锂离子电池正极材料LiMn2O4的低热固相合成与性能表征

锂离子电池具有比能量高、环境污染小等优点,广泛应用于手提电话、便携式电脑、摄像机等设备中。其正极材料的研究是锂离子电池的研究重点。层状结构的LiCoO2、LiNiO2和尖晶石结构的LiMn2O4是仅有的三种能在3.5V以上电位可嵌入Li的正极材料1~3]。目前市售的锂离子电池主要采用LiCoO2作正极材料,但由于Co资源缺乏和价格相对昂贵,而锰资源丰富,价格低廉且无毒,对环境友好,因此世界各国都在大力进行以LiMn2O4为正极材料的锂离子电池的实用化研究。LiMn2O4传统的制备方法是高温固相反应合成法4~7],但由于Mn的变价多,与Li形成贫Li或…

Preparation and Characterization of Positive Electrode Material LiMn2O4 for Lithium Ion Battery by Low Heating Solid State Coordination Method

Cathode material LiMn₂O₄ for lithium ion battery was successfully prepared by low heating solid state coordination method. Mixed precursors were tested by TG-DTA to confirm the temperature of thermal decomposition. The products from thermal decomposition, LiMn₂O₄ powders were characterized by XRD, TEM. The results showed that the samples were composed of nanorods assembled by small nanoparticles. The as-prepared LiMn₂O₄ was of high purity in a good crystal form with a spinel structure type. The powders had uniform chemical composition. The charge-discharge property of LiMn₂O₄ was also tested. The first charge and discharge capacities for LiMn₂O₄ were 125.4 mAh·g^-1 and 115.3mAh·g^-1, respectively. The efficiency of charge-discharge could be up to 91.95%. In conclusion, LiMn₂O₄ with better electrochemical property could be obtained by low heating solid state coordination method.