Single-Source-Derived Nitrogen-Doped Soft Carbons for Application as Anode for Sodium-Ion Storage

Recently sodium-ion batteries have gained considerable attention over lithium-ion batteries because of their high earth abundance and low cost of sodium metal. Soft carbons with higher crystallinity and fewer defects compared to hard carbon are the preferred electrode material for tuning the reversible capacity of Na+ ion storage. In this work, we have successfully prepared N-doped soft carbons from formamide via a simple solvothermal process followed by pyrolysis at high temperatures. The presence of disorders and graphitic character was controlled via variation of the annealing temperature from 800 to 1400 °C. The prepared electrode material as an anode for Na+ storage shows a specific capacity of nearly 201 mA h g–1 under a current density of 20 mA g–1. The designed electrode also shows an excellent cyclic stability of 87% at 100 mA g–1 for 500 cycles. The enhanced performance of the optimized soft carbon may be ascribed to the synergistic interaction of graphitic and disordered domains and the doping of N into the soft carbon structure.