The advent of X-ray (powder) diffraction computed tomography (XRD-CT), a specialised form of tomography, has added a new dimension to the mix. This technique uses a pencil beam scanning method to yield reconstructed images corresponding to a sample's cross-section . What sets XRD-CT apart is its ability to resolve chemical species of similar density, a task that conventional X-ray CT often struggles with. As such, XRD-CT has found applications in a wide array of fields ranging from material science to cultural heritage conservation, as well as biological samples . More importantly, XRD-CT has become an invaluable tool to investigate, non-destructively, functional materials and devices, such catalytic reactors , fuel cells and secondary/rechargeable batteries in custom made laboratory cells as well as in commercially available and industrially relevant cylindrical form , under static or operating conditions (in situ/ operando studies). These studies have shown that the spatially-resolved diffraction patterns in the XRD-CT data can yield unique physicochemical information regarding these complex materials systems and their evolving solid-state chemistry. Recently, the method has also been demonstrated for five dimensional (5D) experiments, where the dimensions correspond to three spatial, one chemical (diffraction) and one temporal or imposed operating condition (e.g. temperature, pressure, potential) .