While the Korea Electrotechnology Research Institute (KERI) has recently been showcasing numerous achievements related to all-solid-state batteries (sulfide-based) that pose no risk of fire or explosion, another technology capable of mass-producing solid electrolytes at a low cost has been developed and is attracting significant attention.

Dr. Park Jun-ho's team at the KERI Secondary Battery Research Group announced on the 15th that they have developed a 'one-pot synthesis method' capable of producing high-purity solid electrolytes without expensive lithium sulfide or additives.

There are two methods for manufacturing solid electrolytes: a 'dry synthesis method' using a high-energy ball milling process and a 'wet synthesis method' utilizing chemical reactions in a solution. The research team focused on the wet synthesis method, which is advantageous in terms of process scale-up and mass production, and succeeded in manufacturing a high-purity solid electrolyte through an optimal synthesis reaction in a solvent.

The biggest advantage is that it eliminates the need to use expensive lithium sulfide (Li2S). Lithium sulfide is so expensive that it accounts for 95% of the cost of starting materials used to manufacture solid electrolytes. Furthermore, lithium sulfide often remains as unreacted impurities during the wet synthesis process, frequently causing a degradation in cell performance. Although some synthesis methods that do not use lithium sulfide have been proposed, they require the additional use of expensive additives, and the results were unsatisfactory due to residual impurities.

On the other hand, KERI's simple synthesis method enables the production of high-quality solid electrolytes without the need for lithium sulfide, additives, or additional processes compared to the existing wet process. Costs can be reduced to as much as 1/25th of the material costs when using lithium sulfide, and the manufacturing process time can also be shortened, which can significantly contribute to the mass production of solid electrolytes.

Dr. Park Jun-ho stated, “Based on the solid electrolyte manufacturing know-how accumulated at the research institute over the years, we have found a method to easily and simply produce high-purity solid electrolytes through the optimal combination of chemical reactions of starting materials within organic solvents.” He added, “We expect this to resolve both price competitiveness and mass production issues, which are the biggest hurdles to the commercialization of all-solid-state batteries.”

KERI, having completed patent applications related to the source technology and the publication of research papers at home and abroad, anticipates that this achievement will attract significant interest from companies related to solid-state batteries and plans to identify potential customers and pursue technology transfer.

Meanwhile, KERI is a government-funded research institute under the National Science and Technology Research Council of the Ministry of Science and ICT. This research was conducted through KERI's basic project, 'Development of Core Manufacturing Process Technologies for the Commercialization of Non-Flammable Batteries.'