Data-driven discovery and first-principles design of novel cathode materials for sodium-ion batteries

Sodium-ion batteries have emerged as a promising alternative to lithium-ion batteries because of the abundance of sodium resources. However, their development remains constrained by the relatively low capacity and insufficient structural stability of cathode materials such as NaCrO 2 , while conventional trial-and-error approaches explore only a small fraction of the available chemical space. This work develops an integrated generative artificial intelligence and first-principles workflow for identifying chromium-containing sodium cathode candidates. A property-conditioned MatterGen model was fine-tuned using approximately 12000 density functional theory-relaxed sodium-containing materials spanning several Na-M-M’-O chemical systems. The fine-tuned model generated 56 chemically plausible structures, which were relaxed using a graph neural network interatomic potential, assessed for novelty, and screened according to the local coordination environments of sodium and transition-metal sites. The screening reduced 25 unique candidates to 9 structures for first-principles validation. All shortlisted compounds exhibited negative formation energies relative to their elemental reference states, ranging from -2.747 to -0.773 eV/atom, although this criterion alone does not establish ground-state stability. Calculated average desodiation voltages ranged from 0.651 to 3.864 V. Combined analysis of Bader charge change, local magnetic moments, and electronic structures identified chromium-dominant cationic redox, secondary-transition-metal-dominant cationic redox, mixed cationic–anionic compensation, and oxygen-dominated charge compensation. The resulting structures extend beyond conventional layered sodium chromium oxide and include layered, disordered-rocksalt, and nonlayered frameworks. These results demonstrate the potential of integrating generative artificial intelligence, machine learning, and quantum-mechanical simulations to expand the design space for sodium-ion battery cathodes and provide a transferable framework for other materials-discovery applications.