high temperature pem fuel cells

FUEL CELL TECHNOLOGY

Samuel Simon Araya Institute of Energy Technology, Aalborg University

ssa@iet.aau.dk

Supervisor: Søren Knudsen KærCo-supervisor: Søren Juhl Andreasen

Outline

• Introduction to Fuel Cells

• HT-PEM fuel cells

• Conclusions

”Imagine driving home in a fuel cell car with nothing but pure water dripping from the tailpipe. Imagine a laptop computer that runs for 30 hours on a single charge. Imagine a world where you plug your house into your car and power lines are a distant memory.”

Introduction

-Fuel cell Fundamentals by O’Hayre et al.

Fuel cells are electrochemical devices that continuously convert the internal energy of gases directly into electricity,

Figure source: http://ssrl.slac.stanford.edu/nilssongroup/nilsson_projects.html (15/ 02/2010)

What is a Fuel cell?

The History

• 1800 – W. Nicholson and A. Carlisle first described electrolysis

• 1836 – William Grove fuel cell Demonstration

• 1889 – three separate teams performed various fuel cell experiments

• 1960’s – T. Grubb and L. Neidrach Invented PEMFC technology at GE

• 1990’s to the present – worldwide research on all types of fuel cells

Advantages

• More efficient• They can be all solid parts – potential for

reliability and durability• No moving parts – Silent• NOx, SOx and Particulate emissions virtually

zero

Disadvantages

•Cost•Power density •Susceptibility to environmental poisons•Durability

Types of Fuel Cells

1. Phosphoric acid fuel cell (PAFC)2. Polymer Electrolyte membrane fuel cell

(PEMFC)3. Alkaline Fuel cell (AFC)4. Molten carbonate Fuel cell (MCFC)5. Solid oxide fuel cell (SOFC)

HT-PEM Fuel cells

Employ a thin solid polymer electrolyte

-PBI (Phosphoric acid doped)

Degradation due to- Peroxide attacks - Pt agglomeration- Acid bleaching….

Applications

•Transportation

• Stationary and semi-

stationary power supplies

• Cogeneration – MicroCHP

• Mobile – cell phones,

laptops and mobile

monitoring devices

Achievements and targets

Targets

CostStationary application 400 -750 $/kW

Background photo source: http://www.flickr.com/photos/rasputern/3462874340/ (15/02/2010)

Data source: U.S department of Energy (DOE)

Durability• Automotive -5000

hours

• Stationary - 40 000 hours

Conclusions

•We are halfway to tackle both the cost and durability challenges for fuel cells to be commercially competitive and the trend is faster than ever

•HT-PEM fuel cells are very promising but Material degradation remains the main issue

Thank you for you attention