Premium
Numerical Study of Solid Oxide Fuel Cell Contacting Mechanics
Author(s) -
Chen Z.,
Wang X.,
Brandon N.,
Atkinson A.
Publication year - 2018
Publication title -
fuel cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 69
eISSN - 1615-6854
pISSN - 1615-6846
DOI - 10.1002/fuce.201700128
Subject(s) - materials science , electrolyte , composite material , anode , solid oxide fuel cell , stack (abstract data type) , stress (linguistics) , oxide , current collector , cathode , contact area , contact force , residual stress , electrode , electrical engineering , chemistry , metallurgy , linguistics , philosophy , computer science , programming language , physics , quantum mechanics , engineering
Assembly of a planar solid oxide fuel cell (SOFC) or solid electrolyzer (SOE) stack involves the lamination of cells and interconnect plates under an applied load. In most designs a pattern of ribs on the interconnector makes contact with a porous ceramic current collector layer on the air side. These localized contacts are regions of increased stress on the cells and can cause damage if the stresses become too large. In this paper the mechanical response of an anode‐supported cell to localized loads from interconnector ribs is simulated. The simulations show that the critical stress for initiating and propagating a crack in the electrolyte (∼300MPa for a 10 μm thick electrolyte) is reached when the interconnector displacement reaches 20 μm (after touching the cathode) with reduced support, or 30 μm when in an oxidized state. The difference is due to the lower stiffness of the reduced support. The residual compressive stress in the electrolyte layer has a major protective effect for the electrolyte. It is concluded that fracture is very unlikely for a geometrically perfect contact, but if the contact is non‐uniform due to manufacturing variability in the contact plate or cell, local displacements >∼20 μm can be dangerous. The simulations are used in an example of contacting geometry optimization.