以聚吡咯(PVP K60)为表面活性剂和碳源,采用流变相法合成了x Li Fe PO4·y Li3V2(PO4)3/C正极材料样品。利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)对样品形貌和结构进行了测试;采用电池测试仪和电化学工作站对样品电化学性能进行了测试,分析了不同复合比(x:y)对其结构和电化学性能的影响。研究表明:复合材料中存在两相复合与元素掺杂两种效应;当复合比为5∶1时材料的电化学性能最优,在0.1和10 C倍率下放电容量分别达到162.7和104.6 m Ah·g-1,且具有良好的循环稳定性。 相似文献
Fluorinated amorphous hydrogenated a-C:F:H carbon thin films were deposited using radio frequency plasma enhanced chemical vapor deposition(RF-PECVD) reactor with CF4 and CH4 as source gases and were annealed in a N2 atmosphere. The properties of these films were evaluated by FTIR spectrometry, UV-VIS spectrophotometry and single-wavelength spectroscopic ellipsometry. A correspondence relativity connection between the deposition rate and technology was found. The chemical bonding structures and the content of CHx and CFx in the films are transformed and the optical band gap decreases monotonically with increasing temperature after annealing.The dielectric constant is increased with decreasing content of F in the films and the optical band gap is decreased with decreasing the content of H in the film. 相似文献
Nitrogen-doped fluorinated diamond-like carbon (FN-DLC) films were prepared on single crystal silicon substrate by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) under different deposited conditions with CF4, CH4 and nitrogen as source gases. The influence of nitrogen content on the structure and electrical properties of the films was studied. The films were investigated in terms of surface morphology, microstructure, chemical composition and electrical properties. Atomic force microscopy (AFM) results revealed that the surface morphology of the films became smooth due to doping nitrogen. Fourier transform infrared absorption spectrometry (FTIR) results showed that amouts of C=N and CN bonds increased gradually with increasing nitrogen partial pressure r (r=p(N2)/p(N2+CF4+CH4)). Gaussian fit results of C 1s and N 1s in X-ray photoelectron spectra (XPS) showed that the incorporation of nitrogen presented mainly in the forms of β-C3N4 and a-CNx (x=1, 2, 3) in the films. The current?voltage (I?V) measurement results showed that the electrical conductivity of the films increased with increasing nitrogen content. 相似文献