Combustible battery with direct methanol

The combustible batteries with direct methanol or DMFC (according to the acronym of English name direct-methanol fuel concealment ) are a subcategory of combustible batteries to membrane of exchange of protons in which the fuel, the Méthanol (CH₃OH), is not reformed but is provided directly to the Combustible battery.

Advantages

Methanol, while being provided directly to the combustible battery, makes it possible to avoid a catalytic Reformage complicated, and allows as a storage easier as the Hydrogène, not requiring neither high pressures nor low temperatures because liquid. The energy density of methanol (quantity of energy slackened during the use of a given volume of methanol) is much more important than that of hydrogen, even strongly compressed.

Developments

However, the effectiveness of fuel is low, because of the high permeability of methanol through the Membrane, its behavior dynamic is relatively slow. Methanol is also strongly toxic and behaves like a poison.

At the current level of technology, the DMFC are limited in their power of production, but can always store energy in low volumes. This means that they can produce a small quantity of energy over one long period.

This operation makes the DMFC unsuitable for the applications of car locomotion, but their characteristic powers are adapted for applications in the telephones or the laptops.

Operation (reactions)

The DMFC are based on the Oxydation methanol on a layer of catalyst in order to form Carbon dioxide. Water is consumed with the Anode and is produced with the Cathode. The Proton S (ion H⁺) are transported through the exchanging membrane of protons towards cathode where they react with Oxygène in order to produce water. The electron S are transported via an external circuit of the anode towards cathode, thus getting energy with the external equipment.

The half-reactions are:

Anode: CH₃OH + H₂O → CO₂ + 6:00 ⁺ + 6e^-
Cathode: 3 O₂ + 12:00 ⁺ + 12e^- → 6:00 ₂O

What gives overall: 2CH ₃OH + 3 O₂ → 2CO₂ + 4:00 ₂O.

Since water is consumed with the anode during the reaction, pure methanol cannot be used without water reserve via is by passive transport like the retro diffusion (Osmose), or a active Transport like pumping. The requirement out of water limits the energy density of fuel.

History

At the end of the years 2004, the subsidiary company of Mechanical Technology Inc., MTI MicroFuel Cells produced its first DMFC for a regular commercial practice. The technology of the battery compact without wire and refillable of MTI' S Mobion™ consists of a combustible battery which works under methanol 100%. This solution was marketed on the military, industrial markets and large-public as a solution at low cost for the batteries lithium-ion.

In 2005, the record of the smallest commercial pile available was held by Toshiba, with for dimension 22 X 56 X 4,5 Misters This object delivers 100 milliwatts over 10 hours per millilitre of fuel, and draws advantage of new technologies allowing the use of methanol not diluted (99,5%).

External bonds

Toshiba close release
standard codes and.

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