ARNAM 2006 Annual Workshop29th June 2006

Developments in Plasma Based Fuel CellResearch at the Australian National University

Devin Ramdutt1, Amael Caillard1,3, Cormac Corr1, Weitang Li1, BradLadewig2, Christine Charles1, Rod Boswell1, Andrew Dicks2 and PascalBrault3.1. Space Plasma, Power and Propulsion (SP3), The Research School of Physical Sciences andEngineering, The Australian National University, Canberra, ACT, Australia, 0200.2. Nanomac, School of Engineering, The University of Queensland, Brisbane, QLD, Australia, 4072.3. GREMI-CNRS Laboratory, University of Orléans, BP 6744, F-45067, Orléans, France

ARNAM 2006 Annual Workshop29th June 2006

Outline

• What is a fuel cell and the different types.• Proton Exchange Membrane Fuel Cells.• Sputter Deposition using plasmas.• Depth profiling and RBS analysis.• Carbon nano-wires• Boron nano-wires• Deposition of proton conducting membranes inpolymerising plasmas.• Effects of plasmas on Nafion

ARNAM 2006 Annual Workshop29th June 2006

Types of Fuel Cells

• An overpriced battery.

• 2H2 + O2 -> 2H2O + energy

ARNAM 2006 Annual Workshop29th June 2006

Proton Exchange Membrane (PEM) Fuel Cells

ARNAM 2006 Annual Workshop29th June 2006

Sputter Deposition in an Argon Plasma

ARNAM 2006 Annual Workshop29th June 2006

Depth Profiling using RBS and PlatinumLoading

Depth profile of Pt on E-Tek GDL

0

5

10

15

20

25

30

0 50 100 150 200 250 300 350 400 450 500

Distance (nm)

Pt

den

sity

(x1

01

5 a

tom

s/cm

2)

ptc11b.rbs Bi-exponential fit

RBS spectra of Pt on GDL deposited in a 1kW Ar plasma for 20 minutes

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

0.15 0.35 0.55 0.75 0.95 1.15 1.35 1.55 1.75 1.95 2.15

Energy (MeV)

Co

un

ts

€

g( t) = Ae−tB +Ce

−tD

Depth profile data can be fit using abi-exponential function that fitsanomalous diffusion.

E-Tek Reference100010001000

Plasma Power(W)

20105

Deposition Time(min)

0.350.0260.0190.008

Pt Loading(mg/cm2)

ARNAM 2006 Annual Workshop29th June 2006

Performance of Plasma Sputtered Electrodes

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 300 600 900 1200 1500 1800Current Density (mA/cm2)

Pot

entia

l (V

)

ARNAM 2006 Annual Workshop29th June 2006

Carbon Nano-fibres and Co-Sputtering ofPlatinum

Rotarypump

Convectrongauge

DC Substrate bias

Pt target bias

Nitarget

Pttarget

Current generator(heater)

Input gas Ar-CH4

ICP antenna powered by a RFgenerator & matching box

Carboncloth

CNF deposition on to carbon paper

Pt nano-particles deposition on CNFs

ARNAM 2006 Annual Workshop29th June 2006

Boron Nano-Wires

ARNAM 2006 Annual Workshop29th June 2006

Proton Conducting Membranes Produced byPlasma Enhanced Chemical Vapour Deposition

(PECVD)

(b)

Plasma membrane isdeposited 6 µm into the

GDL

ARNAM 2006 Annual Workshop29th June 2006

Understanding Effects of Low Power Plasmason Nafion Membranes

€

Eion (J.cm−2) = teµion (Vp −Vf )

= tenion2e(Vp −Vf )

M(Vp −Vf )

≈ tenion2eVp

MVp

Energy dose calculation to Nafionsurface from argon ions in plasma.

Plasma ParametersVp = 32 VVf = 1 - 2 Vnion = 109 - 1011 ions.cm-3

Exposure time = 2 - 120 seconds

ARNAM 2006 Annual Workshop29th June 2006

Understanding Effects of Plasmas on NafionMembranes

Water contact angle

ARNAM 2006 Annual Workshop29th June 2006

Understanding Effects of Plasmas on NafionMembranes

Proton conductivity

ARNAM 2006 Annual Workshop29th June 2006

Understanding Effects of Plasmas on NafionMembranes

Surface morphology

0.476 nm60 secondexposure

0.579 nm10 secondexposure

0.651 nmReferenceRMS RoughnessSample

ARNAM 2006 Annual Workshop29th June 2006

Conclusions

• Our goal for a plasma base fuel cell is well under way.• We are using plasmas to deposits the catalyst layers on ourcarbon GDL.• We are engineering our surfaces in the form of nano -tubes -wires -fibers -belts to increase the available surface for thecatalyst to deposit on.• We are looking at depositing proton conducting polymers usingPECVD.• It is my goal to have a plasma processing production linepumping out model T fuel cell very shortly.