CONTEXT and STATE-OF-THE-ART - Ceramic high-temperature fuel cell and electrolyser are efficient energy-conversion systems for electrical power generation and hydrogen production. This type of electrochemical device is constituted by a stack of elementary Solid Oxide Cells (SOCs), each one being composed of a dense electrolyte sandwiched between two porous electrodes. The industrial deployment of SOCs is still hindered by key issues related to durability and costs. For instance, the instability of the oxygen electrode made of Lanthanum Strontium Cobalt Ferrite (LSCF) is recognized as one of the prevalent mechanisms involved in the loss of SOCs performance, especially when operated in electrolysis mode . The processes of the material deterioration being thermally activated, many studies have been recently undertaken to reduce the operating temperature with new oxygen electrode materials in order to improve the performances as well as to mitigate the degradation. However, the performances of SOCs are not only due to intrinsic properties of materials but they are also strongly related to the association of functionally structured electrodes and the properties of the electrode/electrolyte interface. In this frame, architecturally designed La0.6Sr0.4Co0.2Fe0.8O3- (LSCF) and La2-xPrxNiO4+δ (x=1, LPNO) oxygen electrodes layered by Electrostatic Spray Deposition (ESD) and SP on Ce0.9Gd0.1O2-δ (CGO) electrolyte are selected as innovative solutions for the next generation of SOCs. To date, optimum polarization resistances have been reported [2-4] thanks to the presence of a nanostructured ESD active porous functional layer facilitating the oxygen surface exchange and ions diffusion, fundamental in the oxygen electrode design.
Rédigé par Gilen Oyharcabal
mise à jour le 13 juillet 2018