SnO_(2)/石墨分级纳米异质结构的合成及其电化学性能研究

Synthesis and Electrochemical Performance of SnO_(2)/Graphite Hierarchical Nano-Heterostructure

以石墨为基底,五水合四氯化锡为锡源,氢氧化钠为沉淀剂,采用一步水热法合成了SnO_(2)/石墨分级纳米异质结构。利用FESEM、XRD、EDS、Raman等对SnO_(2)/石墨分级纳米异质结构进行了形貌、结构和成分表征。研究发现,结晶良好的SnO_(2)纳米线首先组装成SnO_(2)纳米棒,纳米棒进一步组装成直径约450 nm的花状结构,并均匀生长在石墨片上,呈现分级结构。用循环伏安法、恒流充放电循环法测试了分级纳米异质结构的电化学性能,结果表明:在50 mA/g的充放电电流密度下首次放电比容量和充电比容量分别为1567.2 mAh/g、825.9 mAh/g,同时多次循环的循环伏安曲线几乎一致,表明SnO_(2)/石墨分级纳米异质结构具有较高的储电容量和改善的循环稳定性。

SnO_(2)/graphite hierarchical nano-heterostructure was synthesized by a one-step hydrothermal method using graphite as the substrate,tin tetrachloride pentahydrate as the tin source,and sodium hydroxide as the precipitant.The morphology,structure and composition of the SnO_(2)/graphite hierarchical nano-heterostructure were characterized by FESEM,XRD,EDS and Raman.It is found that tin dioxide nanowires with good crystallinity are firstly assembled into tin dioxide nanorods,then the tin dioxide nanorods are further assembled into flower-like structures with a diameter of 450 nm and grow uniformly on the graphite sheet,showing a hierarchical structure.The electrochemical performance of those hierarchical nano-heterostructure was tested by cyclic voltammetry and constant current charge-discharge cycle method.The results show that the initial discharge capacity and charge capacity are 1567.2 mAh/g and 825.9 mAh/g respectively at a charge-discharge current density of 50 mA/g.The cyclic voltammetry curves of different cycles are almost the same,indicating that the SnO_(2)/graphite hierarchical nano-heterostructure has high storage capacity and improved cycle stability.