Non-nuclear based Thermoelectric + Battery System Concepts for Space Power Systems

The application of a thermoelectric based RTG (Radioisotope Thermoelectric Generator) to recharge or supplement a space battery power system is a proven technology that has been successfully employed and is currently powering the Curiosity rover on Mars. Similar systems are integrated into the upcoming Mars 2020 rover and Dragonfly rotorcraft missions. These hybrid systems utilize the heat generated from the decay of plutonium-238 to generate electrical power, and are tailored to the particular needs of each mission. A similar non-nuclear based thermoelectric + battery hybrid system concept would employ thermoelectrics to capture heat from other thermal sources, such as the large amounts of excess thermal energy emitted from rocket exhaust during a particular mission profile, to augment the power needs of the mission. This may bring additional design freedom and/or power generation to systems that have large amounts of waste heat generation. In this paper, UDRI will present preliminary work on measurements of power generation from commercial thermoelectric devices exposed to radiant energy heat fluxes of up to 67 kW/m2. Further, new total solid-state battery technologies developed at UDRI utilizing new ceramic electrolytes and thermally stable lithium based chemistry will be discussed. This includes battery technology being optimized for planetary space surface missions in very high operational environments (up to 350 °C). Initial calculations on power generation to augment for short durations these new solid-state batteries, along with some of the potential design freedom that may be enabled by such non-nuclear based thermoelectric + battery hybrid power systems will be presented.