fig7

Figure 7. (A) SEM images of electrospun nanofibers; (B and C) SEM and TEM images of resultant Na_0.76Cu_0.22Fe_0.30Mn_0.48O₂nano-necklaces; (D) Electrochemical performance of Na_0.76Cu_0.22Fe_0.30Mn_0.48O₂ calcinated at different conditions. Reproduced under terms of the CC-BY license, Copyright 2020^[127], The Authors, Wiley-VCH; (E-G) SEM, TEM, and elemental mappings of hierarchical P2-Na_0.67Ni_0.23Mg_0.1Mn_0.67O₂; (H) SEM images of cycled P2 cathodes with hierarchical and bulk morphologies. Reproduced with permission, Copyright 2021^[130], Elsevier B.V.; (I) Schematic illustration of the water-mediated strategy to prepare S-NMO; (J) Electrochemical properties of S-NMO and bulk P2-Na_0.67MnO₂. Reproduced under terms of the CC-BY license, Copyright 2021^[143], The Authors, Nature Publishing Group. (K-M) SEM images of P2-Na_0.66Ni_0.26Zn_0.07Mn_0.67O₂ materials prepared by solid-state, coprecipitation, and combined coprecipitation and molten-salt methods; (N-Q) TEM, HR-TEM, ED pattern, and elemental mappings of the hexagonal single crystal; (R) Schematic illustration comparing the structural stability of primary particles with different proportions of {001} planes. Reproduced with permission, Copyright 2023^[140], Elsevier B.V.