Phographene as a High-Performance Anode Material with High Specific Capacity and Fast Li Diffusion: From Structural, Electronic, and Mechanical Properties to LIB Applications

Abstract

The progress of ecofriendly, clean, and sustainable energy resources always demands suitable anode materials for batteries with high structural stability and superior storage capacity. Herein, we use density functional theory predictions to examine the potential features of newly proposed planar membranes consist of 5-, 6- and 8- membered carbon rings, named as alpha- and beta-phographene (PhoG). Our calculations disclose that both alpha- and beta-PhoG structures possess high structural, thermal, and mechanical stability with intrinsic metallic characteristics. We have further extended our calculations of PhoG as a suitable anode material for use in Lithium-ion batteries. Our results reveal the Li adsorption in PhoG is exothermic and the alpha-PhoG show a higher theoretical specific capacity of Li2.4C6 for Li atoms (892 mAh g(-1)) compared to the LiC6 of graphite. We also found that both the alpha- and beta-PhoG structures show fast Li mobility with a low diffusion barrier for Li atoms (˂0.30 eV) as well as low average open circuit voltage (similar to 0.26 V). Our findings show that both the PhoG structures, especially alpha-PhoG, are suitable anode candidates for use in future Li-ion batteries owing to the metallic characteristic combined with the low open circuit voltage, low diffusion barrier, high Li storage capacity, and high thermo-mechanical stability. Our results would supply guidelines to develop better high-capacity anode materials for future Li-ion batteries.