Dynamic Lithium Distribution upon Dendrite Growth and Shorting Revealed by Operando Neutron Imaging

Lithium (Li) metal has the highest theoretical capacity and is essential for energy storage technologies beyond conventional Li chemistries. However, its utilization inevitably leads to dendrite growth from repeated plating and stripping, eventually shorts the battery. The process that leads to shorting and the consequential electrochemical impacts are not well understood due to its dynamic features. Herein, we apply neutron radiography to study the Li dendrite growth in real time. The dynamic distribution of Li flowing from the anode to cathode during charge, induced by the internal short circuit due to Li dendrite growth, has been observed. Furthermore, a competing mechanism after battery shorting between the short-induced self-discharge and charge is proposed to explain the voltage drop/rise during the extended charging time. Our work provides mechanistic insights with a deep understanding of dendrite Li shorting and redistribution. This can lead to safe design principles of Li metal electrodes in batteries.