Two-dimensional functionalized MBene Mg 2 B 3 T (T = O, H, and F) monolayers as anode materials for high-performance K-ion batteries

• Published in: Physical chemistry chemical physics : PCCP Vol. 26; no. 39; pp. 25623 - 25631
• Main Authors: Tang, Fengzhang, Pang, Jiafei, Yang, Jinni, Kuang, Xiaoyu, Mao, Aijie
• Format: Journal Article
• Language: English
• Published: England 09.10.2024
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/D4CP02402H

Two-dimensional metal borides have received attention as high performance battery anode materials. During the practical application, the 2D surface terminalization is an inevitable problem. This study employs first-principles calculations to investigate the termination of the Mg B monolayer with O, H, F, and Cl groups. These structures' stabilities are examined through energetic, mechanical, kinetic and thermodynamic stability studies. Electronic property analysis shows that Mg B T (T = O, H, F, and Cl) monolayers are all metallic. Calculated results reveal that the Mg B O, Mg B H, and Mg B F monolayers exhibit high K ion storage capacities (up to 826 mA h g , 980 mA h g , and 804 mA h g , respectively), with diffusion barriers of 0.338 eV, 0.490 eV, and 0.507 eV, respectively. More importantly, the calculated in-plane lattice constants of the substrate materials exhibit a minimal variation and the observed volume expansion is almost negligible (less than 0.08%) during the entire potassization process, which is much lower than that of the pristine Mg B monolayer. This structural stability is attributed to the presence of surface functional groups. These results provide helpful insights into designing and discovering other high-capacity anode materials for batteries.