烧结温度对Li_(1.1)Mn_(1.85)Al_(0.05)O_4正极材料结构和电化学性能的影响  

Influence of Sintering Temperatures on Structure and Electrochemical Performance of Li_(1.1)Mn_(1.85)Al_(0.05)O_4 Anode Materials

作　　者：罗飞[1] 张林[1] 黄瑞安[2] 郭玉忠[1] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]昆明理工大学真空冶金国家工程实验室,云南昆明650093

出　　处：《昆明理工大学学报（自然科学版）》2015年第2期27-31,共5页Journal of Kunming University of Science and Technology(Natural Science)

基　　金：国家自然科学基金项目(51464025)

摘　　要：通过共沉淀法制备了正极材料 Li1．1 Mn1．85 Al0．05 O4的前驱体 M3 O4，并探究600～900℃区间烧结温度对细粒度材料样品电化学性能的影响规律．通过 XRD 物相分析、SEM图像分析，激光粒度测试、电化学滴定测定 Mn 价态分布、dQ ／dV －V 微分容量分析以及恒电流充电循环测试，研究了 Li1．1 Mn1．85 Al0．05 O4材料的综合电化学性能等．实验结果表明：经过细化的样品在高温烧结时，存在不同程度的氧缺陷，并随温度升高而增大．细粒样品超过750℃烧结，氧缺位在晶格显著出现并伴随着 Mn3＋富化、Mn4＋贫化现象，并导致晶格膨胀，结构稳定性下降，循环性能劣化．Mn尖晶石系材料制备时应防止粒度过细，并在750℃以下烧结处理．A M3O4 -type precursor of Li1 .1 Mn1 .85 Al0.05 O4 cathode material is prepared by co -precipitation to in-vestigate the impact tendencies of sintering at temperatures from 600℃ to 900℃ on the electrochemical properties of fine particulate.XRD,SEM,particle size distribution test by laser approach,electrochemical titration technique for Mn oxidation states,dQ/dV -V frofiles and galvanostatic charge -discharge tests are carried out for insight into the comprehensive electrochemical performance of the prepared materials.The experimental results show that a diverse degree of oxygen deficiencies appears in the samples sintered at higher temperatures,and they enrich with the elevated temperatures.As fine particulate samples are sintered at temperature above 750℃,oxygen deficien-cies occur significantly in lattice,accompanied with Mn3 ＋ enrichment,Mn4 ＋ depletion,a slight lattice expansion, decrease of the structural stability,and deterioration of the cycleability.An adequate preparation processing for spinel -type LiMn2 O4 as cathode materials should avoid excessive break -down on milling and be sintered below 750 ℃.

关 键 词：LI1 .1 MN1 .85 Al0.05 O4 共沉淀法 电化学性能 氧缺位 

分 类 号：TM912.9[电气工程—电力电子与电力传动]