A failed attempt to produce a "charged" solution.

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goldsilverpro

In Remembrance
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I just posted this on finishing.com and thought some here might be interested. I may have already discussed this. A question from a student was asked, "Why can't we store electricity in water." Since I had an experience of attempting that very thing, here was my answer:

"Many years ago, in the late 70s, I did a lot of experimenting (daily, for about a year) with anodic and cathodic ion-exchange membranes, sometimes called ion traffic controllers by the laity. I arranged several small, clear, plastic tanks (square, hard, transparent, styrene boxes about 2" X 2" X 2" high, about 100ml, or so, each), containing various solutions, in a line, each separated by membranes, with electrodes at the ends. My object in one experiment was to set the positive and negative ions in one of the cells out of balance, to produce an over-abundance of either positive or negative ions so that the solution in that cell would have an over-all positive or negative charge. My idea was to be able to store whatever energy this imbalance would produce. Ultimately, I wondered what would happen if one combined a positive ion rich solution with a negative ion rich solution. Would energy be released?

The experiment worked, as far as my setup being able to produce this ion imbalance. However, nature would not allow this to happen. To make up for the charge deficit in the cell, it automatically split water off one of the membrane surfaces in that particular cell, continually. I could visually see it happening as bubbles (H2 or O2) coming off of a single point on the membrane. If I was producing more positive than negative ions, water split and gave off H2 gas and OH- ions, to make up for the deficit. If the solution were negative ion rich, the water split to give off O2 gas and H+ ions. In other words, I could not store energy in a solution, at least not in the way I was trying to do it. If it had worked, I might have blown up the lab. It was a complete surprise, but a joy, the way the Creation prevented me from doing it."

I did all these experiments by cutting out rectangular windows in square styrene boxes with a Dremel. I then put a layer of teflon lab grease on the outside of the boxes around the windows. I then placed membranes that were larger than the windows on the grease and held several of these boxes together, in a line, with long rubber bands. The most boxes I used in a line was 7, with a membrane between each 2. The "cells" contained various solutions, usually dissolved metal salts. In the 2 end cells, I used various metals as electrodes, depending on the experiment. I'm thinking I used a 10A, 15V rectifier to drive it. Before and after an experiment, I analyzed the solutions in the cells with a AA. Very interesting stuff, I thought. I really got into it.
 
Interesting! Though you were hoping to store, you instead were producing something through an unanticipated reaction. What became of the metals in solution? Anything measurable?
 
Cool stuff :)
I guess this is the core behind the so called "flow cell" batteries.
They have been created and works well (ish), most challenges are concerns regarding higly toxic salts if I remember correct. Thought I've read somwhere that they have been able to make cells using more benign salts.
On further checks, there are a number of technologies with their own pros and cons out there, more than I anticipated.https://en.wikipedia.org/wiki/Flow_battery
There were a upcoming car brand "Quant" i think, that was suppose to use it, but it never emerged from prototype, or maybe it did.
There are so many upcoming and emerging technologies regarding electric drives today its hard to be on top of it, all the time :)
The upsides are formidable though, you can charge a liquid and store it in large tanks and refill as a usual gasoline car when needed, or charge as any electric car. Though two tanks containing a positive and negatively charged liqid are needed.

Cool job though, did you find anything unexpected that you care/are allowed to share with the rest of the mob ;-)

Edit: On further reading and thinking, I see that the concepts are different, the flow battery stores energy by completed reactions. Energy is collected by reversing the reactions. Not by keeping charges in solution. My bad. Still interesting though :)
As an esteemed meber use to say, time for coffee, even if its the first :D :D
 
This made me think of anhydrous ammonia, and how it becomes blue with free electrons from alkali metals.

The color leaves it after time though.

I believe it all comes down to Newtons laws.
Something about entropy, er other.

This may be an interesting read for some:
https://en.m.wikipedia.org/wiki/Solvated_electron
 
Well, putting a charge into a liquid is a fools errand, if that was what you were trying to do. Any unbalanced charge put into a conductive object (metal or liquid electrolyte) would arrange itself along the surface so the electric field inside the object goes toward zero and any electric field is perpendicular to the surface. To put a charge into a bottle for instance would make all the ions end up at the border towards the glass, actually mimic early times capacitors.

The only way you can "charge" a liquid is to have a chemical (or physical) reaction that is changing the energy content in the liquid by altering molecules so the charge is held locally and globally the liquid is electrically neutral. One example of such a molecule is ATP ( https://en.wikipedia.org/wiki/Adenosine_triphosphate ) that our bodies uses to transfer energy internally in the cells.

There are some battery designs that uses electrolysis to charge or split a molecule in separate parts and that can be used later on to extract energy in a reversible process. It is looked at as an energy storage for solar installations, the cell in it self doesn't need to be that big and large tanks can be used to cheaply store the liquid, then pump it back through a cell to extract the energy as electricity again. The energy density is quite low but it is very cheap to store.
I haven't heard of any full scale installation yet, only basic research yet.

The free electron solvated in anhydrous ammonia is really cool, but don't forget that for each electron there is an alkali metal + ion too, making the whole liquid electrically neutral.
Here is one of several cool youtube videos out there.
[youtube]http://www.youtube.com/watch?v=tYjQXjUUvwY[/youtube]

Göran
 
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