Femtosecond X-ray Laser Reveals Intact Sea–Island Structures of Metastable Solid-State Electrolytes for Batteries

Abstract

Experimental characterization of the nanostructure of metastable functional materials has attracted significant attention with recent advances in computational materials discovery. However, since metastable glass–ceramics are easily damaged by irradiation, damage-free nanoimaging has not been realized thus far. Herein, we propose novel high-contrast coherent diffractive imaging that quantitatively analyzes the intact internal nanostructure of metastable glass–ceramics using femtosecond X-ray pulses. The immersion of sample particles in a solvent helps enhance the reconstructed image contrast and allows us to distinguish an ∼7% electron density difference between an amorphous form and crystals. Furthermore, morphological operations with a band-pass filter quantitatively elucidate the depth information. The evaluated volume ratio of the amorphous to crystalline phases is ∼2.5:1 for the measured metastable (Li2S)70–(P2S5)30 glass–ceramic particle. Sulfide glass–ceramics are used as electrolytes for all-solid-state batteries, which are indispensable for reducing the carbon footprint. Our results will facilitate structural studies on fragile metastable materials with important scientific and industrial implications.

Surface Degeneration of Li₃PS₄–LiI Glass-Ceramic Electrolyte by Exposure to Humidity-Controlled Air and Its Recovery by Thermal Treatment

“…[1][2][3] All-solid-state sulfide batteries have high energy density and durability; nevertheless, research is actively being conducted to achieve further improvements in these parameters. [4][5][6][7][8][9][10][11][12][13][14][15] The solid electrolyte is one of the main components that contributes to the high performance of sulfide all-solid-state batteries. Solid sulfide-based electrolytes have high ionic conductivity and plasticity.…”