Electrochemical Dilatometry Study on Si-Embedded Carbon Nanotube Powder Electrodes

Abstract

Si-embedded carbon nanotube (Si–C/NT) powders were prepared by dispersing carbon nanotubes (CNTs) and Si in the tetrahydrofuran solution containing poly(vinyl chloride) (PVC) as a dispersion agent, and then carbonizing the PVC. A better cycle performance was observed with the Si–C/NT containing larger void volume. The origin of this feature was addressed by an electrochemical dilatometry study, where it was found that the electrode swelling becomes less significant when the Si–C/NT possesses a larger void space. It is believed that the void space plays a buffering role against the volume expansion of Si, alleviating the breakdown of electrode integrity.