Study on the Fabrication and Performance of Very Low Pressure Plasma Sprayed Porous Metal Supported Solid Oxide Fuel Cell

Abstract

Solid oxide fuel cell (SOFC) is a high efficiency clean device that directly converts chemical energy of the fuel gas into electric energy. The long-term degradation and stability are the main problems at high temperature, so how to reduce the working temperature becomes a hotspot of research. It is an important way to reduce the thickness of electrolyte. Therefore, how to produce dense and thin electrolyte films economically becomes particularly important. It has been reported that a uniform and dense coating is hopefully prepared by using very low pressure plasma spraying (VLPPS) technology. Due to low operating pressure (~100 Pa), the plasma plume length elongates and its diameter enlarges. Under this condition, the particles can been heated for more time, and it is helpful to form dense coatings. The current study focuses on this technology for application in porous metal supported solid oxide fuel cell (MS-SOFC), especially for preparation in electrolyte. Using SEM, it was found that the densification of the electrolyte was very well, and this could be confirmed by the open-circuit voltage (OCV) of the cell. In the temperature range of 550~750 ℃, the OCV of the cell fairly stabilized between 1.05 V and 1.1 V. The cell was also analyzed by using electrochemical impedance spectroscopy (EIS). The maximum power density of the cell could be up to more than 1200 mW/cm2 at 750 ℃. The long-term stability of the cell was also preliminarily explored, and the result has shown that it is a very promising method for application in MS-SOFC.