SOFC

Posted by RachelHJM on May 13th, 2017

Solid oxide fuel cell (SOFC) has high energy conversion efficiency which is up to 70% ~ 80% and its features are utilization way of clean energy, the simple system device, low noise, good application environment, strong fuel adaptability, strong over load energy, no corrosion resistance and long service life and  etc. The SOFC can be used in power generation, cogeneration, transportation, aerospace and small power plant in residential area, which is considered a kind of green energy in the 21st century, and it is the future trend of the development of new energy system. Cubic stability ZrO2 is widely used as solid electrolyte in solid oxide fuel cell (SOFC) and oxygen sensor, because it has high ionic conduction under high temperature. Zirconia-based solid electrolyte is the core of the solid oxide fuel cell (SOFC) components, to a large extent its ionic conductivity determines the output power of SOFC and current density.

YSZ commonly used as electrolyte in solid oxide fuel cell (SOFC), Y2O3 content at 8% YSZ , namely 8Y stabilized zirconium has the best comprehensive performance, the biggest electrical conductivity and one of the most widely used. With high stability in the oxidation and reduction atmosphere, and high temperature stability of cubic phase ZrO2 could be kept until room temperature, so that 8Y stabilized zirconium is considered to be the best candidate for the industrialization of SOFC. The conductivity of 8Y stabilized zirconium electrolyte material has close relationship with sintering temperature of ceramic body. 8Y zirconia polycrystalline material is composed of grain, grain boundary and porosity, the existence of pores can reduce the grain boundary and conductivity of the material, also improve the sintering temperature of ceramic body and gradually shrinking, as well as reduce connecting hole of grain boundary. Thus, 8% mol Yttria Stabilised Zirconia polycrystalline material could improve the sintering density of porcelain body, increase the conductivity of the material and the high temperature could reach1450℃ in maximum.

8% mol YSZ powder as solid electrolyte used in electrochemical oxygen sensors, solid oxide fuel cell (SOFC) and oxygen pump, also applied in heating equipment in the oxidizing atmosphere when temperature is 2000℃, and etc. Zirconium sensor has become the main technology and device in car engines and industrial burner controller. It is one of the key components to reduce fuel consumption, save energy and reduce air pollution.

There is another important application that ZrO2 solid electrolyte is used as the fourth generation of fuel cell in the electric utility, it can convert the energy of fuel and oxygen combustion reaction to electricity energy, and the solid electrolyte can form 100 microns thin layer by plasma spraying method. Zirconia sensor has become the main technology and device in car engines and industrial burner control, it is one of the key components to reduce fuel consumption, save energy and reduce air pollution. Automobile exhaust purification is closed-loop type exhaust gas purification control system which is composed of ternary catalyst, ZrO2 oxygen sensor, electronic injection and electronic control unit. To make the ternary catalyst achieves the best effect for purification of pollutants at the same time, we should control fuel ratio (A/F) is in theory air-fuel ratio (A/F = 14.8) within small window.ZrO2 sensor ceramic recently has become the most studied in the ZrO2 system, and it is a kind of new outstanding materials.