Quote from: RE on Dec 27, 2023, 11:59 AMSigh.  I'll try to spell it out for you.  I didn't realize EE's were chemically challenged.

Normally, a battery stores its energy by the difference in electric potential between the cathode and anode, which exchange electrons in an oxidation-reduction reaction.  One gets oxidized, the other reduced, and the electrons drop down in their potential making the trip.  This is what makes your electric motors go round as they pass by the magnets in the motor.

As this process occurs in the typical battery, the cathode gets dissolved and metal gets deposited on the anode, that's how you do plating.  Fully discharged, there's nothing left of the cathode, this batt is non-rechargeable and dead.  However, transition metals have several oxidation states they can exist in, so in rechargeable batts when the metal ion moves across the electrolyte solution to the anode it changes state but your cathode doesn't dissolve away.  When you recharge, you push the electrons back up on the cathode side, and it's ready to go again.  However, repeated cycles of this wear out both ccathode and anode so you can't keep doing it.  Rechargeable batt now dead also.

Flow batts get rid of the cathode and anode and replace them with liquids which are suspensions of nanoparticles in water.  You have a tank that holds charged up nano particles and a discharge tank, sorta like the gray water in your RV waste tank.  When you go to the filling station, you empty your discharged nanoelectrolyte tank and refill your charged tank.  You drive away.

At the filling station, your discharged nanoelectrolyte suspension gets recharged, by electricity generated from a non-ff source.  Then when the next customer shows up, this charged up stuff is pumped into his tank.  The fluid itself never disappears.

The nanoparticles are only necessary in order to turn what in normal batts are solids into a liquid you can pump and exchange easily.  The tinier the particles, the greater the density you can squeeze into a given volume without making the fluid too viscous to pump and keeping the particles suspended.  Big particles sink, you can't do this with them.  The greater the density of particles, the greater the energy density you can store this way.

Hopefully this is clear to the chemically challenged doomers inhabiting this website.

RE

they have been pushing flow batteries for the 20 years I have been paying attention. So far they have all been high dollar research monsters. Putting "nano" onto everything is a new buzzword for alternative energy and great for grant farming. Everything is nano this, nano that. So far absolutely nothing you can price, buy and install... Flow batteries so far have been an alternative energy equivalent to fusion power; always 10 years away. Even if they make it work lithium is getting cheaper all the time and the newer ones are using half the lithium and no cobalt. It's hard for a new tech to break through when retail lithium is down as low as $300 a kW Hr for a 3000-10000 cycle battery. There are some low tech stars out there though. I like the sand battery myself or the utility switched hot water heaters and heat pumps. Great potential for storage there. All of these storage techs are going to grow up real fast in the next 10 years. The West is getting desperate for new ways to make and store power and balance loads without putting in a huge power plant. I know here I can install 10 kWHrs of lithium and buy at 4 cents a kWHr and use it during the day when it's 12 cents... 8 cents per kW differential so 0.80 cents a day or $292 a year... 10 year lifespan at least so $2920 of savings... As soon as that number hits a profit level you will not need to build any utility scale storage the home consumer will build and finance it themselves .. that is the future I see ..
Cheers... NF