Ronald C. Miles

The bipolar lead acid battery at Johnson Controls Inc

A sealed lead acid bipolar battery is under development at Johnson Controls Inc. (JCI). Recent progress in the lead acid bipolar battery development at JCI is discussed. The work at JCI has combined the general principles laid out by Bennion for bipolar batteries with state of the art lead acid automotive battery technology. In addition to the bipolar arrangement of the cells, the battery design incorporates three other key features: the electrolyte system, the container, and the paste formulation. Three and six cell bipolar laboratory test batteries containing all of the key features of the final multi-cell batteries have been constructed. The plates used in the test batteries are full-size. Simultaneously with laboratory tests, a mathematical model simulation of the battery was run which has accurately predicted battery discharge test results. Using the model as an adjunct to the laboratory testing, many discharges can be simulated accurately. Simulation results are presented.<<ETX>>

Development testing of zinc/bromine batteries

The zinc/bromine battery is a relatively high energy density system with the potential for bulk energy storage at a low cost. A new design that uses a thermal welding technique to achieve a hermetically sealed battery stack is described. Electrodes in the design are based on polyethylene, instead of polypropylene, since the latter was more susceptible to expansion and warpage in the presence of bromine. Embedded glass fibers are also used to increase the tensile modulus of the electrodes in the new design. Improved separators and improved electrolyte flow distribution within the battery stack have reduced the amount of self-discharge compared to earlier batteries. Specific properties of the batteries were measured by different kinds of tests in the laboratory. The initial test given to each battery was a set of constant current cycles to determine the fundamental operating characteristics. These test results served as a baseline for comparison after other tests were completed.<<ETX>>

THE ZINC/BROMINE BATTERY: RECENT ADVANCES FOR ELECTRIC VEHICLE APPLICATIONS

The advanced Battery Business unit of Johnson Controls, Inc. (JCI) is developing the zinc/bromine battery for elecctric vehicle applications. The batterys potential for good energy density, low manufacturing cost, and long life make itt a particularly attractive candidate. Other advantages include ambient temperature operation, a modular design which facilitates design flexibility, and minimal maintenance.