Ion intercalation across dimensional regimes: from 3D to 0D hosts

Ion intercalation provides a versatile route to controlling material properties by coupling ion transport with structural, electronic, and chemical changes in the host. How this coupling unfolds depends strongly on host dimensionality, since geometric constraints determine the accessible ion-transport pathways, structural responses, and emergent functional behavior. This review surveys intercalation across dimensional regimes, from 3D frameworks and 2D layered compounds to 1D channels and nanostructures, and 0D nanocrystals. We first outline intercalation routes and the characterization strategies used to track the structural, chemical, and electrochemical changes induced by ion insertion, including machine-learning-assisted prediction and analysis. We then examine recent progress in ion transport, property modulation, and device applications across 3D, 2D, 1D, and 0D systems. Finally, we discuss regime-specific challenges and open directions, including operando multimodal characterization, interface control, and predictive modeling, to guide future research on ion-controlled functionality across dimensional regimes.