Aluminum doping improves the energetics of lithium, sodium, and magnesium storage in silicon

Abstract

While Si is an effective insertion type anode for Li-ion batteries, crystalline Si has been shown to be unsuitable for Na and Mg storage due, in particular, to insufficient binding strength. It has recently been reported that Si nanowires could be synthesized with high-concentration (several atomic %) and dispersed Al doping. Here we show based on density functional theory calculations that Al doping significantly improves the energetics for Na and Mg insertion, specifically, making it thermodynamically favored versus vacuum reference states. For high Al concentrations, the energy of Mg in Al-doped Si approaches the cohesive energy of Mg. However, the migration barriers for the diffusion of Li (0.57-0.70 eV), Na (1.07-1.19 eV) and Mg (0.97-1.18 eV) in Al-doped Si are found to remain about as high as in pure Si, likely preventing effective electrochemical sodiation and magnesiation.

References in corpus (2)

• In search of high performance anode materials for Mg batteries: computational studies of Mg in Ge, Si, and Sn
• Comparative Computational Study of the Energetics of Li, Na, and Mg Storage in Amorphous and Crystalline Silicon

Cited by in corpus (8)

• On the oxidation state of titanium in titanium dioxide
• Data-driven kinetic energy density fitting for orbital-free DFT: linear vs Gaussian process regression
• A First-Principles Comparative Study of Lithium, Sodium, and Magnesium Storage in Pure and Gallium-Doped Germanium: Competition between Interstitial and Substitutional Sites
• Stability of charges in titanium compounds and charge transfer to oxygen in titanium dioxide
• Lithium attachment to C60 and nitrogen- and boron-doped C60: a mechanistic study
• Dopant-Dopant Interactions in Beryllium doped Indium Gallium Arsenide: an Ab Initio Study
• Grown-in beryllium diffusion in indium gallium arsenide: An ab initio, continuum theory and kinetic Monte Carlo study
• Atomistic Mechanisms of Mg Insertion Reactions in Group XIV Anodes for Mg-Ion Batteries