Korea’s researchers develop cost-efficient way to make solid-state batteries

[Photo provided by KIST]

South Korean researchers have developed a process that potentially enables the cost-effective mass production of solid-state batteries, which is garnering attention as the next-generation batteries.

According to the Korea Institute of Science and Technology (KIST) on Monday, a joint research team led by Dr. Kang Jin-gu, Senior Researcher at KIST’s Nanophotonics Research Center, and Professor Kim Dong-wan from School of Civil, Environmental and Architectural Engineering at Korea University, has developed a technology to efficiently produce solid electrolytes using a single solvent-based process.

Unlike lithium-ion batteries that utilize liquid electrolytes, solid-state batteries employ solid electrolytes, which offer higher energy density and eliminate the risk of fire incidents.

Among them, lithium argyrodite sulfide-based batteries have drawn attention due to their excellent ion conductivity, lithium compatibility, and electrochemical stability. However, the solid-state manufacturing process using solid-state mixtures has presented challenges in terms of energy consumption, hindering large-scale production. To address this, liquid processes that enable mass production through the reaction of mixtures in solvents have recently been developed. However, these processes required at least two solvents, making the operation complex and difficult to treat waste water.

Instead, the researchers developed a liquid crystal process that can make lithium argyrodite with two elements using only one solvent.

The method involves reacting precursors in a specific order in an acetonitrile solvent, a highly polar, hydrogen-bonding material. The resulting solid electrolytes were not significantly different in terms of ionic conductivity, lithium compatibility, and stability from those made by conventional methods, the research team explained.

The process also allows for the addition of other elements, such as tin and germanium, to compensate for lithium argyrodite’s weakness to moisture, unlike other liquid processes, the team added.

The newly developed process resulted in tinned solid electrolytes with three to four times the water safety of conventional solid electrolytes.

The research findings were initially published online in the Journal of Materials Chemistry A and will be published as a back cover article on July 21.