Fig. 2.

The form and motion of the second kind of defects upon delithiation. a Dissociated dislocation in Li₂MnO₃ with Burgers vector c/2[001] formed dynamically in delithiation. b Atomic model of the dislocation containing lithium vacancies in both Li- and Li-Mn layers. c–f Defect density (green arrowheads) of the Li₂MnO₃ electrode increases as the delithiation process progresses. g Comparison of experimental voltage–composition plot of a Li/Li₂MnO₃ cell (black) with the calculated plot of cells containing Li₂MnO₃ electrodes with b/6[110] defects dominating the first step (4.89 V) and c/2[001] defects dominating the second step (5.03 V). Without the c/2[001] defects, the second step would occur at voltage of 5.13 V. h Illustration of the c/2[001] defects and a proposed mechanism by which oxygen is transported in a highly defective Li₂MnO₃ electrode structure and released at the surface