Anode: The electrode of an
electrochemical cell at which oxidation occurs; the positive terminal of
an electrolytic cell.
Catalysis: A chemical reaction
involving a material which promotes or increases the rate of the
reaction without itself undergoing any permanent chemical change.
Cathode: The electrode of an
electrochemical cell at which reduction occurs; the negative terminal of
an electrolytic cell.
Co-firing: Simultaneous heat
processing of multiple ceramics.
Doping: To treat with an impurity
added in minute amounts to a pure substance to alter its properties.
Electrolyte: A nonmetallic
electric conductor in which current is carried by the movement of
Grain boundary resistance: The
resistance which occurs at the interface between grains in a
Hybrid system: Power generating
system which combines standard engines or gas turbines with solid oxide
Interconnect: The link between
individual fuel cells.
Nanoscale: Of the order of
10-9 meters in size.
N-type: A material in
which electric charge which is carried by surplus electrons.
Oxidizing atmosphere: Gaseous
environment in which an element or ion changes from a lower to a higher
positive oxidation state (i.e., removes one or more electrons from an
atom, ion, or molecule).
P-type: Material in which electric
charge which is carried by a deficit of electrons, or holes.
Perovskite: An oxide having the
same crystalline structure as the mineral, CaTiO3, which is
usually expressed as ABO3. An ideal perovskite has a
structure in which A (cation) is located at the center of the cubic unit
cell, B (cation) is located at each corner and O (anion) is located at
the center of each side.
Plasma spraying: A thermal
spraying process in which the heat source is a jet of highly ionized gas
(plasma). The coating material is melted in the plasma and propelled
onto the substrate.
Reducing atmosphere: Gaseous
environment in which an element or ion changes from a higher to a lower
oxidation state (i.e., adds one or more electrons to an atom, ion or
Sinter: To densify by heating
without complete melting.
Solid oxide: A hard ceramic
compound of oxygen. In the case of fuel cells, the term refers to the
electrolyte material, typically ZrO2, the compound of
zirconium metal and oxygen.
Tape casting: A ceramic forming
process where a slurry is spread evenly onto a flat horizontal surface.
After drying, the flexible, unfired tape can be cut, laminated, or
shaped and then sintered.