Development of Thin Layer Electrochemical Components for Advanced Thermal Batteries

摘要

Thermal Batteries are pyrotechnically initiated molten salt batteries, which provide high power (2 kW/Kg), an extremely long shelf life (over 20 years), fast activation time (up to 500 mSec), a wide range of temperatures over which they are operational (-60°C to +90°C), and very high reliability. For these reasons they are widely used in military and space applications. A Thermal Battery consists of a stack of cells; each cell is comprised of an Anode, Cathode, Electrolyte, and a Pyrotechnic pellet. The electrolyte consists of solid salt mixture, with a melting temperature in the range of 350-450°C. The moment the battery is activated; pyrotechnic pellets are ignited which provide heat to melt the solid electrolyte, allowing a high ionic conductivity. Current pellet manufacturing technology for TB does not allow producing thin layer components (<0.25mm) for diameters larger than 30 mm. This limitation leads to an excess in cell capacity, overweight, higher cost of the pellets, and hinders performance. Development of tape casting methods for thin layer production, allows producing large diameter thin layers and a variety of geometric pellet shapes. Layers may be as thin as 0.1mm in diameters of over 200 mm. Production of thin TB components will allow a decrease in battery size and cost, as thin layer prevent the waste of excess materials, volume, and weight. The ability of the technology to facilitate larger production numbers will also promote a reduction in TB price. Lower cost, weight, and size will enable TB to meet the demands brought upon by the new generation advanced high power applications.