MRI Reveals Dendrite Formation in Solid-State Batteries, Paving Way for Safer Energy Storage

A breakthrough at the National High Magnetic Field Laboratory, Florida State University, unveils the mechanism behind dendrite formation in solid-state batteries, a leading cause of short circuits and failure. Published in *Nature Materials*, the research, led by Professor Yan-Yan Hu, provides unprecedented insight into this phenomenon.Using a custom-built probe and the MagLab's magnetic resonance imaging (MRI) system, researchers visualized dendrite growth during battery charge and discharge cycles. Solid-state batteries, utilizing solid electrolytes instead of liquids, promise higher energy density and improved safety compared to conventional lithium-ion batteries. However, dendrite formation, where metallic lithium needles grow and short-circuit the battery, has hindered their development.The team discovered that dendrites originate both at the electrode-electrolyte interface and within the solid electrolyte itself. These needles then branch and connect, leading to battery failure. "We now have a comprehensive understanding of how these dendrites can form, grow, and evolve," stated graduate student Yudan Chen, a lead author.Professor Sam Grant, director of the MagLab's MRI program, emphasized the role of high-field magnets in analyzing lithium, enabling imaging inaccessible at lower fields. The findings offer a pathway to designing more reliable solid-state batteries for electric vehicles, medical devices, and renewable energy systems. Future research will focus on preventing dendrite buildup through material modifications and interface re-engineering, with magnetic resonance techniques serving as an evaluation toolkit.