以 LiAc ?2 H 2 O、Mn (Ac)2?4H 2 O、Ni (Ac)2?4H 2 O 为原料,采用水溶液法合成锂离子电池正极材料 LiNi0．5 Mn0．5 O 2和 Li1．2 Ni0．3 Mn0．5 O 2.通过 X射线衍射(XRD)、扫描电子显微镜(SEM)对所得样品的结构和形貌进行表征,并测试了该材料的电化学性能.结果表明,样品 LiNi0．5 Mn0．5 O 2首次放电比容量能达到125．6 mAh/g,经过30周循环以后,放电比容量为111．2 mAh/g,容量保持率为96．2％；而富锂样品Li1．2 Ni0．3 Mn0．5 O 2首次放电比容量能达到187．2 mAh/g,经过30周循环以后放电比容量为184．5 mAh/g,容量保持率为98．6％,远高于富锂前样品.另外,富锂后的样品 Li1．2 Ni0．3 Mn0．5 O 2倍率性能优于富锂前.
Li-rich layered cathode material,LiNi0.5 Mn0.5 O 2 and Li1 .2 Ni0.3 Mn0.5 O 2 were synthesized via a solution method.The structure and morphology of the prepared materials were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM).Galvanostatic charge/discharge studies demonstrated the electrochemical performance of two materials.It was found that the material LiNi0.5 Mn0.5 O 2 delivers initial discharge capacity of 125.6 mAh/g and retains a reversible capacity of 1 1 1.2 mAh/g after 30 cycles with a capacity retention of 96.2%.While the sample Li1 .2 Ni0.3 Mn0.5 O 2 exhibited not only a higher discharge capacity of 187.2 mAh/g,but also excellent cycling performance with a capacity retention of over 98.6% after 30 cycles.In addition,the Li-rich Li1 .2 Ni0.3 Mn0.5 O 2 shows better rate capability.
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