【摘要】 全新钴酸锂具有良好的层状晶体结构。对经历不同充放电循环次数后的钴酸锂进行X射线衍射(XRD)测试,发现其衍射特征峰发生了明显的偏移,且衍射峰偏移程度随电池的循环次数增加而增加。由此提出钴酸锂晶体结构值的评价方法:将钴酸锂的4个特征峰(003峰、101峰、006峰和104峰)衍射角度偏差值和晶面间距偏差值相乘后取绝对值,然后将绝对值进行累加得到值,此值即可用于评估钴酸锂晶体结构失效程度。研究表明:由废旧正极材料中回收并再修复的钴酸锂,当值低于0.01时,可视同全新钴酸锂用于电池制造。用X射线光电子光谱法(XPS)分析经历不同充放电循环次数后的钴酸锂,其晶体结构由于衍射角度偏差无法精确测定,这可能是循环后钴酸锂表面存在有机物沉积所致。更多还原

【Abstract】 LiCoO₂ as a kind of cathode material of new lithium-ion batteries, has a good crystalline state in the crystal structure. However, because of oxidation-reduction reaction in charge-discharge process, the diffraction angle of characteristic peak of the spent LiCoO₂ shows the obvious deviation. With the analysis of the X-ray diffraction method（XRD） of different materials, we found that the deviation of the diffraction peak increased with the increase of the battery usage. Based on this principle, a method for evaluating the crystal structure of LiCoO₂ is proposed, which is value method. The results show that the value method can characterize the degree of battery life and recovery of LiCoO₂. When the value of the failed LiCoO₂ is less than 0.01 by the recovery treatment, the positive electrode material can be reused commercially. At the same time, under the analysis of X-ray photoelectron spectroscopy（XPS）, it is found that the main reason for the diffraction peak shift is the organic oxide film attached to the surface of Li CoO₂, which makes the crystal structure of Li CoO₂ unable to be accurately determined.更多还原