Electrical imbalances at grain boundaries in solid-state batteries have been identified as a significant factor in battery failures, according to research conducted by MIT and the Technical University of Munich. Published on July 6, 2026, in Nature Nanotechnology, this study sheds light on how these imbalances affect battery performance.
Understanding Grain Boundaries in Solid-State Batteries
Researchers have long suspected that the boundaries where two grains of electrolyte meet could contribute to the formation of dendrites—tiny spikes of lithium metal that lead to battery inefficiency and failure. These grain boundaries are crucial for understanding the chemical and electrical properties of solid-state batteries.
“Grain boundaries are like defects,” said Harry Tuller, senior author and professor in MIT's Department of Materials Science and Engineering. “The boundaries have a higher level of defects than in the grains themselves, and generally that means as carriers of charge approach the boundary, whether electrons or ions, there's some kind of blockage to overcome.”
Impact of Electrical Imbalances on Battery Efficiency
The MIT research team developed a model to explain how local electrical imbalances at grain boundaries change the movement of lithium ions and electronic charge carriers. They utilized various techniques, including electron microscopy, machine learning modeling, and electrochemical impedance spectroscopy, to analyze these effects.
