All-solid-state batteries promise significant safety and energy density advantages over liquid-electrolyte batteries. The interface between the cathode and the solid electrolyte is an important contributor to charge transfer resistance. Strong bonding of solid oxide electrolytes and cathodes requires sintering at elevated temperatures. Knowledge of the temperature dependence of the composition and charge transfer properties of this interface is important for determining the ideal sintering conditions. To understand the interfacial decomposition processes and their onset temperatures, model systems of LiCoO2 (LCO) thin films deposited on cubic Al-doped Li7La3Zr2O12 (LLZO) pellets were studied as a function of temperature using interface-sensitive techniques. X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, and energy-dispersive X-ray spectroscopy data indicated significant cation interdiffusion and structural changes starting at temperatures as low as 300 °C. La2Zr2O7 and Li2CO3 were identified as decomposition products after annealing at 500 °C by synchrotron X-ray diffraction. X-ray absorption spectroscopy results indicate the presence of also LaCoO3 in addition to La2Zr2O7 and Li2CO3. On the basis of electrochemical impedance spectroscopy and depth profiling of the Li distribution upon potentiostatic hold experiments on symmetric LCO|LLZO|LCO cells, the interfaces exhibited significantly increased impedance, up to 8 times that of the as-deposited samples after annealing at 500 °C. Here, our results indicate that lower-temperature processing conditions, shorter annealing time scales, and CO2-free environments are desirable for obtaining ceramic cathode|electrolyte interfaces that enable fast Li transfer and high capacity.
Vardar, Gulin, et al. "Structure, Chemistry, and Charge Transfer Resistance of the Interface between Li<sub>7</sub>La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub> Electrolyte and LiCoO<sub>2</sub> Cathode." Chemistry of Materials, vol. 30, no. 18, Jul. 2018. https://doi.org/10.1021/acs.chemmater.8b01713
Vardar, Gulin, Bowman, William J., Lu, Qiyang, et al., "Structure, Chemistry, and Charge Transfer Resistance of the Interface between Li<sub>7</sub>La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub> Electrolyte and LiCoO<sub>2</sub> Cathode," Chemistry of Materials 30, no. 18 (2018), https://doi.org/10.1021/acs.chemmater.8b01713
@article{osti_1477177,
author = {Vardar, Gulin and Bowman, William J. and Lu, Qiyang and Wang, Jiayue and Chater, Richard J. and Aguadero, Ainara and Seibert, Rachel and Terry, Jeff and Hunt, Adrian and Waluyo, Iradwikanari and others},
title = {Structure, Chemistry, and Charge Transfer Resistance of the Interface between Li<sub>7</sub>La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub> Electrolyte and LiCoO<sub>2</sub> Cathode},
annote = {All-solid-state batteries promise significant safety and energy density advantages over liquid-electrolyte batteries. The interface between the cathode and the solid electrolyte is an important contributor to charge transfer resistance. Strong bonding of solid oxide electrolytes and cathodes requires sintering at elevated temperatures. Knowledge of the temperature dependence of the composition and charge transfer properties of this interface is important for determining the ideal sintering conditions. To understand the interfacial decomposition processes and their onset temperatures, model systems of LiCoO2 (LCO) thin films deposited on cubic Al-doped Li7La3Zr2O12 (LLZO) pellets were studied as a function of temperature using interface-sensitive techniques. X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, and energy-dispersive X-ray spectroscopy data indicated significant cation interdiffusion and structural changes starting at temperatures as low as 300 °C. La2Zr2O7 and Li2CO3 were identified as decomposition products after annealing at 500 °C by synchrotron X-ray diffraction. X-ray absorption spectroscopy results indicate the presence of also LaCoO3 in addition to La2Zr2O7 and Li2CO3. On the basis of electrochemical impedance spectroscopy and depth profiling of the Li distribution upon potentiostatic hold experiments on symmetric LCO|LLZO|LCO cells, the interfaces exhibited significantly increased impedance, up to 8 times that of the as-deposited samples after annealing at 500 °C. Here, our results indicate that lower-temperature processing conditions, shorter annealing time scales, and CO2-free environments are desirable for obtaining ceramic cathode|electrolyte interfaces that enable fast Li transfer and high capacity.},
doi = {10.1021/acs.chemmater.8b01713},
url = {https://www.osti.gov/biblio/1477177},
journal = {Chemistry of Materials},
issn = {ISSN 0897-4756},
number = {18},
volume = {30},
place = {United States},
publisher = {American Chemical Society (ACS)},
year = {2018},
month = {07}}
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Organization:
National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Scientific User Facilities Division
Grant/Contract Number:
AC02-06CH11357
OSTI ID:
1477177
Alternate ID(s):
OSTI ID: 1483239
Journal Information:
Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 18 Vol. 30; ISSN 0897-4756
