Multi-Cavity Die Technology

"Thermal batteries are mission-critical components utilized in virtually every weapon system. Thermal batteries require four types of pellets that comprise the energy-producing portion of the battery. These include: (1) anode pellets, composed of Li(Si)alloy and electrolyte salt, (2) cathode pellets, consisting of either FeS2 or CoS2 and electrolyte salt, (3) separator pellets, consisting of MgO and electrolyte salt and (4) heat pellets containing iron and potassium perchlorate. Pellet size and numbervary by battery type and application. A pellet is manufactured by compacting its powdered constituents in an automated press. The powder is loaded into a feed shoe, which automatically fills a die cavity. Press tonnage is a function of pellet diameterand thickness.Currently, pellet production is the rate-limiting step in thermal battery manufacture, hence, it is essential to optimize press throughput. At present, only one pellet is produced at a time, i.e., the press tooling is comprised of only one die cavity andone punch. This proposed SBIR project focuses on identifying and addressing the design challenge to implement two (or more) die cavities and punches in order to double, or perhaps even triple, pellet production rate. Virtually every thermal battery production program will benefit as a result of increased production rate capability and concomitant lower unit cost."