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Research Highlight

Robust Imaging of Lithium Columns in Battery Electrode Materials

Robust Imaging of Lithium Columns in Battery Electrode Materials
Atomic-resolution HAADF, integrated iCoM, and divergence dCoM, STEM images of LiCoO2 viewed down the [110] axis, with atomic structure overlaid. (a) HAADF-STEM images produce a large signal on relatively heavy Co atoms and little on the lighter O and Li columns. (b, c) iCoM and dCoM are also sensitive to light elements and can image columns of Co, O, and Li. (d) Line profiles of the HAADF, iCoM, and dCoM signals from location marked in (a–c).

Scientific Achievement

Center of Mass (CoM) scanning transmission electron microscopy (STEM) allows simultaneous and robust atomic-scale imaging of light and heavy elements, which is not possible by conventional high angle annular dark field (HAADF)-STEM.

Significance and Impact

CoM-STEM can provide a better understanding of the full atomic-scale structure of battery materials through direct imaging and analysis, as demonstrated for LiCoO2.

Research Details

- Images showing both light and heavy elements were generated using the CoM of diffraction patterns acquired via a 2D array of probe positions across the sample.

- This technique was used to directly image Li, O, and Co columns in the battery electrode material, LiCoO2.

- Multislice electron scattering calculations were used to explore effects of experimental variables/conditions and sensitivity limits.

M.J. Zachman, Z. Yang, Y. Du, and M. Chi, ACS Nano, 16 1358-1367 (2022). DOI: 10.1021/acsnano.1c09374