材料期刊网

用流变相的方法合成了非整比锂锰尖晶石(Li1.1Mn2.1O4+y).用XRD、XPS、ICP技术对其结构和组成进行了确定;用透射电镜方法观测晶体颗粒的大小和形状.并对其电化学性质进行了研究,结果表明:该化合物作为正极材料,与整比尖晶石化合物相比,具有优良的可充电性能,初始放电容量为126mAh/g(充、放电电流密度为1mA/cm2,电压范围为4.4～3.0V),当锂片为负极时,电池进行充放电循环60次,容量衰减很少,经100次循环后,容量为117mAh/g,仅衰减7%.这一独特的性质使该化合物成为有潜力的正极材料.这一新颖的合成方法为无机材料合成提供了有效可行的途径.

A nonstoichiometric spinel phase (Li1.1Mn2.1O4+y) was synthesized using reheological phase reaction method. It was characterized by XRD and XPS techniques. The particle size and shape of the expected compounds were observed by transmission electron microscopy technique. The composition of new spinel phase was checked by ICP. The electrochemical properties of the spinel phase (Li1.1Mn2.1O4+y) were also investigated. The results showed that the Li1.1Mn2.1O4+y behaved excellent recharge ability to compare with stoichiometric LiMn2O4. The initial discharge capacity of the battery was 126mAh/g when current density was 1mA/cm2 over voltage range of 4.4 to 3.0V. It dropped slowly during 60 cycles. After 100 cycles, the discharge capacity was retained at 117mAh/g (about 93% of initial discharge capacity) when the metallic lithium was the anode. The outstanding electrochemical properties of Li1.1Mn2.1O4+y make it possible to be used as a promising cathode material. The novel synthesis method provides a simple and effective route for inorganic material synthesis.