High‐Rate Capability Silicon Decorated Vertically Aligned Carbon Nanotubes for Li‐Ion Batteries

Abstract

International audienceThe concept of a hybrid nanostructured collector made of thin vertically aligned carbon nanotubes (CNTs) decorated with Si nanoparticles provides high power density anodes in lithium-ion batteries. An impressive rate capability is achieved due to the efficient electronic conduction of CNTs combined with well defined electroactive Si nanoparticles: capacities of 3000 mAh g−1 at 1.3C and 800 mAh g−1 at 15C are achieved

The influence of carrier density and doping type on lithium insertion and extraction processes at silicon surfaces

“…This increase in Coulombic efficiency with increasing applied current has been reported elsewhere [21,28,[92][93][94] where higher rates can promote the Si-alloying process at the expense of the SEI formation for kinetic reasons. SEM images of the surface of p-type and ntype Si(100) electrodes after the variable C-rate constant current experiments (Figs 10(b,c))…”

Advances in Lithium-Ion Battery Technology Based on Functionalized Carbon Nanotubes for Electrochemical Energy Storage

“…The VACNTs/Si sustained at very high C-rates without any significant polarization and without structural damaging. Cycling at 10C leads to a recovered capacity of 800 mAh g À1 , i.e., still two times the capacity of graphite [185]. Si/CNT nanocomposites have been prepared by a cost-effective wet-milling process exhibiting initial capacity $2,000 mAh g À1 , initial coulombic efficiency $80 %, and improved lifetime originated from the suppression of serious oxidation of silicon nanograins by selecting a proper liquid medium such as 1-octanol, the stronger linkage between silicon and CNT by a postthermal treatment, and effective electrical conductivity through network structure by 1D CNTs [186].…”

A Novel High-Power Battery-Pseudocapacitor Hybrid Based on Fast Lithium Reactions in Silicon Anode and Titanium Dioxide Cathode Coated on Vertically Aligned Carbon Nanofibers

“…An additional advantage of nanostructured Si materials is that their larger surface area and shorter Li + diffusion length help to improve the rate performance [12,18,19]. Hybrid core-shell structures utilizing highly conductive nanotubes as the stable cores to support thin Si shells have further demonstrated the ability for providing high specific capacity and good cycle stability around the normal C-rates of C/1 (namely completing the charge/discharge process in 1 hr) [19][20][21][22][23][24][25]. Recently, we have demonstrated the use of a coreshell structure composed of co-axial Si shells deposited on a forest-like array of vertically aligned carbon nanofiber (VACNFs) [26,27].…”