Like dry spaghetti: Brittle lithium spikes found in batteries

Scientists have directly observed the growth and mechanical behavior of lithium dendrites—tiny, needle-like metal structures that form on the anode inside lithium-ion batteries. These dendrites can pierce the battery’s internal separator, causing dangerous short circuits and battery failure. Using specialized experimental platforms and high-resolution electron microscopy, researchers from the U.S. and Singapore captured how dendrites crystallize and deform under stress within sealed battery environments. Contrary to previous assumptions that lithium dendrites are soft and flexible, the study revealed they are actually brittle and strong, snapping like dry spaghetti due to a stiff coating called the solid electrolyte interphase (SEI). This brittleness allows dendrites to puncture battery components, increasing the risk of internal shorts, while broken fragments accumulate as “dead lithium,” reducing battery capacity over time. The findings highlight dendrites as a major obstacle to commercializing lithium-metal batteries, which offer higher energy density than current lithium-ion cells but are limited by dendrite formation. Understanding dendrite mechanics could inform