The optimized composition enables low-cost mass production of solid electrolytes for all solid-state batteries

The Korea Electrotechnology Research Institute (KERI), a pioneering research institute for all-solid-state (sulfide-based) batteries that are free of fire and explosion hazards, has recently developed a new technology that could pave the way for low-volume mass production. Solid electrolytes cost. The study is published in the journal Batteries & Super Caps.

At KERI’s Next Generation Battery Research Center, Dr. A team led by Jun-Ho Park developed a „one-pot” synthesis method to produce high-purity solid electrolytes without the need to use expensive lithium sulfides and additives.

There are two methods for producing solid electrolytes: dry synthesis using high-energy ball milling and wet synthesis using chemical reactions in solution. The team focused on wet synthesis, which has advantages in scale and mass production, and succeeded in producing high-purity solid electrolytes by optimizing the synthesis reaction in solvent.

The main advantage of this method is that it does not require expensive lithium sulfides (Li₂S). Lithium sulfides account for up to 95% of the cost of starting materials for solid electrolyte production. Additionally, lithium sulfides are often unreactive impurities during wet synthesis, leading to degradation of cell performance. Some have proposed synthesis methods without lithium sulfide, but these require expensive additives and often produce residual impurities, resulting in unsatisfactory performance.

Conversely, the one-pot synthesis method developed by KERI enables the production of high-quality solid electrolytes without lithium sulfides, additives or additional processes. Compared to the existing lithium sulfide-based process, the material cost is reduced to 1/25 and the accelerated production time can significantly contribute to the mass production of solid electrolytes.

„KERI’s many years of experience in solid electrolyte production enabled us to find a quick and easy way to produce high-purity solid electrolytes through optimal chemical reaction combinations of starting materials in organic solvents,” said Dr. Park. „We are excited that this technology will help address the biggest challenges in commercializing all solid-state batteries, which are cost competitiveness and mass production issues.”

KERI has filed a patent application for this technology and published papers in local and international journals. Anticipating that this achievement will attract strong interest from all solid-state battery manufacturers, the company plans to explore opportunities for technology transfer.