Selective Lattice Doping Enables a Low-Cost, High-Capacity and Long-Lasting Potassium Layered Oxide Cathode for Potassium and Sodium Storage.

Layered transition metal oxides are highly promising host materials for K ions, owing to their high theoretical capacities and appropriate operational potentials. To address the intrinsic issues of KMnO cathodes and optimize their electrochemical properties, a novel P3-type oxide doped with carefully chosen cost-effective, electrochemically active and multi-functional elements is proposed, namely KCuFeMnO. Compared to the pristine KMnO, its reversible specific is increased from 104 to 135 mAh g.