Constructing three-dimensional Carbon nanotubes/Carbon bifunctional conductive network by in situ chemical vapor deposition for SiOx anode in high-energy lithium-ion batteries

SiOx material has become one of the most promising anode materials to develop high-energy Li-ion batteries (LIBs) beyond 300 Wh kg-1. However, the practical application is usually limited by poor cycling stability due to the serious volume change of SiOx anode during lithiation/delithiation, which is difficult to overcome by the traditional carbon coating method. Herein, we construct a three-dimensional bifunctional conductive network (3D-SiOx@CNTs/C) composite by in-situ chemical vapor deposition under relatively low-temperature pyrolysis conditions. Benefiting from a mechanically flexible buffer generated from the CNTs coating layer, the 3D-SiOx@CNTs/C electrode exhibits a higher lithium storage capacity retention of about 99.8% (807.2 mAh g-1) after 450 cycles at 2 A g-1 than that of conventional carbon-coated strategy. The bifunctional three-dimensional conductive network offers a smooth conduction path to counter the volumetric strain through the demonstration of kinetic and impedance analyses. This work may provide an ingenious strategy to prepare CNTs-modified functional materials and helps to accelerate the application of high-capacity SiOx/C anode in practical batteries.