Monolayer and bilayer AsC5 as promising anode materials for Na-ion batteries

Abstract

Since the abundance of sodium resources is much higher than lithium, the global distribution is uniform, and the price is low and stable, making Na-ion batteries (NIBs) have broad application prospects in the field of next-generation renewable energy storage. However, a significant barrier to the realization of high-performance NIBs is the absence of adequate anode materials. In this work, we perform unbiased first-principles structure-search simulations to find a novel AsC5 monolayer with a variety of functionally advantageous characteristics. Based on theoretical simulations, the proposed AsC5 has been found to be energetically, mechanically, dynamically, and thermally stable, supporting the viability of experiment. Stable adsorption of Na on monolayer (bilayer) AsC5 with an adsorption energy from −2.42eV to −0.33eV is shown by our computational simulations. The metallic behavior of monolayer (bilayer) AsC5 is maintained when Na atoms are inserted, ensuring excellent electric transportation. Furthermore, the Na diffusion barrier on monolayer (bilayer) AsC5 is just 0.16 (0.09) eV, which indicates a rapid charging/discharging capacity. The monolayer (bilayer) AsC5 materials have higher specific capacity than some known 2D materials, reaching a maximum of 794.28 mA h/g (596.01 mA h/g). Small volume fluctuations (<1.2%) after AsC5 sodiation show strong cycle reversibility. Therefore, such crucial characteristics make AsC5 be a promising candidate for anode materials of NIBs.