High‐Entropy Layered Oxide Cathodes for Sodium‐Ion Batteries

Abstract

Material innovation on high‐performance Na‐ion cathodes and the corresponding understanding of structural chemistry still remain elusive. Herein, we report a new concept of high‐entropy chemistry for Na‐ion cathodes. An example of layered O3‐type NaNi 0.12 Cu 0.12 Mg 0.12 Fe 0.15 Co 0.15 Mn 0.1 Ti 0.1 Sn 0.1 Sb 0.04 O 2 has been designed and prepared successfully, which exhibits the l onger cycling stability ( ~ 83% of capacity retention after 500 cycles) and the outstanding rate capability ( ~ 80% of capacity retention at the rate of 5.0C). A highly reversible phase‐transition behavior is presented between O3 and P3 structures during the charge‐discharge process, and importantly, this behavior is delayed effectively with more than 60% of the total capacity being stored in O3‐type region . Possible mechanism can be attributed to the multi‐component transition metals in this high‐entropy material which can accommodate the changes of local interactions during Na + (de)intercalation . This strategy on high‐entropy chemistry opens new insights into the development of advanced cathode materials.