High-speed neutron imaging has captured a 'real-time movie' of exactly how next-generation batteries explode during a fire.

Operando neutron imaging was used to link thermal runaway in all-solid-state batteries to early-stage behavior in the anode. This research reveals that the cathode's chemistry actually dictates when and how the rest of the battery fails. Engineers previously only had theories about the specific chain reaction that causes these high-tech batteries to overheat. This direct evidence shows exactly where the first sparks of failure begin deep inside the cell. These insights will allow battery manufacturers to design safer energy storage for electric cars and smartphones. It turns a dangerous unknown into a manageable engineering problem.