Pentanary transition-metals Na-ion layered oxide cathode with highly reversible O3-P3 phase transition

Abstract

Na-ion O3-type layered oxides have attracted wide attention as cathode materials for Na-ion batteries, owing to their high compositional diversity providing tunable electrochemical performance. However, such cathodes usually suffer from monoclinic phase transitions, resulted from TMO2 (TM = transition metal) slab gliding and local distortion upon Na+ (de)intercalation, which can lead to the serious structural degradation and compromising cycling stability. Herein, a five-components O3-type layered oxide cathode, Na0.94Ni0.29Cu0.1Fe0.16Mn0.3Ti0.15O2, is designed by rationally modulating transition metals and incorporating different functionalities of multiple components. This material presents a highly reversible O3-P3 phase transition during Na+ (de)intercalation, suppressing the unfavorable monoclinic phase transformation which commonly exists in the Na-ion O3-type layered materials. As a result, this as-prepared material delivers a reversible capacity of ~ 122 mAh/g in the voltage range of 2–4.0 V with enhanced cycling stability (more than 79% of capacity retention after 300 cycles). These findings of multicomponent layered oxide cathode provide new insights into the development of structure-performance relationship for advanced Na-ion batteries.