fig5

Figure 5. (A) XRD pattern of Na_0.612K_0.056MnO₂ with Rietveld refinement and the corresponding structural model; (B) Typical charge/discharge curves of Na_0.612K_0.056MnO₂ and Na_0.706MnO₂ at 20 mA g^-1 in the third cycle and their cycling performance at 50 mA g⁻¹; (C) In situ XRD patterns of Na_0.612K_0.056MnO₂ and schematic diagram of the phase transitions. Reproduced under terms of the CC-BY license, Copyright 2021^[89], The Authors, Nature Publishing Group; (D) Computational and experiential investigations of Na_0.76Ca_0.05[Ni_0.23□_0.08Mn_0.69]O₂; (E) Electrochemical properties of P2 cathodes doped with different Ca²⁺ concentrations; (F) Structural evolution of P2-Na_0.76Ca_0.05[Ni_0.23□_0.08Mn_0.69]O₂ during charge and discharge. Reproduced with permission, Copyright 2021^[91], Wiley-VCH; (G) Structural model and XRD pattern of P2-Na_0.67Ni_0.3Co_0.1Mn_0.6O_1.94(BO₃)_0.02; (H) Cycling performance of pristine and BO₃^3--modified P2 cathodes; (I) Structural evolution of BO₃^3--modified P2 cathode. Reproduced with permission, Copyright 2022^[99], Wiley-VCH; (J) A comparison of the structural evolution between undoped and HE-doped P2 cathodes, Copyright 2023^[103], Elsevier B.V.