Unter Wikipedia wird das Prinzip der Flußzellen Batterie erläutert.

Wikipedia

A flow battery is a type of rechargeable battery where rechargeability is provided by two chemical components dissolved in liquids contained within the system and separated by a membrane. Ion exchange (providing flow of electrical current) occurs through the membrane while both liquids circulate in their own respective space. Cell voltage is chemically determined by the Nernst equation and ranges, in practical applications, from 1.0 to 2.2 Volts.


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



Im Vergleich zur Brennstoffzelle findet man den Aufbau der Elektroden anders angeordnet
http://en.wikipedia.org/wiki/Flow_battery#mediaviewer/File:Redox_Flow_Battery_English.png



Eine Variante ist die Vanadium Redox Battery
Die Technik wurde schon in den 50iger Jahren in verschieden Versionen verwendet.
http://en.wikipedia.org/wiki/Vanadium_redox_battery