A computational study of the insertion of Li, Na, and Mg atoms into Si(111) nanosheets

作者：Malyi Oleksandr^*; Kulish Vadym V; Tan Teck L; Manzhos Sergei

来源：Nano Energy, 2013, 2(6): 1149-1157.

DOI：10.1016/j.nanoen.2013.04.007

• Na-ion batteries
• Li-ion batteries
• Mg-ion batteries
• Diffusion
• Nanosheet
• Batteries

Based on first principles calculations, we study the interaction of metal atoms (Li, Na, and Mg) with Si(111) nanosheets of different thicknesses. We show that the chemistry of the interactions is sensitive to both the nanosheet thickness and the dopant-surface distance. Both Li and Na atoms adsorb strongly on the nanosheet surface, accompanied by large charge transfers (similar to 0.9e) from the metal atoms to surrounding atoms. In contrast, Mg atoms have weak adsorption. Compared to bulk Si, we show that nanosheet Si is expected to improve the charge/discharge rate of Li/Na/Mg-ion batteries. Nevertheless, due to large insertion barriers (up to the prohibitive similar to 2.1 and similar to 3.1 eV for Mg and Na, respectively) and significant energy differences between surface and sub-surface sites (similar to 1.0 and similar to 1.9 eV for Mg and Na, respectively), the theoretical capacities of Si for both Na-ion and Mg-ion batteries cannot be achieved at realistic charge/discharge rates.

• 出版日期2013-11
• 单位南阳理工学院