Abstract
We describe here the metal-templated transformation of carbon nitride (C3N4) into nitrogen containing carbons as anodes for Li -ion batteries (LIBs). Changing the template from the carbon- and nitrogen immiscible Cu powder to the carbon- and nitrogen miscible Fe powder yields different carbons; while Fe templating produces graphitized carbons of low (<10%) nitrogen content and moderate pore volume, Cu templating yields high defect -density carbons of high (32-24%) nitrogen content and larger pore volume. The Le storage capacity of the high nitrogen content and larger pore volume Cu-templated carbons exceeds that of the more graphitic Fe-templated carbons due to added contribution from Li+ insertion/extraction from pores and defects and to reversible faradaic Li+ reaction with nitrogen atoms. The Cutemplated carbon annealed at 750 degrees C delivers the highest specific capacity of 900 mAh g(-1) at 0.1 A g(-1) and 275 mAh g(-1) at 20 A g(-1), while also achieving a 96% capacity retention after 2000 cycles at 2 A g(-1). The fabrication of higher mass loading electrodes (4.5 mg cm(-2)) provided a maximum areal capacity of 2.6 mAh cm(-2) at 0.45 mA cm(-2) (0.1 A g(-1)), comparable to the capacities of commercial LIB cells and favorable compared to other reported carbon materials.