掺杂Th对LiMn2O4结构和性能的影响

采用溶胶凝胶法合成了具有尖晶石结构的可用作锂离子蓄电池正极材料的LiMn2O4化合物,并对其进行了掺杂Th元素的修饰.对材料进行了X射线衍射、扫描电镜、红外光谱、交流阻抗、充放电等测试.实验结果表明掺入Th元素所合成的材料具有标准的尖晶石结构,规则的结晶形貌,材料颗粒分布主要在1～2 μm之间;在不同的充放电速率下,所合成的Th掺杂改性材料具有较高的放电比容量,并表现出良好的电化学可逆性及较好的大电流放电性能.在0.2 C及1 C放电速率下,首次放电比容量分别是119.9 mAh/g和118.3 mAh/g,循环20次后,容量保持率分别在98%和97%以上.

Influence of doping Th on the performance and structure of spinel LiMn2O4 for lithium-ion batteries

The cathode material spinel LiMn2O4 for lithium-ion batteries was synthesized by sol-gel route and modified by doping Th.LiMn2O4 cathode materials and the modified materials were tested by X-ray diffraction,SEM,IR spectra,impendance spectra and charge-discharge performance.The results show that the synthesized material doping with Th exhibits standard spinel structure,regular particle morphology,high reversibility of electrochemistry and excellent charge-discharge properties at high current.The capacity retention of materials modified by doping Th is 119.9 mAh/g at 0.2 C,more than 98% of the first discharge specific capacity after 20 cycles,and 118.3 mAh/g at 1 C,more than 97% of the first discharge specific capacity after the same cycles.