Whba, RawdahDogan, EbruHarfouche, MessaoudOzturk, Zeynep ReyhanFarhan, AhlamIpek, SemranCorut, Sumeyye2026-04-042026-04-0420262366-7486https://doi.org/10.1002/adsu.202500678https://hdl.handle.net/11616/110021This study investigates the effect of Cu2+ doping on NaMn1- xCuxO2 layered cathodes. It also explores their integration with Laurus nobilis-derived hard carbon (HC) anodes for sodium-ion batteries (SIBs). Cu doping, particularly at x = 0.20, stabilizes the beta-NaMnO2 phase, suppresses Jahn-Teller distortions, and improves the structural stability of the MnO2 framework. In situ X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations confirm that Cu improved Na+ diffusion kinetics and reduces charge-transfer resistance, despite its electrochemical inactivity. X-ray Difraction (XRD), Raman, and Fourier transform infrared spectroscopy (FTIR) analyses reveal phase destabilization and segregation at higher Cu concentrations, while XPS indicates shifts in the Mn/Cu oxidation states, consistent with improved electronic conductivity and multivalent redox behavior. The scanning electron microscope (SEM and transmission electron microscopy (TEM) images demonstrate Cu-induced morphological transitions toward denser, more crystalline structures. Brunauer-Emmett-Teller (BET) measurements reveal that the L. nobilis-derived hard carbon (HC) anode possesses a high surface area and hierarchical porosity, which facilitated efficient Na + storage and rapid ion transport. Full-cell tests demonstrate high reversible capacity (approximate to 126 mAh g-1), excellent rate capability, and 56% capacity retention over 250 cycles. This work demonstrates that Cu doping and porous HC anodes synergistically enhance the structural and electrochemical performance of SIBs, thereby providing a sustainable strategy for advanced energy storage.eninfo:eu-repo/semantics/closedAccessbiomasselectrochemical performancelaurus nobilis leavesNaMnO2phase transitionstructure characteristicsArticle10110.1002/adsu.2025006782-s2.0-105015174968N/AWOS:001562672900001Q20000-0001-8009-51580009-0005-6858-80600000-0003-3056-7684