Review of solid oxide fuel cell materials: cathode, anode, and electrolyte

Abstract

There is a growing interest in solid oxide fuel cells (SOFCs) technology among the researchers a promising power generation with high energy efficiency, inflated fuel flexibility, and low environmental impact compared to conventional power generation systems. SOFCs are devices in which the chemical energy is directly converted into electrical energy with negligible emission. SOFCs have low pollution characteristics, high efficiency (~ 60%), and possess expanded fuel selection with little environmental effects. A single cell component of SOFCs is consisting an anode, cathode and an electrolyte which are stacked layer by layer to produce higher amount of power. The dense ceramic electrolyte transporting O2− ions and fills the space between the electrodes material. Redox reaction occurred at the electrodes side in the presence of fuels. The operating temperatures of SOFCs of 600–1200 °C which produced heat as a byproduct and fast electro-catalytic activity while using nonprecious metals. Many ceramic materials have been investigated for SOFCs electrolyte. Yttria-stabilized zirconia (YSZ) material was extensively used as dense electrolyte in SOFCs technology. In this review, the article presents; overview of the SOFCs devices and their related materials and mostly reviewed newly available reported.

Analysis of the effect of ionic conductivity of electrolyte materials on the solid oxide fuel cell performance

“…The main requirements for the electrolyte to work efficiently are reliable mechanical properties and high conductivity of the oxide ion. Therefore, the choice of SOFC electrolyte material is a crucial thing [5]. SOFC electrolyte materials have microstructural parts, such as grain and grain boundaries that can affect their ionic conductivity.…”

“…In actual phenomena, ionic conductivity arises based on many aspects, for example, porosity and material composition. In (5), I is the electric current, σ is the ionic conductivity (S/m) and E is the potential component a, while the letter "a" represents the electrode or electrolyte component. With (5), the statement of the relationship of electric power, voltage and electric current in (1) can be related to the value of ionic conductivity.…”

“…In (5), I is the electric current, σ is the ionic conductivity (S/m) and E is the potential component a, while the letter "a" represents the electrode or electrolyte component. With (5), the statement of the relationship of electric power, voltage and electric current in (1) can be related to the value of ionic conductivity. Then the phenomenon that arises due to differences in types of ionic conductivity can be explained by (2) regarding overpotential, (3) regarding the equilibrium conditions and potential difference and (4) regarding the effect of potential differences on the SOFC electric current.…”

DC 4-Point Measurement for Total Electrical Conductivity of SOFC Cathode Material

“…Among the various characteristics of cathode materials for SOFCs, the total electrical conductivity plays an important role in enabling the oxygen reduction reaction (ORR) electrochemical catalyst to exhibit catalytic activity over the entire area of the material, and it is known that the conductivity of the cathode material is preferred to be more than 100S/cm. [10,11]. Accordingly, it is important to accurately and precisely measure the electrical conductivity of a material.…”

Structural and Electrochemical Properties of Scandia Alumina Stabilized Zirconia Thin Films

“…Zirconia doped with 10 mol.% of Sc (10ScSZ) exhibit the highest conductivity at 1000 • C among all ZrO 2 based electrolytes due to low association enthalpy of the defect reactions and similar ionic radii (0.075 nm-Sc 3+ , 0.072 nm-Zr 4+ ) [2,5]. However, the conductivity becomes equal or lower to the conductivity of YSZ at 500 • C due to increased activation energy [6]. Therefore, the oxygen ion conductivity and cubic phase stability should be increased even more.…”