Modeling of chemical–mechanical couplings in anode-supported solid oxide fuel cells and reliability analysis

Abstract

Oxygen ionic transport in conducting ceramics is an important mechanism enabling solid oxide fuel cell

Chemical lattice strain in nonstoichiometric oxides: an overview

“…Cr, Mn, Fe, Co, or Ni, occupy the B-sublattice of La 1-x Sr x M 1-y B y O 3-d , and the fraction of one of them is signicantly greater, eqn (42) can be used in the defect structure model along with either xing the oxidation state of the other one 200 or assuming M and B ions to be indistinguishable within the model's framework. 134,199 In case the M and B concentrations are close, the model usually incorporates eqn (43) taking into account the respective electronegativities of B and M, e.g. 75.…”

“…[32][33][34] As seen, the great multitude of experimental and computational methods does not allow them to be reviewed in this work in detail. Some more applied aspects of chemical expansion, such as the modeling of chemically induced stresses in membranes [35][36][37][38][39][40][41][42] and SOFCs, 43,44 were thought to be beyond the scope of this rather more fundamentally oriented review. However, our leaving them out does not mean that they are somehow unrelatedon the contrary, high quality experimental data on defect equilibria and chemical expansion of materials gure among the necessary parameters of these models.…”

“…However, our leaving them out does not mean that they are somehow unrelatedon the contrary, high quality experimental data on defect equilibria and chemical expansion of materials gure among the necessary parameters of these models. 35,36,38,43 We would also like to draw the attention of interested readers to other existing reviews 10,23,45,46 which may provide additional information on the topic.…”

On governing equations and closure relations for the multiscale modeling of concentration polarization in solid-oxide fuel cells: mass transfer and concentration-induced voltage losses.

“…direct internal reforming of and in anode-supported cells [ 309,310] ; electrochemical cooxidation of and described through elementary reactions [ 311,309] ; numerical assessment of the cell tolerance and failure resulting from delamination phenomenon [ 312] ; and reliability analysis of SOFCs wherein the coupling of chemical-mechanical phenomena develop due to the volumetric expansion of ceramic components, leading to the so-called chemical stresses [ 313] . These authors have not used the same mathematical models of fluid flow and mass transfer throughout their works and important differences exist concerning the way in which concentration losses have been calculated.…”

“…The "extended version" of Bosanquet formula provided in Table 4.15 [313] , when compared to its classical form [62] , is a artifice a few authors in the literature have been using as a "non-rigorous" method to avoid the violation of gas species mass conservation. Although the conditions under which it should be applied, its apparent validity, and its mathematical derivation has not been openly discussed (e.g., see [72,313]), it is most likely that the use of an "averaged Bosanquet diffusion coefficient" is justified in the cases where the assumption of constant total pressure is incorrectly enforced in the presence of chemical reactions (which, in this case, produce a net change in the total number density of gas species). Below it is given a possible explanation for the origin for such "corrected formula" for the case of a ternary gas mixture.…”