Mobility Site - View Single Post - Toshiba Integrates Prototypes Fuel Cell Into Mobile Audio Players

medevo · 09-17-05, 08:02 PM

Originally Posted by transcout

Hmm.. Does no-one see the downside of this?
When i get home, I drop my PDA in the cradle, and it's ready for tomorrow.

With this, I will have to faff around putting methanol in it.. Probably spilling it all over the screen several times a week. I will run out of methanol, and won't be able to find a tech-y shop nearly that sells it. Then maybe one day it will leak in my pocket, and I get a big methanol stain on my suit. It will smell of methanol all the time, and so will my hands..

I really don't think it will be all that great..

All of which are reasonable problems with the technology. What I expect for more "consumer level" devices is a "methanol battery". This could be a fuel cell and a sealed fuel tank in a regular battery size (AA ext) or just the fuel and the fuel cell is built into the device.

I think you could draw a parallel to older car batteries that required distilled water to be added to make up for hydrogen gas that was created during the galvanic reaction. Newer Sealed Lead Acid battery design's (some of which are less efficient then the refillable design's) do not require any maintaining.

The first generation of fuel cell technology will require manual refilling (especially for cars) but convince will win out eventually with sealed one-use fuel blocks or semi-refillable devices.

Why is portable technology moving to fuel cells you ask?
Take for example the 3.7V 1100mA/h battery that the x50v comes with. It stores about 14652 joules. Methanol has an enthalpy of combustion (essentially how much energy can liberated from burning it) of -239KJ/Mol. Assuming a perfect system 2.5mL (2 grams) of methanol has the same stored energy as the x50v battery.

The energy density (critical for small devices) of methanol is 22MJ/Kg. The BEST lithium based batteries are just peaking over 1MJ/Kg. The reason cars are moving to batteries is that power consumption in a car demanded high energy of fuels for along time, but technology has made it so batteries can meet the energy needs of the car. Opposite of this, fuel cells and combustion devices previously could not fit in handheld applications.

Not linked in this article, but another fuel cell Toshiba has got in testing is about the size of a pack of gum (0.5544m^3) and is 8.5g with 2mL of methanol in a tank. It provides 8856 joules on one tank. Its new technology, it only has an energy density of about 1MJ/Kg but this is a prototype and that number should grow rapidly.

Medevo