Zirconium-doped O3-Type layered oxide cathode with mitigated phase transition and enhanced Na+ transport kinetics for sodium-ion batteries

O3-type layered oxides are considered as potential materials for sodium-ion batteries (SIBs) because of their cost competitiveness and high reversible capacity. Whereas, their commercialization is limited by sluggish Na + kinetics, irreversible phase transition, and poor air stability. Herein, to address these challenges, we propose zirconium (Zr) doping to regulate the structure of O3-NaCu 0.2 Fe 0.3 Mn 0.5 O 2 (CFM). With the incorporation of Zr into CFM, the diffusion channel is expanded, and the detrimental phase transition is suppressed, thereby the Na  +  diffusion kinetics is facilitated and the layered structure is stabilized. The optimized NaCu 0.15 Fe 0.3 Mn 0.5 Zr 0.05 O 2 (CFM-Zr0.05) cathode delivers a high capacity of 121.5 mAh g −1 and a favorable capacity retention of 70% after 400 cycles at 1C. When paired with hard carbon anode, the full cell maintains 84.8% of its initial capacity after 100 cycles at 0.5C, demonstrating promising practical application potential. Furthermore, Zr-doped CFM cathode demonstrates enhanced air stability by mitigating Na + /H + exchange. This work presents a rational design strategy to achieve high-performance O3-type layered oxide cathodes, benefitting the development of SIBs for large-scale energy storage.