Abstract:
In this study, force field-based simulations are employed to examine the defects in Li-ion
diffusion pathways together with activation energies and a solution of dopants in Li2Ti6O13. The lowest
defect energy process is found to be the Li Frenkel (0.66 eV/defect), inferring that this defect process
is most likely to occur. This study further identifies that cation exchange (Li–Ti) disorder is the
second lowest defect energy process. Long-range diffusion of Li-ion is observed in the bc-plane with
activation energy of 0.25 eV, inferring that Li ions move fast in this material. The most promising
trivalent dopant at the Ti site is Co3+, which would create more Li interstitials in the lattice required
for high capacity. The favorable isovalent dopant is the Ge4+ at the Ti site, which may alter the
mechanical property of this material. The electronic structures of the favorable dopants are analyzed
using density functional theory (DFT) calculations.
