SBIR-STTR Award

Reserve lithium oxyhalide and silver/zinc batteries are power sources of choice for many missiles and other weapons systems. These batteries achieve long shelf life by storing the liquid electrolyte separately in a reservoir. Upon activation, the electrolyte is injected quickly into the battery cells, most often using a pyrotechnic gas generator. The overall design of the activation system is arguably the most challenging aspect of developing a new battery of this type, and this is more difficult and time-consuming because no analytical tools exist to simulate the activation process. The trial-and-error procedure currently used to develop these batteries also increases the time and expense necessary to qualify a new design. To address this need, Erigo proposes to develop a comprehensive, easy-to-use computer model to simulate pyrotechnic gas generators and to interface this model to a representation of the battery itself. The proposed development plan directly leverages technology developed at Erigo to comprehensively model thermal batteries as well as an on-going effort by our collaborators to simulate fluid flow during the activation process.

Keywords:
Lithium Oxyhalide Reserve Batteries, Gas Generators, Modeling

Reserve lithium oxyhalide and silver/zinc batteries are power sources of choice for many missiles and other weapons systems. These batteries achieve long shelf life by storing the liquid electrolyte separately in a reservoir. Upon activation, the electrolyte is rapidly injected into the battery cells, most often using a pyrotechnic gas generator. The design of the system and the diagnosis of performance problems are challenging for several reasons; one key complication is the feedback of the hydraulic design of the battery on the pressure driving the electrolyte reservoir’s piston and the pressure-dependent gas generation rate. These challenges are made more difficult because no analytical tools are currently available to assist battery engineers. The trial-and-error procedure now used to develop these batteries greatly increases the time and expense necessary to qualify a new design and to deal with problems encountered in service. To address this need, Erigo proposes to develop a comprehensive, easy-to-use computer model that simulates the pyrotechnic gas generator and the battery itself in an integrated fashion. The proposed development directly leverages technology developed at Erigo in Phase I to model the gas generator, as well as a detailed electrochemistry model developed on a separate project.

Keywords:
Lithium Oxyhalide Reserve Batteries, Silver Zinc Batteries, Gas Generators, Modeling