Comparative analysis on the thermal, structural, and electrochemical properties of Al-doped Li7La3Zr2O12 solid electrolytes through solid state and sol-gel routes

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2022-07
Major/Subject
Mcode
Degree programme
Language
en
Pages
10
Series
Solid State Ionics, Volume 380
Abstract
Over the last decade, Li7La3Zr2O12 (LLZO) has shown to be one of the most promising materials as a solid electrolyte in Li-ion batteries. However, several factors can affect the final electrochemical properties of the material, such as the synthesis method and the inclusion of dopants. In this study, we conduct a comparative analysis of undoped and Al-doped LLZO prepared through solid state and sol-gel methods. An in-situ thermal investigation on the synthesis of LLZO shows how solid state synthesis forms LLZO at lower rates, however the resulting LLZO is more stable at higher temperatures. The addition of Al as a dopant further increases the thermal stability of the material by lowering its decomposition rate. Ionic conductivity measurements reveal how sol-gel LLZO samples experience several times higher conductivity than their solid state counterparts due to tightly interconnected grains. With the addition of Al, the conductivity further increases by two orders of magnitude. With that we are able to achieve the highest ionic conductivity of 4.96 × 10−4 S/cm for Al-doped sol-gel LLZO and an activation energy of 0.28(1) eV. This work provides a better understanding of how different synthesis methods affect the final properties of LLZO solid electrolytes.
Description
Publisher Copyright: © 2022 The Authors
Keywords
Al doping, ionic conductivity, LLZO, Solid electrolyte, thermal analysis
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Citation
Košir, J, Mousavihashemi, S, Wilson, B P, Rautama, E-L & Kallio, T 2022, ' Comparative analysis on the thermal, structural, and electrochemical properties of Al-doped Li 7 La 3 Zr 2 O 12 solid electrolytes through solid state and sol-gel routes ', Solid State Ionics, vol. 380, 115943 . https://doi.org/10.1016/j.ssi.2022.115943