Ceramics for Sustainable Energy Technologies with a Focus on Polymer-Derived Ceramics - Novel Combustion Concepts for Sustainable Energy Development - page 493

ceramic TE since they have the potential to operate at higher temperature and be
stable under harsh environmental conditions, e.g., flue gases. In TE applications,

both n-type and p-type materials are required. Several candidate ceramic p-type
materials have been investigated including calcium cobaltite, Ca 3 Co 4 O 9 . There are
limited studies on n-type ceramics, one promising candidate being (Sr(Ba) Nb 2 O 6 )
(Dandeneau et al. 2013 ). Current and potential applications for TE ceramics include
the recovery of waste heat in industrial furnaces or incineration processes and the
harnessing of electric energy from alternative renewable energy sources such as
solar thermal or geothermal.
An increasing concern about greenhouse gas emissions and rising energy
demands has resulted in revitalized interest in the development of next-generation
nuclear power plants. Aside from the classic use of ceramics as nuclear fuels (UO 2 ,
PuO 2 , ThO 2 , mixed oxides) or the application of boron carbide (B 4 C) as nuclear
radiation absorbent, e.g., in control rods, novel reactor designs have resulted in an
increased demand for materials with speci

fl

les in terms of
mechanical, thermal, and radiation stability, many of which can be ful

c requirement pro

lled by
advanced ceramics. Due to their ability to resist high temperatures and its tolerance
to neutron radiation, silicon carbide (SiC) and SiC-based composites have been
intensively investigated for both advanced

fission and fusion energy applications,
e.g., as core or in-vessel components in advanced fission reactors or as structural

components or flow-channel inserts in fusion reactors. In these types of harsh
applications, SiC/SiC composites made from chemically vapor-in

ltrated (CVI),

high-purity crystalline SiC fibers have shown superior performance compared to

conventional systems (Katoh et al. 2003 ).

1.1.2 Energy Storage

The emerging use of intermittent renewable energy sources such as wind or solar
energy results in the need for high-ef ciency and capacity energy storage systems.

This challenge is even more prevalent in the transportation sector, where efforts of
reducing CO 2 emissions have led to the anticipated replacement of vehicles with
internal combustion engines by

vehicles such as electric vehicles.
Electrochemical systems, primarily batteries and supercapacitors, provide a way to
effectively store and release electric energy on demand and are therefore of major
economic and technological importance.
Owing to their high speci

“ zero-emission ”

ciency, and longevity, Li-ion batteries are
currently found in a wide variety of mobile and stationary applications, ranging from
mobile communication devices and consumer electronics to electric vehicles. A
variety of ceramics are used as solid electrolytes in Li-ion batteries. A promising
example for a lithium-ion-conducting oxide is the perovskite (La, Li)TiO 3 . Other
ceramics exhibiting high lithium-ion conductivity are Li 9 SiAlO 8 or garnet-structure-
related compounds such as Li 5 La 3 Ta 2 O 12 (Fergus 2010 ). Aside from using ceramics
as electrolytes, nanoscaled Al 2 O 3 , SiO 2 ,orZrO 2 (or respective mixtures) has been
used as composite separators in liquid electrolyte Li-ion batteries, increasing the

c energy, ef