摘要
以LiOH.H2O和MnAc2.4H2O为原料直接沉淀得到沉淀物后,通过焙烧合成了尖晶石结构LiMn2O4.利用XRD研究了沉淀方式、焙烧温度对沉淀物及其在焙烧过程中结构的影响,并研究了所合成LiMn2O4样品在盐酸溶液中Li的脱嵌性能及Li脱嵌后样品在CuSO4溶液中吸附与插嵌行为.研究表明,正加法有利于前驱体向LiMn2O4的转化,前驱体在800℃以上焙烧才能制备晶形完整,结晶度高的尖晶石结构LiMn2O4;800℃焙烧所合成的尖晶结构LiMn2O4在0.5 mol/L盐酸溶液浸洗20 min即达到平衡,氢离子取代大部分Li离子进入到尖晶石LiMn2O4的晶格中,95%的锂离子被洗出,形成富锰型尖晶石结构HxLi1-xMn2O4,导致LiMn2O4的晶胞发生收缩,晶胞参数和体积减小,但没有改变原有的LiMn2O4尖晶石结构.浸铜后保持了原有的LiMn2O4尖晶石结构,只是晶胞参数比HxLi1-xMn2O4又略有增加,晶粒变大.
LiOH·H2O and MnAc2·4H2O are used as starting materials for preparing spinel structure LiMn2O4 by way of co-precipitation.The effect of precipitation strategy and calcination temperature on the structure of the precursor and transition us stydued by means of XRD.The lithium insertion/extraction reaction first with hydrogen ion then with copper ion is also studied.Results show that normal precipitation strategy is amenable to LiMn2O4 formation from the precursor.Calcination of precursor at 800 ℃ and over may assure the production of spinel LiMn2O4 with fine crystalline integration and high crystallinity.The as-synthesized samples leached by 0.5M hydrochloric acid solution acquire equilibrium in 20 minutes.Hydrogen ions substitute Li＋ and get inserted into the crystal lattices of LiMn2O4,95% of lithium ions are leached,and HxLi1-xMn2O4 is formed.The lattice parameter and volume of LiMn2O4 are decreased,while the original spinel structure of LiMn2O4 remains unchanged.After Cu2＋ substitution takes place when HxLi1-xMn2O4 is immersed in cupric solution,the spinel structure of LiMn2O4 still remains unchanged,only the lattice parameter gets slightly increased than that of HxLi1-xMn2O4 and the size of crystal grain grows larger.
出处
《内蒙古工业大学学报（自然科学版）》
2010年第1期30-35,共6页
Journal of Inner Mongolia University of Technology：Natural Science Edition
基金
教育部"春晖计划"
内蒙古自治区优秀学科带头人计划(20041001)
内蒙古人才基金
内蒙古高等学校科学研究(NJ06065)
内蒙古工业大学重点项目(ZD200612)资助
关键词
LIMN2O4
共沉淀
Li嵌/脱
铜锰复合氧化物
LiMn2O4
co-precipitation
lithium insertion/extraction
copper manganese mixed oxide
