Fig. 4: Mitigation of Li deficiency and disordering in the interior of NCM-300 cycles.
From: Evolution and expansion of Li concentration gradient during charge–discharge cycling
a APT depth profile at ~700 nm from the top surface, showing slightly deficient Li concentration. b, c STEM-HAADF image (b) and intensity profile (c) sampled at depths of 500 nm – 1 µm. A partially disordered structure (inset: magnified image) formed owing to the low degree of TM migration to 3a sites (red arrows) d APT depth profile in the central region of the NCM particle, showing the same Li concentration as that of NCM-pristine. e, f STEM-HAADF image (e) and intensity profile (f) in the central region. Layered structure (inset: magnified image) is well maintained, showing no TM migration. Error bars show the standard deviation of each dataset.
