Nanocrystalline Gadolinium doped Ceria (Ce<inf>0.8</inf>Gd<inf>0.2</inf>O<inf>3-&#x03B4;</inf>) for oxygen sensor and solid oxide fuel cell applications

Abstract

Gadolinium doped Ceria (GDC) is a known oxygen ion conductor in intermediate temperature range. This is a preliminary work aimed at exploring the suitability of using nanocrystalline GDC as oxygen sensor in intermediate operating temperature range (500 o C-700 o C). The nanocrystalline Gadolinium doped Ceria (GDC) has been prepared by sol-gel method with EDTA as chelating agent. Particle size around 10±5nm was obtained after calcination at 600 o C. Pellets prepared using this material were sintered 1350 o C, which show 90% of the theoretical density. The dc and ac (1Hz-1MHz) conductivity of these pellet was measured in the temperature range 200-600 o C and 500-700 o C respectively. Highest conductivity of the order of 4.61X10 -5 S/cm was recorded at 700 o C. Possible reasons for low conductivity are discussed.

Thermal Sensors

“…Such systems are also required to be versatile-provide a large amount of power over a short period of time (burst-mode application)-in addition to the more conventional requirement of continuous low power output. While new battery technologies are being explored, there is also considerable interest in development of micro-fuel cells as high efficiency energy converters (Kulkarni 2014;Mitra 2014;Patil et al 2014;Ramesh 2014;Dimble 2012;and Kulkarni et al 2012).…”

Oxygen ion conducting glass ceramic composites for high temperature sensor applications

“…Hence, in order to achieve sintering compatibility with LTCC, low temperature melting glass needs to be added to these electrolyte / sensor materials.It is known that improved sintering and density above 95% can be achieved at much lower temperature range (800-1000 ˚C) for glass-ceramic composites [9]. Further, an appropriate glass composition may enhance its ionic conductivity at lower operating temperatures.Our earlier report covered synthesis of pure GDC by sol-gel method together with its structural, morphological properties and ionic conductivity in the operating temperature range of 500-700 ˚C [5]. In this work, we report use of glass for preparing GDCglass composites, aimed at achieving lower sintering temperatures and possibly enhance the ionic conductivity.…”

“…Due to the ionic conductivity properties, it has been extensively studied for electrolyte applications in solid oxide fuel cells and as oxygen sensor in boilers, furnaces and combustion engines. The oxygen sensors are required in boilers mainly to monitor the oxygen quantity and to assess completion of combustion reaction for efficient fuel consumption [5]. In such applications, ionic conductivity of the oxygen ion conductor plays an important role vide the Nernst equation.…”