Mg₃Si₃(MoO₆)₂ as a High-Performance Cathode Active Material for Magnesium-Ion Batteries

Abstract

The natural abundance of magnesium together with its high volumetric energy capacity and less-dendritic anodes makes Mg-ion batteries an appealing alternative to the widely used Li-ion batteries. However, Mg cathode materials under current investigation suffer from various shortcomings such as low operation voltage and high energy barrier for ion migration, resulting in poor battery performance. Here, we propose a garnet-type intercalation cathode active material, Mg3Si3(MoO6)2, for high-performance Mg-ion batteries. Through first-principles density functional theory calculations, it is demonstrated that Mg3Si3(MoO6)2 possesses a high average discharge voltage (2.35 V vs Mg/Mg2+), a low ion migration barrier (∼0.2 eV), and a minimal volume change (∼4%) concurrently, which comprises excellent intercalation cathode chemistry. The small energy barrier for ion migration is shown to arise from the favorable change in the Mg coordination along the migration route within the garnet host. These findings present an additional direction to develop competent Mg-ion batteries for future energy storage applications.

Nanostructured Design Cathode Materials for Magnesium-Ion Batteries

“…Due to these properties, it was an excellent candidate to be used in cathodes. First-principles calculations revealed a new path toward the construction of effective MIBs for future energy storage, linking the low energy barrier for ion migration to favorable changes in Mg coordination inside the garnet host …”

“…First-principles calculations revealed a new path toward the construction of effective MIBs for future energy storage, linking the low energy barrier for ion migration to favorable changes in Mg coordination inside the garnet host. 116 According to DFT-based first-principles calculations, the Mg atoms exhibited metallic properties and high electronic conductivity by strongly binding with VS 2 . The highest theoretical capacity for MIBs is 233 mAh g −1 , and this is true for all three types of VS 2 , that is, monolayer VS 2 (M-VS 2 ), double-layer VS 2 (D-VS 2 ), and bulk VS 2 (B-VS 2 ).…”

A single-crystalline Co3O4 nanoparticle-assembled three-dimensional chain as an ultra-stable magnesium-ion battery cathode at different temperatures

“…Magnesium-ion (Mgion) batteries possess a high theoretical capacity (3833 mA h cm −3 and 2205 mA h g −1 ), low-cost Mg resources, and stability without Mg dendrites, etc. [4][5][6] However, they still face some challenges: (i) Mg 2+ ions are highly polarizable, which leads to the destruction of the cathode material and rapid capacity attenuation during insertion/extraction; (ii) poor compatibility between the electrolyte and anode, narrow electrochemical window and high deposition overpotential; (iii) the electrolyte easily reacts with the anode and deposits on its surface to form a passivation layer, which increases the interface resistance and affects the electrochemical performance. [7][8][9] Three-dimensional (3D) structures are promising for electrode materials because of their unique ion diffusion channels.…”

Headway towards contemporary 2D MXene-based hybrid electrodes for alkali-ion batteries

“…Both Sodium-ion batteries (SIBs), Potassium-ion batteries (PIBs), batteries suffered from the low reversible capacity and poor cycling stability due to low open circuit voltages and large ionic radii making it harder to find a suitable host [13] [14]. Multivalent alkali metal-ion batteries like Magnesium-ion batteries (MIBs), calcium-ion batteries (CIBs) have been advantageous of low price, abundant resources and high safety applications [15], [16] [11]. Moreover, all alkali metal batteries are put through the occurrence of dendrite growth, which will intensify their electrochemical performance adversely and call forth terrible safety hazard [17] [18].…”

“…13,14 Multivalent alkali metal-ion batteries such as magnesium-ion batteries (MIBs) and calcium-ion batteries (CIBs) have been advantageous due to their low price, abundant resources and high safety applications. 11,15,16 Moreover, all alkali metal batteries are susceptible to dendrite growth, which will adversely intensify their electrochemical performance and cause a safety hazard. 17,18 To satisfy the requirements, electrode materials are expected to have desirable electron or ion conduction, physicochemical properties, excellent electrochemical performance and structural stability during repeated charge/discharge cycles.…”