Sharp Achieves the World's Highest Power Density for Direct Methanol Fuel Cells; Elemental Technology for the Practical Application of Fuel Cells for Mobile Equipment

Osaka, Japan, May 15, 2008 - Sharp Corporation has
achieved the world's highest(1) power density(2), 0.3W/cc, for direct
methanol fuel cells (DMFC) for mobile equipment. This new technology
enables efficient power generation from a small cell volume. Thus, the
use of this technology can make it possible to develop fuel cells that
have almost the same volume but a longer continuous-use lifespan than
lithium-ion batteries, which are the main type currently in use. Sharp
will promote further research and development for the practical
application of fuel cells for mobile equipment such as PDAs, electronic
dictionaries, and notebook computers. 

Because fuel cells use energy produced by the chemical reaction between
hydrogen and oxygen, they have a small impact on the global environment.
Also, fuel cells are expected to become the next-generation power
generating devices because of their high generating efficiency that
comes from converting chemical energy directly into electrical energy.
In particular, DMFC have a simple structure in which power is generated
through a chemical reaction between methanol supplied directly to the
power generation part and oxygen in the air, making them suitable for
miniaturization. Therefore, since these fuel cells have great potential
for future use in mobile equipment, active research and development on
DMFC is intensifying all over the world. However, there are some
problems that need to be solved, such as their low power density that
increases the size of the power generation part and, as a result,
increases the total cell volume. 

Giving special attention to the power generation part's stack
structure(3), Sharp has developed the three-dimensional highly
integrated stack structure through the use of thin cells made by
microfabrication. This structure can be created by the alternate
lamination of reed-shaped thin cells arranged in parallel at fixed
intervals and reed-shaped (porous) spacers, with the cells and spacers
running perpendicular to each other like a grid. With this structure,
uniform and continuous spaces are secured, making it possible to
increase the cell surface area per unit volume and smoothly circulate
the air that is one of the sources for power generation. Thus, Sharp has
improved power density per unit volume and achieved the world's highest
level, 0.3W/cc (about 7 times greater than previous Sharp technology).
In the future, through continuing to pursue the development of this
elemental technology, cell volume can be further miniaturized, and the
creation of cells with the same volume but a longer lifespan than the
currently mainstream lithium-ion batteries can be achieved. By further
promoting this elemental technology in the future, Sharp will commit
itself to the creation of small fuel cells with a long lifespan.

Sharp will announce this new technology at The 15th Fuel Cell Symposium,
to be held on May 15, 2008 at Tower Hall Funabori (Funabori, Edogawa-ku,
Tokyo), sponsored by the Fuel Cell Development Information Center.

(1) As of May 15, 2008, taken as the unit volume for the power
generation part of passive -type direct methanol fuel cells. 
(2) The output is per unit volume for the power generation part (stack).
The unit is W/cc. 
(3) One of the units constituting the main body of fuel cell, it
consists of the assembly of several unit cells. 


Sharp Corporation

Sharp Corporation is a worldwide developer of innovative
products and core technologies that play a key role in shaping the
future of electronics. As a leader in liquid crystal displays (LCDs) and
digital technologies, Sharp offers one of the broadest and most advanced
lines of consumer electronics, information products and electronic
components, while also creating new network businesses. Sharp
Corporation employs about 57,600 people in the world (as of April 30,
2007) and recorded consolidated annual sales of 3,127,771 million yen
for the fiscal year ended March 31, 2007. For more information, please
visit www.sharp.co.jp .