| Abstract Scope |
Sodium-ion batteries offer a promising route toward affordable and sustainable energy storage by replacing lithium with an earth-abundant element. Beyond abundance, sodium introduces a rich solid-state chemistry landscape arising from its larger ionic radius and the resulting structural flexibility of layered oxide cathodes. In this talk, I will discuss our recent work on both O-type and P-type sodium transition-metal oxide cathodes, highlighting their distinct structural features, electrochemical advantages, and materials challenges. To advance fully sustainable sodium cathodes, we further explore redox chemistries based on more abundant and environmentally benign transition metals, including Mn and Cu, while reducing reliance on Ni. Through targeted elemental substitution, we address key limitations in stability, capacity retention, and phase evolution. Combined electrochemical testing and advanced characterization reveal how local structure, particle morphology, and phase transitions govern cathode performance, providing design principles for next-generation sustainable sodium-ion battery materials. |