Conformal coating of silicon (Si) anode particles is a common strategy for improving their mechanical integrity, to mitigate battery capacity fading due to particle volume expansion, which can result in particle crumbling due to lithiation induced strain and excessive solid-electrolyte interface formation. Here, we use operando transmission electron microscopy in an open cell to show that TiO2 coatings on Si/SiO2 particles undergo thickness dependent rupture on battery cycling where thicker coatings crumble more readily than thinner (∼5 nm) coatings, which corroborates the difference in their capacities.

High-fidelity and facile ex situ transmission electron microscopy (TEM) characterization of lithium−oxygen (Li−O₂) batteries is still limited by challenges in preserving the native environment of Li−O₂ discharge products. The extreme reactivity and moisture sensitivity of the discharge products means that they are quickly altered during sample retrieval from cycled batteries and transfer for TEM analysis, resulting in loss of original information. We here demonstrate that by using a TEM specimen grid directly in Li−O₂ batteries as both support electrode and sample collector overlaid on a standard oxygen diffusion electrode, discharge products that are formed on the grid can be kept pristine.