Effects of CuO Sintering Aid Addition on Neodymium Doped Ceria (NDC) Solid Electrolyte

• Main Author: NUGRA ARIFIADI - Nim: 12514009 , ANINDITYO
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25620
• Institution: Institut Teknologi Bandung

<p align="justify">Population growth followed by the increase of energy consumption has led to excessive CO2 emission. World leaders have reached an agreement to reduce CO2 emission, therefore a more efficient technology to generate energy is required. Solid oxide fuel cell (SOFC) is one of the technology for direct conversion of fuel to electricity with high convertion efficiency. Problem on current SOFC is its relatively high operating temperature (~1000oC). Neodymium doped ceria (NDC) is one of several candidates for SOFC electroyte with lower operating temperature. Addition of CuO as sintering aid may also reduce production cost by lowering its sintering temperature. Thus, a study about the effects of CuO addition on the properties of NDC is required. <br /> <br /> <br /> In this research, NDC powder is synthesized with a chemical formula of Ce0,75Nd0,25O1,875, sintering aid is added by an amount of 0, 0,5, 1, and 1,5 weight %. Powder is mixed through stirring in an ethanol medium. Mixed powder is pressed to form a pellet which is then sintered at 1000oC, 1200oC, and 1400oC for 4 hours. Also, variation of sintering time (2, 3, and 4 hours) is conducted at sintering temperature of 1200oC. The mass and dimension of the pellet before and after sintering is measured for calculating relative density and linear shrinkage mechanism. Impedance is measured using a potentiostat at 500-700oC with 50oC interval. Measurement data in form of Nyquist plot is then processed to obtain the conduvtivity and activation energy value. Characterization using SEM-EDS and XRD is conducted for selected pellets. <br /> <br /> <br /> Result shows that the highest relative density of 65,21% is achieved when pellet with 0,5 wt% addition is sintered at 1200oC for 4 hours. Without CuO addition, linear shrinkage occurs through grain boundary diffusion mechanism and with CuO addition liquid phase sintering phenomena occurs. Electrochemical impedance analysis shows that CuO addition lowers the grain boundary resistance. The highest conductivity of 1,52 x 10-2 S/cm at operating temperature of 700oC with 0,85eV activation energy is achieved by NDC pellet with 0,5wt% CuO addition. <p align="justify"> <br />