Jeongi-yeon Discovers Optimal Mixing Technology for All-Solid-State Batteries

The Korea Electrotechnology Research Institute (KERI) announced on the 29th that Dr. Ha Yoon-cheol from the Next-Generation Battery Research Center, together with Professor Kim Byung-gon’s team from the Department of Applied Chemistry at Kyung Hee University, Professor Moon Jang-hyuk’s team from the Department of Energy Systems Engineering at Chung-Ang University, and Professor Lee Seung-gi’s team from the Department of Materials Engineering at Pusan National University, have developed a technology that can optimally mix cathode active materials and solid electrolytes for sulfide-based all-solid-state batteries.

Dr. Ha Yoon-cheol (left) and KERI researchers are posing with the 'blade mill' equipment used to optimally mix cathode active materials and solid electrolytes for all-solid-state batteries. Photo by Korea Electrotechnology Research Institute

All-solid-state batteries are attracting attention as next-generation batteries due to their extremely low risk of fire or explosion, but they require much more advanced technology and are difficult to manufacture compared to conventional batteries based on liquid electrolytes. In particular, effective mixing and dispersion of cathode active materials, solid electrolytes, conductive agents, and binders within the electrode plate manufacturing process is known to be one of the major challenges.

Until now, methods to composite cathode active materials and solid electrolytes included ▲ mechanically simple mixing in wet or dry environments to manufacture layers tens to hundreds of micrometers thick (one millionth of a meter) ▲ and the ‘core-shell’ structure method, which wraps the cathode active material surface with solid electrolyte. However, these methods faced difficulties such as poor electron or ion mobility or challenges in forming low interfacial resistance.

KERI and the university research teams tackled the problem by utilizing a method that partially coats the cathode active material with solid electrolyte. Since solid electrolytes are sensitive to oxygen and moisture and can degrade if mishandled, the research team developed a special device called a ‘blade mill’ that uses so-called ‘inert gases’ which do not cause chemical reactions. This allowed them to study various forms of solid electrolyte coating structures and experimentally verify the optimal mixing ratios with cathode active materials.

Subsequently, through various simulations, they secured a large amount of data that could improve the ‘active material utilization rate (actual operating capacity relative to theoretical capacity)’ and ‘rate characteristics (high-speed charge/discharge compared to low-current charge/discharge)’ of all-solid-state batteries. They then applied these results to prototypes (pouch cells) and confirmed the performance improvements of the all-solid-state batteries.

The related research findings were published in the internationally renowned energy journal, Energy Storage Materials.

KERI all-solid-state battery with optimally mixed cathode active material and solid electrolyte, resulting in enhanced performance. Photo by Korea Electrotechnology Research Institute

Dr. Ha Yoon-cheol stated, “While enhancing the performance and reducing the cost of solid electrolytes themselves are important for the widespread adoption of all-solid-state batteries, structural design and manufacturing process technologies that effectively produce electrode plates facilitating smooth ion and electron flow are also crucial.” He added, “By using composite materials where solid electrolytes are partially coated on cathode active materials at optimal ratios, we can enhance the functionality of electrode plates and significantly contribute to improving the performance of all-solid-state batteries.”

KERI plans to pursue commercialization by securing patents related to this technology and identifying potential demand companies.

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