TY - JOUR
T1 - Energetic Stability and Its Role in the Mechanism of Ionic Transport in NASICON-Type Solid-State Electrolyte Li1+ xAlxTi2- x(PO4)3
AU - Abramchuk, Mykola
AU - Voskanyan, Albert A.
AU - Arinicheva, Yulia
AU - Lilova, Kristina
AU - Subramani, Tamilarasan
AU - Ma, Qianli
AU - Dashjav, Enkhtsetseg
AU - Finsterbusch, Martin
AU - Navrotsky, Alexandra
N1 - Funding Information:
We are grateful to S. Ushakov and F. Tietz for fruitful discussions. The work at Arizona State University was supported by the U.S. Department of Energy, Office of Basic Energy Sciences (Grant DE-FG02-03ER46053). The work at Forschungszentrum Jülich was funded by the Federal Ministry of Education and Research of Germany (BMBF) (Project 03XP0084A) and the German Research Foundation (DFG) (Project 429409150).
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/5/13
Y1 - 2021/5/13
N2 - We apply high-temperature oxide melt solution calorimetry to assess the thermodynamic properties of the material Li1+xAlxTi2-x(PO4)3, which has been broadly recognized as one of the best Li-ion-conducting solid electrolytes of the NASICON family. The experimental results reveal large exothermic enthalpies of formation from binary oxides (ΔHf,ox°) and elements (ΔHf,el°) for all compositions in the range 0 ≤ x ≤ 0.5. This indicates substantial stability of Li1+xAlxTi2-x(PO4)3, driven by thermodynamics and not just kinetics, during long-term battery operation. The stability increases with increasing Al3+ content. Furthermore, the dependence of the formation enthalpy on the Al3+ content shows a change in behavior at x = 0.3, a composition near which the Li+ conductivity reaches the highest values. The strong correlation among thermodynamic stability, ionic transport, and clustering is a general phenomenon in ionic conductors that is independent of the crystal structure as well as the type of charge carrier. Therefore, the thermodynamic results can serve as guidelines for the selection of compositions with potentially the highest Li+ conductivity among different NASICON-type series with variable dopant contents.
AB - We apply high-temperature oxide melt solution calorimetry to assess the thermodynamic properties of the material Li1+xAlxTi2-x(PO4)3, which has been broadly recognized as one of the best Li-ion-conducting solid electrolytes of the NASICON family. The experimental results reveal large exothermic enthalpies of formation from binary oxides (ΔHf,ox°) and elements (ΔHf,el°) for all compositions in the range 0 ≤ x ≤ 0.5. This indicates substantial stability of Li1+xAlxTi2-x(PO4)3, driven by thermodynamics and not just kinetics, during long-term battery operation. The stability increases with increasing Al3+ content. Furthermore, the dependence of the formation enthalpy on the Al3+ content shows a change in behavior at x = 0.3, a composition near which the Li+ conductivity reaches the highest values. The strong correlation among thermodynamic stability, ionic transport, and clustering is a general phenomenon in ionic conductors that is independent of the crystal structure as well as the type of charge carrier. Therefore, the thermodynamic results can serve as guidelines for the selection of compositions with potentially the highest Li+ conductivity among different NASICON-type series with variable dopant contents.
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U2 - 10.1021/acs.jpclett.1c00925
DO - 10.1021/acs.jpclett.1c00925
M3 - Article
C2 - 33944567
AN - SCOPUS:85106350340
SN - 1948-7185
VL - 12
SP - 4400
EP - 4406
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 18
ER -