The Evaluation of Mg–Ga Compounds as Electrode Materials for Mg-Ion Batteries via Ab Initio Simulation

Abstract

The Mg–Ga alloy-type electrode is one of the potential anode materials for Magnesium-ion batteries (MIBs). In this work, the thermodynamic, electrochemical and kinetic properties of Mg–Ga compounds, i.e. Mg2Ga5, MgGa2, MgGa, Mg2Ga and Mg5Ga2, have been systematically studied. Combining the first-principles calculations and charge-discharge experimental results, the structure evolution and voltage curves of Mg–Ga compounds are presented, where the Mg–Ga compounds show low voltages and high capacity up to 1922 mAh·g−1 with Mg5Ga2. Additionally, the diffusion barriers of Mg in Mg–Ga alloys are low, which is favorable for the fast ion-transmission and then good rate performance as being anodes of MIBs.

Magnesium: properties and rich chemistry for new material synthesis and energy applications

“…Gallium (Ga), with its low melting point (29.8 °C), readily forms alloys with varying compositions with Mg. For instance different moieties of Mg x Ga y mainly; Mg 2 Ga 5 , MgGa 2 , MgGa, Mg 2 Ga, and Mg 5 Ga 2 , have been explored with theoretical specific capacities of 307, 384, 768, 1536, and 1920 mA h g −1 , respectively. 242 Recently, Wang et al reported the development of a high performance Mg 2 Ga 5 alloy anode with an outstanding long-cycle life of 1000 cycles and a relatively high rate performance at 3C. 243 The Mg 2 Ga 5 alloy was synthesized by simply pyrolyzing Ga and Mg chips at a given stoichiometric ratio under argon atmosphere.…”

Potential Application of MgCu2 Alloy as a High-Performance Electrode Material for Mg-Ion Batteries: A Computational Study

“…The theoretical capacity of MgCu 2 reaches 1688 mA h/g, which exceeds that of numerous reported Mg alloy anode materials (Mg 3 Bi 2 , Mg 3 Sb 2 , Mg 2 Sn, Mg 9 Sn 5 , etc. ). ,, The ultralow diffusion energy barrier of MgCu 2 (0.318 eV) and Mg 2 Cu (0.307 eV) implies the potential for excellent rate performance. These characteristics clearly demonstrate that MgCu 2 is an excellent anode material for MIBs.…”