Researchers have unveiled a new family of ionically conductive elastomers (ICEs) capable of achieving remarkable stretchability, strength, and ionic conductivity, paving the way for their use in advanced wearable technologies and stretchable batteries.
These novel materials, synthesized through innovative multiple network elastomer (MNE) architecture, demonstrate room temperature ionic conductivity levels of 10-6 S/cm and tensile strength reaching approximately 8 MPa, representing substantial advancements compared to previous iterations.
While stretchable ionically conductive materials are integral to the development of soft electronics, the pursuit of achieving durability alongside effective ionic conductivity has been fraught with challenges. Traditionally, developing materials with high mechanical strength often compromised ionic conductivity, limiting their applications to less demanding environments.
The newly developed ICEs successfully balance these properties, addressing the longstanding trade-off between mechanical performance and ionic conduction. Researchers have achieved this by utilizing low glass transition temperature (Tg) polymers combined with MNE architecture, which provides both stiffness and improved ionic mobility.
"What sets our ICEs apart is the implementation of sacrificial bond mechanics, which allows the material to exhibit reversible elasticity even under substantial strains," explained the leading research team. This design enables the elastomers to withstand extensive cyclic loading, making them durable and suitable for long-term applications.
The development process involved synthesizing crosslinked networks incorporating ethylene glycol methyl ether acrylate (MEA) and isobornyl acrylate (IBA) as key components. The integration of lithium bis (trifluoromethane sulfonimide) (LiTFSI) as the electrolyte salt enhanced the ionic conductivity without compromising mechanical integrity.
Tests revealed the ICEs maintained not only elasticity but also significant fracture toughness due to the unique mechanical properties imparted by the MNE structure. This allows for enhanced energy dissipation, reducing crack propagation risks during deformation.
Comparative measurements indicate these new ICE materials outperform prior liquid-free stretchable ion conductors, marking significant progress for soft ionotronic devices. "Our findings indicate this approach opens possibilities for developing softer, more efficient energy storage solutions,” emphasized the team.
Further testing confirmed the ICEs retained their superior mechanical and ionic properties even at elevated temperatures, enhancing their applicability for real-world use cases, including flexible electronics and smart textiles.
Looking forward, the researchers believe these ionically conductive elastomers could play transformative roles across various sectors, from bioelectronics interfacing directly with human tissue to facilitating the next generation of portable energy devices.