Lithiation Behavior of Coaxial Hollow Nanocables of Carbon-Silicon Composite.

Ma, Tianyi; Xu, Hanying; Yu, Xiangnan; Li, Huiyu; Zhang, Wenguang; Cheng, Xiaolu; Zhu, Wentao; Qiu, Xinping · ACS Nano · 2019

basic_science · Level V

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Abstract

A design of coaxial hollow nanocables of carbon nanotubes and silicon composite (CNTs@Silicon) was presented, and the lithiation/delithiation behavior was investigated. The FIB-SEM studies demonstrated hollow structured silicon tends to expand inward and shrink outward during lithiation/delithiation, which reveal the mechanism of inhibitive effect of the excessive growth of solid-electrolyte interface by hollow structured silicon. The as-prepared coaxial hollow nanocables demonstrate an impressive reversible specific capacity of 1150 mAh g<sup>-1</sup> over 500 cycles, giving an average Coulombic efficiency of >99.9%. The electrochemical impedance spectroscopy and differential scanning calorimetry confirmed the SEI film excessive growth is prevented.