1. Hydrogen Fuel Cells

2. What is a hydrogen fuel cell?
A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent
Hydrogen fuel cells (HFCs) are a type of electrochemical cell.
HFCs generate electricity by reduction and oxidation reactions within the cell.
They use three main components, a fuel, an oxidant and an electrolyte.
HFCs operate like batteries, although they require external fuel.
HFCs are a thermodynamically open system.
HFCs use hydrogen as a fuel, oxygen as an oxidant, a proton exchange membrane as an electrolyte, and emit only water as waste.

3. FUEL CELLS MAJOR TYPES OF FUEL CELLS ARE PEM Alkaline PHOSPORIC ACID
Molten carbonate
Solid oxide
Regenerative fuel cell

4. PEM FUEL CELL Proton Exchange Membrane (PEM)
This is the leading cell type for passenger car application
Uses a polymer membrane as the electrolyte
Operates at a relatively low temperature, about 175 degrees
Has a high power density, can vary its output quickly and is suited for applications where quick startup is required making it popular for automobiles
Sensitive to fuel impurities

5. Alkaline Fuel Cell Used mainly by military and space programs
Can reach 70% power generating efficiency, but considered to costly for transportation applications
Used on the Apollo spacecraft to provide electricity and drinking water
Uses a solution of potassium hydroxide in water as the electrolyte and operates at degrees
Requires pure hydrogen and oxygen because it is very susceptible to carbon contamination
Purification process of the hydrogen and oxygen is costly
Susceptibility to poisoning affects cell’s lifetime which also affects the cost

6. PAFC FUEL CELL Phosphoric Acid
This is the most commercially developed fuel cell
It generates electricity at more than 40% efficiency
Nearly 85% of the steam produced can be used for cogeneration
Uses liquid phosphoric acid as the electrolyte and operates at about 450 degrees F
One main advantage is that it can use impure hydrogen as fuel

7. How do they work?
Fuel (H2) is first transported to the anode of the cell
Fuel undergoes the anode reaction
Anode reaction splits the fuel into H+ (a proton) and e-
Protons pass through the electrolyte to the cathode
Electrons can not pass through the electrolyte, and must travel through an external circuit which creates a usable electric current
Protons and electrons reach the cathode, and undergo the cathode reaction

8. Chemistry behind the technology
Oxidation
At the anode of the cell, a catalyst (platinum powder) is used to separate the proton from the electron in the hydrogen fuel.
Anode half-reaction:
2H2  4H+ + 4e-
Eo = 0.00V
Reduction
At the cathode of the cell, a second catalyst (nickel) is used to recombine the protons, electrons, and oxygen atoms to form water.
Cathode half- reaction:
4H+ + O2 + 4e-  2H2O
Eo = 0.68V
In electrochemistry, the Eocell value (energy) of a fuel cell is equal to the Eo of the cathode half-reaction minus the Eo of the anode half-reaction. For a hydrogen fuel cell, the two half reactions are shown above. So to calculate the energy of one fuel cell, we need to subtract the anode energy from the cathode energy. For a HFC, the Eocell = 0.68V – 0.00V which equals 0.68V

9. Benefits of Hydrogen fuel cell
Physical Security
Reliability
Efficiency
Environmental Benefits
Battery Replacement /Alternative
Military Applications

10. Problems regarding hydrogen fuel cells
Lack of hydrogen infrastructure
Need for refueling stations
Lack of consumer distribution system
Cost of hydrogen fuel cells
2013 Department of Energy estimated $30/kw
Hyundai i35x costs around $ and price of this is going to be reduced for the promotion
Carbon cost of producing hydrogen is high
Problems with HFC cars
Short range (~365miles)
Warm up time (~5 minutes)
Hydrogen occupies more volume than gasoline so less range

11. Uses of hydrogen fuel cells
There are many different uses of fuel cells being utilized right now. Some of these uses are…
Power sources for vehicles such as cars, trucks, buses and even boats and submarines
Power sources for spacecraft, remote weather stations and military technology
Batteries for electronics such as laptops and smart phones
Sources for uninterruptable power supplies.

12. Conclusion Promising technology
Most viable for niche market use in the near future
The car’s would be in the market by 2015

13. QUERIES

14. THANK YOU