作　　者： ; ; ; ;

机构地区： 四川大学材料科学与工程学院

出　　处： 《功能材料》 2013年第19期2825-2827,共3页

摘　　要： 采用分段高温氧化固相法合成了掺杂La3+、F-的锂离子电池正极材料LiLa x Mn2-x F x O4-x(x=0、0.01、0.02和0.05)。结果发现,在小于等于1C时,掺杂与否对其放电容量影响不大;在2~10C时,掺杂可明显改善倍率性能;在15C时,掺杂量也显示出重要影响,未掺杂的LiMn2O4的高倍率放电能力仅为4%,而掺杂x=0.02的达到56%。XRD物相、CV循环伏安和EIS电化学阻抗分析支撑了倍率性能的实验结果,当不出现第二相时,随掺杂量增加,电荷转移电阻、阳极和阴极反应极化逐渐减小,反应可逆性逐渐增大,但当x=0.05出现第二相时,电荷转移电阻、阳极和阴极反应极化又开始增大。 Co-doping with La and F lithium manganese oxide LiLax Mn2-x Fx O4-x （X = 0,0. 01,0. 02,0. 05） mate- rials were synthesized by segmented solid-state sintering method. The results showed that co-doping had unob- vious effect on the discharge capacity at the current density below or equal to 1C. However, the rate perform- ance from 2 to 10C was significantly improved. Besides, doping amount had great influence on the discharge property at 15C. Especially, when the doping amount was 0.02, the discharge capacity was increased from only 4% to 56%. The results were supported by means of X-ray diffraction （XRD）,cyclic voltammetry （CV） and electrochemical impedance spectroscopy （EIS）. When there was no second phase, the charge transfer resist- ance, the anodic and cathodic polarization decreased and the electrochemical reversibility enhanced gradually with the increase of doping amount. However, when the second phase appeared at x =0.05, the charge transfer resistance, anodic and cathodic polarization began to increase.

关 键 词： 锂离子电池 锰酸锂 离子掺杂 高倍率性能

领　　域： [电气工程]