Rhombic, wie funktioniert die fuel cell - 500 Beiträge pro Seite

[cgurdan]

hi leute,

kann mir jemand erklären, wie so eine fuel cell funktioniert ?
mich würde auch die chemischen abläufe interesieren.

gruß
churdan

[buschert]

Es ist im März 2001 ein Buch erschienen
C.F.Müller Verlag

Brennstoffzellen
Entwicklung, Technologie, Anwendung

[cgurdan]

danke für die info, aber vieleicht hat ja jemand eine erklärung die etwas kürzer ist.

gruß
cgurdan

[Lauwarmduscher]

Hallo!


Frequently Asked Questions regarding Rhombic`s Technologies

What is a fuel cell?

A fuel cell, like a battery, has an anode side and a cathode side with an electrode (the exchange membrane) in between. In
a proton-exchange membrane (PEM) fuel cell, hydrogen is supplied to the anode where it breaks apart into protons and
electrons. The electrode conducts protons but not electrons. The protons flow through the electrode while the electrons travel
through the external circuit and provide electrical power. The electrons and protons are reunited at the cathode and combine
with oxygen from the air to produce water. Fuel cell stacks are created by layering the cells on top of each other, allowing for
more power to be generated. The water evaporates from the fuel cell stack into the surrounding air.

What does PEM stand for?

PEM stands for Proton Exchange Membrane. The proton exchange membrane used in a PEM fuel cell is a thin layer of
material that allows protons (hydrogen ions) to pass through it, but keeps electrons and whole atoms on one side.

What does DEM stand for?

DEM stands for Diamond Exchange Membrane. The diamond exchange membrane used in a DEM fuel cell has the same
operating characterisitics as a PEM fuel cell, but uses a thin layer of diamond material.

What does MEA stand for?

MEA stands for Membrane Electrode Assembly. The MEA consists of a solid polymer, proton exchange membrane. A layer
of platinum-based catalyst and a gas-porous electrode support material are on both sides of the membrane, forming the
anode and cathode of the cell.

What are the advantages of a DEM over a PEM?

This new development in diamond membrane technology will allow high proton transport through the membrane by the
process of a non-porous structure supported by an improved anode and cathode to which hydrogen ions are not affected.
Further, a major advantage of using diamond is that it can withstand temperatures 4 times greater than current membrane
material. Rhombic`s new "DEM" diamond exchange membrane will operate at higher temperatures than current standard
"PEM" polymer exchange membrane fuel cells. As a result, reaction rates are increased considerably while the platinum
content decreases by a similar factor. At the same time manufacturing costs are drastically reduced. Current "PEMs" must
be kept moist, thus restricting operating temperatures, whereas Rhombic`s new "DEM" does not require moisture. In
conclusion the "DEM" fuel cell will allow for higher operating temperatures, increased reaction rate, longevity, and a much
smaller fuel cell stacked system. Reduced platinum and manufacturing costs will provide an opportunity to produce a fuel
cell stacked system at an affordable price, well below the manufacturing guidelines published by the Department of Energy
and the Ford Motor Company.

What is a nanotube?

A one dimensional fullerene (a convex cage of atoms with only hexagonal and/or pentagonal faces) with a cylindrical shape.
Individual single-wall nanotubes have the electrical conductivity of copper or silicon, the thermal conductivity of diamond, and
also happen to be the stiffest and strongest fibers known. Their molecular perfection enables them to be manipulated using
the versatile chemistry of carbon.

What is the function of nanotubes in a fuel cell system?

Carbon nanotubes are a new method for the storage of hydrogen. One way carbon can arrange itself is in a sheet pattern like
a honeycomb. This is the graphite form of carbon. The sheets are not bound tightly together, but if they are wrapped on top
of each other, a very strong carbon nanotube is formed. The interesting part concerning these carbon nanotubes is that their
widths are just large enough for hydrogen molecules but too small for larger molecules. A typical hydrogen molecule
consists of two hydrogen atoms. The hydrogen atom has the second smallest radius of all elements because its one
electron is in the 1s orbital which is the closest orbital to the positively charged nucleus. So the one electron is held very
tightly to the nucleus thus decreasing the atomic radius. It is possible then that perhaps hydrogen can be stored in these
carbon nanotubes.



Mfg Lwd

[cgurdan]

vielen dank lauwarmduscher.

gruß
cgurdan

[PHOENIX-IT]

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