锂电池阴极材料尖晶石型LiMn2－xLaxO4的研究

采用高温固相法,合成了掺杂改性的锂离子电池阴极材料尖晶石结构的LiMn2－xLaxO4（x=0、0.01、0.02、0.03、0.04、0.05、0.10）.用XRD对材料的晶体结构进行了表征.从材料的晶体结构、充放电测试和循环性能等方面分析了掺杂元素镧在稳定晶体结构中的作用.实验表明，掺杂后的材料在常温和高温下的循环性能均得到了明显改善.而且当掺杂量x≤0.04时，材料有较高的放电比容量.

Studies on Spinel LiMn2-xLaxO4 Cathode Material for Lithium-ion Batteries

The lanthanum doped modified spinel lithium manganate LiMn2－xLaxO4 (x=0,0.01, 0.02, 0.03, 0.04, 0.05, 0.10) used for cathode of lithium-ion batteries was prepared by solid-state method. The structure of the prepared cathode material was characterized by XRD. The effects of doping lanthanum on stabilizing the crystal structure were analyzed in terms of the material structure, charge and discharge testing results and cycle performance. The cycle performance of the modified material was obviously improved at both normal temperature and high temperature. Moreover, when the x in LiMn2－xLaxO4 was less than 0.04,high capacity can be observed. For instance, LiMn1.99La0.01O4 and LiMn1.98La0.02O4 have as high capacity as 122.4 mAh•g－1 and 116.7 mAh•g－1(see Fig.5(a)) respectively compared with the 120.8 mAh•g－1 of LiMn2O4. In addition, these two cathode materials can hold 95.60％ and 97.46％ of the initial capacity respectively after 50 cycles.