Zinc-bromide battery systems

Fig. 9.21 Schematic diagrams of zinc-bromine battery systems (a) cell with cation selective membrane (b) cell with reservoir for poly bromide and microporous separator...

The electrochemical reactions which store and release energy take place in a system whose principal components include bipolar electrodes, separators, aqueous electrolyte, and electrolyte storage reservoirs. Figure 39.1 shows a schematie of a three-cell zinc/bromine battery system that illustrates these components (plus other features which are discussed in Sec. 39.3). The electrolyte is an aqueous solution of zinc bromide, which is circulated with pumps past both electrode surfaces. The electrode surfaces are in turn separated by a microporous... 

Vanadium-based flow batteries have been used in Japan, the United Kingdom, and other industrial nations. These batteries use active chemicals in liquid forms that can be stored in portable tanks separate from the battery. Some companies have designed and developed such batteries in the 15 to 25 MW range using sodium bromide and sodium polysulfide and that are based on vanadium or zinc bromide. The liquid electrolyte solution can be added to the battery system when all other batteries are in their respective positions. 

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