摘要
MoO_2@N-doped C nanofibers（MoO_2@NC NFs）were synthesized by electrospinning with polyacrylonitrile as carbon source.The in situ formed MoO_2nanocrystals are completely embedded in the carbon nanofibers,which can not only accelerate ion transition,but also act as a buffer to avoid the mechanical degradation of active material due to the volume changes during charge/discharge cycling.When used as the anode material for both Li/Na-ion batteries,the as-synthesized MoO_2@NC NFs displayed excellent Li~＋/Na~＋storage properties.As the anode for Li-ion battery,the MoO_2@NC NFs display a high discharge capacity of 930 mA h g^（-1）at a current density of 200 mA g^（-1）for 100 cycles,and 720 mA h g^（-1）at a current density of 1 A g^（-1）for 600 cycles.Moreover,the discharge capacity of 350 mA h g^（-1）could be realized at a current density of 100 mA g^（-1）for 200 cycles for Na-ion battery.
以聚丙烯腈(PAN)作为碳源,利用静电纺丝方法成功合成了二氧化钼/氮掺杂碳纳米纤维(MoO_2@NC NF).制备MoO_2@NC NF过程中,原位形成的MoO_2纳米晶体被完全嵌入碳纳米纤维,不仅能加速电子转移,而且还作为缓冲层,避免在充/放电循环过程中由于体积变化引起活性材料在碳纳米纤维中机械降解.当MoO_2@NC NF材料用作锂/钠离子电池的负极材料时,展示出极好的储锂/钠性能.作为锂离子负极材料,MoO_2@NC NF在电流密度为200 mA g^(-1)的条件下,经过100次循环后容量为930 mA h g^(-1);当电流密度为1 A g^(-1),其600次循环后容量为720 mA g^(-1).MoO_2@NC NF用作钠离子负极材料,在电流密度为100 mA g^(-1)的条件下,经过200次循环过程后,其容量稳定在350 mA h g^(-1)左右.
基金
supported by the National Natural Science Foundation of China (51302079)
