Description: NASA's Ocean Worlds exploration missions require batteries which operate as low as -100 C (defined here are "Ultra-Low Temperatures") and lower, a critically difficult challenge using current state-of-art materials. Conventional lithium primary batteries utilize a liquid catholyte with a low melting point which allows operation as low as -80 C. However, these conventional materials will be unable to push the low-temperature operation limit to meet NASA's requirements for Ocean Worlds missions. South 8 Technologies proposes the use of "Liquefied Gas Catholytes for Ultra-Low Temperature Lithium Primary Batteries". These catholytes are gaseous under standard conditions, but may be liquefied under mild pressures, showing exceptionally low melting points, very low viscosities and relatively high dielectric constants, allowing for ultra-low temperature operation of Lithium Primary Batteries. South 8 Technologies believes the technology proposed will enable energy storage at temperatures as low as -140 C, whereas the state-of-art allows operation is limited to -80 C. High temperature operation will be similar with operation limited to about +60 C. Further, the energy density of the active cathode material may be increased by as much as 30%, as will be shown. Voltage delay, a reoccurring issue in lithium primary batteries, may be reduced as well. These items will be discussed throughout the proposal.

Benefits: This SBIR proposal will focus on demonstration of the feasibility of developing Liquefied Gas Catholytes for Ultra-Low Lithium Primary Batteries. Electrochemical energy storage devices are critical to many of NASAs mission requirements. Low temperature energy storage is particularly critical in Ocean Worlds explorations, including Europa, Enceladus, Titan, Ganymede, Callisto, Ceres. Particularly, topic S3.03 of the solicitation calls for "advanced primary and secondary battery systems capable of operating at temperature extremes from -100 C for Titan missions". Further, topics S4.04 (Extreme Environment Technology) and Z1.02 (Surface Energy Storage) can benefit from the Ultra-Low Temperature Battery Technology proposed here for a number of other NASA missions.

Currently, Lithium Primary batteries operate adequately down to -80 C for the majority of applications where used. While there is not a large market for primary batteries with ultra-low temperature operation below -80 C, an increased energy density and/or cell with higher power capabilities with enhanced low temperature capability may find use in military applications where a long shelf life and high power, high energy density are required. Further, development of high-atmosphere drones and balloons are increasingly more common for telecommunications. Google's Loon program and Facebook's Aquilla are two prime examples where high atmosphere telecommunications are being developed. These devices get very cold in the high atmosphere, reaching temperatures as low as -70 C. Thermal insulation is often required to keep the batteries warm, adding to the mass and engineering requirements of the devices. A battery with high gravimetric energy density that operates very well at such temperatures would be ideal in such applications.