Korea Electrotechnology Research Institute Develops World's First 'Solid Electrolyte Particle Size Control Technology'

Dr. Ha Yooncheol's Team Publishes Cover Paper in Top 8% JCR International Journal

Dr. Ha Yoon-cheol, Korea Electrotechnology Research Institute.

[Asia Economy Yeongnam Reporting Headquarters, Reporter Song Jong-gu] Dr. Ha Yun-cheol's team at the Next-Generation Battery Research Center of the Korea Electrotechnology Research Institute (KERI) in Gyeongnam has received excellent evaluations for their research on the world’s first developed ‘solvent displacement-based solid electrolyte (sulfide-based) particle size control technology,’ which has been published as a cover paper in a prestigious international academic journal.

All-solid-state batteries replace the ‘electrolyte’ that transfers ions between the cathode and anode with a solid instead of a liquid, reducing the risk of fire or explosion.

For solid electrolytes to be used in all-solid-state batteries, the particle size must be very small, at the level of 1 micrometer, which is 1/100th the thickness of a human hair.

Currently, a ‘wet ball milling’ method is used, where a small amount of solid electrolyte powder and balls are placed in a container with a non-polar solvent and rotated at high speed for a long time to reduce particle size. However, this process causes significant loss of ionic conductivity.

There is also an ‘air jet milling’ method that mechanically injects air, but due to the solid electrolyte’s sensitivity to oxygen exposure causing severe degradation, there are many difficulties such as compressing, circulating, and recovering nitrogen or argon gases.

In response, KERI utilized a method called ‘solvent displacement.’ First, the solid electrolyte powder (raw material) requiring particle size control is mixed and dissolved in a polar solvent such as alcohol. Next, this solution is injected into a non-polar solvent heated to a temperature higher than the boiling point of the polar solvent. Due to the temperature difference, the polar solvent instantly evaporates, and the solid electrolyte recrystallizes, resulting in smaller particle sizes.

Through numerous demonstrations, the research team verified that even when the solid electrolyte particle size was reduced from 8 micrometers to about 0.8 micrometers (1/10th), the ionic conductivity could be maintained at approximately 85%.

They also confirmed that by adjusting process conditions such as the injection speed of the polar solvent, nozzle size, temperature of the non-polar solvent, and mixing speed, the particle size and purity of the recrystallized solid electrolyte could be controlled.

The related research results were recognized for their excellence and selected as the cover paper of Volume 10, Issue 48 of the ‘Journal of Materials Chemistry A (IF: 14.511),’ an international journal ranked in the top approximately 8% in the Energy & Fuels field according to the Journal Citation Reports (JCR).

Dr. Ha Yun-cheol of KERI stated, “The particle size control technology through solvent displacement will realize ultrafine particle size, high ionic conductivity, and cost reduction, which are most needed for the practical use of solid electrolytes.” He added, “We will promote scale-up of the manufacturing process through technology transfer to companies and strive to contribute to the commercialization of all-solid-state batteries.”

The research team expects this achievement to attract significant interest from companies related to all-solid-state batteries (such as solid electrolyte producers, electrode plate/membrane manufacturing equipment companies, and electrode plate electrolyte membrane and cell manufacturers) and plans to identify related demand companies and promote technology transfer.

This content was produced with the assistance of AI translation services.