Description: Future fuel efficient hybrid aircraft require superconducting electric motors in order to achieve power densities above 10 kW/kg while operating at temperatures above 30 K. The stator operates in AC mode, making it impossible to use high temperature superconducting (HTS) tapes due to their large AC losses, requiring instead fine HTS wires with loss reducing features like axial twist, higher matrix resistances, and fabrication into transposed cables. Now however, groundbreaking technology for producing 2212 that is uniquely suited for low loss operation in ac fields at > 30 K has been established. Specifically, loss-reducing features have been developed in 2212 wires and their cabled forms, also in combination with a low-cost approach that achieves the breakthrough current densities required for > 30 K operation. The objective of this Phase IIE program is a fully developed first-of-its-kind HTS wire, in cable and demo coil product form, that is based on the Bi2212 superconductor, that has low losses in ac ramped fields, that operates at above 30 K, and that enables superconducting stator coils for higher power density aero propulsion motors and applications such as lighter-weight wind generators. Building on Phase II results, full-scale 2212-based wire and cable will now be developed that meet low-loss and current density requirements at >30 K and at commercial field levels with fast ramp ac rates. The 8-wire demo cable design will be extended to a commercial 40 wire design, along with integrated loss-reducing features consisting of precisely engineered inter-wire resistances and a transposed build. Full radial build stator coil designs and fabrication techniques will be established for this cable, to generate 0.5 T at temperatures above 30K that are required to attain the higher power-density motors. A full radial build demo coil will be built and delivered for testing and validation. Additional deliverables include fully reacted cable samples for testing.

Benefits: Mainline Higher specific power, higher efficiency motors (to 13 kW/kg), and generators such as those required for electric airplane propulsion to operate at above 30 K. Additional Magnetic energy storage Superconducting bus bar Magnetic shielding Magnetic energy storage Actuator coils

Electric plane motors and generators Wind generators Ramped field central solenoid coil for fusion reactors More efficient, compact and lighter – weight specialty high-powered motors, generators and transformers