Flow Batteries

today

The weight and volume which are drawbacks for vehicular use are not a problem for solar storage for the home.

you'll never see it in a car but as a daily battery that charges during the day then supplies all your needs until the next sun cycle............its a game changer, utilities are almost obsolete in residential areas once this is out with 30+ panels

You would not want to be anywhere near one of these after a collision due to spillage of bromine water. Zinc bromide, not so much of a hazard.

I checked it out, on redflow's website, and it appears doable. The basic, smaller unit with 8 kWh only seems good to 20 MWh life? Maybe there is a problem with the way the zinc re-deposits on the metal electrode.

I would not count lead-acid as totally out of the picture yet, as supercapacitor incorporation into the cells leads to a battery with less weight, same overall 100% charge capacity, ability to have higher surge current both on charging and discharging, and the ability to not be damaged by cycling within the partial charge envelope of the battery.

I am still waiting to hear further developments on an Aluminum Air battery from Stanford University, that is completely rechargeable. It does not suffer from the hazards associated with Li+ batteries, and actually deposits aluminum metal during recharge. The voltage output is greater, given the charge characteristics of Al3+ ion.

I think flow batteries will be "everywhere" within 10 years

ROBUST AND LONG LIFE DESIGN • Ideal for tough conditions, with high temperature tolerance up to 50°C (122 °F). without air conditioning, mitigating additional cooling costs. • 100% depth of discharge for day-in day-out deep cycling. • 100% depth of discharge is perfect for intermittent energy sources (unstable grids and renewable energy), there is no battery damage from regular power outages. • Guaranteed indefinite battery life, when fully discharged and no maintenance required, meaning no calendar life.

You will find no real argument from me on this, Fredski. The only weak area will probably be direct use in transportation, but even there, containers could be hardened to the point that a rupture of vessels could be avoided except in the worst case scenario, then it is a moot point, I suppose that a container with bromine water was breached.

One strong selling point: Rapid discharge of spent zinc bromide solution, and rapid uploading of new bromine water, and zinc electrodes could be made possible. It would still require a technician for re-fueling (creates jobs). Do you agree on this detail?

Here is where the Aluminum battery comes back into play. Very rapid re-charging - several times faster than Li+ technology. Very large number of cycles. Relatively inexpensive cycle based on the relative costs of materials, electrolyte. Behavior under high G collision is mostly innocuous, other than contact with organic electrolyte, that might present a slight corrosive or irritant reaction on skin, eyes.

Charging (9.2 hour period from 0 to 9.2 hours):  Current (blue trace, using right axis) at -25A DC (negative = charging) for 9.2 hours. 2. Discharging (10 hour period from 9.2 to 19.2 hours):  Current ranges from 25A DC to 0A DC as the voltage (red trace, using left axis) falls from 52V DC to 0V DC.  The ZBM continues to discharge until the battery current is very close to 0A, and the ZBM is empty. 3. Regular Maintenance (0.5 hour period from 19.2 to 19.7 hours):  After discharge is completed, excess zinc is stripped from the ZBM. The user should allow two hours for a full reg

That sounds less like a pit stop, and more like an overnight stay at the local Motel 6.

G'day Fredski. If you re read your post "SUPER BATTERY" you will see where a prof. has started to develop a gel form of the flow battery. That sort could be used in cars.

Jim

Jim: What The Heck? A gel form of flow battery...let me see, now we will waste a tremendous part of the energy of the battery just attempting to pump a gel electrolyte? Is it only supposed to gel during a collision? I suppose one could engineer an outer sheath container in just such a way as to gel the battery electrolyte when the inner container is compromised. Gel seems like a really incredibly stupid idea, unless it has unique rheological properties that only increase the viscosity to a solid-like state under high shear stress, then keep it gelled as things settle back down. I can see the cars with that coming to a screeching halt right after bumping a light pole while backing up, if the accelerometer is slightly off calibration. Certainly sensors could provide for rapid and thorough injection of gel agent only in high G events, where containment failure is 100% certain.

It doesn't flow anymore. So i guess it should no longer be called a flow battery. It uses the chemistry but not the technique.

http://www.abc.net.au/catalyst/stories/4398364.htm About 1/3rd of the way down the page.

Jim

Then basically the entire battery has to be the same size as the reagent vessels in a flow battery, and any efficiencies are thrown out the window with the baby's bath water.