Environmental Engineering Reference
In-Depth Information
Fig. 2 Examples for applications of ceramics in energy, environmental, and sustainable
technologies
systems, next-generation nuclear energy systems, photovoltaics, wind, and geo-
thermal systems.
Solid oxide fuel cells (SOFC) have gained major economic and scienti
c interest
as a result of their high energy conversion ef
flexibility in terms of
fuels used (natural gas, biogas, methane), and the wide range of possible applica-
tions, from combined heat and power plants producing several hundred kW down
to small units suitable as household energy supplies (e.g., Menzler et al.
2010
). In
SOFC designs, oxygen ion-conducting ceramic compounds are used as solid
electrolyte materials. The main materials currently used are partially cation-
substituted zirconia (ZrO
2
), ceria (CeO
2
), LaGaO
3
, as well as apatites such as
La
10
Si
6
O
27
. In addition to electrolytes, ceramics are also used in other parts of
SOFC, including anodes, cathodes, as interconnects, and as sealants in the form of
glass ceramics.
Thermoelectric (TE) materials and systems present a way to generate electrical
power from heat by employing the Seebeck effect, thus using a temperature gradient
to create an electromotive force (i.e., voltage). The absence of moving parts, a high
power density, and the ability to convert waste heat to electricity have fueled an
increasing interest in TE energy conversion systems. Although the primary TE
materials are metallic or intermetallic, there is a growing interest in developing
ciency, their
fl
Search WWH ::
Custom Search