Liaqat, Aneeqa Moeez, Iqra Butt, Annam Akbar, Muhammad Bhatti, Ali Hussain Umar Ali, Ghulam Chung, Kyung Yoon 2026-02-19T05:30:16Z 2026-02-19T05:30:16Z 2026-02-19 2026-03 2352-152X https://pubs.kist.re.kr/handle/201004/154299 Rechargeable sodium-ion batteries (SIBs) are emerging as a viable alternative to lithium-ion batteries, offering comparable electrochemical performance while benefiting from the higher abundance of sodium. Layered oxides are widely regarded as the most promising cathode materials, with significant research focused on phases such as P2- and O3-type materials. However, these layered oxide cathode materials undergo severe structural degradation during cycling, leading to rapid capacity decay. To mitigate this structural instability, Sb-doped Na0.67Fe0.47Mn0.5Al0.03O2 P2-type cathode materials are synthesized in this study. It is observed that Sb inclusion in the transition-metal layer improves Na+ diffusion kinetics. The optimized material Na0.67Fe0.45Mn0.5Al0.03Sb0.02O2 (NFMAS2) exhibits 143.8 mAh g−1 at 0.2C discharge capacity, between 1.5 and 4.3 V, and a rate capability of 58.6 mAh g−1 at 5C. High-resolution transmission electron microscopy reveals remarkable structural reversibility for NFMAS2, confirming that the microstructure remains intact after cycling. In addition, the P2 to O2 reversible phase shift in the sodium de-/intercalation mechanism of NFMAS2 was studied using in-situ X-ray diffraction, elucidating the origin of the structural stability of the active material, its superior electrochemical performance, and excellent capacity retention. This investigation highlights the effectiveness of doping and provides valuable insights into the development of high-performance cathode materials for SIBs. English Elsevier BV Stabilizing the structure of P2-Na0.67Fe0.47Mn0.5Al0.03O2 cathodes through Sb-substitution for sodium-ion batteries Article 10.1016/j.est.2026.120572 1 Journal of Energy Storage, v.152, no.Part B Journal of Energy Storage 152 Part B Y scie scopus 001679168400004 2-s2.0-105028243319 Energy & Fuels Energy & Fuels Article LAYERED OXIDE CATHODE ELECTROCHEMICAL PROPERTIES RATE CAPABILITY PERFORMANCE PHASE TRANSITION INSERTION ELECTRODE SPECTRA layered metal oxide cathode P2-phase Sb doping In-situ XRD Na-ion batteries