TY - JOUR
AU - Ghoshal, Amit
AU - Thakur, Vikas Singh
AU - Pramanik, Susmita
AU - Mehta, Vanshika
AU - Meena, Sher Singh
AU - Hirsbrunner, Moritz
AU - Kaushik, S. D.
AU - Dan, Tinku
AU - Törnblom, Pontus
AU - Duda, Laurent
AU - Ghosh, Anirudha
AU - Såthe, Conny
AU - Tokushima, Takashi
AU - Ghosh, Subham
AU - Banerjee, Swastika
AU - Maitra, Urmimala
TI - Unlocking high performance in a Na–Fe–Mn–O cathode through phase-transition-free cycling
JO - EES batteries
VL - 1
IS - 5
SN - 3033-4071
CY - Washington DC
PB - Royal Society of Chemistry
M1 - PUBDB-2025-04562
SP - 1255 - 1266
PY - 2025
AB - 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
LB - PUB:(DE-HGF)16
DO - DOI:10.1039/D5EB00106D
UR - https://bib-pubdb1.desy.de/record/639476
ER -