Preparation and Characterization of LiNi0.5Co0.5O2 and LiNi0.5Co0.4Al0.1O2 by Molten Salt Synthesis for Li Ion Batteries
Preparation and Characterization of LiNi0.5Co0.5O2 and LiNi0.5Co0.4Al0.1O2 by Molten Salt Synthesis for Li Ion Batteries
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DOI：
10.1021/jp0676890
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发表时间：
2007-07
影响因子：
3.7
通讯作者：
M. Reddy;G. V. Subba Rao;B. Chowdari
中科院分区：
文献类型：
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作者：
M. Reddy;G. V. Subba Rao;B. Chowdari
用共晶混合物LiNO3−LiCl熔盐在750℃和850℃空气中制备了层状化合物LiNi0.5Co0.5O2和LiNi0.5Co0.4Al0.1O2。通过x射线衍射、Rietveld细化、SEM、EDAX、化学分析、表面积和密度技术对其进行了表征。采用循环伏安法、充放电循环和阻抗谱研究了锂金属作为对电极的电池在环境温度下的阴极行为，电流速率为30 mAg-1，截止电压为2.5 V，循环次数为120次。上截止电压范围为4.2 ~ 4.5 V。LiNi0.5Co0.5O2的第10次循环可逆容量随上截止电压变化在131 ~ 186（±3）mAhg-1之间，但在50或80次循环结束时，容量衰减范围为5% ~ 18%。al掺杂化合物的20次循环可逆容量为146（±3）mAhg-1 （4.3 V截止），可稳定到120次循环。还观察到良好的速率能力。因此,LiNi0.5Co0.4……
The layer compounds LiNi0.5Co0.5O2 and LiNi0.5Co0.4Al0.1O2 were prepared by using the molten salt of the eutectic mixture LiNO3−LiCl at temperatures of 750 and 850 °C in air. They were characterized by X-ray diffraction, Rietveld refinement, SEM, EDAX, chemical analysis, surface area, and density techniques. Cathodic behavior was examined at ambient temperature by cyclic voltammetry, charge−discharge cycling, and impedance spectra in cells with Li−metal as the counter electrode at a current rate of 30 mAg-1 with a lower cutoff voltage of 2.5 V up to 120 cycles. The upper cutoff voltages ranged from 4.2 to 4.5 V. The 10th cycle reversible capacities for LiNi0.5Co0.5O2 varied from 131 to 186(±3) mAhg-1 depending on the upper cutoff voltage, but capacity fading occurred ranging from 5 to 18% at the end of 50 or 80 cycles. The Al-doped compound showed a 20th cycle reversible capacity of 146 (±3) mAhg-1 (4.3 V cutoff) which was stable up to 120 cycles. Good rate capability was also observed. Thus, LiNi0.5Co0.4...