Recent Highlights on Chemical Solution-

based REBaCuO Coated Conductors from

Shanghai University

Shanghai Key Laboratory for High Temperature Superconductors, Shanghai University

Shanghai Creative Supercond. Technol. Co. Ltd.

cbcai@t.shu.edu.cn

Chuanbing Cai (蔡传兵)

IAS Program on High Energy Physics-Accelerator Physics

HKUST, Jan. 19-20, 2017

Outline

3、Advance in Cost-effective 2G HTS Tapes in Shanghai

2、China Research & Industrialization on 2G HTS Tapes

1、Technology Roadmap for Practical HTS Materials

4、Power Application Demo in China & Material Challenge

Fundamental Challenges of HTS Application

Jc limited by weak link@GBs

Layered structure

ξab = 1.3-3.5nm；ξc= 0.2-1nm

Bi2223Bi2212 [Amrein, 94]

YBCO

Jc(J) = Jc0 * exp (-(J-4°)/2.4°) for J > 4°

Giant flux motion by thermal

fluctuation high running temperature

Low pinning potential of single vortex(~n)

HTS

LTS

B0

MTG-YBCO Single-domain

Bulks for Mag-lev Devices

MTG-YBCO Bulk

From Prof. Xu，Phys. Dept., Shanghai Uni.

Architectures for HTS Coated Conductors

Buffer：Y2O3, La2Zr2O7

c

ba

Key issues (1)：biaxial texture and

epitaxial growth

Substrate：Textured Ni-W

Untextured

Ni-based Tape

HTS Layer：REBaCuO

Key issues (2)：High-density

flux pinning

centers

C.Cai et al.,

PRB 69(2004)104531

Review Articles:

Cai et al, Progress in Physics (Chinese) ,4(2007)467

Cai et al, Advance in China Materials，30(2010)1

RABiTS IBAD ISD

Technology Routes：Biaxial Textured Buffer + Epitaxial HTS Film

HTS Layer Deposition via:

Buffer Layer Texture via:

Ex-situ techniques

PVD（PLD、RCE）; MOD ; MOCVD

Main Groups and Techniques Applied for 2G HTS Tapes in China

Research Groups

& IndustryPartners

Buffer Layer HTS Layer

textured NiWuntextured

tape via IBADMOCVD PLD MOD

R&D

Tsinghua Uni. √ √ √Beijing Tech. Uni. √ √Northwest INM √ √

Southwest Jiaotong Uni. √ √

IEE CAS √Uni. Electr. Sci.Tech R2R √ √

Beijing GRINM R2R R2R

R & D/

Industry

Suzhou Advanced

Materials(SAMRI)R2R R2R

Shanghai Jiaotong Uni.

/SSTCR2R R2R R2R

Shanghai Uni.

/SCSCR2R R2R √ R2R

Textured Oxide Buffers on Textured or Untextured Tape via RABiTS or IBAD

Epitaxial HTS Films on Textured Oxide Buffer via MOD

HTS Coated Conductors

@Shanghai University & Spinning-off Company, SCSC

Coating &

Pyrolysis

Crystalliztion Protection

Slitting & Package

MOD-HTS Layer

Two ways for Oxide Buffer on

Textured or Untextured

SCSC：Shanghai Creative Supercond. Technol Co. Ltd

Outline

3、Advance in Cost-effective 2G HTS Tapes in Shanghai

2、China Research & Industrialization on 2G HTS Tapes

1、Technology Roadmap for 2G HTS Tapes

4、Power Application Demo and Challenge for 2G Tapes

Coating and

Low-temperature Pyrolysis

MOD-RBaCuO

High-temperature

Crystallization

Cost-effective MOD

Non-vacuum, low cost tools

Easy and accurate to modify composition

100% utilization of precursor solution

Readily scale up for wide-web process

“Dirty”films, but helpful for pinning

Independently developed pilot lines

Smart control system

In-situ quality inspection

Cost-effective Route Developed at Shanghai Uni.

& Shanghai Creative Supercond. Technol. Co.(SCSC)

11Copyright © 2003 Fair Isaac Corporation. All rights reserved.

50s

220s

On-line Observation for Texture Evolution

of Oxide Buffer on Untextured Tape

Peak pattern and intensity with

increasing deposition times

12Copyright © 2003 Fair Isaac Corporation. All rights reserved.

Characteristic

Method Developed

For in-situ Check

of Texture

（024）

Evaluation Method Developed for Texture of Oxide Buffer

Direct comparison of time dependence of

In-situ RHEED pattern and ex-situ x-ray

Phi scanning

On-line Check for Texture of Kilometer’s Oxide

Buffer on Untextured Metallic Tapes

Coating + Low temperature Pyrolysis

High-temperature Crystallization

Solution Preparation

Industrial Process for MOD-RBaCuO Coated Conductors

Oxygenation

15Copyright © 2003 Fair Isaac Corporation. All rights reserved.

To improve performance

Shorter Pyrolysis Time:

Low-fluorine; Additions such as DEA/TEA…

Less Crystallization Time:

Low ambient pressure; Fast gas flow

To increase the production rate

Increased thickness of YBCO layer

Enhanced flux pinning via doping

Improved morphology via doping

Key Issues for MOD-derived YBCO Coated Conductors

1.4-2.1μm YBCO by

single MOD coating

16Copyright © 2003 Fair Isaac Corporation. All rights reserved.

Pyrolysis time reduced to be as short as one minute using extremely low F-content solutions

Smooth and dense films obtained at a pyrolysis rate as high as 25 K/min

Dramatic Reduction For Pyrolysis Time of MOD

)(,

)(,

reactantsTf

GproductsTf

GTG

ΔG < 0， Possible reaction

ΔG ＝ 0，Balanced reaction

ΔG > 0， Impossible reaction

17Copyright © 2003 Fair Isaac Corporation. All rights reserved.

Tc (onset) vs the c-axis parameter in

YBCO films annealed at different

temperature in flowing pure oxygen

gas (solid), and mix of nitrogen and

oxygen (open).

The relationship between XRD intensity

ratio I(006)/I(005) and the c-axis lattice

parameters responding to oxygen

content.

Potential enhancement and optimization of Tc by

preventing from happening the “over-doped”

Jiang HB, Cai CB et al., unpublished

Long REBaCuO Tapes Developed at SCSC

Local JC (77K,self field）

> 2MA/cm2

Texture Properties for Bilayer and Triple HTS Tapes

Overseas

Level

In-plane

~4

Out-of-

plane

~2

From bilayer to

triple HTS layers

In-plane

texture

Out-plane

texture

Dynamic Measurement (77K，self field)

Ic：320~387A , Average Ic: 361A

Mean Derivation: 6.25A

Ic ≈ 368A

C3-1960

Critical Current for Typical MOD-HTS Tapes at SCSC

Inductive Measurement(77K，self field)

Ic：350~420A

Critical Current for Multiple MOD-Coating Tapes at SCSC

Ic: 350-560A

n=27-33

@

77K,Self Field

Typical Performance for SCSC Tapes of 4mm Width

77K

65%

78%

93%

47%

68%

84%

38%

63%

80%

2013 2014 2015

基带

缓冲层

超导层

In case of：Smooth Substrate (RMS<1nm）；High-textured buffer（FWHM<7）;

High HTS performance（Ic>200A-cm@77K, Self-field）

Increasing Yield Rate of HTS Tapes Produced at SCSC

24Copyright © 2003 Fair Isaac Corporation. All rights reserved.

Joint Technology Development at Shanghai Uni.

25Copyright © 2003 Fair Isaac Corporation. All rights reserved.

0 50 100 150 200 250 300 350 400

0

1

2

3

4

5

6

Vo

ltag

e (

E-5

V)

Current (A)

Slope：5.85E-9

Lapping length：10cm； Solder material：Sn-Bi

4mm-width/Cu thickness ~5μm

4mm-width/Brass Lamination

12mm-width/Cu Lamination

Joint Technology Development at Shanghai Uni. & SCSC

Outline

3、Advance in Cost-effective 2G HTS Tapes in Shanghai

2、China Research & Industrialization on 2G HTS Tapes

1、Technology Roadmap for Practical HTS Materials

4、Power Application Demo in China & Material Challenges

HTS Tape Research Project

Power Application Research Project

Main Research

Projects and

Application Demo

in China

Chendu

Xian

Hefei Suzhou

HTS Tape

Manufacturer

Application

demo

上海电缆研究所 SHANGHAI ELECTRIC CABLE RESEARCH INSTITUTE2G HTS Cable System

Electrical Characteristics

- Design 35kV/2000A ~ 120MVA

Physical Characteristics

- Materials ~ 2G HTS Wire

- Length ~ 50m

- HTS Conductor Length ~13km

- Cold Dielectric Design

Hardware Deliverables

- Three ~50 m Long Phase Conductors

- Six 35kV Outdoor Terminations

2G HTS Cable Demo at Baosteel,

since Dec 2013

HTS: Enabling Power Applications, but needing improved Birr ...

0.01 0.1 1 10 1000

20

40

60

80

100

T(K

)

B(T)

Cables Fault CurrentLimiters

MotorsGenerators

MRI NMRMagnets

Fusion

Transformers

SMES

YBa2Cu3O7-x is able to push all the power applications up to the present limitsLenght, allowed cost and required performances strongly differ ( 1 km to 300 km)

X. Obradors, T. Puig, SUST 27, 044003 (2014)

Magnetic Field (T)

Cri

tica

l Cu

rre

nt

De

nsi

ty (

MA

/cm

2)

NbTi(4.2 K)Nb3Sn(4.2 K)

Epitaxial YBCO film

Polycrystalline YBCO tape

Long length Biaxial Texturing

Nanotechnology

APC-Introduced YBCO film

Magnetic Field (T)

Cri

tica

l Cu

rre

nt

De

nsi

ty (

MA

/cm

2)

NbTi(4.2 K)Nb3Sn(4.2 K)

Epitaxial YBCO film

Polycrystalline YBCO tape

Long length Biaxial Texturing

Nanotechnology

APC-Introduced YBCO film

77 K

X. Obradors, T. Puig, SUST 27, 044003 (2014)

• Grain boundaryproblem: low fieldcritical currents

• Vortex pinningproblem: highmagnetic fieldcritical currents

Nanotechnology engineering has enabled YBCO tobit LTS at all regions

Other challenges for power application of 2G HTS tapes

Various stresses in service state;

Electromagnetic force

Thermal induced stress

Bending induced stress

…

Application handling

– round, isotropic shape wanted

Cost/Perfromance

Summary

Main technology roadmaps for HTS tapes, including biaxially textured

routes for buffer, and the industrial coating techniques for HTS layers.

Research groups, and three industrial partners in China, using MOCVD,

PLD as well as MOD coating techniques respectively. Hundreds of meters

long tapes with 200-300A/cm-w at 77K achieved daily.

Recent progress for cost-effective MOD-based HTS tapes at Shanghai

Creative Supercond. Technol. Co. Ltd. , appearing promising for scaling up.

Several HTS power application demos in China, appearing promising, while

materials challenges still there.

Thank you for your attention

上创超导

SCSC

Spinning off

Shanghai

Creative

Supercond.

Technol. Co.

Ltd.(SCSC)

Welcome visit

Shanghai Creative

Supercond. Technol. Co. Ltd.