IDEAL-Cell, a High Temperature Innovative Dual mEmbrAne Fuel-Cell

IDEAL-Cell is a new concept of a high temperature fuel cell operating in the range 600-700\ub0C. It is based on the junction between the anode part of a PCFC and the cathode part of a SOFC through a mixed H+ and O2- conducting porous ceramic membrane. This concept, extensively described in the present paper, aims at avoiding all the severe pitfalls connected with the presence of water at the electrodes in both SOFC and PCFC concepts. Spark Plasma Sintering samples were designed specifically for proving the IDEAL-Cell concept. The first electrochemical results obtained at 600\ub0C under hydrogen on millimeter thick samples show that IDEAL-Cell behaves like a high temperature fuel cell. It is estimated that the overall efficiency of this new concept should greatly surpass that of standard SOFCs and PCFCs and that the material constraints, especially in the case of interconnect materials, should significantly decrease

Mathematical Modeling and Simulation for Optimization of IDEAL-Cell Performance

The IDEAL-Cell is an innovative SOFC concept, comprising the anodic part of a proton conducting fuel cell (i.e., anode and protonic electrolyte) and the cathodic part of a solid oxide fuel cell (i.e., cathode and anionic electrolyte), connected through a porous composite central membrane of proton conducting and anion conducting materials where water recombination reaction between protons and oxygen ions occurs. A mathematical model for the description of transport phenomena and reactions in steady-state conditions is presented. The model is based on charge and mass balances in a continuum approach. Simulations are performed considering negligible polarization resistances due to electrochemical activations in order to evaluate the maximum performance of the cell. Simulations show that the IDEAL-Cell performance is comparable to that provided by the current state of the art for proton conducting fuel cells, and it may be further improved by reducing ohmic losses with thinner layers

Mathematical modeling of mas and charge transport and reaction in a solid oxide fuel cell with mixed ionic conduction

A mathematical model for the description of transport phenomena and reactions in an innovative solid oxide fuelcell (called IDEAL-Cell) under steady-state conditions is presented. This cell is characterized by an intermediate porous composite layer (called central membrane) between cathodic and anodic compartments, which shows mixed conduction of protons and oxygen ions and offers active sites for their recombination to form water vapor. This paper presents an original model of charge transport and reaction in the central membrane. The model, based on local mass and charge balances, accounts for mixed conduction in the solid phase, diffusion and convection in the gas phase and reaction at the solid/gas interface. The model domain is resolved in a continuum approach by using effective properties related to morphology and material properties through percolation theory. The model predictions are successfully compared with experimental data, which provide an estimate of the kinetic parameter of the water recombination reaction. Simulations show strong dependence of predicted results on the kinetic constant of the water incorporation reaction and the effective conductivities. A design analysis on porosity, thickness, particle dimension, composition of central membrane and cell radius is performed and an optimal membrane design is obtained