Ceramics for Sustainable Energy Technologies with a Focus on Polymer-Derived Ceramics - Novel Combustion Concepts for Sustainable Energy Development - page 494

safety of battery cells by providing high-dimensional stability at high temperatures,
thus preventing accidental electrode contact.
Even though rapid progress has been made in terms of storage capacity in recent
years, the large-scale storage of electrical energy from intermittent energy sources is
still a big challenge, primarily due to high costs. The most important alternatives are
the storage of produced energy by chemical (hydrogen storage) or thermal means.
The has been advocated as an alternative to the current fossil-

fuel-based economy and was declared as a dedicated aim for future developments
by many governments. In this proposed system, the safe and economic storage of
hydrogen is of signi

“ hydrogen economy ”

cant importance. Several ceramic materials have been con-
sidered for this function, primarily zeolites (Morris and Wheatley 2008 ).
An alternative way to overcome the gap between the power generation and
demand is the use of thermal energy storage, where excess thermal energy is used
to warm up or melt a material, thus storing it in the form of sensible or latent heat.
When demand rises, the stored energy can be released by cooling of the storage
material. A classic example for a sensible heat storage (SHS) material is ceramic
bricks, or, more recently, porous ceramics with designed pore structure and thermal
properties. In latent heat storage (LHS), phase-change materials with speci

c

properties (including large speci c heat of phase change, high thermal conductivity,

small volume change, and relatively low cost) are used to absorb and release heat
during a phase-change process. Advantages of this technique include the high
energy storage density as well as the small temperature range required during
operation. Porous ceramics have been proposed as containers for storing phase-
change materials.

1.1.3 Energy Distribution

In order to increase the ef ciency of energy grids, a substitution of metallic con-

ductors by superconductive materials has been proposed, offering higher capacities
and avoiding resistive losses. Since the discovery of ceramic-based high-tempera-
ture superconductors (HTS) in the form of cuprates such as yttrium barium copper
oxide (YBCO) in the 1980s, extensive research has been conducted in developing
materials with even higher transition temperatures, with the record currently being
held by Hg-containing cuprates at over 130 K. While not yet quite ready to be
implemented on a large scale, small-scale

field tests of next-generation ceramic
HTS systems are currently underway around the globe (Haught et al. 2007 ).

1.1.4 Sustainable Manufacturing Systems

Finally, ceramics are not only utilized as novel materials in sustainable technologies
as described above, but the emergence of sustainable technologies also has impli-
cations on the manufacturing of ceramics themselves. The adoption of more sus-
tainable concepts for production processes, sometimes referred to as green