Optimization of spin-coated electrodes for electrolyte-supported solid oxide fuel cells

Abstract

Electrodes for electrolyte-supported solid oxide fuel cells (SOFC's) were fabricated by spin coating. Strontium-doped lanthanum manganite (LSM) cathode and nickel yttria-stabilized zirconia cermet anodes were synthesized and processed for enhanced deposition conditions. The influence of electrode microstructural parameters was investigated by a systematic experimental procedure aiming at optimized electrochemical performance of single cells. Polarization curves showed a strong dependence on both electrode thickness and sintering temperature. By a systematic control of such parameters, the performance of single cells was significantly enhanced due to decreasing of polarization resistance from 26 Ω cm² to 0.6 Ω cm² at 800°C. The results showed that spin-coated electrodes can be optimized for fast and cost effective fabrication of SOFCs.

Development of functional layers for direct ethanol solid oxide fuel cells

“…For the anode tape, an additional mass loss is observed at ~800 °C was ascribed to the decomposition of graphite pore former [266]. Those thicknesses were within the typical range used and in agreement with the procedure optimized by the group [265]. The image also evidences good adhesion of anode and the cathode to the electrolyte and a homogeneous interface.…”

“…Complete fuel cells were made by the deposition of anode and cathode inks for the ESC and cathode ink for the ASC. Herein, functional layers (FL) and current collection layers (CCL) of both anode and cathode were prepared following a previously developed method [265]. The anode inks consisted of NiO/YSZ prepared by the liquid mixture method with compositions of 40 vol% NiO for the FL and 60 vol% NiO for the CCL.…”

“…The inks were deposited using the spin coating (Laurel, model WS-400-6NPP-LITE) method [265]. The substrates, i.e., the electrolyte support and the anode supported half-cell, were fixed in the spin coater by vacuum.…”

Desenvolvimento de célula a combustível de óxido sólido pelo método de colagem de fita e co-sinterização

“…As formulações das suspensões de anodos funcionais e coletores foram baseadas e aperfeiçoadas em estudos prévios [31,105] Nesse trabalho foram utilizados pós de catodos comerciais de LSM, para as células à base de YSZ, e de LSCF para as células à base de CGO. Similarmente aos anodos, foram produzidas as camadas funcional e coletora de corrente dos catodos.…”

“…As curvas de TGA e DTA mostram-se praticamente estáveis a partir de 430°C e de 630°C para o NiO/YSZ e para o NiO/CGO, respectivamente. Baseado nos dados de TG/DTA e em acordo com estudos prévios do grupo de pesquisa do IPEN a calcinação do NiO/YSZ obtido por meio do método da mistura líquida foi calcinado em 450°C por 5 horas [90,105]. No caso do NiO/CGO, o evento de perda de massa em temperaturas acima 600°C, provavelmente devido a formação de Ni(OH)2, determinou a temperatura de calcinação em 650°C por 5 horas.…”