Design and synthesis of Mo2C/N, S co-doped porous carbon composites with enhanced electrochemical performance for sodium-ion batteries

• A unique 3D porous composite was designed to construct as a sodium storage medium. • Non-metal doped could effectively enhance capacity and stability. • Pseudocapacitance of Mo 2 C could further improve the electrochemical properties. Carbon materials were regarded as promising anode materials for sodium-ion batteries (SIBs) due to impressive structural integrity and stability upon cycling. However, the moderate discharge capacity and unsatisfactory rate capability had significantly hindered their practical applications. Herein, we reported a Mo 2 C/N, S co-doped porous carbon composite, in which the Mo 2 C nanoparticles were uniformly dispersed in the microstructure of porous carbon, result in providing more reaction interfaces and additional pseudocapacitance. On the other hand, the etching and the N, S doping in porous carbon further reveal more defects and active centers, reducing diffusion pathways and effectively providing buffer space for volume expansion. All above merits remarkably boosted the electrochemical performances. When the as-obtained composites were used as the anode materials for SIBs, which presented a high reversible capacity (600 mAh/g at 0.1 A/g after 500 cycles) and good rate performance (510 mAh/g at 2 A/g after 300 cycles).