Testing an Ion Exchange Membrane in a Zinc–Iodine Battery

Added: 2026-05-25

[00:00:00]Hello everybody. So, these days I make a lot of experimentation on ion exchange membranes and this is uh in the future I want to make a couple of videos on this topic where I will test some ion exchange membranes from the commercial one to some homemade uh ion exchange membranes in some flow battery to see what I will get.

[00:00:27]>> [music] >> And uh of course I will start with some uh commercial available ion exchange membrane like this one.

[00:00:39]Uh but before I will test this membrane in a flow battery uh I will first test also in some static zinc iodine cell.

[00:00:54]And yeah, so over here I have this uh membrane called Vanedium 18 which is some ion exchange membrane from the company called Ion Power. So, super super nice uh to the guys from Ion Power which they sent me a couple of pieces of this ion exchange membrane that I can test this membrane in some zinc based battery.

[00:01:21]Because this Vanedium 80 uh ion exchange membrane is actually specially developed for some Vanedium redox flow batteries.

[00:01:30]>> [snorts] >> And um this kind of membrane is even better like the Nafion 115.

[00:01:37]And uh in case that you make some professionally uh Vanedium redox flow battery, then in this case I recommend that you try this ion exchange membrane.

[00:01:49]But the sad part about this membrane for the DIY makers is of course the price.

[00:01:56]So, this one is a little bit expensive and only in case that you make some professional work on some vanadium redox flow batteries and you want to have good results as possible, then in this case I recommend that you try this ion exchange membrane.

[00:02:15]And like you know me, I don't have too much interest for some vanadium redox flow batteries. For this reason, I will test this ion exchange membrane in some zinc iodine cell.

[00:02:28]So, to make this static zinc iodine test cell with this ion exchange membrane, I placed the ion exchange membrane >> [snorts] >> between two pieces of glass fiber separators because these two glass fiber separators will hold to the electrolyte in place.

[00:02:46]So, one piece of glass fiber will be on the bottom, then on the first glass fiber I will put the ion exchange membrane and on the top of this ion exchange membrane, I will put the second glass fiber separator.

[00:03:02]And these two glass fiber separators are filled with the electrolyte. So, the only role uh for the glass fiber separators is to hold the electrolyte in place.

[00:03:13]And now I will cycle the test cell for 40 cycles and I choose 40 cycles only for this reason because uh to make all these 40 cycles, I need around 1 week of testing.

[00:03:31]So guys, at this point I need to stop with the testing because uh the test cell was shorted.

[00:03:39]So, like you see right here, the test cell was able to make 18 cycles and on the cycle number 19, uh the test cell stopped working because the zinc dendrites penetrate the membrane and the cell was shorted.

[00:04:01]So, I will also show you some pictures of the membrane, but first I will show you the wattage curve which is over here.

[00:04:12]Then the cycles, here you can see that with each cycle I get better capacity.

[00:04:17]And what is really, really nice is of course the efficiency of the cell.

[00:04:23]So, like I see over here, the charge discharge efficiency was 99.8%.

[00:04:31]And then the energy efficiency was 89% which is really, really, really nice.

[00:04:40]So, the efficiency of the cell with this ion exchange membrane was really, really, really good. But sadly, some zinc dendrites penetrate the membrane on the cycle number 19.

[00:04:57]And here are also the pictures.

[00:05:04]So, in this case, some ion exchange membrane is not able to suppress some zinc dendrites in some zinc iodine cell.

[00:05:16]But in the end, I was really impressed by the efficiency which I can get with this membrane.

[00:05:24]And now because this ion exchange membrane was not able to suppress the zinc dendrites, for this reason I was thinking that I will make a second test where I will combine this ion exchange membrane with one of my dendrite blocking separators.

[00:05:41]>> [snorts] >> So, this dendrite blocking separator which I will use together with this membrane is actually specially developed for my APC battery. And it's actually just for fun, I want to see if this composite membrane will be able to suppress the zinc dendrites, and in the end, what results I can get out from this combination. So again, this zinc iodine test cell I will cycle for 40 cycles.

[00:06:11]At this point, the cell complete with the testing, and uh actually the cell was able to make all 40 cycles without any dendrite problems. And now, let's look into the data. So first of all, here I have this discharge curve.

[00:06:29]Um you can clearly see that the cell need around um 10 to 20 cycles uh to be fully format.

[00:06:38]And over here I have the cycles and the efficiency.

[00:06:42]So like I said before, here by the cycles, you can see that the cell need around 20 cycles to be fully format.

[00:06:52]And in the bottom, you can see uh the coulombic and the energy efficiency.

[00:06:58]So the red one is the coulombic efficiency, which is in the region of 99.6%, and the energy efficiency, which is a little bit lower, uh like but the cell which uses only ion exchange membrane, uh so here in this case, uh the energy efficiency was in the region of uh 82%, which is also really, really good. And in the end, what is really important is that the cell complete all 40 cycles.

[00:07:31]And here I have the images of this ion exchange membrane which was used in this test cell.

[00:07:41]>> [music] [music] >> So guys, this was my little testing with this ion exchange membrane in some static zinc iodine test cell.

[00:07:58]So, this membrane was used in the second testing.

[00:08:03]And yeah, so like I said in the beginning of this video, uh definitely I will make more videos where I will use uh some different ion exchange membranes in some uh flow battery.

[00:08:18]And actually that's it.

[00:08:20]So guys, that's it for now and we see us in the next video.

[00:08:24]Bye.

[00:08:25]>> [music]