New Methodology for Cost Effective Coated Conductors—Transient Liquid Assisted Growth (TLAG-CSD)

Superconductivity presents a huge interest worldwide for its opportunities for cleantech energy as superconductors allow transporting electric power with minimal losses. However, the widespread use of high temperature superconductors in large scale applications is limited by the high cost/performance ratio of existing manufacturing processes (1/3 of the final cost of the device is the price of the superconductor). We propose a new solution which consists of an innovative method for manufacturing High Temperature Superconductors Coated Conductors (CC). This method is based on YBCO thin films which are produced via a Transient Liquid Assisted Growth (TLAG) process combined with Chemical Solution Deposition (CSD). While CSD is a relatively mature and low cost process, TLAG technology is disruptive combining low cost Chemical Solution Deposition (CSD), high throughput and ultrafast growth Transient Liquid Assisted Growth (TLAG) process and high performance (nanocomposites). All together allows a commercially and industry scalable manufacturing process for 2G High Temperature Superconductors which can revolutionize superconductivity sector.<br/>TLAG-CSD enables ultrafast growth rates of YBCO films (up to1000 nm/s) thanks to the kinetic preference of Ba-Cu-O to form transient liquids prior to crystalline thermodynamic equilibrium phases. The process enables HTS films fabrication with high critical current densities (5MA/cm² at 77K) [1].This presentation is devoted to the technology transfer of TLAG-CSD from single crystal substrates to metallic tapes. Characterizations by XRD, SEM, TEM, Optical microscopy, T_c, J_c and Hall microscopy have enabled us to determine the parameters to be modified and optimized. Liquid reactivity could be avoided with the use of a manganite buffer layer. CSD deposition by spin coating has been used to prepare 5 x 5 mm² samples on metallic substrates while slot die coating was used for the 3-15 cm tapes. In addition, nanocomposites have been prepared from precursor solutions with stabilized preformed nanoparticles (BaHfO₃) for enhanced superconductor performance at high magnetic fields.<br/>[1] <b>Nature Communications article: </b>11, 344 (2020). https://doi.org/10.1038/s41467-019-13791-1<br/>We acknowledge funding from EU-ERC_AdG-2014-669504 ULTRASUPERTAPE and EU-PoC-2020-IMPACT projects, and the Excellence Program Severo Ochoa SEV2015-0496