摘要
对合成制备的LiNixCo1-xO2 正极材料及其稀土金属Ce元素添加改性的正极材料进行了X射线衍射(XRD)和扩展X射线吸收精细结构 (EXAFS)表征。结果表明 ,随着焙烧温度的升高 ,物相组成趋于单一 ,晶格趋向完整 ,80 0℃时完全形成LiNiO2 、LiCoO2 晶相结构。LiNixCo1-xO2 样品中Ni/Co摩尔比不影响LiNiO2 晶相的形成 ,而只影响其晶相组成 ;掺杂的稀土金属Ce元素以CeO2 状态存在于产物中 ,CeO2 对LiNiO2 晶相形成有一定的影响 ;LiCoO2 的焙烧温度不能大于 90 0℃ ,否则Co被氧化为Co3 O4;样品中Ni与Co原子的局域结构 ,除Ni与Co原子相互影响外 。
Ce element modified LiNi x Co 1- x O 2 cathode materials were prepared by precipitation from nickel acetate, cobalt acetate, lithium acetate, cerous chloride and NH 3·HO 2. The resulted materials were characterized by X ray diffraction and Ni K edge and Co K edge Extended X ray Absorption Fine Structure(EXAFS) spectra. The results show that the crystallite phases of the synthesized cathode materials tend gradually to simplicity and integrity with increasing the calcining temperature, pure LiNiO 2 and LiCoO 2 phase are formed at calcining temperature 800?℃ in air, and Co element in the LiCoO 2 phase is however oxidized and forms Co 3O 4 phase at temperature over 900?℃. The additional Ce element in the sample exits only CeO 2, and more effected on the Ni atom and Co atom local structure is indicated by EXAFS spectra.
出处
《北京化工大学学报（自然科学版）》
CAS
CSCD
2002年第2期63-66,共4页
Journal of Beijing University of Chemical Technology(Natural Science Edition)
基金
教育部科学技术研究重点项目 (0 0 0 16 )
