TY - JOUR
T1 - Lithium ion conductivity of oriented Li0.33La0.56TiO3 solid electrolyte films prepared by a sol-gel process
AU - Teranishi, Takashi
AU - Ishii, Yuki
AU - Hayashi, Hidetaka
AU - Kishimoto, Akira
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Lithium lanthanum titanates (Li3xLa2/3 - xTiO3, LLTOs) having a-axis orientations were synthesized via a simple sol-gel route on SrTiO3 and Nb-doped SrTiO3 substrates. The lithium ion conduction behaviors of the LLTO films were determined. Annealing the films above 1200 °C yielded strong a-axis growth orientation, while heating samples above 1300 °C led to the reduction of the Li transference number, TLi, which was attributed to Li evaporation. The optimized annealing temperature was 1200 °C, where both the bulk conductivity, σdc, and the TLi exhibited their maxima. The bulk conductivity was 4.42 × 10- 5 S/cm for a 411-nm-thick film, which was almost 10-times-higher than that previously reported for sol-gel-derived films. A key reason for the enhancement in conductivity is the expanded bottleneck of the LLTO lattice because of a tensile stress induced by the substrate. Optimization of the annealing temperature and the film thickness further improved the conductivity.
AB - Lithium lanthanum titanates (Li3xLa2/3 - xTiO3, LLTOs) having a-axis orientations were synthesized via a simple sol-gel route on SrTiO3 and Nb-doped SrTiO3 substrates. The lithium ion conduction behaviors of the LLTO films were determined. Annealing the films above 1200 °C yielded strong a-axis growth orientation, while heating samples above 1300 °C led to the reduction of the Li transference number, TLi, which was attributed to Li evaporation. The optimized annealing temperature was 1200 °C, where both the bulk conductivity, σdc, and the TLi exhibited their maxima. The bulk conductivity was 4.42 × 10- 5 S/cm for a 411-nm-thick film, which was almost 10-times-higher than that previously reported for sol-gel-derived films. A key reason for the enhancement in conductivity is the expanded bottleneck of the LLTO lattice because of a tensile stress induced by the substrate. Optimization of the annealing temperature and the film thickness further improved the conductivity.
KW - LiLaTiO
KW - Lithium ion
KW - Sol-gel
UR - http://www.scopus.com/inward/record.url?scp=84949766122&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84949766122&partnerID=8YFLogxK
U2 - 10.1016/j.ssi.2015.11.029
DO - 10.1016/j.ssi.2015.11.029
M3 - Article
AN - SCOPUS:84949766122
VL - 284
SP - 1
EP - 6
JO - Solid State Ionics
JF - Solid State Ionics
SN - 0167-2738
ER -