中文摘要：

利用激光拉曼光谱对LiFePO4／c锂离子正极材料碳外壳的石墨化程度进行了研究，对不同碳源合成的样品进行激光拉曼光谱比较，并结合x射线衍射、扫描电镜、透射电镜、选区电子衍射、电阻率测试等多种检测手段，对材料的性质结构和形貌进行了研究。结果发现，相比对应sp3杂化峰和sP2杂化峰的峰面积比，对应非等向性sp2杂化峰和对应规则sp2杂化峰的ID／IG分布更加均匀，其显示的石墨化程度与材料导电性在一定程度上有相似规律，但同一材料的拉曼光谱信号因受碳包覆均匀性的影响出现较大差别，且相对于单独用柠檬酸或蔗糖做碳源的样品，利用两者混合物做碳源的样品的ID／IG值和sp3杂化峰和sp2。杂化峰的峰面积比值均较高。在扫描电镜和透射电镜图中，可以观察到二次和一次颗粒包覆不均匀的现象，这有可能是导致同个样品中不同点数据不均匀的原因。但是较大的离散性还是影响了拉曼光谱在此类检测中的客观准确性。

英文摘要：

In the present paper, Laser Raman spectral was used to study the carbon structure of LiFePO4/C positive material. The samples were also been characterized by X-ray diffraction（XRD）, scanning electron microscope（SEM）, selected area elec- tron diffraction（SEAD） and resistivity test. The result indicated that compared with the spz/sp3 peak area ratios the ID/IG ratiosare not only more evenly but also exhibited some similar rules. However, the studies indicated that there exist differences of ID/ IG ratios and sp2/sp3 peak area ratios among different points in the same sample. And compared with the samples using citric acid or sucrose as carbon source, the sample which was synthetized with mixed carbon source（mixed by citric acid and sucrose） exhibited higher ID/IG ratios and sp2/sp3 peak area ratios. Also, by contrast, the differences of ID/IG ratios and sp2/sp3 peak area ratios among different points in the same sample are less than the single carbon source samples＇ datas. In the scanning elec- tron microscopy （sere） and transmission electron microscopy （sere） images, we can observed the uneven distributions of carbon coating of the primary particles and the secondary particles, this may be the main reason for not being uniform of difference data in the same sample. The obvious discreteness will affect the normal use of Raman spectroscopy in these tests.