Precise and controllable N/C ratio in graphdiyne for superior Li and Na ions storage capacities

Nitrogen doping is one of the resultful means to modify electrode materials to get improved storage capacity. However, scientific problem of the effect of single pyridine-N on capacity has not yet been discovered. This paper developed a new way for precise preparation of pyridinic-N doped carbon materials. Different N/C ratios of graphdiyne were obtained by accurate adjustment and superior lithium and sodium storage capacities were realized. At 0.05 A g^-1, for Li and Na ions batteries with the asprepared samples as electrodes, the maximum specific capacities could reach up to 1812 and 680 mAh g^-1, respectively. Relationship between specific capacity and nitrogen content was not positively correlated and the maximum value occurs when monomers ratio was 1:1, suggested that besides N/C ratios, morphologies, interlayer spacing, and wettability also take effect on the behavior of battery performances. This investigation makes a new insight and provides guidance to heteroatom doping in energy storage.