Fig. 2
Structural evolution of LNMO after delithiation. a Low magnification HAADF-STEM image with three regions marked with A1, A2, and A3. Right side of the image is the Pt deposition on the LNMO. The green arrow indicates the direction of the electric field of all STEM images in Fig. 2. b Zoomed-in HAADF-STEM image showing the features of A1 region. Beige arrows show the position of transition-metal-rich areas. c Zoomed-in HAADF-STEM image showing the features of A2 and A3 regions. Scale bars of (a, b, c) are 100 nm, 20 nm, and 20 nm, respectively. d Atomic scale HAADF-STEM image of A1 region. Inset is the GPA scale image, which can clearly show feature of A1. e Enlarged image of the white rectangle in d. f Intensity line profile extracted from the red rectangle in e. It clearly shows the presence of transition-metal ions at the 4a sites. g Atomic scale HAADF-STEM image of A2 region and the inset is its corresponding GPA scale image. h Enlarged image of the red rectangle in g, which shows the structure of the antiphase boundary. i Enlarged image of the blue rectangle in g, which shows the structure of linking area between two antiphase boundaries. j Atomic scale HAADF-STEM image of A3 region and its corresponding GPA scale image at the top right. k GPA εyy image of the light-blue rectangle in j, which clearly shows the presence of a dislocation. l Enlarged image of the yellow rectangle in (j). m Atomic structure model of antiphase boundary with marked 4a site. n Enlarged HAADF-STEM image of light blue rectangle in j, which shows the structure of an edge type partial dislocation. Scale bars of d, g, j are all 5 nm
