采用"原位反应-低温裂解"方法,以聚丙烯腈、SnCl2.2 H2O和KBH4为反应物,所得前驱体在300~600℃下煅烧获得纳米锡/热解聚丙烯腈复合材料。通过X射线衍射(XRD)、扫描电镜(TEM)及电化学测试表明:所得产物为热解聚丙烯腈包覆纳米锡颗粒的复合材料,其中锡以纳米球形颗粒(5~30 nm)的形式存在。当PAN与Sn的质量比为1∶5,煅烧温度为500℃时,材料首次充电循环比容量达950.7 mAh/g,30次循环后比容量达449 mAh/g,平均循环比容量衰减率小于1.7%。
Spherical nano Sn encapsulated pyrolytic polyacrylonitrile composite was prepared as anode material for Li-ion batteries.The preparation started with the dissolution of SnCl2.2 H2O and polyacrylonitrile(PAN) in dimethylformamide(DMF) solution,followed by the reduction of Sn using KBH4.The composite was obtained by the pyrolysis of the Sn/PAN mixture at 300-600 ℃.TEM analysis shows that 5-30 nm spherical Sn particles are embedded by the pyrolytic PAN.When the weight ratio of PAN/Sn is 1/5 and the calcination temperature is 500 ℃,the as-prepared composite presents an initial discharge specific capacity of 950.7 mAh/g and it retains 449 mAh/g after 30 charge/discharge cycles.The average capacity fading rate is less than 1.7%/cycle.