Modelling the electrode performance and numerical optimisation of La2NiO4+δ nanoparticle infiltrated GDC scaffolds for solid oxide cells applications

A modelling framework was developed to optimise the microstructure of oxygen electrodes for Solid Oxide Cells (SOCs), based on porous Gadolinium-doped Ceria (GDC) scaffolds infiltrated with La 2 NiO 4 + δ (LNO) nanoparticles as electrocatalyst. An electrochemical kinetic model, considering peroxide and oxygen ion species on the LNO surface, was validated on a single-phase LNO. The validated model was then applied to both composite GDC-LNO and LNO infiltrated GDC scaffolds using synthetic microstructures. Systematic sensitivity analyses on catalyst loading and nanoparticle size were performed to identify key trade-offs between active TPB density and charge transport in LNO. Low catalyst loading yields high LNO effective tortuosity factors limiting electronic transport, counteracting benefits of increased TPB density in infiltrated electrode. The most optimal infiltrated microstructure achieved a very low polarisation resistance at 650 °C compared to a single-solid-phase electrodes or a standard composite electrode. These findings provide quantitative guidelines for fabricating high-performance infiltrated LNO electrodes, offering a pathway towards more durable and efficient SOCs.