中文摘要：

草酸酸硷的一起沉淀方法被采用与命令高度的结构准备 LiNi2/3Mn1/3O2 样品。Li+ ， Ni2+ 和 Mn2+ 醋酸盐被用作开始材料。在 Li+ 内容， Li+-Ni2+ 离子的混乱，和电气化学的性能上的开始的材料的锂来源的数量的影响被调查了。样品在完成式订了的开始的材料展览与 20% 过量 Li 来源准备了的 Rietveld 精炼表演组织。一个特定的分泌物能力象在在 4.35 鈥 ?.7 V 的电压范围的 C/20 的 172 mAh/g 一样高。然而， cyclability 不是令人满意的：大约 25.3% 在能力褪色在 50 个周期上被观察。化学上稳定的 SiO2 在 LiNi2/3Mn1/3O2 粒子的表面上是涂的。在 cyclability 的重要改进与 3 wt% SiO2 涂层被达到，它是到从被溶解进电解质的 LiNi2/3Mn1/3O2 粒子的保护的 ascribable。

英文摘要：

Oxalic-acid-based co-precipitation method was employed to prepare LiNi2/3Mn1/3O2 sample with a high-ordered structure. Li＋, Ni2＋ and Mn2＋ acetates were used as starting materials. The influence of the amount of lithium source in the starting materials on Li~ content, disorder of Li~-Ni2＋ ions, and electrochemical performance has been investigated. Rietveld refinement shows that the sample prepared with 20% excess Li-source in the starting materials exhibits a perfect ordered structure. A specific discharge capacity is as high as 172 mAh/g at C/20 in the voltage range of 4.35-2.7 V. However, the cyclability is not satisfactory： about 25.3% fade in capacity was observed over 50 cycles. Chemically stable SiO2 was coated on the surface of LiNi2/aMn1/3O2 particles A significant improvement in cyclability was attained with 3 wt% SiO2 coating, which is ascribable to the protection of LiNi2＋3Mn1/3O2 particles from being dissolved into the electrolyte.