Good scientific method and attention to detail. I wonder why the energy of two cells was only 13mWh compared with your original 10mWh for one cell. - Martin.
Nicely done William. I have also been playing around with the iron carbon battery after seeing your first video. It is similar but much simpler and easier to build than the battery shown by Dr. Peter Allen on his you tube channel. Keep the videos coming, Cheers
Hi I have a couple of questions that I hope you can answer for me. Have you tried reading the current across the battery to see what it's momentarily "dead short" current can deliver? How long can the battery run the motor after a full charge? My last question may sound silly but you mentioned charging the battery before the test and my question is if it can be charged more than 1 or 2 times before it degrades or loses it's capacity? If it can be recharged, have you experimented enough with this battery build to figure out how many charge/discharge cycles you can get out of the batteries before they degrade? Thank you for sharing this information for others to duplicate.
Hi, sorry but I have never measured the output of the battery when dead shorted across the terminals. Yes, this battery can be charged and discharged multiple times. In my previous video at time 16:27 I show the charge/discharge curves for this battery. I ran it through 56 charge/discharge cycles and the output capacity dropped 7% from the initial value.
@@William_Hada Hi and thank you for replying back. I'm going to be trying my hand at some of the battery projects I see on RU-vid. I'm still in the process of reading up on this stuff along with watching videos on the topic but I do plan on jumping into this somewhere after the New Year....
Great little cell, very keen to give it a go. Been looking for a cheap and safe cell to play with for a while. Once I've built a cell and want to increase the capacity, would this be done by increasing the size of the two electrodes?
Yes, increasing the effective area of the electodes will increase the capacity of the cell ( total amp hours, current ). The voltage will not change because that is predetermined by the cell chemistry. You can also increase the capacity by making the electrode area thicker, like creating a spongy iron or carbon matrix on the electrodes.
@@StefanWiswedel No, on that Iron/Carbon battery Chemistry I have not built any more cells. I got sidetracked exploring other Chemistries but eventually I want to get back to Iron/Carbon and explore some more variations to improve it.
You've not made a battery, you've made a capacitor because it stores the charge you gave it. The iron electrode cannot recombine during the charging phase so it cannot be recharged; it only re-stores energy.
Looking at the discharge curve in my first video, (time: 16:23), the curve is typical for a battery, convex downward. A capacitor discharge curve is always an exponential concave curve downward. The plating of iron metal is a well known phenomenon and commercial process. An iron chloride solution can be purchased commercially for this purpose.
@@William_Hada I'm aware of the plating of metal cathodes. Imho, what you made is a capacitor for the reason the charge/recharge is not achieved through chemical processes. The charge/recharge is stored in what you made. Unless of course you can confirm iron metal was deposited on your cathode during charging.
hi there. Very nice project. Have you considered making an actual bipolar electrode to double the voltage? ie activated carbon on one side of the iron plate. One suggestion: use a Mayer Rod to create uniform thickness of active material. Thanks for sharing this. Doug
Hi, that's an interesting suggestion! I have never built a bipolar cell, but the idea of connecting ( stacking) cells internally is definitely worth trying. Thanks for sharing.
@@William_Hada important thing is you must isolate the electrolyte saturated separators (or use a solid state electrode - ie - PVA based electrolyte membrane.)
@@nitrousman8882 Thanks, I see your point. The electrolyte sections have to be electrically isolated from each other so there is no conductivity between them. Very interesting cell configuration! I've got to try this sometime.
So glad I found this! Would you be able to use shim material on both sides, with grafoil and carbon still one one side? Why is the soak timed for 20mins? Do you need the oxygen to form oxides?
I guess you mean that you want to use iron shimstock on the Grafoil/Carbon electrode as just an additional collector plate? I think that would be OK as long as there is no contact with the electrolyte. But, because Grafoil is actually porous I don't think that is a good idea. If that iron shimstock collector sees/makes contact with the electrolyte, I think it would cause problems with the operation of the cell. The 20 minutes soak time was just an arbitrary time I used to make sure that it was saturated enough. Since the cell was sealed up and performed OK, I don't think ambient oxygen his needed for the cell chemistry, its not an air battery as far as I can tell.
@@carlonlamont511 To seal the outside of the Grafoil electrode from leaking electrolyte you can try painting it with conductive paint. You can easily/cheaply make your own conductive paint : rosieresearch.com/diy-conductive-paint-recipe/ When making the conductive paint use a minimum amount of glue/binder (initially try 5%to 10%). If too much binder/glue is used you will kill the conductivity of the paint. You may have to experiment to get the ideal percentage of binder. If the conductive paint is too thick/viscous for painting, you can thin it out by adding a small amount of water.
@@carlonlamont511 I have used another method to seal the back of Grafoil sheets. It makes the electrode stronger and resists tearing and cracking of the Grafoil. I place a sheet of Grafoil on top of a single sheet of laminating plastic and run it through the rollers of a hot laminating machine multiple times until the two stick together. The only problem with this composite electrode is that the plastic side of course is not conductive at all but I thought I should mention it because it may be useful in some cell constructions by making the Grafoil much stronger and tear resistant.
@@William_Hada Thanks. Will look for it. One more question, you mentioned sugar charcoal as active material. How does it compare with store bought activated carbon?
@@kulkarniniraj14 If you make your own charcoal by carbonizing sugar it will perform better than activated carbon you can buy at the local store. Activation of the charcoal with NaOH or ZnCl2 will improve it even more. Look at Cayrex2 and Robert Murray-Smith's RU-vid channel for detailed videos on how to make activated sugar carbon as well as a number of other carbons useful in batteries and supercapacitors.
Anything made of pure Iron or carbon steel can be used as an anode. Do not use any forms of Stainless Steel which can contain Chromium, Nickel, etc. Ive had good success with using steel wool for the anode. Just be sure that what ever you use is not Stainless Steel or iron plated with another metal.
@@William_Hada ok thank you. How would I use the periodic table to get a better idea of what to use? I know the columns are valance electrons; but am I looking for the biggest difference or is it an shell/orbital things?
@@justthinkalittle8913 The electronegativities of elements are found in the periodic table. Picking two elements with the greatest difference in electronegativity would get you the greatest battery voltage. Here are a couple of articles to read for more details: caplor.co.uk/caplor-news/elements-periodic-table-can-used-make-batteries-oh-many/ and blogs.scientificamerican.com/degrees-of-freedom/the-periodic-table-and-batteries/
More dense solutions of fecl3 (electrolyte),e.g. 3M, 4M, 5M,6M etc to be finally made in electrolytic organic solvents after first aquous solution may be tried to improve it's energy density or some more electronegative element salts may be added ??????? I think ALMIGHTY may provide some way for the needies ?????
Hi Based on the information... the 13mWh and the 6.6g it would have an energy density of 1.9Hh/kg. It is possibble that my calculations are faulty, but if that is not the case, than this is very little energy.
You are correct in your calculations. Although I know that it's energy density can be improved on, it will never be close to the performance of a lithium ion battery for example. Having said that when was the last time someone built a lithium ion battery at home? Iron and carbon are much safer, abundant, and a lot cheaper than lithium. I think my battery chemistry is unique because all other Iron redox batteries were of the " Flow Battery " type requiring external electrolye pumps for recharging. Yes, the energy density numbers are not that impressive but, I thought it was amazing and surprising to me that it did have enough energy stored in itself to move itself across the floor. Thank you for watching the video and showing interest in the battery.
That should be enough amps to charge batteries around the size that I built in the video. If you build batteries much larger than in the video you will need a DC supply that will put out more amperage.
@@danielcesar5251 When I first charge the cell I pay careful attention to the milliamps of current that is being drawn by the cell. So I gradually increase the charging voltage and keep the charging current at about 50 to 200 milliamps. If the cell is taking on a charge normally the current will drop gradually over time approaching zero but will not actually reach zero. Just level off at some low value maybe around 10 to 20 ma. It's just a matter of trial and error once you zero in on an optimal charging voltage. You don't want to push the charging voltage too high because it can destroy the cell.
