Computational Study of Mg3Bi2 as Anodes for Mg-ion batteries

Charging/discharging mechanism in Mg3Bi2 anodes for Mg-ion batteries; The role of the spin-orbit coupling

Magnesum ion batteries are an exciting new technology that offer prospects towards significantly higher capacities of electrochemical storage. During discharge, each magnesium 2+ ion which moves through the electrolyte to the cathode results in 2 electrons driven through an electrical circuit, allowing for potentially higher performance in secondary ion batteries. 

Here we examine through methods of computational materials science, the perfomance of Mg3Bi2 as an anode material. 

• We examine Mg ions insertion/extraction in Mg3Bi2, as an anode for Mg-ion batteries.

• Mg ions first vacate octahedral sites and then diffuse through tetrahedral sites.

• The spin-orbit coupling softens Mg-Bi bond, lowering Mg vacancy formation energy.

• The spin-orbit coupling, however, has a minor effect on diffusion barriers.

• These results aid performance optimization in Mg-ion battery anodes.

https://www.sciencedirect.com/science/article/abs/pii/S000926142200361X