以三维纳米多孔铜膜为集流体锡电极的制备及储锂性能

摘要

通过一种新颖的脱合金方法制备厚度为5μm、平均孔径为200~300 nm的三维纳米多孔铜膜，制备过程涉及铜基体上镀锌层的热处理与酸浸过程。以三维纳米多孔铜膜为基体，采用阴极电沉积法制备纳米多孔结构的锡膜电极。应用扫描电子显微镜(SEM)、X 线衍射分析(XRD)和恒流充放电方法对所制备的膜电极的结构与电化学性能进行表征。所制备的多孔锡电极在0.1 C率下的首次充放电中的可逆储锂容量为864 mA×h/g，该容量已接近锡的理论容量(993 mA∙h/g)；在50次充放电循环后，可逆容量仍有541 mA×h/g。纳米多孔结构、纳米尺度的锡颗粒及高电子导电性的三维纳米多孔铜膜基体等因素是多孔锡电极显示较好储锂性能的主要原因。%A three­dimensional (3D) nanoporous copper film with thickness of 5 μm and average pore diameter of 200-300 nm was fabricated by novel dealloying method. The fabrication process involves the heat treatment of the electrodeposited zinc layer on copper substrate and the subsequent acidic leaching of the annealed film. A porous nanostructured tin film electrode was further prepared by the cathodic electrodeposition of tin film on the obtained 3D nanoporous copper film, and its structure and electrochemical properties were investigated by scanning electron microscopy (SEM), X­ray diffractometry (XRD) and galvanostatic charge­discharge tests. The as­prepared porous tin electrode presents an initial reversible lithium storage capacity of 864 mA×h/g at 0.1C, closing to the theoretical capacity of Sn (993 mA×h/g). And it still delivers a reversible capacity of 541 mA×h/g after 50 cycles. The nanoporous structure, nanosized tin particles and 3D porous copper substrate with high electronic conductivity can be responsible for the enhanced lithium storage performance of the porous tin electrode.