锂离子电池正极材料LiV_(3-x)Mn_xO_8的水热合成与性能(英文)  

Hydrothermal Syntheses and Properties of LiV_(3-x)Mn_xO_8 as Cathode Materials for Lithium Ion Batteries

作　　者：冯季军[1,2] 刘祥哲[1] 刘晓贞[1] 姜建壮[2] 赵静[1,2] 

机构地区：[1]济南大学化学化工学院,济南250022 [2]山东大学化学化工学院,济南250100

出　　处：《物理化学学报》2009年第8期1490-1494,共5页Acta Physico-Chimica Sinica

基　　金：supported by the National Natural Science Foundation of China(20573047);Natural Science Foundation of Shandong Province,China(Y2008B64);Foundation for Excellent Young Scientists of Shandong Province,China(2006BS09001)~~

摘　　要：采用水热法制备了Mn掺杂改性的锂二次电池钒基层状正极材料LiV3-xMnxO8(x=0.00,0.01,0.02,0.04,0.06,0.08,0.10).用X射线衍射(XRD)和扫描电镜(SEM)对材料的晶体结构和形貌进行表征,并以50mA·g-1的电流对材料进行恒流充放电测试.研究了Mn掺杂对材料晶体结构和电化学性能的影响.结果表明,Mn掺杂能够明显改善材料的电化学性能.在掺杂改性的LiV3-xMnxO8材料中,LiV2.94Mn0.06O8的初始容量最高,达到295mAh·g-1.当掺杂量控制在0.01≤x≤0.08范围内时,LiV3-xMnxO8材料均具有较好的循环性能和充放电可逆性,经20次循环后放电比容量都保持在120mAh·g-1以上,40次循环后都保持在100mAh·g-1以上,且材料的充放电效率始终维持在93%以上.The Mn modified lithiated vanadium oxides LiV3-xMnxO8 （x=0.00, 0.01, 0.02, 0.04, 0.06, 0.08, 0.10） as promising cathode materials for secondary lithium batteries were prepared using a hydrothermal method. Crystalline phases were characterized by powder X-ray diffraction （XRD） and the morphology was observed by scanning electron microscopy （SEM）. The electrochemical properties of the synthesized samples were investigated by galvanostatic charge and discharge at a current density of 50 mA·g^-1. The effects of manganese doping on crystal stability were analyzed in terms of the material structure and electrochemical performance. The electrochemical properties were greatly improved after manganese doping. Among the doping modified materials, LiV2.94Mn0.06O8 showed the highest initial specific discharge capacity which was 295 mAh ·g^-1. Good cycle performance was achieved when 0.01≤x≤0.08. All the LiV3-xMnxO8 （0.01≤x≤0.08） materials maintained the specific discharge capacities of more than 120 mAh·g^-1 after 20 cycles and 100 mAh·g^-1 after 40 cycles thereby preserving the high charge-discharge efficiencies of no less than 93%.

关 键 词：锂离子电池 正极材料 水热合成 钒酸锂 锰掺杂 

分 类 号：TM912[电气工程—电力电子与电力传动]