fig4

Figure 4. (A) Schematic illustration of the design of the P2/O3 biphasic structure for sodium Fe/Mn-based layered oxide cathode (Reproduced with permission from Ref.^[81]. Copyright 2021, Elsevier); (B) HAADF-STEM image of the P3/O′3 composite (Reproduced with permission from Ref.^[82]. Copyright 2018, Elsevier); (C) Graphic abstract of the Deciphering the Origin of High Electrochemical Performance in a Novel Ti-Substituted P2/O3 Biphasic Cathode for Sodium-Ion Batteries (Reproduced with permission from Ref.^[83]. Copyright 2022, Elsevier); (D) Schematic illustration of phase transition process with increasing Ti content (Reproduced with permission from Ref.^[84]. Copyright 2020, American Chemical Society); (E) HRTEM images of the P2 + T material. The amplified figure of the rectangular region (d1-d3) and the corresponding Fast Fourier Transform (FFT) diffraction (d1′-d3′) (Reproduced with permission from Ref.^[85]. Copyright 2018, Royal Society of Chemistry).