嵌锂正极材料锂镍锰氧化物的合成及其性能研究

Synthesis of the Wedge Lithium Positive Material Lithium Nickel Manganese Oxides and Research of Their Properties

运用溶胶—凝胶法合成了系列正极材料LiNi1- yMnyO2 +δ(0≤y≤ 0 5)。采用X射线衍射研究了其晶体结构特征。X射线衍射表明 ,该材料为典型的层状α—NaFeO2 结构。这些材料作为锂离子电池的正极时 ,其电化学性能是烧结温度和锰含量的函数。在烧结温度为 70 0℃时 ,具有最好的循环稳定性 ,在这一温度下 ,材料的结晶性最好。随着锰含量的增加 ,比容量增加 ,到Ni∶Mn =9∶1时 ,初始放电容量达到 1 60mAh/g。循环 80次后 ,容量还能达到 1 2 0mAh/g。LiNi0 9Mn0 1O2有望可做为锂离子电池的正极材料。

Lithium nickel manganese oxides, LiNi 1-y Mn yO 2+δ (0≤y≤0 5) were prepared via sol-gel technique. By X-ray diffraction method, we researched the structure of LiNi 1-y Mn yO 2+δ , with a partially disordered layered-typed-NaFeO 2 structure. The electrochemical performance of these materials as positive electrodes in lithium-ion batteries was evaluated as function of the calcination temperature and manganese content. A calcination temperature of 700℃ leads to the best cycling stability. At this temperature, a sufficiently high degree of crystallinity was achieved. With increasing manganese content, the first discharge specific charge increased to about 160 mAh/g for material with a Ni∶Mn ratio of about 9∶1. After cycling 80 times, special charge is about 120 mAh/g. It is expect for LiNi 0.9 Mn 0.1 O 2 to be used to the positive electrodes in lithium-ion batteries.