无定形Li-Mn-Al-Co-O前驱体制备改性尖晶石锰酸锂

Synthesis Modified Spinel Li Mn_2O_4 Via Amorphous Li-Mn-Al-Co-O Precursor

采用水热法合成了无定形Li-Mn-Al-Co-O前驱体,经过后续热处理制备了Al-Co复合掺杂LiMn_2O_4正极材料Li_(1.035)Co_(0.02)Al_(0.025)Mn_(1.92)0O_4,并对其物理及电化学性能进行了测试。SEM、XRD结果表明:Al-Co的掺入对尖晶石锰酸锂的形貌和晶体结构会有微弱影响。电化学测试结果表明:Al-Co掺杂后,材料的循环性能和倍率性能都获得了显著的改善,其在0.5 C下的首次放电容量为113.9 m A.h/g,经过100次循环后比容量保持率仍然有92.4%,8 C下容量依然高达85.5 m A·h/g。

Li1.035Co0.02A10.025Mn1.920O4 cathode materials was prepared from the amorphous Li-Mn-A1-Co-O precursor which was obtained by a hydrodrothermal process by heat treatment. The physical and electrochemical properties were characterized. The results from the X-ray diffraction （XRD） and the scanning electron microscope （SEM） analysis show that the incorporation of A1 and Co has a slight influence on the morphology and the crystal structure of the spinel lithium manganese. Electrochemical test results indicate that the cycling ability and the rate capability of the material at room temperature are significantly improved after doped with Al and Co. It delivers a reversible specific capacity of 113.9 mAh·g-1 in 1st cycle and retains 92.4% of its initial capacity after 100 cycles at 0.5C rate, and the capacity is still as high as 85.5mAh·g-1 at 8 C.