Page 200 - Battery Reference Book

14/4 Zinc-halogen secondary batteries

14.2 Zinc- bromine secondary Both companies used a bipolar stack configuration
batteries with electrolyte storage and recirculation systems feed-
ing the positive and negative electrodes. Liquid quar-
This is a long-term battery development with poten- ternary ammonium bromide is used as a bromine stor-
tial future applications in load levelling and vehicle age agent and microporous polyethylene as a separator.
propulsion where its long life and low cost would be These batteries, in effect, resemble chemical plants.
very attractive. This battery is discussed only briefly Many problems remain to be solved regarding con-
here. The performance characteristics are summarized struction materials used in these batteries that could
in Table 14.2. survive the extremely corrosive environment to which
The theoretical density is 430 W fig-' against a they are subject over a battery life of 10 years or more.
practically realized value of 15-85 W kg-'. Various polymer and composite materials are being
Exxon Research and Engineering Co. and Gould investigated.
Inc. are major companies carrying out research on this Both 30KWh and 45kWh experimental electric
battery system, although both companies have now vehicle battery designs are being investigated, also
licensed this battery technology with other developers, a conceptual design for a very large 50 MW h utility
e.g. Gould transferred to Energy Research Corporation. battery for load levelling.