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Challenges in Fuel Cell Stack Development
Dr. Mathias ReumSenior Manager R&D
Phone
Fax
+49 (0) 89 1276265‐66
+49 (0) 89 1276265 99
Challenges in Fuel Cell Stack Development
Senior Manager R&D
Proton Motor Fuel Cell GmbHBenzstraße 7, D‐82178 Puchheim
Fax
Web
+49 (0) 89 1276265‐99
m.reum@proton‐motor.de
www.proton‐motor.de
Company Structurep y
Proton Motor Fuel Cell GmbH, Headquarters Puchheim,
d ti l t l b & ffi 6000 2
PEFC d l t i 1994 (M t M t )
production plant, labs & offices on 6000m2.
PEFC‐development since 1994 (Magnet Motor),PM founded 1998, today 57 employees.Proton Motor is a subsidiary of:
Proton Power Systems PLCHolding founded 2006Holding, founded 2006,Listed in London since 31.10.2006.
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Fuel Cells for industrial applications
Stack products
ll d fl f ld l
pp
System products
l f f‐ Cell design: flow field layout & simulation of fuel cell performance
‐ Stack design: construction & design of
‐ Development of components for BoP (incl. control system) in cooperations
‐ Development and production of PEFC stack components, material testing
‐ Evaluation and certification of the Proton Motor stack products
systems in different levels of integration
‐ Development and assembly of fuel cell based prototype turnkey applications
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Proton Motor Stack History
PM Stack Development Timeline:
y
28x7 prototype
1994 1998 2002 2006 2010
t l dG‐series
PM600 seriesair cooled
water cooled
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
PM200 series
air cooled
Proton Motor Stack History
active area ca 200 cm2
1994: The 28x7 Prototype
y
active area: ca. 200 cm2
usage: prototype only, proof of principleproof of principle
attribute: metal mesh as gas diffusiongas diffusion medium
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Proton Motor Stack History
1998: The G‐series
y
active area ca 450 cm2active area: ca. 450 cm2
usage: prototype system module with SGLmodule with SGL, prototype car E2G(VW Golf II: 30 kW)
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Proton Motor Stack History
2002: The PM600 series
y
active area 525 cm2active area: 525 cm2
usage: 20kW and 50kW multi stack vehiclemulti‐stack vehicle propulsion systems (Maritime, Busses)
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Proton Motor Stack History
2006: The PM200 Series
y
active area 155 cm2active area: 155 cm2
usage: stack product, single stack andsingle‐stack and multi‐stack systems for stationary and mobile applicationsmobile applications (Module S5, PM‐Basic50, PM‐REX)
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
PEFC-Stacks PM200 / PM400/
Since 2010: Product State PM200 Prototype State PM400
2 kW – 8 kW continuous power (24, 48, 96 cells) FC‐Systems of 2 – 50 kW net power TÜV‐certificate according to EEC 62282‐2
9 kW – 20 kW continuous power (only 96 cells) FC‐Systems of 10 – 200 kW net power commercially available in 2013
Focus on low cost technology and components suitable for mass production:• concept for fast hand manufacturing, as well as semi‐ and fully automated manufacturing. • good servicability cells can be quickly and easily replaced• good servicability cells can be quickly and easily replaced.• operating on low cost components from mass production.
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
PEFC-Stack PM200 Specificationsp
Voltage and Performance
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
PEFC-Stack PM200 Specificationsp
Air pressure and stoichiometry,temperature Adaption dry gases
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Conflicts in Stack developmentp
Stack specifications forStack specifications for fulfillment of market requirements moving in tension field.
Performance
nominal‐ & peak power
servicability
manufacturability
p p
operating parameters
Cost
y
recyclability gas impurity tolerance
size, weight & volume
voltage degradation
part reduction
reliability
Lifetime
Any worthwhile balance has to be appli ation spe ifi !
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Lifetimeapplication‐specific!
Performance - related issues
The choice of material and design denominates performance losses in PEFC!
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Performance - related issues
The choice of material and design denominates performance losses in PEFC!
mass transport losses(reactant supply)(reactant supply)
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Performance - related issues
The choice of material and design denominates performance losses in PEFC!
ohmic losses(current flux)(current flux)
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Performance - related issues
The choice of material and design denominates performance losses in PEFC!
activation losses(catalysis reactant crossover)(catalysis, reactant crossover)
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Performance - related issues
As a Stack Developer:Flow Field Design is most obvious aspect of performance‐related engineeringFlow Field Design is most obvious aspect of performance related engineering
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Performance - related issues
The impact of flow field design on stack performance:
decrease of channel dimension is limited by reactant pressure drop. increase of channel dimension is limited by electric contact and mechanical support.
increase of rib dimension is limited by reactant transport losses increase of rib dimension is limited by reactant transport losses. decrease of rib dimension is limited by ohmic resistance and manufacturability.
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Performance - related issues
The impact of flow field design on stack performance:
percentage of rib coverage is significant!
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Lifetime - related issues
St k D iS t D i Stack DesignSystem Design
choice of cell material cell compression
load dynamics start/stop cycles start/stop cycles p
flow field design operating conditions
sta t/stop cyc es freeze/thaw cycles reactant impurities …
flow field design/ p y
FC lifetime
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Lifetime - related issues
Physico‐Chemical Membrane Degradation (Start‐Stop‐Problem): an issue inflicted by the operational conditions of the application System Designan issue inflicted by the operational conditions of the application System Design
0.64 A/cm2 in UPS‐systemincreasing the number of
ynumber of starts/hour by factor of 3
ca. 0.7 Starts/h 8.2 V/h
degradationincreases by
ca. 2 Starts/h 73.3 V/h
increases byfactor of 8!
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Lifetime - related issues
Mechanical Membrane Degradation: an issue inflicted by shortcomings in flow field geometry Stack Designan issue inflicted by shortcomings in flow field geometry Stack Design
design‐relatedcurrent peaks orcurrent peaks orlocal starvation /local drying
membrane damage atair inlet „bottle neck“
membrane failure afterfailure after a specific time!
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Cost - related issues
Low Fuel Cell Performance
Low Fuel Cell Life Time
service expenses total cost of ownership
system/stack size ffi i
Higher
total cost of ownership efficiency
Higher Cost
Pricing ofCell Material
Production Process
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Cost - related issues
bipolar platecatalyst coated membrane (w/o Pt)
The PM200 cost cake:
50.38%
y ( )Platinum (trade price)gas diffusion layer + sealingend plate + restraintmedia connectors
3.04%
miscellaneous
21.00%
2.52%19 43%
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
3.58%19.43%
0.05%
Cost - related issues
Prognosis of cost degression for the fuel cell stack
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Cost - related issues
Prognosis of cost degression for the fuel cell stack
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
Summaryy
‐ PEM Fuel Cell stack development is a tension field between Fuel Cell Performance, Lifetime and Cost.
‐ Performance issues are dominated by the chemical engineering of the‐ Performance issues are dominated by the chemical engineering of the heterogenous catalysis, for performance optimization stack manufacturers have to resort on flow field design and the choice of material. a lot of things can be done wrong! a lot of things can be done wrong!
‐ Lifetime is strongly impacted by both, system design and stack design. longevity is a product of material, design and application!
‐ Approximately 80% of possible Cost‐Down to the incremental costs isApproximately 80% of possible Cost Down to the incremental costs is achieved by volume degression, only ca. 20% of cost gap can be filled by design‐to‐cost techniques with today´s state of the art fuel cells. sales seem to count more than sufficient engineering!
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de
sales seem to count more than sufficient engineering!
© Proton Motor 201226.04.2012 m.reum@proton‐motor.de