摘要
采用简易的草酸盐共沉淀方法,结合后续混锂焙烧制备了锂离子电池0.5Li2MnO3·0.5LiCo0.5Mn0.5O2富锂锰基正极材料。利用X射线衍射、场发射扫描电镜、透射电镜、X射线光电子能谱仪、激光粒度分析仪和振实密度仪等测试表征了所制备材料的物相、形貌、元素价态和粒度分布。利用充放电测试仪对材料的电化学性能进行了测试。结果表明:在低搅拌转速条件下共沉淀法制备的样品呈规则球状形貌,球体是由许多棒状一次粒子聚集而成;在高搅拌转速条件下,所制备出的样品呈现较为分散的棒状形貌。低搅拌转速下所制备的球状颗粒样品展现出了更高的振实密度(1.7 g/cm3)和更优异的电化学性能:0.2 C倍率条件下首次放电比容量为233.8 mA·h/g,2 C/0.2 C放电比容量比值为62.2%,0.5 C循环100次容量保持率为90.8%,倍率性能和循环稳定性能优异。
Li-rich manganese-based 0.5Li2MnO3·0.5LiCo0.5Mn0.5O2 cathode materials for lithium ion battery were prepared by a co-precipitation method and subsequnet lithium mixing and calcination.The phase composition,morphology and structure,valance state,particle size distribution and tap density of the prepared samples were characterized by X-ray diffraction,field emission scanning electron microscopy,transmission electron microscopy,X-ray photoelectron spectroscopy,laser particle size analysis and tap density measurement.The electrochemical performance of the samples was analyzed by means of charge and discharge tester.The results show that the sample prepared by co-precipitation at a low stirring speeds has a solid spherical morphology,which is assembly of massiverod-like primary particles.The sample prepared at high stirring speeds has a morphology of dispersed microrods.The as-prepared solid sphere sample exhibits a greater tap density of 1.7 g/cm3 and better electrochemical performances(i.e.,discharge capacity of 233.8 m A·h/g at 0.2 C rate,2 C/0.2 C specific discharge capacity ratio of 62.2%and capacity retention up to90.8%at 0.5 C rate after 100 cycles),compared to the dispersed microrod sample.
作者
李文明
邱茂琴
杨则恒
张卫新
LI Wenming;QIU Maoqin;YANG Zeheng;ZHANG Weixin(School of Chemistry and Chemical Engineering,Hefei University of Technology,Hefei 230009,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2020年第2期174-181,共8页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金项目(91834301,91534102,21271058)
安徽省科技攻关项目(1501021013).
关键词
共沉淀法
钴锰酸锂
富锂锰基
正极材料
锂电子电池
co-precipitation
lithium cobalt manganese oxide
lithium-rich manganese-based
cathode material
lithium ion battery
作者简介
第一作者:李文明(1986—),男,博士研究生;通信作者:杨则恒(1961—),男,博士,教授。
