A team of researchers at UNIST has unveiled a breakthrough gel-like material that could dramatically extend the lifespan and safety of high-voltage electric vehicle (EV) batteries. The novel electrolyte prevents the formation of reactive oxygen species (ROS)—the main driver of battery aging—boosting battery life by 2.8 times and reducing swelling by one-sixth.
The innovation comes from an anthracene-based semi-solid gel polymer electrolyte (An-PVA-CN), which directly blocks ROS formation during high-voltage charging. Unlike previous approaches that neutralized ROS after they formed, this material prevents ROS at the source, ensuring longer-lasting, safer batteries.
High-voltage lithium-ion batteries (LIBs) store more energy but also risk destabilizing oxygen in nickel-rich cathodes, leading to ROS generation, gas buildup, and shorter lifespans. The new electrolyte addresses these challenges in two ways: the anthracene component captures unstable surface oxygen, while a nitrile (-CN) group stabilizes the cathode’s nickel metal structure.
In testing, batteries with this electrolyte retained 81% of their capacity after 500 charge-discharge cycles at 4.55V, compared to conventional batteries dropping below 80% after just 180 cycles. Swelling was also drastically reduced, with expansion limited to 13 micrometers, versus 85 micrometers in standard cells—a nearly sixfold improvement.
Professor Hyun-Kon Song, leading the research, noted, “This study shows oxygen reactions in high-voltage batteries can be controlled at the electrolyte design stage. The same principle could enable lightweight batteries for aerospace and large-scale energy storage applications.”
The research, a collaboration with Dr. Seo-Hyun Jung (KRICT) and Dr. Chihyun Hwang (KETI), was published online in Advanced Energy Materials on October 5, 2025, and supported by UNIST’s InnoCore program, KEIT, and KRICT.
