SnO2/石墨纳米片复合电极及其在超级电容器中的应用

在电场的作用下对石墨棒进行电化学剥离, 使其表面形成相互平行排列, 且垂直于石墨棒基底的二维(2D)石墨纳米片阵列(GNSA). 然后通过阴极还原电沉积法制备SnO₂/石墨纳米片阵列(SnO₂/GNSA)复合电极.采用场发射扫描电镜(FE-SEM)、X射线衍射(XRD)和傅里叶变换红外(FT-IR)光谱对其形貌和结构进行了表征.电化学测试表明该复合电极具有优异的超电容性能, 在0.5 mol·L^-1 LiNO₃电解质中, 扫描速率为5 mV·s^-1, 电位窗口为1.4 V时, 比电容达4015 F·m^-2. 由SnO₂/GNSA复合电极和相同电解质组装成的对称型超级电容器, 在扫描速率为5 mV·s^-1时, 其电位窗口可增至1.8 V, 能量密度达到0.41 Wh·m^-2, 循环5000 圈后其比电容仍保持为初始比电容的81%.

SnO2/Graphite Nanosheet Composite Electrodes and Their Application in Supercapacitors

Electrochemical exfoliation of graphite rods under the action of an electric field force led to the formation of two-dimensional (2D) graphite nanosheet arrays (GNSAs) perpendicular to the surface of the graphite substrate and parallel to each other in arrangement. Subsequently, SnO₂/graphite nanosheet array (SnO₂/GNSA) composite electrodes were prepared by the cathodic reduction electrodeposition method. The morphology, composition, and microstructure of the samples were characterized using field emission scanning electron microscopy (FESEM), powder X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy, respectively. Electrochemical measurements showed that the composite electrodes achieved specific capacitance values as high as 4105 F·m^-2 in the potential window up to 1.4 V with a scan rate of 5 mV·s^-1 in 0.5 mol·L^-1 LiNO₃ solution. Asymmetric supercapacitor fabricated with the as-prepared SnO₂/GNSAs exhibited excellent capacitive performance with energy density of 0.41 Wh·m^-2 in the potential window up to 1.8 V and retention of 81% after 5000 cycles.