Electrochemically Stable Coating Materials for Li, Na, and Mg Metal Anodes in Durable High Energy Batteries

Anodes made of Li, Na, or Mg metal present a rare opportunity to double the energy density of rechargeable batteries. However, these metals are highly reactive with many electrolytes and yield electronically conductive phases that allow continued electrochemical reduction of the electrolyte. This reactivity degrades cell performance over time and poses a safety risk. Surface coatings on metal anodes can limit reactivity with electrolytes and improve durability. In this paper, we screen the Open Quantum Materials Database (OQMD) to identify coatings that exhibit chemical equilibrium with the anode metals and are electronic insulators. We rank the coatings according to their electronic bandgap. We identify 92 coatings for Li anodes, 118 for Na anodes, and 97 for Mg anodes. Only two compounds that are commonly studied as Li solid electrolytes pass our screens: Li3N and Li7La3Hf2O12. Many of the coatings that we identify are new to the battery literature. We suggest further study of these coatings to validate their performance in cells.