (space group R3m) and a high BET specific surface area of 13 m2·g-1. Electrochemical measurements confirm that this cathode has excellent high capacity, good cycling stability and outstanding rate performance. At 2.0~4.8 V, the discharge capacities of the material at 0.1C, 0.2C, 0.5C, 1C, 3C, 5C and 10C are 266, 254, 235, 205, 186, 149 and 107 mAh·g-1, respectively. After 100 cycles at 0.5C, the cathode also exhibits a discharge capacity of 217 mAh·g-1 with capacity retention of 94%. |
Keywords: micro-nano structure carbonate co-precipitation Li-rich cathodes electrochemical performance Lithium-ion batteries |
投稿时间:2016-11-11 修订日期:2016-12-25 |
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郑卓,吴振国,向伟,杨秀山.多孔微纳结构富锂正极材料0.6Li2MnO3·0.4LiNi0.5Mn0.5O2的制备及其电化学性能[J].无机化学学报,2017,33(3):479-486. |
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