Feasibility Study on Copper-Clad Lithium Conductors for Cryogenic Applications

Abstract

The trend towards efficient turbo-electric distributed propulsion aircraft calls for more research concerning lightweight power distribution and power conversion, especially in the context of cryogenic power systems. This paper explores one such avenue in this context – the prospect of manufacturing and using copper-clad lithium (CuCLi) wires at cryogenic conditions for aircraft and high frequency applications – and compares it to Yttrium Barium Copper Oxide (YBCO) coated superconductors. Lithium, a lightweight and inexpensive metal, exhibits superior conductivity per unit weight characteristics compared to copper, aluminum, and other metals at cryogenic temperatures. While the metal always remains in its resistive hence lossy state, it is unlikely to reach the same current densities as superconductors. On the other hand, copper-clad lithium wires are expected to be less expensive, are round, and can be manufactured at long lengths and in large quantities. In this paper, the relevant electric parameters of these wires, such as current carrying capability and power losses, are estimated and compared to those of superconductors. The paper also includes a brief study of the manufacturing method of proposed copper-clad lithium wires.