Graphdiyne-porphyrin composite materials GDY/Por and Por@GDY for lithium ion battery anodes

Abstract

Due to the structure containing sp-/sp2-hybridized carbon atoms and porous property, graphdiyne (GDY) is predicted and demonstrated as a novel anode material in lithium-ion batteries. In this paper, two different graphdiyne-porphyrin composite materials (GDY/Por and Por@GDY) were prepared by the reaction of the precursors hexaethynylbenzene and 5,10,15,20-tetrakis(4-tert-butylphenyl)porphyrin or 5,10,15,20-(tetra-4-ethynyphenyl)porphyrin, result in the out-of-plane GDY/Por material through π–π interaction or in-plane conjugated Por@GDY structure. When the as-prepared graphdiyne-porphyrin composite materials were used as anodes for lithium-ion batteries, GDY/Por exhibited more excellent electrochemical performance in capacity, rate performance, and cycling stability than that of Por@GDY. Combined with the theoretical calculations, the improvement can be ascribed to the larger specific surface area as well as the well-defined nitrogen active sites and the organic porphyrin layer intercalation in GDY/Por, which probably led to the interlayer expansion and the increase of the lithium storage ability.