Mg、F共掺杂锂锰尖晶石的合成与性能研究  

Synthesis and property of F-Mg co-doped spinel as cathode material for Li-ion battery

作　　者：周华 张海朗 

机构地区：[1]江南大学化学与材料工程学院,无锡214122

出　　处：《化工新型材料》2008年第3期65-67,共3页New Chemical Materials

摘　　要：采用"熔融浸渍法"合成了Mg和F共掺杂的不同温度下的锂离子电池正极材料LiMn1.9Mg0.1O4-yFy(y=0.03、0.05、0.1);煅烧温度为700、750和800℃。通过XRD对样品进行测试,样品为单一尖晶石结构的物相;并用SEM对样品进行了形貌研究。当y=0.05时样品表面光滑,粒度分布范围小。用所制备的材料作为正极材料组装了模拟锂离子电池;在室温下进行恒电流充-放电性能测试,随着材料制备温度的升高,电池的初始放电容量逐渐增加,但充放电循环的容量损失也逐渐增加;而在800下℃,y=0.05时,其初始放电容量高达117 mAh/g;60次充-放电循环后,容量保持其初始容量的83%,该材料具有高的放电容量和优良的循环性能。F-Mg co-doped spinel LiMn1.9Mg0.1O4-yFy（y=0. 03,0. 05,0.1）as cathode materials for lithium-ion batteries were synthesized by a ＂melting-impregnation＂ method. The calcinating temperatures were 700, 750,and 800℃, respectively. Their morphologies and microstructure were examined by powder XRD analysis and SEM. The XRD spectra showed that the samples had pure spinel structure phase. The sample with y=0.05 had a smoother surface and a narrow particle size distribution. Their electrochemical properties were studied by constant current charge-discharge testing. The initial discharge capacity of LiMn1. 9 Mg0.1O3.97 F0. 03 increased with rising calcinating temperatures. Their capacity loss also increased gradually. Results indicated that ： LiMn1.9 Mg0.1O3.95 F0.05 being synthesized at 800 ℃ delivers an discharge capacity of 117 mAh/g for the first cycle and still retained 83% of the initial capacity after 60 cycles at room temperature. It exhibited an excellent cycling stability and a high capacity.

关 键 词：锂锰尖晶石 正极材料 锂离子电池 熔融浸渍法 共掺杂 

分 类 号：O611.3[理学—无机化学]