摘要
采用在加温的水溶液中电沉积然后烧结方法制备锂离子电池的纳米Co3O4PTFE复合负极材料。XRD分析表明,电沉积的物质在245℃真空热处理后转变为Co3O4PTFE。SEM观察可以发现,Co3O4PTFE中的Co3O4呈现蜂窝结构,其厚度为30～50nm;PTFE则形成交联的柱状体吸附在片状Co3O4两侧,其直径为50～100nm。这种纳米Co3O4PTFE复合沉积层具有结构稳定、抗粉化的特点。充放电实验结果表明,Co3O4掺杂PTFE可明显提高负极材料的可逆比容量和循环性能,其首次放锂比容量为920.1mAh·g-1,20次循环后放锂比容量为685.6mAh·g-1;而没有掺杂PTFE的试样对应的数据分别为865.1mAh·g-1和180.4mAh·g-1。
A Co3O4-PTFE composite negative electrode used for lithium-ion batteries was prepared by electrochemical-deposition in heated aqueous solution and then sintered at elevated temperature in vacuum. XRD analysis illustrates that the deposited layer Co(OH)2 transforms to Co3O4-PTFE after sintering in vacuum at 245°C. The SEM images show that the Co3O4 phase appears a morphology of honeycomb with thickness of 30-50 nm and the PTEF, which adsorbs on the surfaces of Co3O4, forms a cross-linked columnar structure with a diameter about 50-100 nm in Co3O4-PTFE electrode material. Such nano Co3O4-PTFE composite layer is stable and resistant to be powdered. The results of charge-discharge tests show that the cycle life and reversible specific capacity of the Co3O4 electrode doped with PTFE are improved obviously. The first discharging specific capacity of the Co3O4-PTFE electrode is 920.1 mAh · g-1, and its discharging specific capacity is 685.6 mAh · g-1 after 20 cycles. However, the first discharging specific capacity of the Co3O4 electrode is 865.1 mAh · g-1, and its charging specific capacity is 180.4 mAh · g-1 after 20 cycles without doped with PTFE.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2005年第5期14-17,共4页
Transactions of Materials and Heat Treatment
基金
国家"863"计划(2002AA323010)
关键词
锂离子电池
Co3O4-PTFE
电沉积
烧结
Capacitance
Charging (batteries)
Cobalt compounds
Composite materials
Doping (additives)
Electroplating
Nanostructured materials
Oxides
Polytetrafluoroethylenes
Scanning electron microscopy
Secondary batteries
Sintering
X ray diffraction analysis
