Yasutaka Nagai (Toyota Central R&D Labs., Inc, Japan)

transcript

Synchrotron X-Ray and Pulsed Neutron Imaging

of Water Transport Distribution in Fuel Cells

240th ECS Meeting :I01A-11 Gas Diffusion Layer #I01A-1025

Synchrotron X-ray NeutronMPL

Micrometer Nanometer Millimeter Meter

MEGA(material) Cell/Stack Vehicle

Quantum beam(X-ray/Neutron)

Analysis

Catalyst/Membrane

Neutron

Carbon

Ionomer

Topic 1 Topic 2

Yasutaka Nagai (Toyota Central R&D Labs., Inc, Japan)

e1062@mosk.tytlabs.co.jp

2/38Outline

1. Research Activity on Quantum Beam at Toyota Central R&D Labs.

2. Synchrotron X-ray Imaging

3. Pulsed Neutron Imaging

4. Conclusion

3/38Outline

4. Conclusion

4/38Visualize the Invisible with Quantum Beam

Quantum BeamA beam-like flow of particles and waves of quantum nature, such as electrons, neutrons, protons, and

photons, in the same direction

Neutronatomic nucleus

Electron Proton Quark

Synchrotron radiation

Medical X-ray

Others：

Feature : Non-destructive visualization of the internal structure and conditionof parts and materials

SynchrotronX-ray

Neutron MuonToyota CRDL：

5/38Quantum Beam Applications in the World

Experiment on a global scale to acquire elemental technologies, and establish a foothold

Phase 1Use of external

facilities1999

Operando High speed and sensitivity 2D/3D

Depth analysis As in partsLow concentration

6/38Quantum Beam Platform

Toyota Beamline

Since 2009

Generation principle

Phase 2 2009

SynchrotronX-ray

Electron

Accelerating electrons to the speed of light

7/38SPring-8 Toyota Beamline

Toyota Beamline FacilitySince 2009

Contract beamlines installed and operated by Toyota Central R&D Labs.

Gas cylinder cabinet

Toyota Beamline FacilityExperimental Hall

ExperimentalHutch

Remote operation

Experimental hutch shielded by lead to prevent exposure to synchrotron X-rays

2nd hutch

3rd hutch

Toyota Beamline FacilityExperimental Hall

1st hutch

Inside the 2nd hutch

SynchrotronX-ray

①FC power generation jig

③X-ray camera(High speed/sensitivity)

②Evaluation bench(Simulated operation)FC experiment

11/38Quantum Beam Platform

Strengthening collaboration since 2019

Proton(p)

Proton(p) Nuclear

ミュオン(μ)

Neutrino(v)k meson(k)

Antiproton

Neutron(n)

Accelerated protons are irradiated to the target and a

nuclear reaction occurs.

Muon(µ)

Phase 3 2019

Neutron Muon

Toyota Beamline

Since 2009

Phase 2 2009

SynchrotronX-ray

Electron

Accelerating electrons to the speed of light

NeutronX-ray

Resin partsMetal parts

Fountain toyCourtesy of J-PARC

Position of Each Quantum Beam

nm(nano)

Visualization of functions (structure, composition, electronic state)

from materials to components

PartsMaterials

Structure

Electronstate

μm(micron) mm(milli)

SynchrotronX-ray

・Extremely bright・High directivity・High spatial resolution

FC stack PCULi

Neutron・High transparent (Metal)

・High sensitivity to H atom・Large-field observation

Muon・Local magnetic field・Heavy electron

Cathode material

Crack, Ice/water

Valence

Application of Quantum Beams:Electrification of Vehicles

Auto exhaust catalyst

Power control unit(PCU)

Drive battery

FC stack

Quantum beam: Application in the development of various electrified components

Hydrogen tank

14/38Higher Output of FC Stack

A power generator that produces electricity through a simple chemical reaction between hydrogen and oxygen.

Only water (H2O) is discharged.

H2 Tank

Fuel cell Motor

Air(O2)

Electric H2

Hydrogen station

💡 💡

Fuel cell

Electric

Hydrogen is an environmentally friendly energy source for the future.

H2 + ½O2 → 2e- + H2O

【Higher output】 Sophisticated water management is important. (in sub-zero, cold start-up and dry-up at hot temperatures)

Fuel Cell Electric VehicleHydrogen-powered electric vehicles

15/38Water in FC：SPring-8×J-PARC

Gas diffusion layerCatalyst layer Flow channel

Channel

µmnm mm

Selection of ionomerDesign for water-repellent and

a hydrophilicControl of freezing protection

H+ H2O

Carbon

Ionomer

Flow of H2O

GDL(200 μm)

Multi-scale

Catalyst layer(10 μm)

Higher output due to both drainage and gas diffusivitySophisticated water (ice) management from nano to millimeter

IceSub-zero start－30℃

Analysis using quantum beams of neutrons and synchrotron X-rays

Approach

16/38Water in FC：SPring-8/PSI×J-PARC

Channel

µmnm mm

H+ H2O

Carbon

Ionomer

Flow of H2O

GDL(200 μm)

Multi-scale

Pt3 nm

アイオノマ+H2O

Synchrotron X-rayNeutron(Scattering, reflectivity)

Neutron

100%CathodeAnode

H2 Air

500 mm

Ionomer + H20

17/38Outline

4. Conclusion

18/38Synchrotron radiation X-ray imaging in FC

Channel

H+ H2O

GDL(200 μm)MPL Substrate

200 μm

GDL（Optical microscope）

MPL(SEM)

Carbon

(sub～)Micron scale pore control

CT : Computed Tomography

Micro-CTNano-CT

Rotation

Sample Cam

Objective lens

Rotation

Sample

Condenser

X-rayWater

visualization

19/38Water management through MPL modifications

Substrate

No large pores in/on MPL

nanoscale pores

Oxygen transfer pathways in the MPL region compete with liquid water pathways

Large pores in/on MPL

large pores

Oxygen pathways Liquid water pathways

O2 O2 O2

H2O H2O H2O

Large MPL pores create primary water pathways for effective drainage

Hypothesis 1：Liquid water formed in large pores of MPLHypothesis 2：Large pores in MPL merge liquid water

pathways and decreas liquid water in the substrate

Substrate

nanoscale pores

Water vapor

Hypothesis 1：Liquid water formation in large MPL pores

Cooling plate(Peltier device)

Glass capillary MPL carbon

(Vulcal 30 nm)＋PTFE

15 μm

Large pores

Small pores

Condensation by introducing water vapor inside the simulated MPL

MPL carbon particles

Liquid water formation in large pores surrounded by MPL carbon particles

Nano-CTObjective lens

Rotation

Sample

Condenser

Small pores

Toyota Beamline

21/38Hypothesis 2：Decrease in liquid water in the GDL

O2 inH2 in

O2 outH2 out

Operando CT cell

Fast operando tomographicimaging of liquid water

Micro-CT

Rotation

Sample Cam

CellX-raycamera

Rotation stage

Gasket

Flow field

Journal of Power Sources 435 (2019) 226809

TOMCAT Beamline

100 μm 100 μm

In-plane slice images of the MPL region Large pores

Operando CT cell

Fabrication of two types of cells with and without large pores in the MPL on the cathode side

Hypothesis 2：Decrease in liquid water in the GDL

Substrate

No large pores in/on MPL

nanoscale pores

Large pores in/on MPL

large pores

O2 O2 O2

H2O H2O H2O

Substrate

nanoscale pores

several microns to several tens of microns

Rib RibRib Ch. Ch.30x speed

MPL large pores improves drainage by 15%

Top connected

Non connected

Full conected

Bottom connected

Hypothesis 2：Decrease in liquid water in the GDL

No large pores in/on MPL Large pores in/on MPL

H2O H2O H2O

Rib RibRib Ch. Ch.

Channel

Different water cluster types

30x speed

Conditions: 1.0 A cm-2, cell temperature 40 oC, dry gas velocities 7.6 m s-1 for air and 5.3 m s-1 for H2, relative humidity 105% for air and 100% for H2, gas pressure 100 kPa.

Current-voltage curves: about 20% improvement

24/38Outline

4. Conclusion

25/38Water in FC：SPring-8/PSI×J-PARC

Channel

µmnm mm

H+ H2O

Carbon

Ionomer

Flow of H2O

GDL(200 μm)

Multi-scale

Pt3 nm

アイオノマ+H2O

Synchrotron X-rayNeutron(Scattering, reflectivity)

Neutron

100%CathodeAnode

H2 Air

500 mm

Ionomer + H20

26/38Sub-zero start-up operation

Heatgeneration

Powergeneration

Temperature

Freezing point

Raises the temperature of the stack by generating heat

-20℃

Proceedings of the Society of Automotive Engineers of Japan,44(2013)、1021-1026

Several ancillary systems are equipped in commercial FCVs, including a rapid warm-up system, cell monitoring system and various other safety systems.

Feedback to cell design, operation mode (fuel efficiency)

Lower cost (elimination of cell monitor, pre-purge system, etc.)

In-situ observation of the behavior of water and ice in cells is important.

Ice Water

27/38Principle of water/ice identification

Approach: Pulsed neutron imaging

Detector

Metal pipe

PulsedNeutron

Y. Higuchi et al., PCCP, 23, (2021), DOI:10.1039/D0CP03887C.

Metal pipe

PulsedNeutron

Principle of water/ice identification

Metal pipe

Detector

Metal pipe

Neutron energy (meV)

0.1 1 10 100 1000

)Water（16℃）

Ice(-6℃)

Difference

PulsedNeutron

Detector

Metal pipe

0.1 1 10 100 1000

)Water（16℃）

Ice(-6℃)

Difference

Molecular mobility

Liquid

PulsedNeutron

Detector

Metal pipe

0.1 1 10 100 1000

)Water（16℃）

Ice(-6℃)

Difference

QuantificationIdentification

Blue： Red

-5.5℃ 17℃

Ice Water

-7.0 ˚C 1.2 ˚CMetal tube

720x speedIce

Water/ice identification images throughout the thawing process.

The transition from ice to liquid water could be confirmed by the volume change of water, and the hues in the images changed accordingly from blue to red.

Transmissionimage

Water/Ice identification images

Thawing process

Blue：

Detector

300 mm x 300 mm

Large field observation:Pulsed neutron beam with high intensity and large area, and 300 mm x 300 mm CCD camera

Fuel cell

Cooling method:Fluorinert, which is negligible for neutron transmission, flowed as the refrigerant.

PulsedNeutron

Full-size scale imaging

J-PARC, BL22(RADEN)

Thermal insulation chamber

250 mm

Full-size mock-up sample

Water-filled capillaries

Al foilbag with water

and Ti plate

＠BL22(RADEN)

Al alloy case

Ti plate with the raised logo of Toyota chuken

Full-size sample was cooled down to -30oC, and carried out liquid water/ice identification by neutron imaging.

Thermal insulation chamber

Detector

PulsedNeutron

1800x speed

0.3 mm/pixel

Transmission image

Freezing process

Blue：

35/38Outline

4. Conclusion

36/38Conclusion

Analysis

Catalyst/Membrane

Neutron

Carbon

Ionomer

Topic 1 Topic 2

Toyota Beamline

37/38Acknowledgments

Paul Scherrer Institut, SwitzerlandFelix N. Büchi, Jens Eller, Federica Marone, Hong Xu, Adrian Mularczyk, Thomas Gloor, Marcel Hottiger

J-PARC, JapanTakenao Shinohara, Kazuhisa Isegawa, Yusuke Tsuchikawa, Yoshihiro Matsumoto, Joseph Don Parker, Tetsuya Kai, Hirotoshi Hayashida

Toyota Motor Europe, BelgiumHai P. Nguyen, Keisuke Kishita

Toyota Motor Corp., JapanHirohito Hirata, Hiroaki Takahashi, Atsushi Ida, Tatsuya Kawahara

Toyota Central R&D Labs., JapanTatsuya Hatanaka, Satoshi Yamaguchi, Satoru Kato, Akihiko Kato, Takahisa Suzuki, Yuki Higuchi, Daigo Setoyam, Tadao Ozawa, Naoki Katayama, Mikiya Mori, Yumie Furuhashi, Tadanobu Ueda, Takafumi Yamauchi

Thank you very much for your kind attention.

Exhibition Hall at SPring-8

1st Generation

2nd Generation

Synchrotron X-Ray and Pulsed Neutron Imaging

of Water Transport Distribution in Fuel Cells

240th ECS Meeting :I01A-11 Gas Diffusion Layer #I01A-1025

Analysis

Catalyst/Membrane

Neutron

Carbon

Ionomer

Topic 1 Topic 2

Yasutaka Nagai (Toyota Central R&D Labs., Inc, Japan)

e1062@mosk.tytlabs.co.jp

Yasutaka Nagai (Toyota Central R&D Labs., Inc, Japan)

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