A major step toward commercial all‑solid‑state batteries (ASSBs) has been achieved by the Korea Research Institute of Standards and Science (KRISS), which has developed a materials technology that cuts the production cost of oxide-based solid electrolytes by more than 90%.
The advance supports low-cost, large-scale manufacturing of next‑generation batteries designed to eliminate fire and explosion risks.
KRISS’s Emerging Material Metrology Group has demonstrated ultra‑dense, large‑area solid electrolyte membranes using a method that coats electrolyte powders with multifunctional compounds. This approach reduces production costs to around one‑tenth of conventional processes.
Lithium-ion batteries used in EVs and energy storage systems still depend on flammable liquid electrolytes, and recent incidents – including fires at a government data centre and EV battery explosions – have highlighted the need for safer alternatives. ASSBs replace liquid electrolytes with non‑flammable solid materials, and oxide-based systems are attracting attention for their high energy density and stability.
Garnet-type solid electrolytes are central to these batteries but require sintering at temperatures above 1,000°C. A long-standing challenge has been lithium evaporation during sintering, which degrades membrane quality and increases resistance. Traditional methods use large quantities of mother powder to compensate, but most of it is discarded, driving up costs.
KRISS has overcome this by coating electrolyte powders with Li–Al–O multifunctional compounds. The coating supplies lithium during sintering, prevents evaporation, and improves particle bonding. The team achieved a density above 98.2% without mother powder, doubling ionic conductivity and reducing electronic conductivity more than twentyfold.
Large-area membranes of 16 cm² were produced with a 99.9% yield. As Dr Baek Seung‑Wook noted, “This achievement fully resolves long-standing materials and manufacturing challenges.” Dr Kim Hwa‑Jung added that the breakthrough in ASSBs could enable domestic production of high-value battery materials.
