Research News

Jun 21, 2023

  • Engineering

Key material, solid electrolyte, created for all-solid-state batteries

Fabricating solid electrolytes with high ion conductivity via rapid heating

All-solid-state lithium battery

Osaka Metropolitan University scientists crystalized Li3PS4, a solid electrolyte material, via rapid heating, enabling the stabilization of its high-temperature phase with exceptional ionic conductivity even at room temperature.

Credit: Akitoshi Hayashi, Osaka Metropolitan University

Osaka, Japan - While most of us only associate room temperature with personal comfort, this temperature is exactly what scientists hope for to make certain material phases possible. Osaka Metropolitan University scientists have achieved an unprecedented stabilization of the high-temperature phase of Li3PS4—a critical material for all-solid-state batteries—thus attaining exceptional ionic conductivity even at room temperature. This breakthrough brings us one step closer to the realization of all-solid-state batteries and the adoption of this technology in a broad range of applications, including electric vehicles.

All-solid-state batteries are expected to be put to practical use as next-generation energy storage devices that integrate high levels of safety and enhanced energy density, thereby realizing a sustainable society. All-solid-state lithium batteries operate by facilitating the movement of lithium ions through a solid electrolyte. However, since ions cannot move freely within solids, the development of solid electrolytes with high ion conductivity that, like liquid electrolytes, enable the rapid movement of lithium ions, is imperative.

A research group led by Professor Akitoshi Hayashi and Associate Professor Atsushi Sakuda of the Graduate School of Engineering at Osaka Metropolitan University succeeded in stabilizing, for the first time, the high-temperature phase of Li3PS4 (α-Li3PS4), which exhibits high ion conductivity, at room temperature via rapid heating to crystallize Li3PS4 at 400 °C min−1. Since Li3PS4 is a promising solid electrolyte, this achievement makes possible the development of materials for all-solid-state batteries with higher performance.

Professor Hayashi elaborated, “Li3PS4 showcases varied crystal structures depending on temperature variations. The high-temperature phase is generally recognized for its superior ionic conductivity; however, the challenge has been to stabilize this phase at room temperature. We finally accomplished it by focusing on the heating rate during crystallization. This is the culmination of nearly 20 years dedicated to the development of all-solid-state battery materials.”

The results were published in the Journal of the American Chemical Society.


This work was financially supported by the Japan Science and Technology Agency ALCA-SPRING project (grant number JPMJAL1301) and Japan Society for the Promotion of Science KAKENHI grants (grant numbers JP18H05255 and JP19H05816).

Paper Information

Journal: Journal of the American Chemical Society
Title: Stabilizing High-Temperature α-Li3PS4 by Rapidly Heating the Glass
DOI: 10.1021/jacs.3c03827
Author: Takuya Kimura, Takeaki Inaoka, Ryo Izawa, Takumi Nakano, Chie Hotehama, Atsushi Sakuda, Masahiro Tatsumisago, Akitoshi Hayashi
Publication date: June 21, 2023


Graduate School of Engineering
Akitoshi Hayashi
E-mail: akitoshihayashi[at]
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