Designing the efficient lithium diffusion and storage channels based on graphdiyne

We report the first synthesized sp-sp²-sp³ hybridized two-dimensional porous carbon, methyl substituted graphdiyne (MsGDY). The conjugated sp and sp² carbons construct a conductive framework and well-distributed pores, and methyl units (sp³-C) are introduced into the well-distributed pores by coupling on benzene ring, which directly results in enlarged layer spacing (0.41 nm). Combining the advantages of three hybrid carbons in one, MsGDY provides much more lithium storage sites (theoretical capacity of 1701 mAh g⁻¹) and lower lithium ion diffusion barriers than those of existed carbon materials. The experimental results confirm that MsGDY has high capacity for Li storage (1020 mA g⁻¹ at the current of 50 mA g⁻¹) and excellent rate performance. The studies indicate that MsGDY is a novel candidate as an anode for lithium-ion batteries (LIBs), and the rational introduction of carbon with different hybrid forms can be of great meaningful for the design of new carbon-based 2D materials.