Construction of 3D carbon networks with well-dispersed SiOx nanodomains from gelable building blocks for lithium-ion batteries

Abstract

Nonstoichiometric silicon oxide (SiOx) with high theoretical capacity is a promising anode material for lithium-ion batteries (LIBs). However, volume changes and poor electronic conductivity of SiOx are major impediments to its practical application. The modification of SiOx with carbonaceous materials to accommodate volume variations and improve conductivity is a valuable strategy. Nanonetwork-structured (NNS) carbons have been paid great attention because of their unique three-dimensional structure, and high electronic and ionic conductivity. Incorporating SiOx with well-designed NNS carbons is a promising method to prepare high quality electrode materials for lithium-ion batteries. In this work, a fabrication approach is developed to synthesize a 3D carbon network composed of carbonaceous hybrid nanotubes with well-dispersed SiOx nanodomains (CNT@SiOx–C) from 1D gelable bottlebrushes as network building blocks based on molecular-scale interface engineering technology. Herein, nano-sized SiOx particles are embedded into the carbonaceous matrix to prevent their volume change during cycling. The experimental results indicated that the CNT@SiOx–C presents high reversible capacity, remarkable cycle life and high rate capability due to the high dispersion of nano-sized SiOx and conductive 3D carbon nanonetwork.