fig3

From: Phase programming: microstructural design in rechargeable battery materials

Figure 3. Phase programming strategies toward high-rate performance. (A) Schematic illustration of fast ion transport channels; (B) STEM image and structural model showing twin boundary induced fast ion transport channels in a spinel cathode^[45]. Reprinted with permission from Ref.^[45] Copyright © 2021 Springer Nature; (C) Schematic illustration of grain-boundary-rich cathodes formed through controlled heat treatment, enabling enhanced ion transport kinetics^[46]. Reprinted with permission from Ref.^[46] Copyright © 2025 The Royal Society of Chemistry; (D) Schematic diagram illustrating the mechanism of interfacial electric field and site doping for fast kinetics and stable structure^[47]. Reprinted with permission from Ref.^[47] Copyright © 2025 Wiley. STEM: Scanning transmission electron microscope.