Korea Does It Again... Accelerating Commercialization of Next-Generation Batteries to Reshape the Electric Vehicle Market [Reading Science]

KRISS Develops Core Material Technology
to Reduce Production Costs of Oxide-Based Solid Electrolyte Membranes to One-Tenth

A core material technology that will accelerate the commercialization of all-solid-state batteries-next-generation batteries fundamentally eliminating the risk of fire and explosion-has been developed by a domestic research team. By solving a long-standing challenge in the manufacturing process of solid electrolyte membranes and dramatically reducing production costs, this breakthrough is being hailed as a turning point that could reshape the electric vehicle and energy storage system (ESS) markets.

On January 7, the Advanced Materials Measurement Group at the Korea Research Institute of Standards and Science (KRISS) announced that it has developed a material technology that enables the large-area, high-density production of solid electrolyte membranes-key components of oxide-based all-solid-state batteries-at just one-tenth of the conventional cost.

Research team developing core material technology for oxide-based solid electrolyte membranes. From left: Seungwook Baek, Principal Researcher of the Advanced Materials Measurement Group at KRISS; Hwajeong Kim, Postdoctoral Researcher; Minseo Choi, Student Researcher; Hyukjun Park, Professor of Materials Science and Engineering at Korea University. Provided by KRISS

Currently, widely used lithium-ion batteries pose significant fire and explosion risks due to their flammable liquid electrolytes. In contrast, all-solid-state batteries use non-flammable solid electrolytes, making them a next-generation battery technology with dramatically improved safety. In particular, oxide-based all-solid-state batteries are regarded as the safest battery technology, as they do not pose the risk of toxic gas leakage and offer high mechanical strength.

Garnet-type solid electrolytes are mainly used in oxide-based all-solid-state batteries. While this material boasts excellent ionic conductivity and chemical stability, it has faced limitations in producing large-area, high-quality electrolyte membranes due to lithium volatilization during ultra-high temperature sintering processes above 1,000°C. The previously used "base powder" method, intended to address this issue, resulted in significant material waste and greatly increased production costs.

Innovative Sintering Process with Functional Coating Enables Large-Area, Low-Cost Production

Schematic diagram of the high-performance large-area solid electrolyte processing technology developed by KRISS. To address the limitations of conventional oxide-based solid electrolytes, such as structural collapse and reduced sinterability caused by lithium volatilization, as well as high production costs, the research team developed a process that coats the surface of solid electrolyte powder with a high-functionality lithium compound to form grain boundaries, followed by sintering without base powder. This process effectively suppresses lithium volatilization and structural collapse while eliminating the use of base powder, significantly reducing manufacturing processes and production costs. It also successfully achieves a high-density large-area electrolyte film with high ionic conductivity and low electrical conductivity simultaneously. Provided by the research team

The research team solved this problem by developing a technology to coat the surface of solid electrolyte powder with a functional lithium compound. During the sintering process, this coating suppresses lithium volatilization, supplies the necessary lithium, and enhances the bonding strength between particles, thereby maximizing the density of the electrolyte membrane.

As a result, the team achieved a high-density electrolyte membrane with a density of over 98.2% without the need for expensive base powder, while more than doubling the ionic conductivity compared to conventional methods. Electrical conductivity was reduced by more than twentyfold, significantly lowering the risk of internal current loss in the battery. Furthermore, the team succeeded in producing a large-area solid electrolyte membrane of 16 cm² with a yield of 99.9%, demonstrating the potential for mass production.

Seungwook Baek, Principal Researcher of the Advanced Materials Measurement Group at KRISS, stated, "This achievement fundamentally resolves the processing challenges of garnet-type solid electrolytes that have remained unsolved for over 20 years, and will serve as a decisive catalyst for accelerating the commercialization of all-solid-state batteries." Hwajeong Kim, Postdoctoral Researcher, commented, "This research has opened the possibility for domestic production of core materials for next-generation batteries."

This research was conducted in collaboration with Professor Hyukjun Park's team at Korea University and was supported by the Ministry of Science and ICT, the National Research Foundation of Korea's Nano and Materials Technology Development Program, and the basic research program of KRISS.

The results of this research were published online on December 10, 2025, in Materials Today, a leading international journal in the field of materials science, under the title "Revitalizing multifunctionality of Li-Al-O system enabling mother-powder-free sintering of garnet-type solid electrolytes."