多壁碳纳米管对SiO电极电化学性能的影响

Effects of MWNTs on Electrochemical Performance of SiO Electrode

以多壁碳纳米管(MWNTs)作负极材料导电剂制备了SiO/MWNTs复合电极.采用恒流充放电测试对比考察了不同含量及类型的导电剂对SiO电极电化学性能的影响.乙炔黑(AB)的SiO电极首次可逆比容量仅为582.3mAh·g^(-1),而20%MWNTs的电极比容量高达1463.9mAh·g^(-1),且SiO的循环性能得到显著改善.SEM、EIS测试结果表明:多次循环后SiO/MWNTs电极仍能较好地保持活性颗粒的导电网络,而脆性乙炔黑所形成的桥连作用遭到破坏,导致活性颗粒间的接触电阻增大.

SiO/MWNTs anode was prepared by mixing SiO particles with Multi-Walled carbon nanotubes as conductive agent. The galvanostatic charge-discharge cycling was used to investigate the effects of the type and contents of conducting agents on the electrochemical performances of SiO electrode. The results indicate that the electrochemical performance of SiO is improved obviously by adding MWNTs. The SiO/（20%）MWNTs composite anode shows an initial specific reversible capacity of 1463.9mAh·g^-1, much higher than 582.3mAh·g^-1 for SiO/（20%）AB. The results of SEM and EIS confirm that the excellent cycle performance is attribute to the perfect flexibility and good electric conductivity of MWNTs network, while SiO/AB has larger interparticle contact resistance, which is resulted from the crumbling and conduction network breakage.