Graphdiyne and its heteroatom-doped derivatives for Li-ion/metal batteries

Graphdiyne (GDY), which is composed of benzene rings and acetylene linkage units, is a new allotrope of carbon material. In particular, the large triangular pores of GDY, with a diameter of 5.4 & Aring;, theoretically predict a higher lithium embedding density than traditional graphite anodes, making it a promising candidate for energy storage materials in lithium-ion (Li-ion) batteries. GDY is primarily synthesized via a cross-coupling reaction of hexaethynylbenzene (HEB). Under similar preparation conditions, the cross-coupling reaction of aryne precursors, other than HEB, yields many GDY heteroatom-doped derivatives. This introduces numerous heteroatomic defects as well as electrochemically active sites, potentially enhancing electrochemical performance. Recent advancements have focused on utilizing GDY and its heteroatom-doped derivatives as electrode materials or composite materials in Li-ion/metal batteries. This review systematically summarizes the strategies developed for GDY and its heteroatom-doped derivatives. Notably, recent research on the effects of morphology and chemical/electronic structure on performance, particularly new conceptual mechanisms in Li-ion/metal batteries, including self-expanding Li-ion transport channels and a capture/pore filling-intercalation hybrid mechanism, is briefly described. The results presented herein highlight the significant potential of GDY and its heteroatom-doped derivatives for energy storage applications and inspire further development.