Researchers may have found a promising alternative to conventional lithium-ion batteries made from a common material: rubber. For electric vehicles (EVs) to become mainstream, they need cost-effective, safer, longer-lasting batteries that won't explode during use or harm the environment.
These unique characteristics of the rubber electrolytes prevent lithium dendrite growth and allow for faster moving ions, enabling reliable operation of solid-state batteries even at room temperature.
"Rubber has been used everywhere because of its high mechanical properties, and it will allow us to make cheap, more reliable and safer batteries," said Lee. "Higher ionic conductivity means you can move more ions at the same time," said Michael Lee, a mechanical engineering graduate researcher.
Elastomeric electrolytes for high-energy solid-state lithium batteries. Nature, 2022; 601 (7892): 217 DOI: 10.1038/s41586-021-04209-4 Georgia Institute of Technology. "Rubber material holds key to long-lasting, safer EV batteries." ScienceDaily.
This unique structure has resulted in high ionic conductivity, superior mechanical properties and electrochemical stability. This rubber electrolyte can be made using a simple polymerization process at low temperature conditions, generating robust and smooth interfaces on the surface of electrodes.
Georgia Tech engineers have solved common problems (slow lithium-ion transport and poor mechanical properties) using the rubber electrolytes. The key breakthrough was allowing the material to form a three-dimensional (3D) interconnected plastic crystal phase within the robust rubber matrix.