Monolayer BGe as a promising anode material with ultrahigh specific capacity for Mg-ion batteries

• Published in: Physics letters. A Vol. 475; p. 128848
• Main Authors: Chen, Si-Yu, Ye, Xiao-Juan, Liu, Chun-Sheng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.07.2023
• Subjects: First-principles calculations; Mg-ion batteries; Two-dimensional materials; Two-dimensional materials; First-principles calculations; Mg-ion batteries
• ISSN: 0375-9601; 1873-2429
• DOI: 10.1016/j.physleta.2023.128848

Recently, the increasing development of electronic equipment has promoted the researches of rechargeable batteries. Magnesium-ion batteries (MIBs) have the potential to replace lithium-ion batteries (LIBs) because of low cost, high capacity, and safety. Herein, we perform first-principles calculations to investigate the feasibility of BGe monolayer as an electrode material for MIBs. The low diffusion barriers (0.14 ∼ 0.76 eV) of Mg give rise to the high-rate performance. More importantly, BGe exhibits a remarkable theoretical capacity of 3856 mA h⋅g−1 and a relatively low open-circuit voltage of 0.264 V. The slight volume expansion (5.63%) for fully magnesiated BGe is beneficial to maintain the electrode stability during cycling. Finally, the solvent effects are considered, and the solvent with a high dielectric constant is beneficial to the migration of Mg, contributing to a high charging rate. The above-mentioned intriguing theoretical findings suggest the BGe monolayer could be an efficient anode material for MIBs. •The BGe monolayer has stable plane structure and good conductivity.•The low diffusion barriers (0.14∼0.76 eV) of Mg at different concentrations give rise to the high-rate performance of BGe.•BGe exhibits remarkable theoretical capacity of 3856 mA h⋅g−1, low OCV of 0.264 V, and slight change in volume (5.63%).•The solvent with a high DC is beneficial to the migration of Mg, contributing to a high charging rate.