Toray’s Breakthrough Polymer Speeds Up Solid State Battery Adoption

Toray, a leading materials innovation company, has announced a major advancement in battery technology. The company revealed that it has successfully developed an ion-conductive polymer membrane that boasts a remarkable 10-fold increase in ion conductivity compared to its predecessors. This breakthrough has the potential to significantly accelerate the deployment of both solid-state and lithium-ion batteries, marking a significant step forward in the quest for more efficient and reliable energy storage solutions.

One of the key challenges associated with lithium metal, a promising material for advanced batteries, is its high surface reactivity. This reactivity can lead to stability issues, particularly during charging and discharging cycles, due to the dissolution and precipitation morphology of lithium. A notable concern is the formation of lithium dendrites, tiny needle-like structures that can grow on the surface of lithium metal and potentially cause short circuits in batteries.

The use of metallic lithium anodes in batteries that employ solid electrolytes presents similar obstacles, which have so far hindered their practical applications. Toray's innovative polymer membranes address these challenges by offering ion conductivity through a mechanism known as hopping conduction. This mechanism allows lithium ions to move between interacting sites within the polymer membranes by effectively "jumping" across these sites, all while maintaining a non-porous structure.

Leveraging its expertise in molecular design technology, particularly with aramid polymers, Toray has succeeded in enhancing the hopping site structure and developing a new polymer with more hopping sites. As a result, the company has achieved an impressive ionic conductivity in the range of 10-4 S/cm for a hopping-conductive polymer film. This significant milestone paves the way for the widespread adoption of this innovative technology in next-generation battery systems.

In collaboration with Professor Nobuyuki Imanishi of the Graduate School of Engineering at Mie University, Toray conducted joint research to validate the effectiveness of the polymer membrane. The research confirmed that the polymer film serves as an efficient protective layer on lithium metal surfaces, effectively addressing the stability issues associated with lithium dendrite formation. Furthermore, the polymer membrane has demonstrated the ability to extend the service lives of batteries utilizing lithium metal anodes, as evidenced by the successful completion of 100 charge-discharge cycles in a dual-component lithium-air battery configuration.