Battery Powered Vehicles, The Future??

[ppppenguin]

For flow batteries the service stations would have to carry extra stocks of electrolyte on site to feed in the power to satisfy the demand.

Indeed they would, but petrol statiosn already keep large volumes of liquids in tanks to satisfy peak demand. This is part of the attraction of flow batteries - the cell is separate from the stuff that gets charged.  It works well for static installations as capacity (kWh) is limited only by the size of the tanks. It works for cars because the stuff that gets charged is a liquid and quickly replenished at a filling station.  Sounds a bit like petrol to me Except that it's regenerated on site rather than brought in by tanker.

If they can really make it work then it's a great looking solution to low emission cars. Lithium has a massive head start but new technologies can make huge leaps very fast. Let's hope it's one of them.

Elsewhere I've read about flow batteries with lower cost and low toxicity electrolytes. At present the main electrolytes are vanadium based. Relatively expensive and not nice in the environment. Newer organic electrolytes are showing promise: https://en.wikipedia.org/wiki/Flow_battery#Organic For transport use, energy density probably trumps cost and toxicity.

Imagine a future filling station. Instead of petrol and diesel you might have a vanadium pump and an organic pump. Fuelling might be a 2 stage process. First the pump extracts the old electrolyte, then it fills up with fresh. All inside 5 minutes. Who would want hydrogen with all the cryogenic handling. Or lithium batteries with 20 to 40 minute stops.