Summary - Hierarchical Nanostructures for Energy Devices - page 292

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CHAPTER 13
Summary

SEUNG HWAN KO

Applied Nano and Thermal Science (ANTS) Lab Department of
Mechanical Engineering, Seoul National University, 1 Gwanak-ro,
Gwanak-gu, Seoul 151-742, Korea
Email: [e-mail]

Hierarchical nanostructures are usually a combination of multiscale, multi-
dimensional nanostructures such as nanowires, nanoparticles, nanosheets,
nanopores and so on. Hierarchical nanostructures are expected to overcome
the limitations of simple single-scale nanostructures. However, simple geo-
metric combinations or a mixture of those multidimensional nanomaterials
cannot be called true hierarchical nanostructures. To be functional hier-
archical nanostructures, smart structuring or organization of each nano-
material should be carried out to obtain ultimate performance compared with
single component nanomaterials. To satisfy those requirements, functional
hierarchical nanostructures should not only have a large surface area but also
enhanced electrical, chemical, mechanical and optical performance.
This topic has introduced recent developments in hierarchical nano-
structuring especially for highly ecient energy device applications. Surface
and electrical properties are the primary concerns in most energy devices.
Maximizing eciency in energy devices can be achieved by either new
material development or functional structuring. Hierarchical functional
nanostructuring has rapidly gained interest to achieve an increase in surface
area and favourable electrical properties.
The energy devices covered in this topic are (1) energy generation devices
(solar cells (DSSCs, OPVs), fuel cells, piezoelectric, thermoelectric, water
splitting and so on),

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(2) energy storage devices (secondary battery,