氮掺杂碗状空心碳微球的制备及其 在超级电容器中的应用

针对碳电极材料存在比电容小、能量密度低的问题,采用异质成核合成路径制备了新型的碗状空心碳微球,进一步以尿素为氮源,通过水热法制备了高性能氮掺杂碗状空心碳微球。采用X射线衍射仪、场发射扫描电子显微镜、能谱仪、傅立叶红外光谱仪和X射线光电子能谱分析仪对碗状空心碳微球和氮掺杂碗状空心碳微球的形貌及结构进行表征,并分析了氮掺杂对碗状空心碳微球的电化学性能。实验结果表明:氮掺杂对碗状空心碳微球的电化学性能有显著的改善,在1 A/g的电流密度下,氮掺杂碗状空心碳微球的比电容(235.5 F/g)远高于碗状空心碳微球的比电容(121.0 F/g),此外,氮掺杂碗状空心碳微球在3 A/g的电流密度下循环5 000次后,其比电容保持率为78.3%。

Preparation of Nitrogen-Doped Bowl-Like Hollow Carbon Microspheres and Application in Supercapacitors

Aimed at the issues of lower specific capacitance and lower energy density in carbon electrode materials, the novel bowl-like hollow carbon microspheres (BHCSs) were synthesized through heterogeneous nucleation route, and further utilized to prepare the high-performance nitrogen-doped bowl-like hollow carbon microspheres (N-BHCSs) by hydrothermal method using urea as nitrogen source. The morphology and structure of the BHCSs and N-BHCSs were characterized by XRD, FTIR XPS, FESEM and EDS. The effects of nitrogen doping on the electrochemical properties of the BHCSs were analyzed. The results showed that the electrochemical performances of the BHCSs were significantly improved by nitrogen doping. The N-BHCSs showed a much higher specific capacitance (235.5 F/g at a current density of 1 A/g) than that of the BHCSs (121.0 F/g at 1 A/g). In addition, the N- BHCSs exhibited good cycling stability with 78.3% of its initial capacitance retention after 5 000 cycles at a current density of 3 A/g.