Excellent Anode Performance of N-, P-, and As-Doped Graphdiynes for Lithium-Ion Batteries

Recently, graphdiyne (GDY) as a two-dimensional planar carbon allotrope has received significant research attention in the fields of rechargeable batteries, catalysis, biomedicine, and so forth. However, the theoretical capacity of a perfect GDY anode is only 744 mA h/g in the configuration of LiC₃, encouraging further efforts to increase the capacity. In this study, we explore the anode performance of N-, P-, and As-doped GDYs by using first-principles calculations. Ab initio molecular dynamics simulations show that the doped GDYs can remain stable at 1000 K, indicating good thermal stability. With the loss of part acetylenic linkages, the rhomboid-like pores produce more Li sites, and the theoretical capacities reach 2209, 2031, and 1681 mA h/g for the N-, P-, and As-doped GDYs, respectively. In addition, the transition-state calculations indicate that the Li diffusion barriers of the three doped GDYs are similar to the perfect GDY. This study demonstrates that doping is an effective strategy to improve the anode performance of GDY.