非晶态中空ZnSnO_3立方体的制备及其电化学性能

Synthesis and Electrochemical Performance of Amorphous ZnSnO_3 Hollow Cubes

采用碱蚀刻-热解法制备了无定形中空ZnSnO_3立方体,并利用X射线衍射、扫描电子显微镜、透射电子显微镜、热重分析、N_2吸附-脱附曲线、循环伏安和恒流充放电技术对样品的结构、形貌及电化学性能进行表征。结果表明:所制备的ZnSnO_3呈边长约为1μm的无定型中空立方体。作为锂电池负极材料,在100 m A/g电流密度下,首次放电容量高达1 591 m A·h/g,50次循环后放电容量保持在305 m A·h/g。无定形中空ZnSnO_3立方体良好的电化学性能可归因于无定形态及有效缓冲了锂离子嵌入-脱嵌过程引起的体积变化的中空结构。

The amorphous ZnSnO3 hollow cubes were synthesized via a facile alkali etching and a subsequent pyrolysis method. The structure, morphology and electrochemical properties of samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermal gravimetric analysis, N2 adsorption-desorption curves, cyclic voltametry and galvanostatic charge-discharge measurements, respectively. The results indicate the ZnSnO3 as-synthesized exists in amorphous state, and shows the hollow cube structure with the average edge size of approximately 1 pan. As an anode material for lithium-ion batteries, ZnSnO3 hollow cubes exhibit a large specific capacity of 1 591 mA·h/g in initial discharge, and retains 305 mA·h/g after 50 cycles at 100 mA/g current. The excellent electrochemical performances are attributed to the amorphous state and hollow structure that accommodate the large volume change during the Li^＋ insertion-extraction process.