Boosting sodium-ion batteries performance by N-doped carbon spheres featuring porous and hollow structures

Carbon materials are considered among the most promosing candidates for sodium ion batteries because of their competitive performance. Nevertheless, they suffer from low initial coulombic efficiencies (ICEs) and limited electrochemical performance. Herein, nitrogen-doped hollow carbon spheres (NHCSs) with a distinct porous structure are developed by a template-assisted carbonization of dopamine, followed by a template removal procedure. This advanced structural design, coupled with the surface chemistry of carbonized polydopamine, leads to an impressive ICE of 89.18% and a reversible capacity stabilized at ∼700 mA h g