Zinc Bromine Flow batteries

I agree that they show some promise. I notice the the large ones proposed for grid power storage contain electronic cabinets, so perhaps there is more to the circulation control than meets the eye. So far,in storage density, they seem to be a little less than twice as efficient (watts/kg) as existing lead acid batteries. (Promoters claim 2-3 times). It seems as if they should scale down well, but I don't know. I hope others know more.

I remember hearing about a system that used an electrolyte that came as two separate components that when combined in the reaction cell produced electricity. The resultant waste fluid was collected and could be separated back into the two electrolytes for later use. The idea was that you hat three thanks two containing the separated electrolytes and one the waste product. When you wished to refuel you vehicle it was simply a matter of removing the waste and toppling up the electrolyte tanks. The waste was then reprocessed and turned back into the two electrolytes for use again.

From what I can remember it worked along the lines of a fuel cell but they had played around with the fuel and oxidizer to make the whole system more stable, reliable, easier to control and cheaper to produce. This however was about 15 years go and I havn't seen or heard anything about the system since. I have a feeling though it was being developed under the control or the CSIRO (Commonwealth Scientific & Industrial Research Organization) which is an autonomous scientific research organization funded by the Australian Federal Government.

I did a Google search for the details I could remember and found these results and it might also be worth checking out the CSIRO web site to see if they have anything that might be of help. I am interested in what you ultimately find so would you be kind enough to post any links you do eventually find here.

Hello,

I viewed your forum comment today (26/03/07) a bit late... sorry

ZBB Technologies in Australia or ZBB Energy Corp is US manufacturer of this product. R&D based in Australia, Perth WA.

Gavin Peiris.

Pryde Measurement.

All success with developing this product for use with motor vehicle.

Thanks for the info.

Dasdav,

I have often thought that such a system would solve many problems of electric vehicles, but I had no idea they already existed, especially for such a long time!

"It was first used in 1884 by Charles Reynard to power his airship La France which contained its own on board chlorine generator."

http://www.mpoweruk.com/flow.htm

http://en.wikipedia.org/wiki/Flow_Battery

http://thefraserdomain.typepad.com/energy/2006/01/about_flow_batt.html

Regards, Greg

I saw that aricle about the airship. What happened to the days when you just had an idea and you made it fly? What an age to have lived in.

I would really like to build one of these batteries but my big concern is how toxic Bromine is. You have to handle it very carefully from what I understand. It is easy to make I have found a formula and a procedure for making it. I wish I could find more info on concentrations and surface area's and what not. I was also wondering if the flow rate of the electrolyte mattered. If you increase the rate of flow will that increase or decrease the current flow. If the flow rate is proprtional to the current rate then could you regulate the flow to change your speed instead of using an expensive voltage regulator. I don't know I have a lot of questions and don't seem to have a lot of answers.

Thanks for the encouragement

If the flow rate is proportional to the current rate then could you regulate the flow to change your speed instead of using an expensive voltage regulator.

That's a really neat idea. I think there would be a very long lag -- but i really don't know. It would be a nice simple system.

These things can be scary toxic!

See my other post.

Bromine is dangerous alright, but it exists as a liquid at room temperature and is also quite soluble in water as the hypobromous acid (similar to chlorine, but much less vapor pressure since chlorine is a gas).

Apparently, the zinc-bromine flow battery is catching on fast.

There are several things to consider in all vehicle propulsion selection decisions:

• Energy stored per unit weight.
• Power generated per unit weight.
• Shape/air resistance performance.
• Start-up time for the energy system, from switch-on.
• Replenish time for the energy stored.
• Availability of energy replenishment locations.

...among others.

The sodium-sulphur battery ticks the boxes as far as energy storage/tonne and power availabilty/tonne is concerned, giving scope for a decent range for a road vehicle comparable in operation to today's fossil-fuel guzzlers. The particular problem with sodium-sulphur is that in order for it to become a battery system, the temperature must exceed, typically, 300degC or so, Therefore an auxiliary battery must be carried and a significant start-up time will result while the secondary battery creates the conditions for the traction battery to perform. And like Zinc-Bromine, the Sodium-Sulphur system poses significant threats to both occupants and others were the vehicle to become involved in an accident. Given that there are >3500 deaths on the UK's roads each year any fuel system change will be scrutinised to ensure that its presence does not significantly infuence that figure upwards. It's not just a question of changing the engine and tank for a motor and a battery, and away one goes. There are other things to consider. Otherwise, why not just go nuclear instead of battery (rhetorical question)?

All 'alternative technology' energy sources for road vehicle use require levels of compromise not currently acceptable to sufficient road users to make today's liquid-based combustion engines a thing of the past (like the solid-based combustion engined vehicles found in museums and at heritage sites today). Over time, the compatibility and acceptability will improve. The reason most people don't recognise opportunity, is that it is frequently disguised as hard work.

Please publish reports on the Zinc-Bromine system after road vehicle trials have been completed.

Have you considered vanadium flow batteries.? These have been scaled up from lab modules and are in use in King Island Australia.so would work as a scaled down version. Bromine and the halines always seem to me to be a little toxic if they get out of the jar. See New Scientist 13 Jan 07

Everything is possible. Selection and evaluation of practical and economic solutions to problems is what the game is all about.

I was kind of hoping to find something that I could build, and build cheaply. Vanadium batteries look kind of expensive. Your right about how toxic bromine is and I have a real concern about that, but it seems to me that you could build a safe container that you would be able to keep the chance of spills at a minimum if down to near none. What would be fun is if someone had a kit for any kind of flow battery, vanadium or bromine. I really think the flow batteries have some much potental in electric cars. They could go a long way to solving the range problem all electric cars have.

Again: "the more active the materials, the more spectacular the failure!"

For as long as i worked in the EV industry, we had a pix of a FoMoCo Ecostar in FLAMES (molten NaS battery) posted on the wall, to remind us of the hazards of falling blindly in love w/ exotic chemistry.

I MUST insert a major caveat here:

I worked ~7yr @ Solectria, spending much time at the bleeding edge of then current technology.

Just B4 i got there, our CEO was utilising ZnBr storage http://www.findarticles.com/p/articles/mi_m3165/is_n6_v28/ai_12275282

We were most fortunate that Janey (To be M.D. in weeks) was there & convinced the EMT's in proper measures, so we got to keep James!

The more active the materials, the more exciting the failure.

I'm glad there is finally someone that knows anything about them. I only know what I have read and that isn't much. I have had a hard time find anything about these batteries. So any input is more then welcome. Thanks for the heads up on how dangerous they are.

Of course the reason Bromine is hazardous is that it is a very powerful 'oxydising' agent (see position on periodic tables). It will cause carbonaceous materials (ie: you) to react (burn). The swelling in (specifically)lungs (most area) can be troublesome.

Reading from the ZBB website they were suggesting that the bromide is not in a toxic state for the most part, and that the flow of the electrolyte actually cools the battery, and if there is a spill it washes away without quarm (dilusion) and its easily neutralised. Mind you they are not promoting them in cars. www.zbbenergy.com

I think the reason they have not developed a car unit is because they are focused on the industrial utility market.

The amount of time our guy spent at hospital, under emergency care, tells me otherwise!

I had almost forgotten about this thread. I can tell from the fact that you are still keeping an eye on the subject that you are very concerned about safety. It's to bad the chemicals are so volatile. I still think it would make a great battery. The one thing that I do think is that I'm sure that the company I work for could design and build a safe casing for this type of battery. We are a sheetmetal company but we specialize in industrial welding. I would think a SS tank and piping would take about anything you could throw at it. Now don't get me wrong it wouldn't be cheap, but I'm confident would could build something very safe, that could handle temperature, pressure and any corrosion problems as well as rupturing from some kind of collision/impact. Now I'm not trying to put down your concern for safety but I feel that there are ways to make the system safe.

hi, I've been reading this thread and trying to do some research on the zinc bromine battery. I'm confused about this whole "refill as you would a gas tank" thing. In my understanding, the battery only has voltage to discharge when there is zinc plated to the cell, and bromine present which can be reduced as the zinc oxidizes.

How is it that you can replace the electrolyte solution without throwing off the balance of the other pieces? (ie: without zinc having been attached to the cell surface) Also... what exactly are you replaced, and what are you replacing it with?

thanks!

That would only apply if you had surplus zinc

Zinc Bromine is a prove EV battery as proven by the following: UCS Davis built a research project that resulted in the construction of the "California 1" battery, the highest voltage zinc bromine battery ever to be constructed for use in an electric vehicle in 1995, David H. Swan and J. T. Guerin's US Electricar S10 light-duty truck, Toyota's zinc-bromine powered EV-30. Now liquid bromine is harmless and can be diluted and washed away relatively harmlessly, but in high temperatures it does vaporize and in the gaseous state it is similar to chlorine (both are used in cleaning swimming pools) and is toxic. Solectra electric vehicle race team that demonstrated a zinc-bromine battery powered car capable of a top speed of 95 mph., and a Fiat Panda entered by SEA from Austria for The 12 hours of Namur. Solectra's James Worden was hospitalized for three days after their recirculating hose came loose leaking bromine onto the track and into the car. Under normal conditions this should have been picked up by the computer and then a it would have initiated a complete shut down, but unfortunately it failed. But he made a full recover and went back to work. Research will also show you that plastic can be used to make the battery and therefore decrease the weight.