First-principles study of Li adsorption and diffusion in naphyne

Abstract

The Li adsorption and diffusion properties in naphyne are explored by first-principles calculations. The porous structure of naphyne facilitates the adsorption of Li atoms, and the adsorption performance of large pores is better than that of small pores. The average open circuit potential is 0.78 V and the maximum Li storage capacity of bulk naphyne is up to 620 mAh/g, much larger than the up limit of the popular graphite. Upon Li intercalation, the interlayer spacing dilatation of bulk naphyne is only 1.78 %, implying that naphyne would not undergo significant structural degradation during cycling. The average adsorption energy between Li and naphyne in LiC3.6 is −2.38 eV/Li, which is feasible to realize their free migration. The porous structure enables Li atoms to diffuse either parallel or perpendicular to the naphyne plane. About 0.41–0.70 eV barriers are needed to overcome for the three-dimensional Li diffusion. Compared to commercial graphite, the higher Li capacity, the smaller structural distortion, and the unique three-dimensional diffusion performance of Li atoms make naphyne a promising candidate as the anode material of LIB.