Magnetic microscopy for operando imaging of battery dynamics.

Battery development pivots around understanding the complex processes governing battery operation and degradation. Most degradation pathways link structural and chemical inhomogeneities with strongly heterogeneous carrier transport at the nano- and microscale, which remains challenging to resolve with current operando imaging techniques. Here, we provide a data-driven perspective on using operando magnetic microscopy to examine the charge and discharge cycles in lithium and post-lithium batteries. Through quantitatively imaging ionic and electronic current distributions and probing the associated chemical reactions at the nanoscale, valuable insights into battery inhomogeneities and degradations can be gained. The approach facilitates spatially resolving heterogeneous redox reactions, buried current distributions, and mechanistic contributions to short-circuit endurance in batteries.