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采用碳酸盐共沉淀法合成出前驱体,然后通过高温固相法制备了富锂锰基材料0.6Li[Li1/3Mn2/3]O2·0.4Li NixMnyCo1-x-yO2(x<0.6,y>0).使用扫描电镜(SEM)、X射线衍射(XRD)以及电化学方法等手段进行了表征.高温原位XRD测试结果表明,随着温度和Ni含量增加,材料的晶胞参数发生较大变化,温度达800 o C时,高Ni组成的材料阳离子混排现象严重,并伴有尖晶石相生成.电性能测试结果表明,在充放电电压为2.0~4.6 V、电流密度20m A·g-1条件下,低Ni含量材料表现出较好的电化学性能,首周放电容量达260.1 m Ah·g-1,首次效率为83.2%,经过50次循环后放电容量保持率高达99.7%,且在电池循环过程中,放电电压平台下降较少.
The precursors were synthesized by carbonate coprecipitation method, then the Li-rich manganese-based material 0.6Li [Li1 / 3Mn2 / 3] O2 · 0.4Li NixMnyCo1-x- 0), characterized by SEM, XRD and electrochemical methods.The in situ XRD results showed that as the temperature and Ni content increased, the unit cell parameters of the material were larger The results show that when the temperature is up to 800 o C, the positive ion mixing of materials with high Ni content is serious and the spinel phase is formed. The results of electrical property test show that when the charge-discharge voltage is 2.0-4.6 V and the current density is 20 mA · g-1, the material with low Ni content showed good electrochemical performance with a discharge capacity of 260.1 mAh · g-1 in the first week and a first-time efficiency of 83.2%. After 50 cycles, the discharge capacity retention rate was as high as 99.7% , And in the battery cycle process, the discharge voltage platform decreased less.