First-principles study of dual-doped graphene: towards promising anode materials for Li/Na-ion batteries. (31st May 2018)

• Record Type: Journal Article
• Authors: Ullah, Saif; Denis, Pablo A.; Sato, Fernando
• Is Part Of: New journal of chemistry. Volume 42:Number 13(2018)
• Page Start: 10842
• Page End: 10851
• Publication Date: 2018-05-31
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c8nj01098f
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : The interaction of Li/Na with various DDG is studied with the help of DFT. Among them, the Be–B DDG systems exhibit exceptional properties, such as large storage capacities, excellent OCVs, good electronic conductivities, and minor changes in their planes. These properties show that Be–B DDG can serve as promising anode materials for LIBs/SIBs. Abstract : Two-dimensional materials as electrodes have significant potential in energy storage and conversion and can address the issues related to battery technologies. Accordingly, first-principles calculations were executed to search for the best possible anode material for Li/Na ion batteries. Three families of dual-doped graphene (DDG) including Be–B, BeN, and BeO were studied because it is easier to synthesize DDG instead of its mono-doped counterpart. Among them, Be–B DDG was found to be the most promising since it can cause a massive increase in the adsorption of Li (2.33 eV, by 3.1 times) and Na (2.24 eV, by 4.3 times) at the vdW-DF/DZP level of theory. The integration of these ions caused the structures to become metallic, resulting in good electronic conductivity, which is essential for anode materials. Furthermore, Be–B DDG exhibited an average open circuit voltage of 2.34 V (1.3* V) and 1.82 V (1.02* V) for Li and Na, respectively, when the energy of the isolated gas-phase (* represents the energy of one atom taken from the bulk) is used for Li and Na. This modest average open circuit voltage of 1.3* V for Li is in the range of that of the most commonly used graphite-Li (0.11 V) and TiO2 -Li (1.5–1.8 V). Moreover, the negligible percentage change in the plane of Be–B DDG during the intercalation of Li/Na ensured good cyclic stability. Additionally, the exceptional storage capacities of 2334 mA h g −1 for Li and 1012 mA h g −1 for Na with an open circuit voltage of 0.23* V and 0.25* V, respectively, shows that Be–B DDG has potential as a remarkable anode material for LIBs and SIBs.