To examine the phase transition upon deintercalation of Li from graphite at elevated temperatures, structural changes in C₆Li_x (x = 0.284, 0.532, 0.666, 0.739, 0.812) samples during heating were evaluated by in situ X-ray diffraction (XRD) analysis. The diffraction patterns of the sample, in which the stage-1 and the stage-2 structures coexist, drastically converted to the profile of a Li-defect stage-1 structure at temperatures above 200 °C without Li intercalation and/or deintercalation. Meanwhile, the reflection peak corresponding to the stage-1 structure in the XRD patterns of C₆Li_0.812 continuously shifted to higher angles at temperature above 330 °C, which implied deintercalation of Li through reaction with the binder and the formation of the Li-defect stage-1 structure. Li deintercalated from C₆Li_x while maintaining the same stage structure, likely via a solid-state reaction at temperatures above 330 °C. The lattice misfit calculated from the difference in interlayer spacing between stage-1 and stage-2 in C₆Li_0.666 drastically decreased from 4.58% at 50 °C to 1.43% at 350 °C. These kinetics for Li graphite intercalation compounds at elevated temperatures are formulated for the first time and should be helpful in understanding the Li intercalation/deintercalation mechanism of the graphite electrodes used in Li-ion batteries.

为了检查在高温下锂从石墨中脱嵌锂后的相变， 通过原位X射线衍射（XRD）评估了加热期间C ₆ Li _x（x = 0.284，0.532，0.666，0.739，0.812）样品的结构变化分析。阶段1和阶段2共存的样品衍射图样在200℃以上的温度下急剧转变为锂缺陷1阶段结构的轮廓，而没有嵌入和/或脱嵌锂。同时，在C ₆ Li _0.812的XRD图谱中，对应于第一阶段结构的反射峰在高于330°C的温度下连续移至更高的角度，这意味着通过与粘合剂反应和形成Li缺陷1级结构来实现Li的脱嵌。Li从C ₆ Li _x脱嵌，同时保持相同的阶段结构，这可能是通过在330°C以上的温度下进行的固相反应实现的。根据C ₆ Li _0.666中第1阶段和第2阶段的层间间距差异计算出的晶格失配从50°C的4.58％急剧下降到350°C的1.43％。首次制定了高温下锂石墨嵌入化合物的动力学，有助于理解锂离子电池中石墨电极的锂嵌入/脱嵌机理。