新型三维网状锡-钴合金负极材料的结构与性能  

Structure and Properties of Three-dimensional Reticular Sn-Co Alloy Electrodes as Anode Material for Lithium Batteries

作　　者：黄令[1] 江宏宏[1] 柯福生[1] 樊小勇[1] 庄全超[1] 杨防祖[1] 孙世刚[1] 

机构地区：[1]厦门大学化学化工学院化学系,福建厦门361005

出　　处：《物理化学学报》2006年第12期1537-1541,共5页Acta Physico-Chimica Sinica

基　　金：国家重点基础研究和发展规划(973项目;2002CB211804)资助项目

摘　　要：应用电沉积技术制备了三维网状结构的Sn-Co合金负极材料,采用XRD、SEM和电化学方法考察了该负极材料的结构和性能.XRD分析表明,该三维网状结构的Sn-Co合金镀层为六方固溶体结构.其电化学性能测试表明:三维网状结构Sn-Co合金微晶电极的性能稳定,其首次放电容量高达493.4mAh·g-1,首次库仑效率达80.03%,而平面结构Sn-Co合金电极的首次库仑效率为63.47%.经50周充放电循环后,三维网状结构Sn-Co合金电极的放电容量为329.6mAh·g-1,放电容量保持率为66.8%;SEM分析表明:三维网状Sn-Co合金电极表面是由大小不一、高低不同的“岛”紧密排列在一起;“岛”和多孔结构的存在,缓冲了锂嵌入时体积的膨胀,部分抑制了材料结构的变化,减缓了电极容量的衰减,改善了电极的循环性能.The three-dimensional reticular Sn-Co alloy deposits were prepared by electroplating. The structure and electrochemical performance of the electroplated three-dimensional reticular Sn-Co alloys have been investigated in detail. Experimental results show that the Sn-Co alloy film is of hexagonal solid solution, with Sn as the solvent, Co as the solute. Electrochemical tests show that the three-dimensional reticular Sn-Co alloy coating electrodes can deliver a discharge capacity of 493.4 mAh·g^-1 in the first cycle. At the 50th cycle the charge was 329.6 mAh·g^-1. The three- dimensional reticular structure in Sn-Co alloy electrode was beneficial in reducing the irreversible capacity of Sn-Co alloy electrode at initial charge-discharge, and in relaxing the volume expansion during cycling, which improved the cyclability of Sn-Co alloy electrode. They are also beneficial to diffusion of Li into/out of rnacroporous materials, and improve coulomb efficiency in charge-discharge cycle.

关 键 词：电沉积 三维网状Sn-Co合金 锂离子电池 电化学性能 

分 类 号：TM912[电气工程—电力电子与电力传动]