This dataset contains sodium-ion battery cathode candidate materials generated using data from the Materials Project database. The dataset is not directly available from Materials Project because several electrochemical properties are estimated and derived using analytical formulas and heuristic rules. The following derived properties were computed:

Sodium fraction: calculated from atomic composition.

Theoretical capacity (mAh/g): estimated using Faraday’s law based on sodium content and molar mass.

Average sodium voltage (V): approximated from formation energy per atom normalized by sodium fraction and constrained to a realistic voltage window (1.5–4.2 V).

Energy density (Wh/kg): calculated as the product of estimated voltage and theoretical capacity.

Structure family (Prussian Blue, NASICON, layered oxide, polyanionic, framework): classified using heuristic rules based on elemental composition and crystal symmetry.

Sodium diffusion barrier (eV): assigned using typical literature-based values for each structure family. All electrochemical properties in this dataset are computational estimates based on analytical approximations and heuristic rules. The dataset should be used for research, educational, and screening purposes only, not as experimentally validated performance data.