Enhancing Lithium-Storage Performance via Graphdiyne/Graphene Interface by Self-Supporting Framework Synthesized

The self-supporting graphdiyne/exfoliated graphene (GDY/EG) composites materials were prepared by the solvothermal method and applied as lithium-ion batteries (LIBs). Graphdiyne (GDY) is a new type of carbon allotrope with a natural macroporous structure, but its conductivity is poor. A small amount of highly conductive graphene can improve surface conductivity and facilitate electron transport. The layered GDY/graphene heterogeneous interface can reduce the electron aggregation polarization, enhance the ability to obtain electrons from the electrolyte, and form a more uniform solid-electrolyte interface (SEI) film. The structural performance and electrochemical performance have been systematically studied. The results showed that the GDY/EG composite electrode has a reversible capacity of 1253 mA h g^-1 after 600 cycles at a current density of 0.5 A g^-1. When the current density is 5 A g^-1, the GDY/EG composite electrode can still maintain a reversible capacity of 324 mA h g^-1 after 2000 cycles, and the electrode can still maintain a good morphology after recycling. GDY/EG has a high reversible capacity, excellent rate capability, and cycle stability. A small amount of EG and inner foam copper form a double-layer conductivity, which changes the storage method of lithium ions and facilitates the rapid diffusion of lithium ions.