电沉积制备的两种形貌Sn薄膜锂离子嵌入电极性能的比较

用电沉积方法在Cu集流体上分别制备出用于锂离子电池负极材料的密集细粒状(＜0.5 μm)和分散粗粒状(≈3 μm)两种Sn薄膜电极.用X射线衍射、扫描电镜、循环伏安及充、放电实验研究比较了两电极的组织与性能.结果表明,在氟硼酸盐溶液中使用以醛类为主的复合添加剂,在静止条件下可制得细粒Sn薄膜电极,在搅拌条件下可制得粗粒Sn薄膜电极;细粒Sn薄膜电极比粗粒Sn薄膜电极具有较优的初始嵌锂容量和循环稳定性:细粒Sn薄膜电极首次放电比容量达到787 mA·h/g,40次循环时放电比容量仍保持在630 mA·h/g;而粗粒Sn薄膜电极首次放电比容量只有576 mA·h/g,至20次循环放电比容量降至150 mA·h/g.

A comparative study on the performances of thin film and granular tin as Li ion insertion electrodes prepared by electrodeposition

Thin film and granular tin electrodes as negative materials for lithium-ion batteries were prepared by electrodeposition onto copper foil collector. Their performances were studied with X-ray diffraction(XRD), scanning electron microscopy (SEM), cyclic voltammetry and charging-discharge experiments. The granular tin electrode and the film tin electrode can be prepared in fluoborate solution containing additives under stirred and unstirred condition, respectively. The thin film tin electrode shows its better discharge capacity and cyclic stability than the granular tin electrode: the discharge capacity of the film tin electrode is 787mAh/g for the first cycle and keeps 630 mAh/g after 40 cycles; but that of the granular tin electrode is only 576 mAh/g for the first cycle and keeps only 150mAh/g after 20 cycles.