Medium‐Entropy Doping Stimulated Multielectron Redox for Ultrastable High‐Capacity Na <sub>3</sub> V <sub>2</sub> (PO <sub>4</sub> ) <sub>3</sub>
Polyanion‐based sodium‐ion cathodes are attractive candidates for next‐generation energy storage owing to the excellent structural stability, yet the practical deployment is hindered by limited specific capacity. Here, a medium‐entropy Na superionic conductor (NASICON)‐type Na 3 Fe 0.3 Cr 0.3 V 1.1 Ti 0.3 (...