Exfoliated Superconducting Filaments for Lower Magnetization Loss

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Solution Overview

Problem

Current high-temperature superconducting wires face issues such as high magnetization losses, non-uniform conductor heating leading to delamination, poor mechanical properties, and labor-intensive splicing requirements, limiting their application in magnets and power transmission.

Innovation Solution

The method involves exfoliating the superconducting layer from the metal substrate to create a tape that is then coated with a protective layer and encapsulated with a conductive material, allowing for uniform electrical properties and enhanced mechanical strength, enabling the formation of continuous filaments and cables with reduced magnetization losses and improved splicing capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a high-aspect ratio tape architecture is used, then the superconducting layer can be manufactured with record high upper critical field and critical temperature, but the magnetization (AC) losses increase significantly

Engineering Contradiction:
Improvecritical temperatureVSAvoidmagnetization losses
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The patent divides the superconducting tape into multiple thin superconducting layers separated by stabilizing layers. This segmentation reduces the aspect ratio of each individual superconducting layer, thereby reducing magnetization losses while maintaining the high critical temperature properties through the layered architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single thick superconducting layer to a multi-layered structure with stabilizing layers interspersed between superconducting layers. This dimensional change in the structure allows current to flow through multiple parallel paths, reducing the effective aspect ratio and magnetization losses while preserving high-temperature superconducting properties.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If the superconducting layer is deposited on an insulating oxide buffer, then the superconducting layer can be grown with proper orientation, but the bottom surface of the superconducting layer lacks good electrical pathway to the exterior

Engineering Contradiction:
Improvesuperconducting layer orientationVSAvoidelectrical stabilization
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent introduces a conductive stabilizing layer as an intermediary between the insulating oxide buffer and the superconducting layer. This stabilizing layer provides the necessary electrical pathway from the bottom surface of the superconducting layer to the exterior, while the oxide buffer maintains its function of providing proper crystal orientation during deposition.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite structure combining the insulating oxide buffer layer (for orientation control), the conductive stabilizing layer (for electrical pathways), and the superconducting layer. This composite architecture resolves the contradiction by allowing each layer to fulfill its specific function without interfering with the others.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If the stabilizing layer is positioned only at the top surface, then the manufacturing process is simplified, but the conductor heating during quench becomes non-uniform causing de-lamination

Engineering Contradiction:
Improvestabilizing layer depositionVSAvoidconductor uniformity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent segments the stabilizing function by placing stabilizing layers at both the top and bottom surfaces of the superconducting layer, rather than only at the top. This symmetric segmentation ensures uniform heat dissipation during quench events, preventing de-lamination while maintaining manufacturing feasibility through standardized deposition processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent addresses the asymmetric heating problem by introducing symmetry into the stabilizing layer configuration. By placing identical stabilizing layers at both top and bottom surfaces, the structure achieves symmetric thermal management, preventing the non-uniform heating that causes de-lamination in asymmetric designs.

Inventive Principle:
Principle #4Asymmetry

4Loss of energy

If the superconducting layer is separated from the substrate, then the aspect ratio is reduced and magnetization losses decrease, but additional processing steps are required

Engineering Contradiction:
Improvemagnetization lossesVSAvoidmanufacturing process
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent incorporates the stabilizing layer during the initial deposition process on the substrate, before the superconducting layer is fully formed. This preliminary action integrates the separation function into the manufacturing process itself, reducing the need for additional post-processing steps while achieving the desired low-aspect-ratio structure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges the stabilizing layer deposition with the superconducting layer formation process. By combining these functions into a single integrated manufacturing process, the patent reduces the number of separate processing steps required, making the separation of superconducting layers from substrate more efficient despite the added structural complexity.

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach results in high-temperature superconducting filaments and cables with reduced delamination risk, enhanced mechanical properties, and lower magnetization losses, facilitating the use in high-field magnets and power transmission with improved efficiency and reduced splicing complexity.

Implementation Method 1

separating the superconducting layer from the metal substrate

Methodology Applied
Scientific EffectExfoliation:

Implementation Method 2

coated with a protective layer

Methodology Applied
Scientific EffectCoating: Coatings

Implementation Method 3

galvanically electroplating a conductive metal (e.g., copper) thereabout

Methodology Applied
Scientific EffectElectroplating: Electroplating

Implementation Method 4

the exfoliation is accomplished by rapidly heating the substrate with an inductive coil

Methodology Applied
Scientific EffectInductive heating: Induction Heating

Data Source

PatentEP3411884B1Second generation superconducting filaments and cable
Publication Date: 2024.06.19 BROOKHAVEN TECH GROUP INC
  • EP3411884B1 patent drawingFigure 1~2
  • EP3411884B1 patent drawingFigure 3~6
  • EP3411884B1 patent drawingFigure 7~8

AI summary

A high-temperature superconducting filament and cable, and a method for manufacturing same. The substrate used to grow the superconducting layer is removed, and the exfoliated superconducting layer is coated with a protective layer, and then sliced into narrow strips. The strips are thereafter encapsulated with a conductive metal to provide a high-temperature superconducting filament. The filaments may be bundled together to provide a high-temperature superconducting cable.