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

Abstract

Nonstoichiometric silicon oxide (SiO_x) with high theoretical capacity is a promising anode material for lithium-ion batteries (LIBs). However, volume changes and poor electronic conductivity of SiO_x are major impediments to its practical application. The modification of SiO_x 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 SiO_x 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 SiO_x nanodomains (CNT@SiO_x–C) from 1D gelable bottlebrushes as network building blocks based on molecular-scale interface engineering technology. Herein, nano-sized SiO_x particles are embedded into the carbonaceous matrix to prevent their volume change during cycling. The experimental results indicated that the CNT@SiO_x–C presents high reversible capacity, remarkable cycle life and high rate capability due to the high dispersion of nano-sized SiO_x and conductive 3D carbon nanonetwork.