# Evaluation of Mg compounds as coating materials in Mg batteries

## TL;DR

This study uses first-principles calculations to identify promising Mg compounds as protective coatings for Mg batteries, aiming to improve electrolyte stability and battery performance.

## Contribution

It systematically maps electrochemical stability windows of Mg compounds, revealing new potential coating materials for Mg battery anodes and cathodes.

## Key findings

- Mg-halides and Mg(BH$_4$)$_2$ are promising anode coatings.
- MgF$_2$, Mg(PO$_3$)$_2$, and MgP$_4$O$_11$ are effective cathode passivators.
- Identified materials could enhance electrolyte compatibility and battery stability.

## Abstract

Mg batteries utilizing a Mg metal anode with a high-voltage intercalation cathode define a potential pathway toward energy storage with high energy density. However, the realization of Mg batteries is plagued by the instability of existing electrolytes against the Mg-metal anode and high-voltage cathode materials. One viable solution to this problem is the identification of protective coating materials that could effectively separate the distinct chemistries of the metal-anode and the cathode materials from the electrolyte. Using first-principles calculations we map the electrochemical stability windows for non-redox-active Mg binary and ternary compounds in order to identify potential coating materials for Mg batteries. Our results identify Mg-halides and Mg(BH$_4$)$_2$ as promising anode coating materials based on their significant reductive stability. On the cathode side, we single out MgF$_2$, Mg(PO$_3$)$_2$ and MgP$_4$O$_11$ as effective passivating agents.

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Source: https://tomesphere.com/paper/1902.01925