Spin coating deposition of 8YSZ electrolyte by sol-gel and ceramics nanoparticles suspension for application in metal-supported solid oxide fuel cells

• Grant number: 24/01745-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2024
• End date: August 31, 2025
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Gustavo Doubek
• Grantee: Thiago Setti Aguila Martins
• Host Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated scholarship(s): 24/16656-7 - Studies on DBLs fabricated by Physical Laser Deposition (PLD) and electrochemical characterization for Solid Oxide Fuel Cells (SOFCs), BE.EP.IC

Abstract

This project focuses on mitigating a pivotal technological obstacle hindering the industrial implementation of Solid Oxide Fuel Cells (SOFCs) within the automotive sector, i.e., the issue of cell costs surpassing 1066 R$/kW. Addressing this concern entails resolving it through the manufacturing of large area cells utilizing scalable and cost-effective electrolyte deposition techniques, such as spin coating involving sol-gel or ceramic nanoparticle suspensions. The 8YSZ ceramic electrolyte assumes a critical role within SOFCs, as it dictates the operational temperature of the device and serves the purpose of delineating the anodic regions, where fuel oxidation occurs, from the cathodic zones, where the reduction of molecular oxygen into oxygen anions takes place. In this project, two synthesis routes of 8YSZ will be investigated, encompassing methodologies such as sol-gel and ceramic nanoparticle slurry techniques. The primary objective is to expand the area of deposition up to 216 cm2 by spin coating. The 8YSZ electrolyte sol gel or ceramic nanoparticle suspension will be deposited over the porous ceramic anodes NiO-10GDC and NiO-8YSZ by spin-coating. This project also contemplates as specific objectives the correlation of the deposition parameters of the films, such as speed and rotation time of the substrate and deposition cycles, with the homogeneity of the film, thickness (between 5-20 mm), stoichiometry, structure, microstructure and roughness. To characterize the deposited film, the following techniques will be employed: scanning electron microscopy (SEM) to assess the microstructure and thickness of the electrolyte films, EDS (Semi-quantitative Energy Dispersive Spectroscopy) will analyze the stoichiometry of the ceramic film, XRD (X rays Difracion) will evaluate the phases, crystallographic orientation, crystallinity, and crystallite size, while AFM (Atomic Force Microscopy) will measure roughness and topography. These comprehensive characterization techniques aim to provide a thorough assessment of the film's properties. Hence, after morphological assessments, it's desired to conduct electrochemical evaluations of the SOFCs utilizing Electrochemical Impedance Spectroscopy (EIS) and the development of polarization curves.This project additionally contemplates the optimization of deposition cycles to attain the targeted electrolyte thickness ranging from 5 to 20 microns in areas up to 216 cm2. To characterize the deposited film, the following techniques will be employed: scanning electron microscopy to assess the microstructure and thickness of the electrolyte films, EDS will analyze mass and atomic composition, BET will determine specific surface area of the nanopowders synthesized, XRD will evaluate the phases, crystallographic orientation, crystallinity, and crystallite size, while AFM will measure roughness and topography. These comprehensive characterization techniques aim to provide a thorough assessment of the film's properties. Hence, after morphological assessments, it's desired to conduct electrochemical evaluations of the SOFCs utilizing Electrochemical Impedance Spectroscopy (EIS) and the development of polarization curves.