The overarching aim of this data workflow was to be able to track particles across multiple tomograms acquired at different states-of-charge (SoC). This allowed us to track changes in grey level within these particles. The data processing pipeline is shown schematically in Figure in the SI. The data processing was performed with python scripts which allowed for a well-documented, repeatable, and modifiable workflow using opensource software. Rendering and visualisation tasks were carried out in Avizo (V2020.2, Thermo-Fisher Scientific).