Al3 掺杂对LiNi0.5Mn1.5O4材料性能的影响

制备了不同Al~(3+)掺杂量(x)的Li_(1+x)Al_xNi_(0.5)Mn_(1.5–x)O_4(LNMO)材料,通过XRD、SEM等对LNMO材料的结构进行了表征,通过CV测试、交流阻抗谱测试等方法测定了材料的电化学性能,讨论了Al~(3+)的掺杂量对材料结构和性能的影响。结果表明,适当的Al~(3+)掺杂会提高材料的结构稳定性及循环、倍率性能。当x=0.06时改性效果最好,在0.5和2.0 C下循环100次的容量保持率分别达到95.2%和90.0%。而且氧化还原峰的电势差较小,循环可逆性能最好。在该基础上,通过聚合物辅助法制备的样品由于{111}晶面族取向性更强,进一步提升了循环性能,0.5和2.0 C下循环100次容量保持率分别达到97.1%和93.0%。

Effect of Al3 Doping on the Properties of LiNi0.5Mn1.5O4 Cathode Ma-terials

In this study, LNMO materials with different Al3+ doping amount were prepared. The structure of Li1+xAlxNi0.5Mn1.5-xO4 was characterized by XRD and SEM. The electrochemical properties of the materials were determined by CV test and AC impedance spectroscopy. Discussed the influence of the doping amount of Al3+ on various aspects of the material. Studies have shown that proper doping increases the structural stability of the material and improves the cycle and rate performance of the material. The modification effect was best when the doping amount was x=0.06, and the retention rates of circulating 100 times at 0.5C and 2C reached 95.2% and 90%, respectively. Moreover, the potential difference of the redox peak is small, and the cycle reversibility is the best. The samples prepared by the polymer-assisted method further improved the cycle performance due to the stronger orientation of the {111} crystal face group, and the 100-time retention rate at 0.5C and 2C reached 97.1% and 93%, respectively.