A kit for plating Iron onto other metals?

[MountainMan]

I'm wanting to experiment with homemade NiFe batteries and want to start by doing some plating experiments with different possible anode and cathode materials. Looks like it is easy to find a kit for plating nickel onto other metals, but finding one for plating iron onto other metals has not gone so well. Any suggestions welcome.

thanks,
jp

[chromo]

Re: A kit for plating Iron onto other metals?

Why would you want to plate iron onto another metal, and what other metal would you be wanting to plate onto?

I mean can't you just get a solid steel/iron sheet and have your iron?
I know what you mean about Nickel Iron batteries, but I would think the nickel is the hard part not the iron.

[MountainMan]

Re: A kit for plating Iron onto other metals?

Why would you want to plate iron onto another metal, and what other metal would you be wanting to plate onto?

I mean can't you just get a solid steel/iron sheet and have your iron?
I know what you mean about Nickel Iron batteries, but I would think the nickel is the hard part not the iron.

It's a good point. With batteries, a big part of the equation is the surface area of the cathode and anode. Just having a chunk of metal in there isn't the same as having the same chunk with lots of holes in it such that the electrolyte can get in there all over and do some more "reacting".

So I was looking for a way to take various available forms of metal such as screens and expanded lathe etc. and then give them the proper surface for the NiFe battery reaction.

After some more reading, I've discovered that it is primarily the nickel side of the equation that needs lots of surface area in an NiFe battery. I probably will go with just an iron rod, combined with something as described above to get a high surface area nickel anode.

It seems there are kits here at Caswell that should make that side fairly painless. I'll probably start with a few different easily available materials with lots of surface area, and copper coat them first for better conductivity, then plate the nickel on. I wonder if it is possible to copper and then nickel plate un-soaped steel wool?

Happily, with NiFe, the battery chemistry uses the cathode and anode in a purely catalytic way, so I don't need thick iron or nickel.

thanks,
jp

[MountainMan]

Re: A kit for plating Iron onto other metals?

One other point regarding my original question is that the finished battery would be more efficient (that is, give up less of the charging energy to heat) if the "iron electrode" was more conductive. To that end, I would rather have my iron electrodes be copper electrodes plated with iron rather than a simple iron bar or rod.

thanks,
jp

[engineerscott]

Re: A kit for plating Iron onto other metals?

I don't think an electrode constructed out of copper plated with iron will really help you out. If the material thicknesses are fairly substantial then the electrode impedance will be small whether it is solid iron or copper plated iron. In fact, most battery's internal impedance is generally not dominated by the electrode impedance. Don't forget that current is flowing through the electrolyte as well and this is an imperfect conductor which will generally dominate the cell impedance. Aside from this, iron is consumed in the cell as it is discharged so a thin plating layer would tend to limit the total amount of energy you could extract from the cell (i.e. the as the cell discharged you would consume the iron plating and the battery would stop).


You are correct that electrode surface area is a hugely important parameter both in the total amount of energy the cell can store (measured in Joules (J) ) and the cell impedance. Generally, increased electrode surface area will reduce internal cell impedance.

Most of the battery manufactures have methods for making spongiform nickel. Unfortunately I do not know the details of this process. If you really wanted to use an electroplated electrode it occurs to me that you could make a type of sponge form nickel electrode by starting with a sponge form carbon. When you were a kid in chemistry lab you may have made a sponge form of carbon by reacting a sugar (regular table sugar works fine) with sulphuric acid. You take a couple of table spoons of sugar in a 50ml beaker. Pour in concentrated sulphuric acid to completely cover the sugar plus an extra 10% or so. Stir the sugar into the acid. You will notice it start to thicken and then turn dark. Suddenly, a black foamy mass will start rising out of the beaker. After a minute or so you will have a black foamy tube many times the depth of the beaker in length. This tube will harden and is a very porous tube of almost pure carbon. If you carefully wash this carbon foam in distilled water your will remove the residual sulphuric acid. If you then heat it to a couple of hundred degrees F you will drive off any other impurities. This should be moderately conductive. What would be interesting to do would be to take this material and then attempt to plate it using either electrolytic nickel plating or even better electroless nickel plating (however I am a little unsure of how the latter would work). You could either use as is for a nickel sponge electrode or consider chemically removing the carbon to leave you a pure nickel sponge matrix (which would be more optimal for a battery).

[bhhodges]

Re: A kit for plating Iron onto other metals?

as far as i know--you cant plate iron on too anything else.....

bill