Fuel Cells: Basics and Applications & How do fuel cell cars work?

1. Fuel Cells: Basics and Applications&How do fuel cell cars work? Ajay K. Prasad Professor, Department of Mechanical Engineering Director, Center for Fuel Cell Research University of Delaware prasad@udel.edu

2. Fuel Cell Technology: Basics and Applications © Prof. Ajay K. Prasad University of Delaware Fuel Cell Hydrogen Oxygen Heat Electric power Water What is a Fuel Cell? • A fuel cell combines fuel and oxidant electrochemically to produce electricity • Two to three times more efficient that an internal combustion engine • Fuel cell stack is quiet, has no moving parts, produces zero emissions

3. Fuel Cell Technology: Basics and Applications © Prof. Ajay K. Prasad University of Delaware PEM fuel cell Load e- Carbon black H2 Air Platinum Catalyst Anode H+ Cathode NIST Bipolar plate Bipolar plate Gas Diffusion Layer Membrane Electrode Assembly Gas Diffusion Layer Voltage = 0.6 V Anode Reaction 2H2 4H+ + 4e- Cathode Reaction O2 + 4H+ + 4e-  2H2O

4. Fuel Cell Technology: Basics and Applications © Prof. Ajay K. Prasad University of Delaware NREL NMSEA 3kW, 48V fuelcellstore.com A small stack of about 10 cells PEM fuel cell “stack”

5. Fuel Cell Technology: Basics and Applications © Prof. Ajay K. Prasad University of Delaware Automotive fuel cells (PEM) Honda FCX Clarity GM’s skateboard chassis idea.

6. Fuel Cell Technology: Basics and Applications © Prof. Ajay K. Prasad University of Delaware Mercedes-Benz: Citaro fuel cell bus on the streets of London. Engine supplied by Ballard. European Fuel Cell Bus Project, which saw 30 fuel cell buses operating on the roads of Europe over the past two years. Toyota: The FCHV-BUS2 is a large, low-floor, fuel-cell hybrid bus. Since its exhaust is free of NOx (nitrogen oxides) and PM (particulate matter), it can help improve air quality in urban areas.

7. Fuel Cell Technology: Basics and Applications © Prof. Ajay K. Prasad University of Delaware Samsung Electronics: 100Wh laptop PC fuel cell using 100cc of methanol solution, enabling continuous usage for more than 10 hours without recharging. Fuel cells for portable power (DMFC) Casio: World's smallest fuel cell for use in laptop PC. The polymer electrolyte fuel can power a typical laptop computer for eight to 16 hours.

8. UTC Fuel Cells: 5kW fuel cell power plants for backup power for telecommunications towers, power for small businesses, and residential use. Fuel Cell Technology: Basics and Applications © Prof. Ajay K. Prasad University of Delaware UTC Fuel Cells: (PureCell™ 200) 200kW of electricity and 900,000 BTUs of usable heat. This system provides clean, reliable power at locations including a New York City police station, a major postal facility in Alaska, a credit-card processing system facility in Nebraska, and a science center in Japan. Fuel cells for stationary power (SOFC)

9. Fuel Cell Technology: Basics and Applications © Prof. Ajay K. Prasad University of Delaware Pros and Cons of Fuel Cells

10. H2 Refueling station atAir Liquide • UD Fuel Cell Bus Program: 2005-2011 • Phase 1: 22-ft bus, 20 kW stack, Ni-Cad batteries (in operation, 100 students/day) • Phase 2: 22-ft bus, 40 kW stack, Ni-Cadbatteries (Spring ’09) • Phase 3: 30-ft bus, 40 kW stack, Li-Ti batteries (2010) • Phase 4: 30-ft bus, 40 kW stack, Li-Ti batteries (2011) UD Fuel Cell Hybrid Bus Program • H2 refueling station in Newark since 2007 • Two more H2 stations in Wilmington and Dover

11. Components of a fuel cell car • Fuel cell stack • Balance of plant: Air compressor, hydrogen recirculating pump, air and hydrogen humidifiers, coolant pump and radiator • Hydrogen storage tank • Battery for hybrid operation • Boost converter and inverter • Traction motor and transmission • Computer for control and management How do fuel cell cars work?

12. Schematic of direct-hydrogen pressurized FCS R.K. Ahluwalia et al. / Journal of Power Sources 152 (2005) 233–244

13. Schematic of electric drive train for FCHEV R.K. Ahluwalia et al. / Journal of Power Sources 152 (2005) 233–244

14. Energy Flow within components for FCHEV Energy flow within the components of FCHEV for FUDS: FCHEV with 65kWe FCS and 55kWe ESS. R.K. Ahluwalia et al. / Journal of Power Sources 152 (2005) 233–244

15. To be competitive with the conventional ICE propulsion system in terms of drivability and performance, the FCS must satisfy the following requirements: • FCS alone must meet vehicle power demands under all driving conditions: Top sustained speed of 100 mph, and 55 mph at 6.5% grade for 20 min. • With the assistance of ESS, the FCS must allow 0 to 60 mph in 10 s. • 1 s transient response time for 10–90% power. • FCS must reach maximum power in 15 s for cold start from 20 ◦C ambient temperature, and in 30 s from −20 ◦C ambient temperature. Requirements for FCHEV

16. Series Hybrid: • Small fuel cell, large battery bank • Battery drives motor at all times • Fuel cell operates continuously and keeps battery charged • Fuel cell is not “load-following” Series and Parallel Hybrid Fuel Cell Vehicles • Parallel Hybrid: • Large fuel cell, small battery bank • Fuel cell drives motor at all times, it is “load-following” • Battery provides boost power as and when required

17. The Honda FCX Clarity Engine: 100 kW, 57 liters, 148 lb Fuel economy: 74 mpgge Range: 280 miles H2 Storage: 4.1 kg at 5000 psi