Mechanochemical Synthesis of γ-Graphyne with Enhanced Lithium Storage Performance.

γ-Graphyne is a new nanostructured carbon material with large theoretical Li storage due to its unique large conjugate rings, which makes it a potential anode for high-capacity lithium-ion batteries (LIBs). In this work, γ-graphyne-based high-capacity LIBs are demonstrated experimentally. γ-Graphyne is synthesized through mechanochemical and calcination processes by using CaC and C Br . Brunauer-Emmett-Teller, atomic force microscopy, X-ray photoelectron spectroscopy, solid-state C NMR and Raman spectra are conducted to confirm its morphology and chemical structure. The sample presents 2D mesoporous structure and is exactly composed of sp and sp -hybridized carbon atoms as the γ-graphyne structure. The electrode shows high Li storage (1104.5 mAh g at 100 mA g ) and rate capability (435.1 mAh g at 5 A g ). The capacity retention can be up to 948.6 (200 mA g for 350 cycles) and 730.4 mAh g (1 A g for 600 cycles), respectively. These excellent electrochemical performances are ascribed to the mesoporous architecture, large conjugate rings, enlarged interplanar distance, and high structural integrity for fast Li diffusion and improved cycling stability in γ-graphyne. This work provides an environmentally benign and cost-effective mechanochemical method to synthesize γ-graphyne and demonstrates its superior Li storage experimentally.