Abstract
One of the tubular cell designs for solid oxide fuel cells is based on a closed-end tube made from the cathode material, with an electrolyte layer coating the outside of the cathode tube, and the anode coating the electrolyte layer. The outer anode layer of one tubular cell is connected to the inner cathode layer of the next tube by the interconnect material. High density is required in the interconnects to prevent mixing of the air and fuel gases. The fabrication of interconnect strips in tubular fuel cell stacks by DC-arc plasma spray deposition has been demonstrated in the past, both in air (APS) and in low pressure (vacuum) conditions (VPS). The High Velocity Oxy Fuel (HVOF) spray deposition technique typically yields among the highest density coatings of all common thermal spray techniques due to the high gas and particle velocities achieved, and therefore would appear to be an excellent method for depositing the interconnects if the powder could be sufficiently melted during spraying. The most common material choice is a doped LaCrO3, a ceramic material with a good thermal expansion coefficient match with the other components of the cell and an acceptable electrical conductivity. The microstructure, phase and chemical composition, and electrical properties of doped LaCrO3 deposited on (La,Sr,Mn)2O3 cathode tubes by HVOF was examined as a function of deposition conditions. Abstract only; no full-text paper available.
