Novel Methods to Improve Performance of Silver-Zinc Batteries Navy SBIR FY2010.1 Sol No.: Navy SBIR FY2010.1 Topic No.: N101-054 Topic Title: Novel Methods to Improve Performance of Silver-Zinc Batteries Proposal No.: N101-054-1462 Firm: BST Systems Inc 78 Plainfield Pike Road Plainfield, Connecticut 06374 Contact: Patrick Imhof Phone: (860) 564-4078 Web Site: www.bstsys.com Abstract: BST Systems proposes a development program that will result in the elimination of the deficiencies of the silver zinc chemistry: Specifically, the program will result in large format silver zinc cells and batteries that have longer life, longer cycle life, are sealed and will require minimal maintenance requirements. Energy densities and power densities will equal or exceed that of lithium ion, however, unlike the lithium ion electrochemistry, they will be safe. This new technology will greatly benefit the Navy as they will have available a safe high energy electric propulsion capability utilizing a safe high energy large format battery. In the recent past, a vast amount of technologic advances have been made in electrochemical and fuel cell technologies with synthetic polymer membrane development. BST proposes to incorporate these technologies into large format silver zinc cells to achieve: a) An increase in calendar life and cycle life by eliminating the cellulosic separator systems b) An increase the cyclic capacity retention by significantly reducing the loss of negative electrode active material. c) The production of a maintenance free product by sealing the cell. This is achievable by reducing internal cell corrosion, reducing and recombining gaseous by-products and automatically micro-managing the charge process. Benefits: The goals of BST Systems program is to develop a rechargeable silver zinc cell with the following attributes: A wet life greater than 5 years A cycle life greater than 100 high energy cycles at (100% DOD) with a capacity retention of greater than 90% An improvement in volumetric energy density of 20% An increase in gravimetric energy density of greater 20% A cell with improved zinc electrode stability A cell which operates sealed thus eliminating the need for purge gases and increased maintenance costs. The benefits of such a cell and design concept are obvious. Because of the greater number of high capacity useful cycles, the cost per cycle of the product would be reduced thereby reducing the operational cost to the user. Greater wet life would enhance vehicle and/or weapon availability to the user and would also alleviate logistical issues. Maintenance costs would be drastically reduced. The resulting technology would be applicable and be of benefit to all Navy silver zinc applications. The design of a sealed silver zinc cell would reduce maintenance costs, eliminate the use of purging systems and allow the silver zinc chemistry to be utilized in other applications which, up to now, have not been possible. Further, such a product would also render itself to non-military commercialization. Return