• 3 min read
Magnesium Oxide Boosts Solid-State Battery Stability
Argonne researchers identify magnesium oxide as a promising nanometer-scale coating for stabilizing sulfide solid electrolytes.
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Computation and experiment were combined to identify protective coatings for sulfide-based solid electrolytes and determine why they work. Credit: Argonne National Laboratory
A coating just one nanometer thick—roughly 100,000 times thinner than a human hair—could help solve one of the key durability problems facing solid-state batteries.
Scientists at the U.S. Department of Energy’s Argonne National Laboratory combined computational screening with experiments to identify protective coatings for sulfide-based solid electrolytes. Their results, published in Advanced Science, highlight magnesium oxide as a particularly promising option and offer a faster method for finding alternatives.
Solid-state batteries could store more energy and improve safety compared with today’s lithium-ion batteries. However, sulfide-based electrolytes are chemically fragile and can react at critical interfaces, especially where the electrolyte contacts lithium metal. Those reactions can reduce performance and shorten battery life.
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How the coating candidates were screened
The researchers focused on lithium phosphorus sulfur chloride, or LPSCl, a sulfide solid electrolyte. Using density functional theory, they screened oxide coatings that can be deposited through atomic layer deposition (ALD), a technique capable of creating uniform layers with near-atomic precision.
The calculations modeled behavior at three interfaces: between the coating and the electrolyte, lithium metal, and cathode materials.
“We can’t experimentally explore the full range of possible materials in any reasonable way. That would take forever, and it’s just not possible.”
The most successful coatings were not necessarily the least reactive. Instead, performance depended on the compounds created when a coating reacted at the interface. The best reaction products allowed lithium ions to move while restricting electron flow.
“Zirconium oxide was one of the most stable materials by itself, but it was one of the worst-performing coatings we investigated,” Connell said.
Magnesium oxide’s battery performance
The team applied several candidate coatings to LPSCl powder using ALD. Magnesium oxide improved the electrolyte’s stability against lithium metal, reduced interfacial resistance, and improved performance. It also blocked electron flow while allowing lithium ions to move efficiently.
“Atomic layer deposition gives us a unique way to apply uniform coatings that are only about a nanometer thick, even on complex powder surfaces. That level of control lets us test new coating chemistries efficiently and connect computational predictions to real materials.”
Scanning transmission electron microscopy and energy dispersive X-ray spectroscopy at Argonne’s Center for Nanoscale Materials confirmed that the coatings were distributed uniformly across the powder surfaces.
Zirconium oxide produced less favorable reaction products and performed poorly. Zinc oxide, although predicted to be more reactive overall, still produced beneficial transport behavior because of the compounds formed at its interfaces.
A broader search for battery coatings
The researchers say their workflow can replace much of the trial-and-error involved in evaluating protective materials. The calculations identified likely interfacial reactions and showed which products would support or hinder battery performance.
“That gives us a more predictive way to evaluate coating candidates, rather than relying on trial and error.”
The approach could be extended beyond the oxide coatings studied here to sulfides, fluorides, other binary chemistries, ternary coatings, or combinations of materials.
The study, led computationally by Zapol, was published as “Computationally-Guided Development of Sulfide Solid Electrolyte Powder Coatings for Enhanced Stability and Performance of Solid-State Batteries” by Aditya Sundar et al. in Advanced Science (2025). DOI: 10.1002/advs.202513191.
Sadie Harley, BSc Life Sciences & Ecology
Andrew Zinin, physics researcher and science editor
Frontier Editor
Dan is our resident futurist, covering electric mobility, space exploration, and the smart home. He's interested in atoms just as much as bits. Whether it's a new battery chemistry, a reusable rocket, or a protocol that finally makes IoT devices talk to each other, Dan breaks down the engineering that pushes humanity forward.
via TechXplore
