Every time a smartphone is charged or an electric vehicle is plugged in, billions of lithium ions move through a battery to store energy. Future devices could perform far better with solid-state batteries, a technology that promises longer-lasting phones, safer energy storage, and electric vehicles capable of traveling much farther on a single charge. Yet one stubborn problem has kept these batteries from reaching the mainstream: tiny structures called dendrites that can destroy a battery from the inside.

Now, researchers at the Max Planck Institute for Sustainable Materials (MPI-SusMat) have uncovered exactly how these microscopic defects trigger battery failure. Their findings, published in Nature, provide new insight into one of the most important challenges facing next-generation energy storage.

Unlike conventional lithium-ion batteries, which rely on a liquid electrolyte to move ions between electrodes, solid-state batteries use a solid ceramic electrolyte. Eliminating the liquid component offers several advantages. Solid-state designs can potentially store more energy in the same amount of space, reduce fire risks, and remain functional for longer periods.

The technology has attracted enormous interest from automakers and electronics manufacturers because it could dramatically improve battery performance. In theory, smartphones could go days without charging, while electric vehicles could achieve driving ranges up to three times greater than current models.