A three-dimensional silicon/nitrogen-doped graphitized carbon composite as high-performance anode material for lithium ion batteries.

Abstract The three-dimensional conductive skeleton plays an important role for silicon-based anode materials to achieve good electrochemical performance in lithium ion batteries with high energy density. Here, we prepared a three-dimensional silicon/N-doped graphitized carbon composite (3D Si/NGC) from ZIF-67 precursor by magnesiothermic reduction reaction. The N-doped and graphitized conductive carbon acts as a robust three-dimensional configuration for the silicon nanoparticles, not only improving the conductivity of electrode, but also buffering the volume expansion of silicon nanoparticles. The 3D Si/NGC electrode exhibits good long-term cycle stability and impressive rate performance, delivering reversible capacity of 900 mA h g−1 at 0.2 A g−1 after 300 cycles with a capacity retention of 85.5% and a high discharge capacity of 880 mA h g−1 at 1 A g−1. The 3D Si/NGC with good electrochemical performance shows great potential as the next generation anode material for lithium ion batteries. Graphical abstract Image 1 Highlights • 3D Si/NGC composite derived from ZIF-67 is prepared by the magnesiothermic reduction. • Si/NGC composite displays a robust porous three-dimensional structure. • The N-doping and the graphitization enhance the electronic conductivity of composite. [ABSTRACT FROM AUTHOR]