Fuel Cells
EEYORE, Mon Aug 14 2006, 07:23AMHello all,
I have decided I would like to build a fuel cell. I would like to either build a hydrogen fuel cell, or a methanol fuel cell. I am not sure how to bypass spending $$$$$$ though. I have thourally checked out ebay and google and just see "kits" rather than materials. What is the membrane made of?Seems this is the one most costly part of the fuel cell. Which would be easier?Methanol, or hydrogen?
I have seen platinum wire glow in the presence of methanol. I wonder how hot?Perhaps a thermocouple heated by the glowing platinum creating some current?I am not looking to power my car, just looking to demonstrate the technology, perhaps lighting an LED at most...
Any tips?Has anyone made a good reliable one?I am really more interested in hearing ideas, or experience, rather than having others go research it online for me, unless they too would like to build one...(Hate doing others HW!)
Thanks!
Matt
Re: Fuel Cells
Marko, Mon Aug 14 2006, 02:06PM
PE membrane is usually some kind of proton-porous polymer doped with tiny particles of platinum (hardly something you can come by).
Except membrane I don't think there's anything unacessable for you. Those 'kits' are usually consisting simply of two pieces of acrylic, two electrodes and PEM pressed between.
FUel cells are usually capable of giving lots of power out and have very high energy/weight ratio when compared to standard batteries.
Usually these stacks are paralelled to get high output voltage (putting this just because of nice picture)
If you are unable to get a carpet roll of PEM or large amounts of exotic platinated metals I doubt you can come to building somethigng (but guys who produce 'kits' got their membranes from somewhere..?)
Marko, Mon Aug 14 2006, 02:06PM
PE membrane is usually some kind of proton-porous polymer doped with tiny particles of platinum (hardly something you can come by).
Except membrane I don't think there's anything unacessable for you. Those 'kits' are usually consisting simply of two pieces of acrylic, two electrodes and PEM pressed between.
FUel cells are usually capable of giving lots of power out and have very high energy/weight ratio when compared to standard batteries.
Usually these stacks are paralelled to get high output voltage (putting this just because of nice picture)
If you are unable to get a carpet roll of PEM or large amounts of exotic platinated metals I doubt you can come to building somethigng (but guys who produce 'kits' got their membranes from somewhere..?)
Re: Fuel Cells
Bjørn, Mon Aug 14 2006, 05:06PM
You can demonstrate a primitive fuel cell without membranes, there are a few websites that describe how. The power output is extremely low.
Platinum wire glowing in metanol and a peltier element could give 5-20W. The peltier element has an efficiency of up to 10% but it is difficult to regulate the temperature.
If you want to run a car you should look into steam engines, a modern steam engine has a higher efficiency and lower weight than an internal combustion engine.
Bjørn, Mon Aug 14 2006, 05:06PM
You can demonstrate a primitive fuel cell without membranes, there are a few websites that describe how. The power output is extremely low.
Platinum wire glowing in metanol and a peltier element could give 5-20W. The peltier element has an efficiency of up to 10% but it is difficult to regulate the temperature.
If you want to run a car you should look into steam engines, a modern steam engine has a higher efficiency and lower weight than an internal combustion engine.
Re: Fuel Cells
Marko, Mon Aug 14 2006, 07:03PM
Some available membranes and prices
Marko, Mon Aug 14 2006, 07:03PM
Some available membranes and prices
Re: Fuel Cells
EEYORE, Mon Aug 14 2006, 07:29PM
That site seems a bit overpriced. 22$ for a small plate of graphite'?Come on...
So the methanol heating platinum wire inturn heating a peltier sounds feasible?I dont need more than maybe say 50mW.(around 2 volts)
What about pumping Hydrogen and Oxygen gas over two platinum wire coils?One coil gets hydrogen, the other gets oxygen?Are there ANY other materials that are cheaper than platinum that can be used as the catalyst?The only source of platinum i have is of like 44awg wire, 12inches for 5$. That is gosh darn THIN!
Matt
EEYORE, Mon Aug 14 2006, 07:29PM
Firkragg wrote ...
Some available membranes and prices
Some available membranes and prices
That site seems a bit overpriced. 22$ for a small plate of graphite'?Come on...
So the methanol heating platinum wire inturn heating a peltier sounds feasible?I dont need more than maybe say 50mW.(around 2 volts)
What about pumping Hydrogen and Oxygen gas over two platinum wire coils?One coil gets hydrogen, the other gets oxygen?Are there ANY other materials that are cheaper than platinum that can be used as the catalyst?The only source of platinum i have is of like 44awg wire, 12inches for 5$. That is gosh darn THIN!
Matt
Re: Fuel Cells
Marko, Mon Aug 14 2006, 07:47PM
Yep, such things get a bit expensive if you want soem really useful power.
I didn't find much places where you could get that membrane for cheaper.
Heating a peltier with platinum wire dipped in methanol wouldn't really be an electrochemical reaction and it would be unfair to call that a fuel cell.
Produced voltage and power is also going to be very low, after pouring liquid nitrogen on a side e of a peltier tesladownunder got some 150mA at 350mV (you'l have to stack a lot of these to light a led)
Marko, Mon Aug 14 2006, 07:47PM
Yep, such things get a bit expensive if you want soem really useful power.
I didn't find much places where you could get that membrane for cheaper.
Heating a peltier with platinum wire dipped in methanol wouldn't really be an electrochemical reaction and it would be unfair to call that a fuel cell.
Produced voltage and power is also going to be very low, after pouring liquid nitrogen on a side e of a peltier tesladownunder got some 150mA at 350mV (you'l have to stack a lot of these to light a led)
Re: Fuel Cells
EEYORE, Mon Aug 14 2006, 08:12PM
There goes the methanol idea...
Well, i bought the guy out on ebay. I figure 3 strands of 43 awg wire twisted together should be much more manageable. Its is 92%platinum, 8%tungsten.
What I want to do now is coil them into two coils. Place them into a container filled with distilled water. Each coil will have a glass tube to direct hydrogen and oxygen gas over. This should allow the two gasses to recombine to form water, and thus produce a current, no?
Comments?
Matt
EEYORE, Mon Aug 14 2006, 08:12PM
There goes the methanol idea...
Well, i bought the guy out on ebay. I figure 3 strands of 43 awg wire twisted together should be much more manageable. Its is 92%platinum, 8%tungsten.
What I want to do now is coil them into two coils. Place them into a container filled with distilled water. Each coil will have a glass tube to direct hydrogen and oxygen gas over. This should allow the two gasses to recombine to form water, and thus produce a current, no?
Comments?
Matt
Re: Fuel Cells
Electroholic, Mon Aug 14 2006, 08:43PM
you might need some electrolyte in the water.
say koh or something like that.
turnign the thin wires into coils is actually a very good idea.
good luck. and keep us posted.
Electroholic, Mon Aug 14 2006, 08:43PM
you might need some electrolyte in the water.
say koh or something like that.
turnign the thin wires into coils is actually a very good idea.
good luck. and keep us posted.
Re: Fuel Cells
EEYORE, Mon Aug 14 2006, 09:01PM
How about NaOH?I can get that as RedDevil Lye in the store here...Im wondering how the direct methanol cells work. Seems it would be much easier to poor methanol into the cell than to pump H2 and O in there...The fuel cell store sells a methanol kit for 30$ which must be able to be built for like 5$ considering THEIR markups.
That looks QUITE simple and something tells me I wouldnt need to spend 30$ to get the results...So how might that thing work?What is converting methanol into electricity?Platinum?
Also, just how pure does the platinum need to be?My wire is 92% platinum...Might a platinum coated wire of much great thickness work better?
I plan to make a small dc-dc converter for this.
EDIT:
After some more googling, a methonal fuel cell needs just two electrodes ( could be graphite/stainless stell mesh ect, ) an electrolyte (KOH, maybe NaOH?) and fuel(methanol). So, what kinda methanol should i buy?I see it listed as plane methyl alcohol, and also as ANAHYDROUS?I guess it means, dry?Like, i mix it myself?In that case, I could make a strong molar solution and boost the cell?
Matt
EEYORE, Mon Aug 14 2006, 09:01PM
Electroholic wrote ...
you might need some electrolyte in the water.
say koh or something like that.
turnign the thin wires into coils is actually a very good idea.
good luck. and keep us posted.
you might need some electrolyte in the water.
say koh or something like that.
turnign the thin wires into coils is actually a very good idea.
good luck. and keep us posted.
How about NaOH?I can get that as RedDevil Lye in the store here...Im wondering how the direct methanol cells work. Seems it would be much easier to poor methanol into the cell than to pump H2 and O in there...The fuel cell store sells a methanol kit for 30$ which must be able to be built for like 5$ considering THEIR markups.
That looks QUITE simple and something tells me I wouldnt need to spend 30$ to get the results...So how might that thing work?What is converting methanol into electricity?Platinum?
Also, just how pure does the platinum need to be?My wire is 92% platinum...Might a platinum coated wire of much great thickness work better?
I plan to make a small dc-dc converter for this.
EDIT:
After some more googling, a methonal fuel cell needs just two electrodes ( could be graphite/stainless stell mesh ect, ) an electrolyte (KOH, maybe NaOH?) and fuel(methanol). So, what kinda methanol should i buy?I see it listed as plane methyl alcohol, and also as ANAHYDROUS?I guess it means, dry?Like, i mix it myself?In that case, I could make a strong molar solution and boost the cell?
Matt
Re: Fuel Cells
..., Mon Aug 14 2006, 11:36PM
Seems like for making the H2/O2 you would be best off using a little bit of metal dipped in a pool of water, with a little bit of salt in there to get the current flowing... As long as you only use a little voltage (3v) you should get mostly O2 and H2 out. Then let the bubbles rise up onto the electrodes and life would be good
As to their prices, I didn't see a $22 piece of pure carbon, but some pieces of carbon that had been machined with small channels in them ($$$) or pieces that had been doped with platinum ($$$$)... Their prices for the pem membrane seems decent for the quantities they are selling...
As to the % methanol; I would assume you would just mix a little pure methanol into the KOH solution. You could use something weaker, but add more of it to compensate. A page linked by yours states that 1-4M KOH should be used, so it is mostly water anyway.
Also, about the platinum... I think that instead of using wire you would get much more bag for the buck with Pt plated wire or foil. Seems like a 300u layer is pretty cheap... I calculate 15mg/in^2 (double for double sided) so at $38/g that is only $1/in^2 of platinum
But since we can't get foil with a 300u Pt plating for anywhere near what it costs in the platinum I think we should stick with a 2mg/in^2 Pt doped carbon for $20/in^2 as sold by the fuelcellstore 
..., Mon Aug 14 2006, 11:36PM
Seems like for making the H2/O2 you would be best off using a little bit of metal dipped in a pool of water, with a little bit of salt in there to get the current flowing... As long as you only use a little voltage (3v) you should get mostly O2 and H2 out. Then let the bubbles rise up onto the electrodes and life would be good
As to their prices, I didn't see a $22 piece of pure carbon, but some pieces of carbon that had been machined with small channels in them ($$$) or pieces that had been doped with platinum ($$$$)... Their prices for the pem membrane seems decent for the quantities they are selling...
As to the % methanol; I would assume you would just mix a little pure methanol into the KOH solution. You could use something weaker, but add more of it to compensate. A page linked by yours states that 1-4M KOH should be used, so it is mostly water anyway.
Also, about the platinum... I think that instead of using wire you would get much more bag for the buck with Pt plated wire or foil. Seems like a 300u layer is pretty cheap... I calculate 15mg/in^2 (double for double sided) so at $38/g that is only $1/in^2 of platinum
But since we can't get foil with a 300u Pt plating for anywhere near what it costs in the platinum I think we should stick with a 2mg/in^2 Pt doped carbon for $20/in^2 as sold by the fuelcellstore Re: Fuel Cells
EEYORE, Tue Aug 15 2006, 03:24AM
Yea, all very costly. As to the relatively low price and decent output of the mini fuel cell using methanol, i beleive that it is actually much cheaper than they are selling for. The smart thing they do is NOT mention what the electrodes are made of. From the picture, they look like glass/plastic beaker and some red tube made of plastic. Im betting a small piece of carbon sheet lays at the bottom of the "beaker/electrode" and the other electrodes lays in the red thing. They are kept almost touching and both emersed in the KOH electrolyte/methanol mixture and viola! So, since I already have bought the 3 feet of hair thin 92%Platinum, 8%tungsten wire, perhpas I will get myself some cheap carbon(deffinataley not from them) and recreate that arrangemet...How about this->
Electrodes->Two round carbon rods like those found in old batteries. Both will have the platinum allow wire coiled around them. They will be emeresed into the KOH (NaOH instead?) eletrolyte. Then when i want the magic to happen, in goes the methanol.
If this all sounds good, I will order some methanol, ( i saw 500mL of anahydrous methanol online for like 5$) plus some KOH. If I cannot find some old batteries, anyone know where I can find some carbon electrodes?
Matt
EEYORE, Tue Aug 15 2006, 03:24AM
... wrote ...
Seems like for making the H2/O2 you would be best off using a little bit of metal dipped in a pool of water, with a little bit of salt in there to get the current flowing... As long as you only use a little voltage (3v) you should get mostly O2 and H2 out. Then let the bubbles rise up onto the electrodes and life would be good
As to their prices, I didn't see a $22 piece of pure carbon, but some pieces of carbon that had been machined with small channels in them ($$$) or pieces that had been doped with platinum ($$$$)... Their prices for the pem membrane seems decent for the quantities they are selling...
As to the % methanol; I would assume you would just mix a little pure methanol into the KOH solution. You could use something weaker, but add more of it to compensate. A page linked by yours states that 1-4M KOH should be used, so it is mostly water anyway.
Also, about the platinum... I think that instead of using wire you would get much more bag for the buck with Pt plated wire or foil. Seems like a 300u layer is pretty cheap... I calculate 15mg/in^2 (double for double sided) so at $38/g that is only $1/in^2 of platinum But since we can't get foil with a 300u Pt plating for anywhere near what it costs in the platinum I think we should stick with a 2mg/in^2 Pt doped carbon for $20/in^2 as sold by the fuelcellstore
Seems like for making the H2/O2 you would be best off using a little bit of metal dipped in a pool of water, with a little bit of salt in there to get the current flowing... As long as you only use a little voltage (3v) you should get mostly O2 and H2 out. Then let the bubbles rise up onto the electrodes and life would be good
As to their prices, I didn't see a $22 piece of pure carbon, but some pieces of carbon that had been machined with small channels in them ($$$) or pieces that had been doped with platinum ($$$$)... Their prices for the pem membrane seems decent for the quantities they are selling...
As to the % methanol; I would assume you would just mix a little pure methanol into the KOH solution. You could use something weaker, but add more of it to compensate. A page linked by yours states that 1-4M KOH should be used, so it is mostly water anyway.
Also, about the platinum... I think that instead of using wire you would get much more bag for the buck with Pt plated wire or foil. Seems like a 300u layer is pretty cheap... I calculate 15mg/in^2 (double for double sided) so at $38/g that is only $1/in^2 of platinum
But since we can't get foil with a 300u Pt plating for anywhere near what it costs in the platinum I think we should stick with a 2mg/in^2 Pt doped carbon for $20/in^2 as sold by the fuelcellstore Yea, all very costly. As to the relatively low price and decent output of the mini fuel cell using methanol, i beleive that it is actually much cheaper than they are selling for. The smart thing they do is NOT mention what the electrodes are made of. From the picture, they look like glass/plastic beaker and some red tube made of plastic. Im betting a small piece of carbon sheet lays at the bottom of the "beaker/electrode" and the other electrodes lays in the red thing. They are kept almost touching and both emersed in the KOH electrolyte/methanol mixture and viola! So, since I already have bought the 3 feet of hair thin 92%Platinum, 8%tungsten wire, perhpas I will get myself some cheap carbon(deffinataley not from them) and recreate that arrangemet...How about this->
Electrodes->Two round carbon rods like those found in old batteries. Both will have the platinum allow wire coiled around them. They will be emeresed into the KOH (NaOH instead?) eletrolyte. Then when i want the magic to happen, in goes the methanol.
If this all sounds good, I will order some methanol, ( i saw 500mL of anahydrous methanol online for like 5$) plus some KOH. If I cannot find some old batteries, anyone know where I can find some carbon electrodes?
Matt
Re: Fuel Cells
Electroholic, Tue Aug 15 2006, 12:32PM
i think i saw a demo somewhere on the, where they first connect the cell setup to a powersource, let it run as electrolysis of water, let teh H2 and O2 forms on the Pt wires. then if you take away hte power source, the H2 and O2 will recombine, and give out power. not sure about efficiency tho.
as for carbon rods, if you can find old batteries, get new ones? dollar store batteries? as lond as they are Zinc Carbon type, they will have the carbon rods.
Electroholic, Tue Aug 15 2006, 12:32PM
i think i saw a demo somewhere on the, where they first connect the cell setup to a powersource, let it run as electrolysis of water, let teh H2 and O2 forms on the Pt wires. then if you take away hte power source, the H2 and O2 will recombine, and give out power. not sure about efficiency tho.
as for carbon rods, if you can find old batteries, get new ones? dollar store batteries? as lond as they are Zinc Carbon type, they will have the carbon rods.
Re: Fuel Cells
Marko, Tue Aug 15 2006, 12:45PM
You can get 10cm long, 2mm thick carbon rods in a bookstores for cheap.
I have some here, they are used in a mechanical pencil.
Marko, Tue Aug 15 2006, 12:45PM
You can get 10cm long, 2mm thick carbon rods in a bookstores for cheap.
I have some here, they are used in a mechanical pencil.
Re: Fuel Cells
EEYORE, Tue Aug 15 2006, 03:53PM
I will go to the dollar store today, get some cheapo batteries and "rape" them for the carbon rods. Then, I will look for sodium hydroxide there(pure), else i will order some KOH online. Whats the difference between the two? As far as fuel cell goes? After that, i just will wait for my Pt. wire and some methanol, and see if it is sufficient enough. If not, im just going to buy their 50$ fuel cell capable of some 350mA at im guessing .5 volts. Open source is .9volts, so i plan to build a joule thief style converter to boost that tiny voltage up enough for an LED. Seeing as I only need some 10mA or so at a few volts, this fuel cell should be more than enough. Can a PEM cell designed for hydrogen gas work with methanol?Doesnt methanol release hydrogen gas anyways?Perhaps the mthanol will damage the PEM...Id ask fuel cell store, but i doubt they would reveal those secrets
Matt
EEYORE, Tue Aug 15 2006, 03:53PM
Electroholic wrote ...
i think i saw a demo somewhere on the, where they first connect the cell setup to a powersource, let it run as electrolysis of water, let teh H2 and O2 forms on the Pt wires. then if you take away hte power source, the H2 and O2 will recombine, and give out power. not sure about efficiency tho.
as for carbon rods, if you can find old batteries, get new ones? dollar store batteries? as lond as they are Zinc Carbon type, they will have the carbon rods.
I did this last night with some drain cleaner and pencil lead. It worked...But such a mess it makes!I cant find pure sodium hydroxide in town anymore(and my stupid little brother used it up when i showed him what it does to aluminum foil). I got something else with lotsa other crap in it.i think i saw a demo somewhere on the, where they first connect the cell setup to a powersource, let it run as electrolysis of water, let teh H2 and O2 forms on the Pt wires. then if you take away hte power source, the H2 and O2 will recombine, and give out power. not sure about efficiency tho.
as for carbon rods, if you can find old batteries, get new ones? dollar store batteries? as lond as they are Zinc Carbon type, they will have the carbon rods.
I will go to the dollar store today, get some cheapo batteries and "rape" them for the carbon rods. Then, I will look for sodium hydroxide there(pure), else i will order some KOH online. Whats the difference between the two? As far as fuel cell goes? After that, i just will wait for my Pt. wire and some methanol, and see if it is sufficient enough. If not, im just going to buy their 50$ fuel cell capable of some 350mA at im guessing .5 volts. Open source is .9volts, so i plan to build a joule thief style converter to boost that tiny voltage up enough for an LED. Seeing as I only need some 10mA or so at a few volts, this fuel cell should be more than enough. Can a PEM cell designed for hydrogen gas work with methanol?Doesnt methanol release hydrogen gas anyways?Perhaps the mthanol will damage the PEM...Id ask fuel cell store, but i doubt they would reveal those secrets
Matt
Re: Fuel Cells
Marko, Tue Aug 15 2006, 07:47PM
Methanol would poison the PEM with CO and it will die very quickly. (read wiki)
PEMFC is probably only 'usable' type of cell when many of them are stacked, those small methanol-dipping cells probably won't go much further than lighting a LED.
Maybe if you find a way to greatly reduce their size and stack a lot of them together.
SInce you only need it for demonstrative purposes then I think you are on a right way...
Marko, Tue Aug 15 2006, 07:47PM
Methanol would poison the PEM with CO and it will die very quickly. (read wiki)
PEMFC is probably only 'usable' type of cell when many of them are stacked, those small methanol-dipping cells probably won't go much further than lighting a LED.
Maybe if you find a way to greatly reduce their size and stack a lot of them together.
SInce you only need it for demonstrative purposes then I think you are on a right way...
Re: Fuel Cells
EEYORE, Tue Aug 15 2006, 08:27PM
I spoke with the guy from fuelcellstore about it. He said it may work, just wont be as efficient. Since it went on sale today down to 39$, i decided to give in and get it. It will output.6-.9 volts at 350mA. I dont need more than 10mA for a superbright LED, so along with a "joule thief" this out to do it for now. I just need a clean way to produce and reliably store hydrogen gas. Ideas?
I did get some carbon rods from a dollar store 6volt battery. What a messy job, and they have TAR in them, goddarn!They are soaking in water to get clean. I will still do the methanol cell experiement. I plan to use two of these large carbon rods. Wrap the Pt. wire around each, and dunk them in a KOH + Methanol solution. See what happens! Any ideas? Any predictions? 3 feet of 43awg 92%platinum wire/8%tungsten...
Now im off to make a new joule thief...
Matt
EEYORE, Tue Aug 15 2006, 08:27PM
Firkragg wrote ...
Methanol would poison the PEM with CO and it will die very quickly. (read wiki)
PEMFC is probably only 'usable' type of cell when many of them are stacked, those small methanol-dipping cells probably won't go much further than lighting a LED.
Maybe if you find a way to greatly reduce their size and stack a lot of them together.
SInce you only need it for demonstrative purposes then I think you are on a right way...
Methanol would poison the PEM with CO and it will die very quickly. (read wiki)
PEMFC is probably only 'usable' type of cell when many of them are stacked, those small methanol-dipping cells probably won't go much further than lighting a LED.
Maybe if you find a way to greatly reduce their size and stack a lot of them together.
SInce you only need it for demonstrative purposes then I think you are on a right way...
I spoke with the guy from fuelcellstore about it. He said it may work, just wont be as efficient. Since it went on sale today down to 39$, i decided to give in and get it. It will output.6-.9 volts at 350mA. I dont need more than 10mA for a superbright LED, so along with a "joule thief" this out to do it for now. I just need a clean way to produce and reliably store hydrogen gas. Ideas?
I did get some carbon rods from a dollar store 6volt battery. What a messy job, and they have TAR in them, goddarn!They are soaking in water to get clean. I will still do the methanol cell experiement. I plan to use two of these large carbon rods. Wrap the Pt. wire around each, and dunk them in a KOH + Methanol solution. See what happens! Any ideas? Any predictions? 3 feet of 43awg 92%platinum wire/8%tungsten...
Now im off to make a new joule thief...
Matt
Re: Fuel Cells
Carbon_Rod, Tue Aug 15 2006, 11:56PM
Read this:
Then this fuel cell page:
Cheers,
Keep in mind this page is not publicly linkable – save it to your drives!
(robot blind probe found it last year)
Carbon_Rod, Tue Aug 15 2006, 11:56PM
Read this:
Then this fuel cell page:
Cheers,
Keep in mind this page is not publicly linkable – save it to your drives!
(robot blind probe found it last year)
Re: Fuel Cells
the_anomaly, Wed Aug 16 2006, 02:26AM
I built a small fuel cell with NaOH, some of that hair thin platinum wire for the electrodes, and bubbling h2 and o2 over them. It produced about 150ma average and probably only several ma. I tried using platinum wrapped around carbon but I ended up making a battery. That seemed to happen every time I put two different conductors in the solution. I think the fuel cell page posted by carbon rod is the best guide I have seen but it will cost a bit of $$.
the_anomaly, Wed Aug 16 2006, 02:26AM
I built a small fuel cell with NaOH, some of that hair thin platinum wire for the electrodes, and bubbling h2 and o2 over them. It produced about 150ma average and probably only several ma. I tried using platinum wrapped around carbon but I ended up making a battery. That seemed to happen every time I put two different conductors in the solution. I think the fuel cell page posted by carbon rod is the best guide I have seen but it will cost a bit of $$.
Re: Fuel Cells
EEYORE, Wed Aug 16 2006, 03:00AM
That fuel cell construction seemed poorly planned out considering the cost of the stuff used. If i had spent the money to get that stuff, id opt for a bit better than plastic syringe tubes and such
Anyways, I ordered a reversible PEM cell from the place for 40$ (was on sale). It will output .6 to .95 volts and 350mA. With a joule thief, I should have no trouble lighting a superbright LED. The cell is reverisble too, so I can use it to produce hydrogen gas via a solar cell and some water.
Seeing as I already bought the stuff to make a methanol fuel cell, I will give it a go. Its GOT to work, as fuelcell store has a super simple one, looks like maybe just carbon electrodes with platinum on them emeresed in a KOH + methanol solution. Its GOT to work...
EDIT: I think i may have just created a fuel cell! NaOH electrolyte, and two carbon electrodes emersed in the solution. I applied 9 volts to create H2 bubbles, then connected the joule thief to the output. Very brightly lit LED! The LED stayed lit for maybe a minute, then turned off. After turning off, there was about 0.5 volts stil showing up on the DMM. When the electrodes were pulled out (removing the bubbles attached to both electrodes, and put back in, no output at all present. This appears to be fuel cell, no? I dont understand why this is working without a platinum catalyst? Next step is to add the platinum wire to the electrodes and see if that improves the operation any...
Hurray joule thief! So lets hope a methanol cell will work like this as well. That will consist of a KOH solution with the same electrodes, except covered in Pt. wire and of course methanol added.
Matt
Matt
EEYORE, Wed Aug 16 2006, 03:00AM
Nick wrote ...
I built a small fuel cell with NaOH, some of that hair thin platinum wire for the electrodes, and bubbling h2 and o2 over them. It produced about 150ma average and probably only several ma. I tried using platinum wrapped around carbon but I ended up making a battery. That seemed to happen every time I put two different conductors in the solution. I think the fuel cell page posted by carbon rod is the best guide I have seen but it will cost a bit of $$.
I built a small fuel cell with NaOH, some of that hair thin platinum wire for the electrodes, and bubbling h2 and o2 over them. It produced about 150ma average and probably only several ma. I tried using platinum wrapped around carbon but I ended up making a battery. That seemed to happen every time I put two different conductors in the solution. I think the fuel cell page posted by carbon rod is the best guide I have seen but it will cost a bit of $$.
That fuel cell construction seemed poorly planned out considering the cost of the stuff used. If i had spent the money to get that stuff, id opt for a bit better than plastic syringe tubes and such
Anyways, I ordered a reversible PEM cell from the place for 40$ (was on sale). It will output .6 to .95 volts and 350mA. With a joule thief, I should have no trouble lighting a superbright LED. The cell is reverisble too, so I can use it to produce hydrogen gas via a solar cell and some water.
Seeing as I already bought the stuff to make a methanol fuel cell, I will give it a go. Its GOT to work, as fuelcell store has a super simple one, looks like maybe just carbon electrodes with platinum on them emeresed in a KOH + methanol solution. Its GOT to work...
EDIT: I think i may have just created a fuel cell! NaOH electrolyte, and two carbon electrodes emersed in the solution. I applied 9 volts to create H2 bubbles, then connected the joule thief to the output. Very brightly lit LED! The LED stayed lit for maybe a minute, then turned off. After turning off, there was about 0.5 volts stil showing up on the DMM. When the electrodes were pulled out (removing the bubbles attached to both electrodes, and put back in, no output at all present. This appears to be fuel cell, no? I dont understand why this is working without a platinum catalyst? Next step is to add the platinum wire to the electrodes and see if that improves the operation any...
Hurray joule thief! So lets hope a methanol cell will work like this as well. That will consist of a KOH solution with the same electrodes, except covered in Pt. wire and of course methanol added.
Matt
Matt
Re: Fuel Cells
Marko, Sat Sept 02 2006, 12:52PM
I just tried the peltier experiment, common refrigerator peltiers work pretty well
By just heating one side with hand I get few hundreds of milivolts.
After heating one side quickly with cigarette lighter I can get up to 1,3 volts at almost an amp. I also get pretty good results if I throw and ice cube on one side. No liquid nitrogen needed
Marko, Sat Sept 02 2006, 12:52PM
I just tried the peltier experiment, common refrigerator peltiers work pretty well
By just heating one side with hand I get few hundreds of milivolts.
After heating one side quickly with cigarette lighter I can get up to 1,3 volts at almost an amp. I also get pretty good results if I throw and ice cube on one side. No liquid nitrogen needed
Re: Fuel Cells
Conundrum, Sun Sept 03 2006, 01:15PM
Hmm. I'd heard about using Peltiers as power generators, the main problem is getting the low voltage output converted efficiently to useable levels.
One approach that has been used before is to charge up a capacitor using the peltier output (1000 uF 6V tantalums are good for this) and then connect it in series with the peltier to momentarily get 2* voltage; this then gets fed into the charger etc.
the efficiency of this is pretty high and the required circuitry can be as simple as a three transistor "lm3909 clone" or just a MAX660 or ICL7660.
Its very unfortunate that tunnel diodes are extinct, they are nearly ideal for this application and there is no modern equivalent that runs down to <1V.
-A
Conundrum, Sun Sept 03 2006, 01:15PM
Hmm. I'd heard about using Peltiers as power generators, the main problem is getting the low voltage output converted efficiently to useable levels.
One approach that has been used before is to charge up a capacitor using the peltier output (1000 uF 6V tantalums are good for this) and then connect it in series with the peltier to momentarily get 2* voltage; this then gets fed into the charger etc.
the efficiency of this is pretty high and the required circuitry can be as simple as a three transistor "lm3909 clone" or just a MAX660 or ICL7660.
Its very unfortunate that tunnel diodes are extinct, they are nearly ideal for this application and there is no modern equivalent that runs down to <1V.
-A
Re: Fuel Cells
EEYORE, Sun Sept 03 2006, 05:12PM
Hmmm, sounds pretty neat. I wonder how long before the "cold" side warms too much?
Seems that if the cold side could be kept cool without the need of any other such power, then a simple butane powered generator could be possible. Kinda like a low pressure torch built to run for long periods. 1.3volts at 1amp is very usable...Perhaps one could series two or more to increase voltage?
Matt
EEYORE, Sun Sept 03 2006, 05:12PM
Hmmm, sounds pretty neat. I wonder how long before the "cold" side warms too much?
Seems that if the cold side could be kept cool without the need of any other such power, then a simple butane powered generator could be possible. Kinda like a low pressure torch built to run for long periods. 1.3volts at 1amp is very usable...Perhaps one could series two or more to increase voltage?
Matt
Re: Fuel Cells
Marko, Sun Sept 03 2006, 07:01PM
IT takes few tens of seconds, depending how evenly and how fast I heat etc.
With few peltiers, good heatsink and fan one could make fan sustain itself from the power of ''cell'' (actually a thermoelectric converter
from some source of heat, some burning coal maybe or butane torch..
It needs good cooling altough, I got some real current only after throwing a block of ice on cold side..
Someone can put few hot rocks inside too (just kidding, I hope nobody here owns *that hot* rocks )
Although thing isn't really related to fuel cells.
As far as I figured out that commercial minicell doesn't require platinum at all (?) and it will be able to power small stuff like led's etc.
why don't you just series two or more cells and use much simpler and more efficient mosfet boost converter..?
Marko, Sun Sept 03 2006, 07:01PM
IT takes few tens of seconds, depending how evenly and how fast I heat etc.
With few peltiers, good heatsink and fan one could make fan sustain itself from the power of ''cell'' (actually a thermoelectric converter
from some source of heat, some burning coal maybe or butane torch..
It needs good cooling altough, I got some real current only after throwing a block of ice on cold side..
Someone can put few hot rocks inside too (just kidding, I hope nobody here owns *that hot* rocks
)Although thing isn't really related to fuel cells.
As far as I figured out that commercial minicell doesn't require platinum at all (?) and it will be able to power small stuff like led's etc.
why don't you just series two or more cells and use much simpler and more efficient mosfet boost converter..?
Re: Fuel Cells
EEYORE, Tue Sept 05 2006, 06:20PM
I dont have the money to series enough of the fuel cells...The joule thief works alright for lighing ultrabright LEDs anyways...By the time the voltage drops below what the transistor will accept, the fuel cells has almost exhausted all its gas anyways...
I dont see how the mini fuel cell, or any fuel cell could work w/o platinum. I believe the platinum is the key to getting it to work anyways. Their methanol fuel cell membrane + electrodes all use platinum as well. I think the anode uses managanese to catalyse oxygen also, and the cathode uses platinum.
Matt
EEYORE, Tue Sept 05 2006, 06:20PM
Firkragg wrote ...
IT takes few tens of seconds, depending how evenly and how fast I heat etc.
With few peltiers, good heatsink and fan one could make fan sustain itself from the power of ''cell'' (actually a thermoelectric converter
from some source of heat, some burning coal maybe or butane torch..
It needs good cooling altough, I got some real current only after throwing a block of ice on cold side..
Someone can put few hot rocks inside too (just kidding, I hope nobody here owns *that hot* rocks )
Although thing isn't really related to fuel cells.
As far as I figured out that commercial minicell doesn't require platinum at all (?) and it will be able to power small stuff like led's etc.
why don't you just series two or more cells and use much simpler and more efficient mosfet boost converter..?
IT takes few tens of seconds, depending how evenly and how fast I heat etc.
With few peltiers, good heatsink and fan one could make fan sustain itself from the power of ''cell'' (actually a thermoelectric converter
from some source of heat, some burning coal maybe or butane torch..
It needs good cooling altough, I got some real current only after throwing a block of ice on cold side..
Someone can put few hot rocks inside too (just kidding, I hope nobody here owns *that hot* rocks
)Although thing isn't really related to fuel cells.
As far as I figured out that commercial minicell doesn't require platinum at all (?) and it will be able to power small stuff like led's etc.
why don't you just series two or more cells and use much simpler and more efficient mosfet boost converter..?
I dont have the money to series enough of the fuel cells...The joule thief works alright for lighing ultrabright LEDs anyways...By the time the voltage drops below what the transistor will accept, the fuel cells has almost exhausted all its gas anyways...
I dont see how the mini fuel cell, or any fuel cell could work w/o platinum. I believe the platinum is the key to getting it to work anyways. Their methanol fuel cell membrane + electrodes all use platinum as well. I think the anode uses managanese to catalyse oxygen also, and the cathode uses platinum.
Matt
Re: Fuel Cells
Marko, Tue Sept 05 2006, 10:13PM
Measured current from that peltier was actually short circuit, I doubt I get more than 100-200mW from it as maximum
After checking mini has electrodes platinum-coated (wasn't apparent at first).
Can you post pics, better explanations, you can give me 1 fromchermistry, etc. about that NaOH thing?
Seems easily replicate-able but doesn't fullfil definition of fuel cell for much.
I don't see why would gasses sitting on inert electrodes in NaOH dp 'something' really.
Marko, Tue Sept 05 2006, 10:13PM
Measured current from that peltier was actually short circuit, I doubt I get more than 100-200mW from it as maximum
After checking mini has electrodes platinum-coated (wasn't apparent at first).
Can you post pics, better explanations, you can give me 1 fromchermistry, etc. about that NaOH thing?
Seems easily replicate-able but doesn't fullfil definition of fuel cell for much.
I don't see why would gasses sitting on inert electrodes in NaOH dp 'something' really.
Re: Fuel Cells
EEYORE, Wed Sept 06 2006, 03:46AM
Im not much of a chem buff, but I beleive the NaOH, or KOH(popular) are used in what are called alkaline fuel cells. In other words, the solution partly acts like a membrane, allowing only H+ ions to pass leaving behind e-. Since the hydrogen as a gas is H2, that leaves two e- and two H+ right?The electrons flow through the circuit to meet back up on the other side(cathode?). The OH ion also serves some purpose(general chemisrty stopped there for me)
So the platinum causes the H2 to split into protons and electrons I beleive, and the manganese somehow causes the solution to give up O2 (which recombine with H2 to form H2O. Here is how I try to explain it in simple terms..
H2 is a big bro and little bro. When big bros friends come over, he leaves lil bro behind. (Platinum is friend of big bro). Since lil bro cant stand to be away from big bro, he finds a way back!(the circuit), and thus the fuel cell.
Someone please help me out with my chemistry!I have no idea what im talking about
Matt
EEYORE, Wed Sept 06 2006, 03:46AM
Firkragg wrote ...
Measured current from that peltier was actually short circuit, I doubt I get more than 100-200mW from it as maximum
After checking mini has electrodes platinum-coated (wasn't apparent at first).
Can you post pics, better explanations, you can give me 1 fromchermistry, etc. about that NaOH thing?
Seems easily replicate-able but doesn't fullfil definition of fuel cell for much.
I don't see why would gasses sitting on inert electrodes in NaOH dp 'something' really.
Measured current from that peltier was actually short circuit, I doubt I get more than 100-200mW from it as maximum
After checking mini has electrodes platinum-coated (wasn't apparent at first).
Can you post pics, better explanations, you can give me 1 fromchermistry, etc. about that NaOH thing?
Seems easily replicate-able but doesn't fullfil definition of fuel cell for much.
I don't see why would gasses sitting on inert electrodes in NaOH dp 'something' really.
Im not much of a chem buff, but I beleive the NaOH, or KOH(popular) are used in what are called alkaline fuel cells. In other words, the solution partly acts like a membrane, allowing only H+ ions to pass leaving behind e-. Since the hydrogen as a gas is H2, that leaves two e- and two H+ right?The electrons flow through the circuit to meet back up on the other side(cathode?). The OH ion also serves some purpose(general chemisrty stopped there for me
)So the platinum causes the H2 to split into protons and electrons I beleive, and the manganese somehow causes the solution to give up O2 (which recombine with H2 to form H2O. Here is how I try to explain it in simple terms..
H2 is a big bro and little bro. When big bros friends come over, he leaves lil bro behind. (Platinum is friend of big bro). Since lil bro cant stand to be away from big bro, he finds a way back!(the circuit), and thus the fuel cell.
Someone please help me out with my chemistry!I have no idea what im talking about
Matt
Re: Fuel Cells
Bored Chemist, Wed Sept 06 2006, 05:33PM
This site
gives a fairly good explanation.
The NaOH solution acts like the polymer membrane (In fact, in the old days, there weren't any ion exchange polymer membranes so all fuel cells just used a tank of elecrtolyte so, from my point of view, the polymer is acting as a slightly strange electrolyte)
Bored Chemist, Wed Sept 06 2006, 05:33PM
This site
gives a fairly good explanation.
The NaOH solution acts like the polymer membrane (In fact, in the old days, there weren't any ion exchange polymer membranes so all fuel cells just used a tank of elecrtolyte so, from my point of view, the polymer is acting as a slightly strange electrolyte)
Re: Fuel Cells
Marko, Wed Sept 06 2006, 08:23PM
I made a small alkaline cell of my own, sort of at least.
Firstly I dipped two carbon rods in NaOH and fired them up, but after each 'charging' I could get my small motor make just a revolution or two. Voltage was about 1V, but it would start to drop as I connected voltmeter to the cell.
I tried to save created gases by wrapping the rods in cotton wool, but it worked even worse.
Later I filled entire bottle with less dense wool but it didn't help.
It didn't hold small bubbles since solution was too viscous, and I would just get a big bubble burped out after a period of time.
I tried copper wires instead of graphite rods and they work as well, but positive electrode kept oxydising so I tossed them away.
Now I'm using graphite rods again with copper-zinc litz wire (from ATX cable) coiled around them.
WIre doesn't do anything itself (0V) but it keeps more gas around each electrode after 'charge'.
Most I got now is the small motor spun for few seconds.
I guess your platinum wire used same way could create some pretty good results.
Marko, Wed Sept 06 2006, 08:23PM
I made a small alkaline cell of my own, sort of at least.
Firstly I dipped two carbon rods in NaOH and fired them up, but after each 'charging' I could get my small motor make just a revolution or two. Voltage was about 1V, but it would start to drop as I connected voltmeter to the cell.
I tried to save created gases by wrapping the rods in cotton wool, but it worked even worse.
Later I filled entire bottle with less dense wool but it didn't help.
It didn't hold small bubbles since solution was too viscous, and I would just get a big bubble burped out after a period of time.
I tried copper wires instead of graphite rods and they work as well, but positive electrode kept oxydising so I tossed them away.
Now I'm using graphite rods again with copper-zinc litz wire (from ATX cable) coiled around them.
WIre doesn't do anything itself (0V) but it keeps more gas around each electrode after 'charge'.
Most I got now is the small motor spun for few seconds.
I guess your platinum wire used same way could create some pretty good results.
Re: Fuel Cells
EEYORE, Thu Sept 07 2006, 05:08AM
Matt
EEYORE, Thu Sept 07 2006, 05:08AM
Firkragg wrote ...
I made a small alkaline cell of my own, sort of at least.
Firstly I dipped two carbon rods in NaOH and fired them up, but after each 'charging' I could get my small motor make just a revolution or two. Voltage was about 1V, but it would start to drop as I connected voltmeter to the cell.
I tried to save created gases by wrapping the rods in cotton wool, but it worked even worse.
Later I filled entire bottle with less dense wool but it didn't help.
It didn't hold small bubbles since solution was too viscous, and I would just get a big bubble burped out after a period of time.
I tried copper wires instead of graphite rods and they work as well, but positive electrode kept oxydising so I tossed them away.
Now I'm using graphite rods again with copper-zinc litz wire (from ATX cable) coiled around them.
WIre doesn't do anything itself (0V) but it keeps more gas around each electrode after 'charge'.
Most I got now is the small motor spun for few seconds.
I guess your platinum wire used same way could create some pretty good results.
Yea, i did this also awhile ago. I used NaOH and carbon electrodes. I got it to run my joule thief for a few seconds. If you have gas supply, you could bubble it over them. When i attempted to use methanol+KOH, i got nothing. I now beleive i got ripped off(ebay). Dont do business with Texas Supply...The platinum wire I have does catalyse H2O2 so I know its good, but the "methanol" does nothing in the pressence of the platinum wire.I made a small alkaline cell of my own, sort of at least.
Firstly I dipped two carbon rods in NaOH and fired them up, but after each 'charging' I could get my small motor make just a revolution or two. Voltage was about 1V, but it would start to drop as I connected voltmeter to the cell.
I tried to save created gases by wrapping the rods in cotton wool, but it worked even worse.
Later I filled entire bottle with less dense wool but it didn't help.
It didn't hold small bubbles since solution was too viscous, and I would just get a big bubble burped out after a period of time.
I tried copper wires instead of graphite rods and they work as well, but positive electrode kept oxydising so I tossed them away.
Now I'm using graphite rods again with copper-zinc litz wire (from ATX cable) coiled around them.
WIre doesn't do anything itself (0V) but it keeps more gas around each electrode after 'charge'.
Most I got now is the small motor spun for few seconds.
I guess your platinum wire used same way could create some pretty good results.
Matt
Re: Fuel Cells
Marko, Thu Sept 07 2006, 12:02PM
Can you try to wind the wire over the electrodes to catalyse the reaction?
Sadly for good performance you would need some kind of porous graphite electrodes with platinum particles (no something to find in trash)..
Marko, Thu Sept 07 2006, 12:02PM
Can you try to wind the wire over the electrodes to catalyse the reaction?
Sadly for good performance you would need some kind of porous graphite electrodes with platinum particles (no something to find in trash)..
Re: Fuel Cells
EEYORE, Sat Sept 23 2006, 06:43PM
Its been a while since I updated things. I did try coiling the "platinum" wire to no avail. I now fully beleive that the wire being 92% Pt and 8% Tungsten is just not enough to do anything. I bought some HEET brand anitfreeze which is listed as being 99% methanol. Didnt do anything at all. Perhaps the tungsten is retarding the catalyste action somehow? Having the wire in the cell actually makes things worse Im willing to bet its the tungsten.
Anyways, I have been doing much with my commerical fuel cell. Really neat!I got a solar cell on ebay for 7$ and boy it is nice. It was made by some small company selling their products on ebay, and aside from the great power output, it is constructed really well! Fully water proof. 6.5volts, 210mA. I leave it in partial sun so that I dont overvolt the fuel cell when run in electrolysis mode.
I built a small joule thief onto a nice proto board, and it powers 3 UV LEDs really well. I use it to light up my autunite at night for a night lightThe cell also directly runs alot of electric motors quite well too. Right now, Im using a 60mL syring to contain the gas. I pull a vacuum in the cell with another syringe. The thing leaks bad though, as the tubing i have is a tad to large for the ports on the cell. Water leaks have also rusted one of the electrodes a bit at the bottom. A large tank to store the gas, and a fuel cell stack could really be quite useful to power some things, like a fan to keep my room cool
I still do plan to try to methanol fuel cell some time when I get some money together. I really would rather opt for platinum coated nickel screen, rather than that mini fuel cell thing with the KOH electrolyte. Perhaps some Nafion membrane as well while im at it. It would seem this would work really well providing I was able to get a really good platinum coating on some nickel screen. From what I see, I dont know if the oxygen side even needs a catalyste. It seems its all about the hydrogen side. Pure O2 and "air" work equally well. I now have some pics of my fuel cell setup. I will post them soon, once I figure out how to!
Matt
EEYORE, Sat Sept 23 2006, 06:43PM
Its been a while since I updated things. I did try coiling the "platinum" wire to no avail. I now fully beleive that the wire being 92% Pt and 8% Tungsten is just not enough to do anything. I bought some HEET brand anitfreeze which is listed as being 99% methanol. Didnt do anything at all. Perhaps the tungsten is retarding the catalyste action somehow? Having the wire in the cell actually makes things worse
Im willing to bet its the tungsten. Anyways, I have been doing much with my commerical fuel cell. Really neat!I got a solar cell on ebay for 7$ and boy it is nice. It was made by some small company selling their products on ebay, and aside from the great power output, it is constructed really well! Fully water proof. 6.5volts, 210mA. I leave it in partial sun so that I dont overvolt the fuel cell when run in electrolysis mode.
I built a small joule thief onto a nice proto board, and it powers 3 UV LEDs really well. I use it to light up my autunite at night for a night light
The cell also directly runs alot of electric motors quite well too. Right now, Im using a 60mL syring to contain the gas. I pull a vacuum in the cell with another syringe. The thing leaks bad though, as the tubing i have is a tad to large for the ports on the cell. Water leaks have also rusted one of the electrodes a bit at the bottom. A large tank to store the gas, and a fuel cell stack could really be quite useful to power some things, like a fan to keep my room cool I still do plan to try to methanol fuel cell some time when I get some money together. I really would rather opt for platinum coated nickel screen, rather than that mini fuel cell thing with the KOH electrolyte. Perhaps some Nafion membrane as well while im at it. It would seem this would work really well providing I was able to get a really good platinum coating on some nickel screen. From what I see, I dont know if the oxygen side even needs a catalyste. It seems its all about the hydrogen side. Pure O2 and "air" work equally well. I now have some pics of my fuel cell setup. I will post them soon, once I figure out how to!
Matt
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