Abstract
Conventional liquid-electrolyte lithium-ion batteries face safety concerns from leakage and flammability, together with limited stability at high operating voltages. Solid-state batteries (SSBs) offer a promising alternative, with the potential to increase energy density without increasing battery size or weight. However, practical implementation remains challenging because long cycle life and rapid identification of degradation mechanisms are still unresolved, particularly at high voltages that place severe demands on the solid polymer electrolyte. Single-ion-conducting polymer electrolytes (SiCPs) offer a potential solution by immobilizing negatively charged anions within the polymer framework, leaving lithium ions as the main mobile charge carriers. This can reduce concentration polarization, support more uniform lithium deposition, and improve compatibility with lithium-metal SSBs. Their key challenge is to combine fast room-temperature ion transport with mechanical strength, high-voltage stability, and scalable manufacturing. The EU-funded HyLiST project addresses these requirements by developing hybrid SiCPs for solid-state cells using lithium metal and a cobalt-free, high-voltage LNMO cathode.
About the author
Kevin Vattappara is a researcher and project manager at the Materials for Energy Unit of CIDETEC Energy Storage, Spain. He finished his joint Ph.D. in 2026 at CIDETEC Energy Storage, Forschungszentrum Jülich and University of Duisburg-Essen. He specialized in “Ceramic-rich composite separators for lithium metal solid-state batteries”. His research spans solid-state electrolyte systems, while his current work is dedicated to the research and development of advanced cell components and scalable processes for high-energy solid-state batteries.