Fig. 4: Surface degradation induced by protons.
From: Proton-exchange induced reactivity in layered oxides for lithium-ion batteries
a–d HAADF-STEM images of NCM111 and NCM811 materials treated with pure water (W-NCM) and 4M LiOH solution (4M-NCM). e–h Spatially resolved EELS spectra from the bulk to the surface of NCM111 and NCM811 materials treated with pure water and 4M LiOH solution. In (a–d), the green dashed box highlights the surface region of the materials, while the orange dashed box indicates the bulk region. The EELS spectra obtained from the surface regions are shown as solid lines, whereas spectra from the bulk regions are depicted as dashed lines with shaded regions. i Content of L-O in D-NCM and P-NCM, as well as the resulting materials after treatment with pure water, 0.1M, 1M, and 4M LiOH solutions. j Titration curves of W-NCM111, 523, 622 and 811. Source data are provided as a Source Data file.
