Mechanochemical Synthesis of γ-Graphyne with Enhanced Lithium Storage Performance

gamma-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, gamma-graphyne-based high-capacity LIBs are demonstrated experimentally. gamma-Graphyne is synthesized through mechanochemical and calcination processes by using CaC2 and C6Br6. Brunauer-Emmett-Teller, atomic force microscopy, X-ray photoelectron spectroscopy, solid-state C-13 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(2)-hybridized carbon atoms as the gamma-graphyne structure. The electrode shows high Li+ storage (1104.5 mAh g(-1) at 100 mA g(-1)) and rate capability (435.1 mAh g(-1) at 5 A g(-1)). The capacity retention can be up to 948.6 (200 mA g(-1) for 350 cycles) and 730.4 mAh g(-1) (1 A g(-1) 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 gamma-graphyne. This work provides an environmentally benign and cost-effective mechanochemical method to synthesize gamma-graphyne and demonstrates its superior Li+ storage experimentally.