Battery Liquid Refilling Stations?

[safe]

Going Backwards in Time...

After scanning the internet a little I see that the solid electrolyte idea has been something that has been pursued as an alternative to the liquid electrolyte approach. The idea is to make longer lasting batteries this way.

Maybe the idea would (like the Vandium battery) go back to the old way and use liquid electrolytes in the LiFePO4 cells so that you could swap out the liquid at a refilling station and then wash the cathode and anode clean again.

I'm thinking that the choice of electrolyte seems to be a "free choice" and it doesn't matter that much what you use as long as the lithium metal gets transferred.

In effect this process would be to "burn lithium" (chemically) and so you would have to replace the cathode and anode over time, but that might be the way to make infinite running batteries. If you can wash out the electrolyte, replace the cathode and anode then all the rest of the battery could stay in place. (which is basically the shell and control circuitry)

If the electrolyte is 50% of the weight of the battery it's easier to drain it and replace it than to have to lift it out of the car. Replacing the cathode and anode might be as easy as changing spark plugs...

 

[paultrafalgar]

The important elements of this thread are in danger of being swamped by LiFePO4.
1. FORGET LiFePO4 for the purposes of this thread.
2. The significant point is a chain of "battery refueling stations".
3. The most likely candidate for this is the VRB (Vanadium Redox Battery).

VRB has been highly developed for STATIC applications (see http://www.vrbpower.com/technology/index.html)
As I pointed out above the watthours per kg (80) seem suitable for our application. We just need to find out why they have neglected TRANSPORT (i.e. non-static) applications. And then we need to persuade them to change tack!
I just emailed them as follows:

I am interested in VRB for electric bicycles. It would seem that 80watts per kg energy density would make this possible. Why have you ruled out non-static uses of VRB? With a refuelling infrastructure it would seem possible to use your technology to replace petrol/diesel transportation systems.

And here's the reply:
----------
Paul,
Our systems are designed for stationary applications only. The VRB technology will not facilitate mobile applications due to low energy densities.
Regards,
Vince Sorace
-----------
So that's that!

 

[safe]

So that's that!

For VRB technology yes, but there's no reason that the electrolyte for LiFePO4 needs to be a solid. Any electrolyte would work and so the only question becomes whether that idea could work.

I think what it comes down to is you would be forced to scrub off the Lithium that gets deposited on the graphite. Once the graphite (anode or cathode whichever) is clean then you could reinstall the electrolyte and have a fresh and full battery again.

All a battery does is:

The cathode and anode have differing properties that cause a chemical reaction to take place using the electrolyte as the "transport medium" between the two. If you reverse the charge on a battery that has "transported" already then there is a reverse process that puts things back into place.

What I'm suggesting is that you could simply "wipe the slate clean" and start with fresh materials. The only loss is the depeletion of the Lithium. (it would be slowly used up)

You trade instant refills as a "positive" with a need to replace your lithium "spark plugs" so to speak... over time as your "negative".

But this would mean that you have an "infinite battery" because every time you replace the Lithium it's fresh agian.

So there is good and bad in it... but you would need a liquid to make this all happen because you need to flush out the electrolyte then scrub the graphite. Replace electrolyte and you are off again.

The main idea is that you could do this fluid refill at a rate equal to refilling a gas tank... very fast.

And please... let no one accidentally misread this and ignore that at present solids are being used. I know that. There's no neccessity to use solids, it's okay to use liquids for the electrolyte. This is a battery design choice not a mandate.

"LiFePO4 can use solid or liquid electrolytes."

 

[paultrafalgar]

So that's that!

For VRB technology yes, but there's no reason that the electrolyte for LiFePO4 needs to be a solid. Any electrolyte would work and so the only question becomes whether that idea could work.

I think what it comes down to is you would be forced to scrub off the Lithium that gets deposited on the graphite. Once the graphite (anode or cathode whichever) is clean then you could reinstall the electrolyte and have a fresh and full battery again.

All a battery does is:

The cathode and anode have differing properties that cause a chemical reaction to take place using the electrolyte as the "transport medium" between the two. If you reverse the charge on a battery that has "transported" already then there is a reverse process that puts things back into place.

What I'm suggesting is that you could simply "wipe the slate clean" and start with fresh materials. The only loss is the depeletion of the Lithium. (it would be slowly used up)

You trade instant refills as a "positive" with a need to replace your lithium "spark plugs" so to speak... over time as your "negative".

But this would mean that you have an "infinite battery" because every time you replace the Lithium it's fresh agian.

So there is good and bad in it... but you would need a liquid to make this all happen because you need to flush out the electrolyte then scrub the graphite. Replace electrolyte and you are off again.

The main idea is that you could do this fluid refill at a rate equal to refilling a gas tank... very fast.

And please... let no one accidentally misread this and ignore that at present solids are being used. I know that. There's no neccessity to use solids, it's okay to use liquids for the electrolyte. This is a battery design choice not a mandate.

"LiFePO4 can use solid or liquid electrolytes."

Doctorbass mentions here:
viewtopic.php?f=14&t=2764&start=30
his latest LiFePO4 pack is: "(30 lbs of battery for 1.8kWh)"
My maths says that is 132 watthours per kg
Whereas here:
viewtopic.php?f=14&t=4114&st=0&sk=t&sd=a&hilit=VRB&start=15
The manufacturer of the VRB says:
----------------
Paul,
Our systems are designed for stationary applications only. The VRB technology will not facilitate mobile applications due to low energy densities.
Regards,
Vince Sorace
----------------
But the energy density of VRB is 80 watthours per kg which must be as good or better than lead!?
Why have the manufacturer rejected VRB for transport? Is it just that they are thinking in terms of pushing a Hummer along? I still think that this offers a basis for Safe's refuelling battery idea.
BTW Safe YOU MUST GIVE UP THE IDEA LiFePO4 FOR THIS! It's as daft as suggesting you extract a horses blood and fill it with sulphuric acid to make a battery! LiFePO4 relies on carbon nanotubes to conduct the ions from one electrode to the other, you can't take out the "electrolyte" and replace it with a recharged sample as you can with VRB.

 

[safe]

Safe YOU MUST GIVE UP THE IDEA LiFePO4 FOR THIS!

I have read that LiFePO4 is capable of any type of electrolyte... so I know it's possible... but to focus on it exclusively is a problem.

I'm going to "rename" the thread if that's okay to simply:

"Battery Liquid Refilling Stations"

 

[paultrafalgar]

Excellent! Way to go!