Nitrogen-rich mesoporous carbon materials were obtained by pyrolyzing gelatin between 700 and 900 °C with a nano-CaCO3 template. The mesoporous structure and the high nitrogen content endowed these materials with reversible capacities up to ca. 1200 mA h g−1. The high specific surface area and the nitrogen doping are responsible for the capacity loss in the initial cycle. FTIR and XPS studies indicate that the nitrogen in the material exists in the form of pyridinic, pyrrolic/pyridonic and graphitic nitrogen. The Raman spectroscopic analysis indicates that the structure of the mesoporous carbon becomes more disordered during discharge and is restored during recharge, a behavior similar to that in nitrogen-free hard carbon materials. The reversible structural variation of these carbon materials ensures their high cyclic reversibility.
