Georgia Tech develops hybrid ceramic polymer electrolytes to improve safety, performance of solid-state batteries

Currently commonly used lithium-ion batteries use electrolytes, which are prone to thermal runaway and fire if damaged. According to foreign media reports, future solid-state lithium-ion batteries based on ceramic-polymer hybrid electrolytes are expected to provide greater energy storage, faster charging speeds, higher electrochemical and thermal stability, while overcoming the problems of early solid-state batteries. Many technical challenges.

Researchers at the Georgia Institute of Technology (Georgia Tech) are working to deepen the fundamental understanding of hybrid electrolytes. These components transfer charge between the electrodes, creating an electric current that allows the battery to power an electric vehicle and then recharge it. "Researchers have demonstrated that these hybrid solid-state electrolytes can be made and placed in coin cells to demonstrate high performance and high stability," said Ilan Stern, principal research scientist at the Georgia Tech Research Institute (GTRI). "This study shows that The next step for solid-state battery innovation based on these ceramic-polymer hybrid materials is to integrate this technology into pouch batteries for electric vehicles."

The researchers explored an electrolyte called lithium aluminum germanium phosphate (LAGP). Surrounding the LAGP electrolyte with a polymer component called polyDOL provides internal ionic conductivity that far exceeds that of existing ceramic electrolytes, while being non-flammable.

The researchers believe that traditional ceramic electrolytes offer safety and energy storage advantages, but have limitations in making contact with electrodes to transfer ionic charges. By adding polymers, the interfacial contact between electrode and electrolyte can be greatly improved while maintaining most of the advantages of ceramics. Stern said: "Very different from the electrolyte, the mixed electrolyte has electrochemical stability, thermal stability and mechanical stability. In addition, the solid-state battery uses lithium metal anode, and the upper capacity limit is significantly increased. It is indeed the best of both worlds." "

This hybrid ceramic-polymer electrolyte looks like a hockey puck but is more durable than pure ceramic. "Even if microcracks occur, the polymer provides scaffolding to ensure its structural integrity," Stern said.

This research is based on small laboratory-scale cells and has yielded good results. The researchers plan further development and testing to enable large-scale manufacturing.

In addition to demonstrating the potential of this technology, the team also modeled battery operation to help guide future technology development and evaluate the potential life cycle of hybrid electrolyte solid-state batteries. One of the goals for the future is to integrate the technology into supply chains, no longer rely on materials from conflict zones around the world, and evaluate new electrode materials such as lithium metal and silicon to replace standard graphite.

Solid electrolytes offer many advantages, but challenges remain. Because the fabrication process for hybrid electrolyte systems is more complex, the electrical, mechanical, and chemical interactions between materials must be thoroughly studied. "The more complex it is, the more questions you need to understand," Stern said.