Research team of CNU Professor Park Chan-jin (Department of Materials Science and Engineering) succeeded in developing an all-solid-state batteries that greatly improved fire safety and practicality.

The team led by Professor Park has developed solid-state battery technology for electric vehicles that overcomes the limitations of existing solid-state batterie and increases their practicality.

While previous ceramic solid electrolyte materials were successful in achieving ion conductivity comparable to liquid electrolytes at room temperature, there were issues when applying them to actual batteries. These included a high interfacial resistance between the electrode and solid electrolyte, requiring high pressure to ensure good adhesion between the electrode and solid electrolyte, or the need to operate the battery at temperatures exceeding 60°C.

Similarly, polymer solid electrolytes had the advantage of relatively good bonding with the electrode due to their unique elasticity. However, they still required temperatures above 60°C for normal operation due to their low ion conductivity at room temperature.

The research team addressed the issues related to the high operating temperature above 60°C and the interfacial resistance between the electrode and solid electrolyte in existing solid-state electrolytes.

They developed a novel composite solid-state electrolyte with an optimized ion conductivity by combining a continuous 3D ceramic solid-state electrolyte structure with a polymer solid electrolyte. In particular, they resolved the interfacial resistance problem between the electrode and solid electrolyte by directly flowing liquid monomers into the porous electrode while the 3D ceramic structure and electrode were combined, followed by in-situ polymerization. The resulting solid-state battery does not require external pressure and can operate stably at room temperature.

This development is significant as it proposes a more economical and practical solid-state battery. The technology is expected to be applied to electric vehicles, energy storage systems (ESS), portable electronic devices, wearable devices, and more.

The research results were published in Advanced Science (impact factor: 17.521), a top-tier academic journal in the fields of basic science and engineering. This research was supported by the Ministry of Science and ICT (National Research Foundation Leading Research Center and Mid-Career Researcher Program).