Fig. 3: Molecular dynamics simulation of Li⁺ and Na⁺ transport.

The cross-section number density of A Li⁺ and B water in the simulated scenario. Different phases are divided by background colors and captions at the top. C Trajectories of Li⁺ (light blue) and Na⁺ (purple) transport through an LTO crystal at an electric field intensity of 0.87 V Å⁻¹. The electric field is applied along the +x direction. LTO size: ~15 Å in the x direction; ~26 Å in the z direction. D The number of Li⁺ and Na⁺ ions transported through the LTO structure as a function of simulation time and electric field intensity. The steady-state transport rates, determined by linear regression of the data, are also shown (see Supplementary Table 5 for the goodness of fit). For Na⁺, no transport was observed at all electrical field intensities; data are only shown for the highest intensity (0.95 V Å⁻¹). E The enlarged LTO structure highlights a (Li₃) interlayer sandwiched between two (LiTi₂) layers. The distance between (LiTi₂) layer centers is ~4.4 Å and the width of the vacancies in (Li₃) layers is ~1.5 Å. F Schematic of the transport model within the N-LTO-PA layer. The PA matrix (gray-stripped background) and N-LTO (light-blue diamonds) were simplified for clarity. Molecular dynamics trajectory data at the initial and final configurations can be found in Supplementary Data file.