TY - JOUR

T1 - Mixed Electronic-Ionic Conductivity and Stability of Spark Plasma Sintered Graphene-Augmented Alumina Nanofibres Doped Yttria Stabilized Zirconia GAlN/YSZ Composites

AU - Kurapova , Olga

AU - Glumov, Oleg

AU - Smirnov , Ivan

AU - Konakov, Yaroslav

AU - Konakov , Vladimir

N1 - Kurapova, O.; Glumov, O.; Smirnov, I.; Konakov, Y.; Konakov, V. Mixed Electronic-Ionic Conductivity and Stability of Spark Plasma Sintered Graphene-Augmented Alumina Nanofibres Doped Yttria Stabilized Zirconia GAlN/YSZ Composites. Materials 2023, 16, 618. https://doi.org/10.3390/ma16020618

PY - 2023/1/9

Y1 - 2023/1/9

N2 - Graphene-doped ceramic composites with mixed electronic-ionic conductivity are currently attracting attention for their application in electrochemical devices, in particular membranes for solid electrolyte fuel cells with no necessity to use the current collector. In this work, composites of the Y2O3-ZrO2 matrix with graphene-augmented γ-Al2O3 nanofibres (GAlN) were spark plasma sintered. The conductivity and electrical stability in cyclic experiments were tested using electrical impedance spectroscopy. Composites with 0.5 and 1 wt.% GAlN show high ionic conductivity of 10−2–10−3 S/cm at 773 K. Around 3 wt.% GAlN percolation threshold was achieved and a gradual increase of electronic conductivity from ~10−2 to 4 × 10−2 S/cm with an activation energy of 0.2 eV was observed from 298 to 773 K while ionic conductivity was maintained at elevated temperatures. The investigation of the evolution of conductivity was performed at 298–973 K. Besides, the composites with 1–3 wt.% of GAlN addition show a remarkable hardness of 14.9–15.8 GPa due to ZrC formation on the surfaces of the materials.

AB - Graphene-doped ceramic composites with mixed electronic-ionic conductivity are currently attracting attention for their application in electrochemical devices, in particular membranes for solid electrolyte fuel cells with no necessity to use the current collector. In this work, composites of the Y2O3-ZrO2 matrix with graphene-augmented γ-Al2O3 nanofibres (GAlN) were spark plasma sintered. The conductivity and electrical stability in cyclic experiments were tested using electrical impedance spectroscopy. Composites with 0.5 and 1 wt.% GAlN show high ionic conductivity of 10−2–10−3 S/cm at 773 K. Around 3 wt.% GAlN percolation threshold was achieved and a gradual increase of electronic conductivity from ~10−2 to 4 × 10−2 S/cm with an activation energy of 0.2 eV was observed from 298 to 773 K while ionic conductivity was maintained at elevated temperatures. The investigation of the evolution of conductivity was performed at 298–973 K. Besides, the composites with 1–3 wt.% of GAlN addition show a remarkable hardness of 14.9–15.8 GPa due to ZrC formation on the surfaces of the materials.

KW - yttria stabilized zirconia

KW - graphene-augmented γ-Al2O3 nanofibres

KW - Spark plasma sintering

KW - nanocomposite

KW - mixed electronic-ionic conductivity

KW - impedance spectroscopy

KW - spark plasma sintering

UR - https://www.mendeley.com/catalogue/e8942e9a-8dfc-3d48-a174-99520b4cb615/

U2 - 10.3390/ma16020618

DO - 10.3390/ma16020618

M3 - Article

C2 - 36676356

VL - 16

JO - Materials

JF - Materials

SN - 1996-1944

IS - 2

M1 - 618

ER -