Researchers have broken the boundaries of previously developed solid-state cells to create a 5V version that addresses the technology’s safety and energy density limitations.
Scientists at the South Korean Yonsei University applied a fluoride solid electrolyte (LiCl–4Li2TiF6) protective coating on high-voltage cathodes to suppress interfacial degradation between the cathode and the electrolyte.
Historically researchers have found conventional solid electrolytes, such as sulfides and oxides, break down above 4V.
The team’s paper was published in the peer-reviewed Nature Energy journal.
The paper reports how the fluoride solid electrolyte remains stable beyond 5V and exhibits a Li+ conductivity of 1.7 × 10⁻⁵ S/cm at 30°C.
The team reported their battery retains over 75% capacity after 500 cycles and supports an areal capacity of 35.3 mAh/cm².
Professor Yoon Seok Jung and his team say the technology could be used in pouch-format cells.
Professor Jung said, “Our fluoride solid electrolyte opens a previously forbidden route for high-voltage operation in solid-state batteries, marking a true paradigm shift in energy storage design.”
The team’s fluoride-based shield also allows the technology to be used with halide catholytes such as zirconium-based systems.
