K Fuel Cell Materials list
End plate material. Electrical grade fiberglass sheet GP03 ,3 8 thick, 12x12, red, part 8549K372. McMaster-Carr. You can substitute other material for this. Graphite for gas flow conductor plates. Specified graphite pieces can be ordered in five pound lots or more from Jim Sciuto. Also, local graphite companies often have discarded pieces that can be obtained quite cheaply from their scrap piles. Silicone rubber for gasket and spacer material. Thin gauge silicone rubber .020 thick, 12x12, 35A...
Powdering platinum
Another method would be to mix lamp black fine soot with the platinum foil leaf in a mortar and grind until the foil combines with the lamp black well. Thin leaf has a tendency to break up so this should be easily accomplished. Finely powdered platinum and or platinum black can be substituted for the platinum foil. To make a more finely divided platinum powder for a carbon platinum mix or just as is for a catalyst layer, the platinum can be ground with salt and honey in a mortar. Then add...
Thinner and lighter designs
Electrical contacts and wires can be made by drawing lines and terminals with conductive epoxy for a more lightweight and low profile. Fuel cells can get by with extremely small gas flow fields and it should be possible for anyone in their workshop to produce almost credit card size thin fuel cells with a little experimenting. Researchers have also been finding that thinner membranes permit a greater power density so the use of a Nafion type 112 membrane would appear to be more efficient than a...
Accessible technology
For the average experimenter, this means that with very little equipment one can deposit very large surface area loadings with as little metal as possible, without the expense and outlay for high tech equipment. Not bad thank you Ben The technique is definitely viable. If you wish to pursue it, research Franklin's experiments and pick up a copy of Exploding Wires - Principles, Apparatus, and Experiments by Steve Hansen. Instead of thinking wires when you read Hansen's book, think platinum leaf....
Electrode separators
Although electrolyzers work with low voltage, the amperage is high, so do not ignore any safety rules for working with electricity if you work with electrolyzers. Most tank electrolyzers have a separator between the electrodes. At one time asbestos diaphragms were used. . The asbestos separator allowed the passage of the electrolyte back and forth but kept the gases separated and the electrodes insulated from each other. With the P38 design I don't have to worry about the gases mixing, since I...
Electrostatic dispersion
If you have experienced static cling or have ever worked with a Van DeGraff generator, you will understand the effect of attraction for an electrostatically charged material to a material with the opposite charge. The material to be coated electrostatically can be set upon a plate with one charge and the materials to be attracted to that substance are connected to the opposite pole of the generator. The lighter powders can thus be 169 attracted to the surface of the conductive carbon cloth or...
Oxygenhydrogen fuel cells
To build an oxygen-hydrogen fuel cell, simply make the oxygen side of the fuel cell the same as the hydrogen side that is, the oxygen graphite plate would have a serpentine flow field instead of vertical, there would be oxygen side barbed hose connectors and gas ports that go through the oxygen side components. There would be a rubber gasket on the oxygen side, the same as for the hydrogen side. I have included two sets of templates for oxygen-hydrogen single slice fuel cells, one set based on...
Materials needed
Dual or single sided copper clad circuit board. Can be purchased from any electronics supplier. Radio Shack has a dual sided PC Board 41 2 x 63 8, part 276-1499a. One piece is sufficient for making the two endplates. Graphite foil. One 12x 12 graphite sheet gasket, McMaster-Carr part 95715K63 Thin gauge silicone rubber sheet, .020 thick. One 12x 12, 35A durometer, McMaster-Carr, part 86435 K35. Mylar sheet. Comes free as carrier sheet for silicone rubber sheet when you order from McMaster-Carr...
About the materials
As previously mentioned, you can choose your level of do-it-yourself comfort for fuel cell construction. If you are new to fuel cell technology then, I suggest purchasing a PEMbrane. Element 1 Power Systems Inc. sells what they call PEMbranes in raw form with no testing, assembly or guarantee. The size of the membranes is 11 4 by 11 4. These raw membranes are actually membrane electrode assemblies without the Mylar surround. You can add the Mylar surround yourself. I have used these particular...
Fuel cell geometry
Consider adding slices to make a convection fuel cell stack configuration, or go with a banded structure design. You can also create fuel cells in a cylindrical form - a tubular configuration with hydrogen piped in through the center of a tube with MEAs making up part of the tube wall, and oxygen air is supplied to the MEA on the outside surface of the tube wall. The geometrical configurations can be numerous. One can imagine round, or geometrical configurations like Buckminster Fuller's...
Types of fuel cells
There are five basic types of fuel cells AFC alkaline PEMFC proton exchange membrane or polymer electrolyte membrane either is correct Fuel cells are named or defined by their electrolyte, ie phosphoric acid, molten carbonate, solid oxide, or proton exchange membrane. PEMFCs have a solid ion exchange membrane made of a sulfonated Teflon-like material which is the electrolyte , and platinum catalysts. SOFCs use solid yttria stabilized zirconia as an electrolyte and per-ovskites as a catalyst....
Assembling the K fuel cell
This is the easy part. Push the cap screws through the corner holes in the oxygen side end plate and lay the plate down with the screws sticking upward and simply put each part in its place, one atop the other following the diagram. If you purchased a MEA from Element 1, you will notice that one side is marked anode. The anode side should face the serpentine hydrogen gas flow plate. Although I am not sure what the difference is, it may be that one side has wetproofing or a combination catalyst....
Electrochemical deposition
Another method of catalyst deposition would be electrochemical, such as through electroplating. In electroplating, the object to be plated is connected to the negative terminal of an electrical source, such as a battery or rectifier power supply and the metal to be deposited is connected to the positive terminal of the power supply, with both immersed in an elec trolyte bath of the metal salt that one wishes to plate with. When electrical current flows through the electrolyte bath, atoms of the...
Photovoltaic fuel cell systems
A photovoltaic fuel cell system consists of a low voltage, high current photovoltaic source solar panels , an electrolyzer, gas scrubber, hydrogen and oxygen storage vessels and fuel cells. During peak sunlight hours, the solar panels produce electricity to power the electrolyzer and produce hydrogen and oxygen, which is then stored at low pressure in tanks. At night, the hydrogen and oxygen is released to the fuel cell and electricity is generated. There are advantages in the use of fuel cells...
A transparent electrolyzer
I also considered transparent PVC or acrylic or polycarbonate pipe which comes in a variety of sizes from McMaster-Carr and MSC. Transparent pipe can be valuable in that you can see all the action going on inside your electrolyzer. This is interesting and provides experimental observation opportunities, plus it's a good safety feature. Both of these suppliers have information on their web sites about the chemical tolerance etc. of all of these materials so it's possible to assess their...
MEA Materials list
Hydrogen peroxide 3 . Available at any drug store Sulphuric acid. Can be purchased at most hardware stores in the plumbing section, or auto parts store as battery electrolyte, or any chemical supply house. Nafion 112 membrane. Can be purchased at Alfa Aesar, stock 42177 15 X15 cm piece 0.05 mm thick. You can order other sizes if you wish. Nafion 117 is thicker. Also can be purchased at other suppliers such as Fuel Cell Scientific LLC. and other sources-chemical supply houses Nafion solution....
Resources books
by Janine M. Benyus William Morrow amp Co. 1997 New York Engineer's Mini-Notebook by Forrest M. Mims III Radio Shack Siliconcepts, 1996 Fort Worth TX Getting Started in Electronics by Forrest M. Mims III Radio Shack, 1983 Fort Worth TX High Voltage Capacitor Design Handbook by Kenneth R. Scott Lambda Publishing Group P.O. Box 1894, Lawrence, KS 66044 High Voltage Experimenter's Handbook Homemade Lightning by R. A. Ford TAB Books, 1991 Blue Ridge Summit PA Procedures in Experimental Physics by...
Gas flow regulator
For experimenting with gas flow rates I would suggest an inexpensive flow regulator such as offered by American Science and Surplus part 30066 . It has an inlet pressure of 300 psig and outlet pressure of 0-60 per fine tune setting. You will basically be working with pressures under 2 psi and you must be careful to not use too much pressure to avoid the possibility of membrane blowout. This will depend on the size and number of your stacks. Pressure regulators are available from a wide variety...
Assemble the MEA in the Mylar surround
Match the MEA with the square opening in the Mylar surround, to get an idea of how it fits. If the Mylar surround has been cut correctly, the carbon cloth should fit into the center hole with just a little Mounting the MEA in the Mylar surrounds gap all the way around between the carbon cloth and the edge of the Mylar. The clear PEMbrane margin will overlap the surface of the Mylar surround. With silicone glue, draw a thin, continuous bead of glue around the square opening on one of the Mylar...
Bucky balls
At the nano level, experimenters are picking up on the geometry concept by using Bucky balls Fullerenes - geodesic structures in the form of carbon that are platinized to provide more surface area for the catalytic reaction. This reduces the amount of platinum needed and thus the cost. Also nano tubes have been experimented with for gas storage, and these hold promise for the future. At present, nano fuel cells, and biological fuel cells are being constructed and this should be very interesting...
Sputter diffusion
To apply the catalyst layer to the cloth, paper or membrane substrate, there are a number of ways to proceed. The common practice at present is to use the sputter diffusion method of applying the catalyst layer. This is a good technique as very thin films can be deposited on a substrate with a greater or lesser degree of control, making a very precise deposition in regard to thickness and amount of materials used. The method works by bombarding a platinum target with high velocity gaseous argon...
PEM fuel cell components
Building a fuel cell is easy. Anyone can construct a commercial quality PEM fuel cell with some very basic tools and materials. There are very few components that make up fuel cells and the materials are easy to access. The heart of the fuel cell is the MEA membrane electrode assembly which is sandwiched between graphite plates that act as electrodes and gas flow fields. On either side of the cell are the end plates. In detail, a PEM fuel cell consists of the MEA, graphite plates that serve as...
Stick technology
This version of a PEM fuel cell is very easy to make. I developed it so that it could be made without using any power equipment whatsoever -what I like to call stick technology. The only tools needed are a hand drill either power or not , a dull knife, scissors or Exacto knife, magic marker etc. and a plastic artist's brush or chopsticks or a wooden dowel with a rounded end the stick . The stick is used to form the flow fields in the graphite foil plates. The components are easily available and...
Preparing the graphite
the graphite particles while cutting and drilling. When handling graphite you will notice that it has a slightly greasy feeling and that it rubs off on the hands and clothes quite readily. So, when you work with this substance, wear clothes that you don't mind getting graphite on. Also, and most important, cover the motor housing on the bottom of the bandsaw so that no water or graphite can get into the motor. Graphite is conductive and will short out the motor - so, cover the motor very well....
Purpose of the P
Although the concept of the tank electrolyzer is basic and simple, the actual construction of a workable electrolyzer takes some planning and engineering expertise. I designed the P38 electrolyzer to be a bench-type electrolyzer to provide small quantities of hydrogen and oxygen for the purpose of testing fuel cells. It is not the most efficient or state of the art design, but my primary considerations were for lowest cost and sufficient quantities of gas for experimental purposes. I wanted...
Vinegar
Vinegar scrubs the potassium hydroxide by neutralizing it and picking up any particulates. Water also soaks up the caustic vapors and picks up particulates. This gives a cleaner gas entering the fuel cell and will add to the longevity of the fuel cell's operation. - The vinegar should have no sulphur additives. Even if it says natural on it., check the fine print. Pure vinegar is available from health food stores and food co-ops, and many regular supermarkets now carry vinegar that has no...
Types of electrolyzers
The two most common types of electrolyzer are tank electrolyzers and filter press electrolyzers. Also, with polymer membrane technology it is 83 possible to have an electrolyzer with a solid polymer membrane. This polymer membrane is the same as used in the fuel cell, and as a matter of fact there are regenerative fuel cells that act as both an electrolyzer and a fuel cell. With a regenerative fuel cell, you can first use it as an electrolyzer and store your hydrogen and then feed the hydrogen...
Surround Gasket Alternative To Graphite Serpentine Flow Plates
CUT AND PUNCH FROM .020 SILICONE RUBBER USE THE TEMPLATE TO MARK THE TUNNELS ON THE GRAPHITE PLATE USE THE TEMPLATE TO MARK THE TUNNELS ON THE GRAPHITE PLATE USE A FENCE TO ROUT THE STRAIGHT PARTS OF THE GROOVES FIRST USE A FENCE TO ROUT THE STRAIGHT PARTS OF THE GROOVES FIRST USE A FENCE TO ROUT THE STRAIGHT PARTS OF THE GROOVES FIRST USE A FENCE TO ROUT THE STRAIGHT PARTS OF THE GROOVES FIRST USE A FENCE TO ROUT THE STRAIGHT PARTS OF THE GROOVES FIRST USE A FENCE TO ROUT THE STRAIGHT PARTS OF...
Graphite Serpentine Flow Plate Hydrogen Side 1
1 piece from w graphite foil drillholes press grooves shaded area 1 wide, depth Vie11 to L-78 GRAPHITE FOIL FUEL CELL SINGLE SLICE CONVECTION
Fuels for fuel cells
where the protons and electrons recombine and bond with oxygen to create water molecules. All fuel cells use hydrogen as a fuel. Hydrogen is the most abundant element in the universe, and fuel cells are quite versatile as to what forms of fuel they can use. On our planet hydrogen is not a free floater but is combined with other elements and locked in compounds. So, there are many different sources of hydrogen, and the method of liberating the hydrogen for fuel cell consumption can be green and...
Precautions
Before you turn on the gas supply to the fuel cell, be absolutely certain that there is no open flame in the area and that no one is smoking. Test your fuel cell outdoors. Do not have electrical contacts and switches nearby that can be turned on or off and that could produce tiny sparks that might ignite the hydrogen mixed with air. Hydrogen is as safe as any other flammable gas but as with any other flammable gas you must take proper precautions to ensure your safety. Actually hydrogen in some...
Hotpressing the MEA
Hot pressing the MEA is easy. You will need liquid nafion 5 solution, an oven do not use a microwave oven , a few stiff metal plates, an oven thermometer, four C clamps, some graphite powder or pencil lead and some gloves. An hour before you are going to hot press, coat the catalyst side of the carbon fabric with a 5 nafion solution and let it dry. Don't overcoat or undercoat, and try to coat the piece evenly. The nafion solution does not need to drip through the fabric it should just coat the...
Graphite Serpentine Flow Plates
2 PIECES FROM W THICK GRAPHITE DRILL FASTENER HOLES ROUT GAS GROOVES SHADED AREA , W BIT, DEPTH W K-18 MILLED GRAPHITE FUEL CELL SINGLE SLICE OXYGEN HYDROGEN
Soft graphite is forgiving
As always, try out these techniques on a practice piece to get a feel for it. I chose graphite foil for the L78 because it is easy to work with, requires minimal tools and is fairly forgiving if you make mistakes. The grooves and surfaces do not need to be picture perfect. The foil itself acts as a gasket and when the fuel cell is assembled, tightening the fasteners will compress everything down to a good seal if your mistakes are not too outrageous. This fuel cell would also be a fairly easy...
Silicone cement vs epoxy
For the screw holes for the binding post screws and holding screws, I used silicone cement in case I had to change electrodes. The silicone is much easier to remove than epoxy. When it dries, it remains rubbery and soft yet provides an excellent seal. The first prototype of the P38 had cheap steel for the electrodes. After just a short time of use the electrodes were coated with sludge and I quickly understood that this cheaper type of steel was not what I needed. The cheap steel was replaced...
Building an electrolyzer
Another alternative is to build your own electrolyzer and this is easy enough. I have included in this book a detailed account of how I built an electrolyzer, however I must warn you and you will see this warning again in this book that this is not a safe project measured by any known safety standards. If you build this electrolyzer you must do so at your own risk. I discuss those risks in the electrolyzer chapter.
Epoxy the pipe to the bottom cap
After inserting and seating those components, I spread an epoxy layer on the inside rim of the cap and the outside rim of the pipe for the full length that both would mate. I was liberal with the epoxy in order to assure there would be no gaps for leakage. I then inserted the pipe into the bottom cap and with a long stick wooden shishkebob stick dripped epoxy and rubbed it along the inside bottom seam where the cap and pipe came together. I took my time with this and used a lot of epoxy to make...
Bottom cap
I also removed the nubbin from the inside center of the bottom cap and drilled five holes see template . Four Looking down into the electrolyzer, with the electrodes in place. The height gauge tube is visible at the upper left. It is connected to the black barb splicer, visible in the center. Looking down into the electrolyzer, with the electrodes in place. The height gauge tube is visible at the upper left. It is connected to the black barb splicer, visible in the center. accept the binding...
MEA components
To make an MEA, you need a proton exchange membrane material such as Nafion in its solid form Nafion 5 in liquid form and a carbon fabric or paper which acts as a conductive carrier substrate for the catalyst, and acts as a GDL gas diffusion layer . You also need the catalyst, which in most cases will be platinum. Platinum can be used in several different forms to act as a catalyst. - Depending on the technique you use, you may need lamp black, Bucky balls Fullerenes etc. and other materials...