Structural Properties and Bandgap Energy of Ga-doped Garnet-type Li7La3Zr2O12 (LLZO) Solid Electrolyte Depending on Sintering Atmosphere

Developing solid-state batteries for higher energy densities and safety has been a popular research subject in recent years. Since their first report, Li7La3Zr2O12 (LLZO) solid electrolytes have attracted extended attention due to their high ionic conductivity, chemical stability, and wide electroch...

Full description

Saved in:
Bibliographic Details
Main Author: Sevda Saran
Format: Article
Language:English
Published: Sakarya University 2025-04-01
Series:Sakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi
Subjects:
Online Access:https://dergipark.org.tr/en/download/article-file/4389650
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849314101928394752
author Sevda Saran
author_facet Sevda Saran
author_sort Sevda Saran
collection DOAJ
description Developing solid-state batteries for higher energy densities and safety has been a popular research subject in recent years. Since their first report, Li7La3Zr2O12 (LLZO) solid electrolytes have attracted extended attention due to their high ionic conductivity, chemical stability, and wide electrochemical window. Although LLZO fulfills all the requirements for high energy density and a longer lifespan, its intrinsic electronic conductivity accelerates the Li dendrite growth short-circuiting the battery. In this study, we have applied air and oxygen sintering atmospheres to prepare two types of Ga-doped LLZO pellets, to identify the effect of sintering atmospheres on the physical properties such as crystal phase, ionic conductivity, roughness, and electronic band gap energy (Eg). Both the crystal structures were found to be in cubic phase with a relatively small amount of secondary phase impurities. On the other hand, the oxygen-sintered sample showed better properties with high ionic conductivity of 1.04x10-4 Scm-1, lower surface root-mean-square roughness of 0.1833 µm, and a relative density of 90.5%. Furthermore, the electronic indirect band gap energy of the oxygen-sintered sample was larger, Eg=5.77 eV, which is desired for lower electrical conductivity. It is important to note that the precise determination of Eg values of powders would be erroneous through Ultraviolet-Visible (UV-Vis) absorption spectroscopy due to the scattering effects of solids. So, to the best of our knowledge, for the first time, this study reports Eg values of oxygen and air-sintered LLZO determined by the Kubelka-Munk model on Ultraviolet-Visible-Near Infra-Red (UV-Vis-NIR) diffuse reflectance spectroscopy.
format Article
id doaj-art-0f4f2bd669664ff18bcfba394566d20b
institution Kabale University
issn 2147-835X
language English
publishDate 2025-04-01
publisher Sakarya University
record_format Article
series Sakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi
spelling doaj-art-0f4f2bd669664ff18bcfba394566d20b2025-08-20T03:52:33ZengSakarya UniversitySakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi2147-835X2025-04-0129216017010.16984/saufenbilder.159040728Structural Properties and Bandgap Energy of Ga-doped Garnet-type Li7La3Zr2O12 (LLZO) Solid Electrolyte Depending on Sintering AtmosphereSevda Saran0https://orcid.org/0000-0002-2647-0700SELÇUK ÜNİVERSİTESİDeveloping solid-state batteries for higher energy densities and safety has been a popular research subject in recent years. Since their first report, Li7La3Zr2O12 (LLZO) solid electrolytes have attracted extended attention due to their high ionic conductivity, chemical stability, and wide electrochemical window. Although LLZO fulfills all the requirements for high energy density and a longer lifespan, its intrinsic electronic conductivity accelerates the Li dendrite growth short-circuiting the battery. In this study, we have applied air and oxygen sintering atmospheres to prepare two types of Ga-doped LLZO pellets, to identify the effect of sintering atmospheres on the physical properties such as crystal phase, ionic conductivity, roughness, and electronic band gap energy (Eg). Both the crystal structures were found to be in cubic phase with a relatively small amount of secondary phase impurities. On the other hand, the oxygen-sintered sample showed better properties with high ionic conductivity of 1.04x10-4 Scm-1, lower surface root-mean-square roughness of 0.1833 µm, and a relative density of 90.5%. Furthermore, the electronic indirect band gap energy of the oxygen-sintered sample was larger, Eg=5.77 eV, which is desired for lower electrical conductivity. It is important to note that the precise determination of Eg values of powders would be erroneous through Ultraviolet-Visible (UV-Vis) absorption spectroscopy due to the scattering effects of solids. So, to the best of our knowledge, for the first time, this study reports Eg values of oxygen and air-sintered LLZO determined by the Kubelka-Munk model on Ultraviolet-Visible-Near Infra-Red (UV-Vis-NIR) diffuse reflectance spectroscopy.https://dergipark.org.tr/en/download/article-file/4389650garnet-type llzo solid electrolytesintering atmospheredrsband gap energygarnet- benzeri llzo kati elektrolittavlama sıcaklığıdrsbant aralığı enerjisi
spellingShingle Sevda Saran
Structural Properties and Bandgap Energy of Ga-doped Garnet-type Li7La3Zr2O12 (LLZO) Solid Electrolyte Depending on Sintering Atmosphere
Sakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi
garnet-type llzo solid electrolyte
sintering atmosphere
drs
band gap energy
garnet- benzeri llzo kati elektrolit
tavlama sıcaklığı
drs
bant aralığı enerjisi
title Structural Properties and Bandgap Energy of Ga-doped Garnet-type Li7La3Zr2O12 (LLZO) Solid Electrolyte Depending on Sintering Atmosphere
title_full Structural Properties and Bandgap Energy of Ga-doped Garnet-type Li7La3Zr2O12 (LLZO) Solid Electrolyte Depending on Sintering Atmosphere
title_fullStr Structural Properties and Bandgap Energy of Ga-doped Garnet-type Li7La3Zr2O12 (LLZO) Solid Electrolyte Depending on Sintering Atmosphere
title_full_unstemmed Structural Properties and Bandgap Energy of Ga-doped Garnet-type Li7La3Zr2O12 (LLZO) Solid Electrolyte Depending on Sintering Atmosphere
title_short Structural Properties and Bandgap Energy of Ga-doped Garnet-type Li7La3Zr2O12 (LLZO) Solid Electrolyte Depending on Sintering Atmosphere
title_sort structural properties and bandgap energy of ga doped garnet type li7la3zr2o12 llzo solid electrolyte depending on sintering atmosphere
topic garnet-type llzo solid electrolyte
sintering atmosphere
drs
band gap energy
garnet- benzeri llzo kati elektrolit
tavlama sıcaklığı
drs
bant aralığı enerjisi
url https://dergipark.org.tr/en/download/article-file/4389650
work_keys_str_mv AT sevdasaran structuralpropertiesandbandgapenergyofgadopedgarnettypeli7la3zr2o12llzosolidelectrolytedependingonsinteringatmosphere