固体電池の性能を新たな保護コーティングで向上（Solid-state batteries get a boost with new protective coating）

2025-09-09 アルゴンヌ国立研究所（ANL）

A comparison of uncoated LPSCI (a sulfide-based electrolyte) with aluminum oxide ALD-coated LPSCI when exposed to humid air, illustrating how the coating suppresses degradation. (Image by Taewoo Kim/Argonne National Laboratory.)

＜関連情報＞

• https://www.anl.gov/article/solidstate-batteries-get-a-boost-with-new-protective-coating
• https://pubs.acs.org/doi/10.1021/acsmaterialslett.4c01923

超薄膜金属酸化物層による硫化物系固体電解質の大気劣化抑制 Suppressing Atmospheric Degradation of Sulfide-Based Solid Electrolytes via Ultrathin Metal Oxide Layers

Taewoo Kim,Zachary D. Hood,Aditya Sundar,Anil U. Mane,Francisco Lagunas,Khagesh Kumar,Neelam Sunariwal,Jordi Cabana,Sanja Tepavcevic,Jeffrey W. Elam,Peter Zapol,and Justin G. Connell
ACS Materials Letters  Published: November 12, 2024
DOI:https://doi.org/10.1021/acsmaterialslett.4c01923

Abstract

Sulfide-based solid-state electrolytes (SSEs) are promising materials with superior Li-ion conductivity; however, their poor atmospheric stability limits commercial manufacturing at scale. Here, we investigate the impact of ultrathin metal oxide layers deposited via atomic layer deposition (ALD) on the stability of Li₆PS₅Cl (LPSCl). Al₂O₃ layers grown directly on LPSCl particles significantly stabilize the surface chemistry and Li-ion transport properties relative to uncoated material upon exposure to both an ambient atmosphere (22% relative humidity, RH) and humidified O₂ (100% RH). Detailed investigations indicate that coatings impede the surface and bulk degradation kinetics of exposed materials, even for coatings as thin as ∼1 Å. This suggests that stabilization is due to more than just a physical barrier. Shifts in valence band edge positions of coated LPSCl indicate that ALD coatings alter the surface electronic structure and resulting oxidation tendency of underlying LPSCl, suggesting new avenues to improving the environmental stability of sulfide SSEs.