原位技术在锂离子电池中的应用

The application of in-situ technique in lithium-ion batteries

利用原位拉曼、原位XRD以及SEM技术相互佐证,对电芯材料在充放电过程中的氧化/还原反应产物、晶体变化、表面形貌等进行分析,是对电芯充放电过程机理研究的一次探索。利用激光共聚焦拉曼光谱仪对镍锰酸锂电池充放电过程进行光谱分析,拉曼光谱采集与电池充放电循环同步进行。同时利用X射线衍射仪进行检测,在充放电循环过程中,每隔一段时间对其进行XRD检测,并且忽略采集过程中电池反应的变化。通过对镍锰酸锂电池在充放电过程中的拉曼光谱和XRD研究,在线监测充放电过程的可逆现象,并通过拉曼光谱解析说明材料的价态变化,通过原位XRD表征晶体结构变化,同时利用SEM观察循环前后的极片,分析极片循环后表面的差异性沉积物,验证了拉曼光谱强度降低的原因。通过这次研究,掌握了原位拉曼/XRD技术、镍锰酸锂电池的特征峰位及归属等,并且对实验中遇到的强度变化现象进行了分析,对出现该情况的原因做了简单剖析,并提供了理论依据。通过此次关于原位技术在锂离子电池方面的应用研究,可以为电池化成、循环等过程中出现的问题提供解决思路,指导研发人员对电池的机理研究和质量分析进行更深入的探索。

Using the in-situ Raman,in-situ XRD,and SEM technology,the oxidation/reduction reaction products,crystal changes and surface morphology of the core materials in the charging and discharging process were analyzed,which is the exploration of the mechanism research in the charging and discharging process of the cell.The charging and discharging process of lithium nickel-manganate were analyzed by the laser confocal Raman spectrometer.The Raman spectrum was collected synchronously with the battery charging and discharging cycle.Each period during the charge-discharge cycle of the battery was detect by X-ray diffractometer,the changes in battery reaction during the collection process were ignored.Through the Raman spectrum and XRD research of the charging and discharging process about lithium nickel-manganate material,the reversible phenomenon of the charging and discharging process was monitored online,and the valence state changes of the material were illustrated by Raman spectrum analysis.The crystal structure changes were characterized by in-situ XRD and the pole piece before and after the battery cycle were observed by SEM in order to research the different sediments on the surface of the electrode plates after the cycle and verify the reason for the decrease of Raman intensity.According to the research,we mastered the in-situ Raman/XRD technology and the characteristic peak position of lithium nickel-manganate materials,and conducted relevant experiments about the phenomenon of strength changes encountered in the experiment.At the same time,we made simple analysis about the reasons for this situation,providing a theoretical basis for the analysis.The research on the application of in-situ technology in lithium-ion batteries can provide solutions to problems in the process of battery formation and cycling,and guide research personnel to further research on the mechanism and quality analysis of batteries.