Ionic conductivity YSZ electrolyte material for solid oxide fuel cell applications.

Objective

Ionic conductivity YSZ electrolyte material for solid oxide fuel cell applications.

Introduction

Ionic conductivity is the ability of a material to conduct electric current. The conductivity (σ), is expressed as the inverse of resistivity (ρ) i.e., σ = 1/ρ and its unit is Siemens. Specific conductivity is the reciprocal of the specific resistance of a solution measured between two electrodes 1 cm2 in area and 1 cm apart. Conductivity is measured by placing two electrodes (with opposite electrical charge) in the electrolyte. For a known electrical current, the voltage drop across the electrodes reveals the electrolyte's resistance.

Methodology

1) sample is fixed in between the electrodes of sample holder and is placed in furnace.
2) Thermocouple wires of sample holder are connected to furnace temperature controller and furnace temperature is programmed as per requirement.
3) Electrode wires of sample holder are connected to LCR meter.
4) LCR meter generates impedance(z) - phase angle(theta) data for frequencies varying from 20 to 2 MHz using Lab view software.
5) Plot of z' (Zcos(theta) i.e.resisatance ) Vs z" ((-)Zsin(theta) i.e. capacitance ), named as 'Nyquist plot', is drawn.
6) bulk, grain and electrode impedance behavior are figured out from this Nyquist plot.

Results

following Ionic conductivity YSZ electrolyte material for solid oxide fuel cell applications.

Arrhenius plots for the 8YSZ sample
Arrhenius plots for the 5 wt.% CeO2 doped 8YSZ sample

Conclusions

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VIRTUAL EXPERIMENTS

Please select the following to view the image. Arrhenius plots for the 8YSZ sample Arrhenius plots for the 5 wt.% CeO2 doped 8YSZ sample