复合掺杂改性的尖晶石LiMn_(1.98)Cr_(0.02)O_(4-y)Cl_y的研究  

Studies on the Co-doping Modified Spinel LiMn_(1.98)Cr_(0.02)O_(4-y)Cl_y

作　　者：冯季军[1] 徐荣琪[1] 唐致远[2] 艾洪奇[1] 

机构地区：[1]济南大学化学与化工学院,济南250022 [2]天津大学化工学院,天津300072

出　　处：《高等学校化学学报》2007年第8期1532-1536,共5页Chemical Journal of Chinese Universities

基　　金：济南大学博士基金(批准号:BS0509);山东省中青年科学家奖励基金(批准号:2006BS09001);国家自然科学基金(批准号:20573047)资助

摘　　要：采用改进的高温固相法合成了阴阳离子复合掺杂改性的锂离子电池尖晶石结构正极材料LiMn1.98Cr0.02O4-yC ly(y=0,0.01,0.02,0.03,0.04,0.05,0.10).采用X射线衍射手段对材料的晶体结构进行了表征.从材料的晶体结构、充放电容量、循环性能和倍率放电特性等方面分析了复合掺杂在稳定晶体结构和改善材料电化学性能方面的作用.实验结果表明,由于复合掺杂的综合作用,改性后的材料既保持了高的初始容量,又具有优良的循环性能,倍率放电性能也得到了有效的改善.其中LiMn1.98Cr0.02O3.96Cl0.04的综合性能最优,初始放电比容量达到127 mA.h/g以上,循环50次后仍有110 mA.h/g的放电比容量.The co-doping modified spinel LiMn（1.98）Cr（0.02）O（4-y）Cly（y =0, 0.01, 0.02, 0.03, 0.04, 0.05, 0. 10） as the cathode for lithium ion battery were synthesized with high-temperature solid-state reaction methed. X-ray diffraction were used to characterize the crystal structure of the produced materials. The effects of co-doping modification in stabilizing the crystal frame and improving the electrochemical properties were comparatively investigated in terms of crystal structure, charge and discharge capacity, cycle performance and rate performance. The investigation comes to the conclusions that the co-doping modified cathode materials held the high enough initial capacity and represented an excellent cycle performance as well. In addition, the rate performance was also improved obviously. Among the co-doped materials, the most outstanding general performance belongs to LiMn（1.98）Cr（0.02）O（3.96）Cl（0.04） which showed an initial specific discharge capacity of more than 127 mA·h/g and kept 110 mA· h/g after 50 cycles.

关 键 词：正极材料 尖晶石 复合掺杂 循环性能 

分 类 号：O646[理学—物理化学]