High Rate Performing in Situ Nitrogen Enriched Spherical Carbon Particles for Li/Na-Ion Cells.

Nitrogen rich, porous spherical carbon particle with the large surface area was synthesized by simple pyrolysis of the amorphous covalent organic framework. The obtained mesoporous spherical carbon particles with dilated interlayer distance (0.377 nm), large surface area (390 m g) and high level nitrogen doping (10.9%) offer eminent electrochemical performance as an anode for both lithium ion (LIBs) and sodium ion batteries (SIBs). In LIB applications, the synthesized material delivers an average reversible capacity of 820 mAh g after 100 cycles at 0.1 A g, superior rate capability of 410 and 305 mAh g at 4.0 and 8.0 A g respectively. In SIBs, the material shows the stable reversible capacity of about 238 mAh g for the studied 500 cycles at 0.5 A g. The rate and steady state cycling performance at high current densities are impressive, being as high as 165 mAh g even after 250 cycles at 2.0 A g.