VN nanocrystals on N, S co-doped carbon framework: Topochemical self-nitridation and superior performance for lithium-ion battery

Transition metal nitrides have attracted extensive attention due to their high electronic conductivity and considerable theoretical capacity. However, large volume change and sluggish reaction kinetics during electrochemical reaction process impede their further application. Herein, we report a topochemical self-nitridation approach in-situ to synthesize VN nanocrystals embedded in N, S co-doped porous carbon framework and prove that the as-obtained composite nanocrystals are good anode for Li ion battery (LIB). The composite nanocrystals deliver a high reversible capacity of 294 mA h g −1 at 10 A g −1 after 1000 cycles for LIBs. Systematic characterizations coupled with the kinetic analysis manifest that VN nanocrystals exhibit short ions diffusion path and N, S co-doped porous carbon framework improves electronic conductivity as well as buffers volume change during electrochemical process. Furthermore, when using the composite nanocrystals as an anode and commercial LiFePO 4 as a cathode to package a full cell, three red LEDs are easily lightened up, indicating a huge potential of VN nanocrystals as electrode materials for practical application.