【摘要】 研究了用Li2CO3和Co3O4固相合成锂离子电池正极材料钴酸锂(LiCoO2)过程中,LiCoO2的晶体结构随合成温度的变化。利用X射线衍射、扫描和透射电子显微技术等各种分析测试方法,对750～900℃范围内合成的LiCoO2的形貌、晶体结构以及电化学性能进行了表征。实验证实,随着合成温度的增加,合成的LiCoO2颗粒的形貌没有明显变化,但颗粒尺寸会增加;电子衍射结果表明,合成温度为800℃时可以合成Li、Co原子各自分层的六方晶体结构的LiCoO2,随着合成温度的升高LiCoO2中Li、Co原子层之间可能发生部分混合,合成温度为900℃时LiCoO2为立方岩盐型晶体结构;800℃合成的LiCoO2的充放电循环性能较好。更多还原

【Abstract】 The effect of synthesis temperature was investigated on crystal structure of LiCoO2 cathode materials synthesized from Li2CO3 and Co3O4 via solid state reaction. Morphology, crystal structure and electrochemical properties of LiCoO2 synthesized in 750~900 ℃ were characterized by using X-ray diffraction,scanning electron microscopy , transmission electron microscopy and other methods. Although an obvious change in morphology of LiCoO2 particle was not observed, the size of LiCoO2 particle increased with synthesis temperature. The result from electron diffraction shows that LiCoO2 synthesized at 800 ℃ has a hexagonal structure with Li and Co atoms laminally arranged. Li and Co atoms would be partially mixed when synthesis temperature increased. The crystal structure of LiCoO2 synthesized at 900 ℃ is of cubic rock salt type. LiCoO2 synthesized at 800 ℃ has better charge and discharge reversibility than that synthesized at 900 ℃.更多还原