Operando Visualization of Dynamic Lithium and Electrolyte Transport in 18650‐Type Lithium‐Ion Cells

Details of the nonlinear volume changes of the electrode materials in commercial 18650‐type cylindrical cells, particularly in relation to the electrolyte distribution, have been investigated on a macroscopic level. An experimental study employed optical micrometry, cold neutron radiography and thermal neutron computed tomography to investigate the interior of two cylinder‐type lithium‐ion batteries. Anisotropic cell breathing was correlated with lithium transport and electrolyte redistribution throughout the cell volume during cell operation. The obtained results revealed a complex interaction of the cell electrode–electronic subsystem, opening a broad field of research with potential impact on reducing accelerated cell aging and increasing cell lifetime and safety.