Abstract
The origin of ionic conductivity in bulk lithium lanthanum titanate, a promising solid electrolyte for Li-ion batteries, has long been under debate, with experiments showing lower conductivity than predictions. Using first-principles-based calculations, we find that experimentally observed type I boundaries are more stable compared with the type II grain boundaries, consistent with their observed relative abundance. Grain boundary stability appears to strongly anti-correlate with the field strength as well as the spatial extent of the space charge region. Ion migration is faster along type II grain boundaries than across, consistent with recent experiments of increased conductivity when type II densities were increased.
| Original language | English |
|---|---|
| Pages (from-to) | 455-463 |
| Number of pages | 9 |
| Journal | MRS Communications |
| Volume | 6 |
| Issue number | 4 |
| DOIs | |
| State | Published - Dec 1 2016 |
Funding
This work was performed at the Center for Nanophase Materials Sciences, a US Department of Energy Office of Science User Facility. This work made use of computational resources at the NERSC computing facility which is supported by the U.S. DOE Office of Science under Contract No. DE-AC02-05CH11231. K.C.A. acknowledges support from a DOE Computational Science Graduate Fellowship under Grant No. DE-FG02-97ER25308 and support from the Fannie and John Hertz Foundation. P. G. would like to acknowledge the Laboratory Directed Research and Development Program (LDRD) of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy.
