%0 Journal Article
%A Ghoshal, Amit
%A Thakur, Vikas Singh
%A Pramanik, Susmita
%A Mehta, Vanshika
%A Meena, Sher Singh
%A Hirsbrunner, Moritz
%A Kaushik, S. D.
%A Dan, Tinku
%A Törnblom, Pontus
%A Duda, Laurent
%A Ghosh, Anirudha
%A Såthe, Conny
%A Tokushima, Takashi
%A Ghosh, Subham
%A Banerjee, Swastika
%A Maitra, Urmimala
%T Unlocking high performance in a Na–Fe–Mn–O cathode through phase-transition-free cycling
%J EES batteries
%V 1
%N 5
%@ 3033-4071
%C Washington DC
%I Royal Society of Chemistry
%M PUBDB-2025-04562
%P 1255 - 1266
%D 2025
%X Fe–Mn-based Na-layered oxide cathodes suffer from severe phase transitions at high states of charge, accompanied by transition metal migration and large-volume collapse. We propose the incorporation of a small amount of Li+ into the transition metal layer to enable phase-transition-free cycling across a wide state-of-charge (SOC) range. In contrast to the previously studied undoped or Li/Mg/Ni doped P2-type Na–Fe–Mn–O cathodes, our P2-Na0.7Li0.127Fe0.127Mn0.746O2 (NLFM) cathode, which has optimized Li, Fe and Mn contents and a disordered transition-metal layer, exhibits the remarkable property of complete suppression of O-type layer formation up to the highest charge voltage of 4.5 V. The cathode demonstrates reversible high-voltage Fe and O redox reactions without any phase transition. The P to O phase transition, accompanied by transition-metal-migration and □–O–□ (□ = vacancy) formation, is essential for the activation of O-redox in undoped Fe–Mn cathodes. The highly ionic character of Li–O bonds in NLFM increases the electron density over the O orbitals, making O-redox feasible in the P2-phase even in the absence of □–O–□. By retaining its P2 phase at the highest state of charge, the cathode shows a negligible volume change of less than 1.8
%F PUB:(DE-HGF)16
%9 Journal Article
%R 10.1039/D5EB00106D
%U https://bib-pubdb1.desy.de/record/639476