Electrochemical dilatometry study on Si-embedded carbon nanotube powder electrodes

Abstract

Si-embedded carbon nanotube (Si-CNT) 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-CNT 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-CNT 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. © 2007 The Electrochemical Society.