Fuel Cells

Topic and Area of Science Topic: Creating Energy From Fuel Cells Areas of Science: Chemistry, Physics, Engineering What is a fuel cell? A fuel cell operates like a battery, converting chemical energy directly into electrical and thermal energy. A fuel cell and a battery are similar in many respects.

Big Question Purpose (Big Question) Do fuel cells provide an efficient form of energy?

Hypothesis Hypothesis Fuel cells do not provide an efficient enough form of energy because if they did they would be used more widely today in cars, trucks, and other vehicles.

Interesting facts A fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive electrode and one negative electrode cell. A fuel cell has an electrolyte, which carries electrically charged particals. Hydrogen is the basic fuel to power a fuel cell but fuel cells also require oxygen. The five major types of fuel cells are alkali, solid oxide, phosphoric acid, molten carbonate, and proton exchange membrane. Each one of the fuel cells listed above works a bit different from each other. Friedrich Wilhelm Ostwald ( ), a founder of the field of physical chemistry, provided much of the theoretical understanding of how fuel cells operate.

Materials – Fuel cell car kit – 5 AA batteries – Distilled water – Electrical tape – Two books 1 in thick – Computer – Computer paper – Pencils – Computer ink – Binder – Paper protectors

Procedures Assemble Fuel Cell Car – Body – Wheels – Motor Cover – Fuel Cell Membrane – Cylinders for Hydrogen and Oxygen Collection Charge Fuel Cell Using Electrolysis – Fill fuel cell with water – Connect fuel cell to gas collection cylinders – Connect battery pack to fuel cell – Convert water to hydrogen and oxygen – Measure the amount of time required to produce oxygen and hydrogen using electrolysis Measure the ratio of oxygen to hydrogen Measure Time to Drain Fuel Cell – Connect the fuel cell wires to the car motor and operate until fuel cell is drained – Record the amount of time the car operates before draining the fuel cell

Procedures Repeat steps 3 & 4 several times to break in fuel cell membrane Measure the Impact of Friction on the Time to Drain the Fuel Cell – Operate the car suspended in air, on hardwood floors and on carpet – Record the amount of time the car runs on each surface before draining the fuel cell Measure the Amount of Battery Power Used to Charge the Fuel Cell Compared to Powering the Car – Get three new AA batteries – Using two batteries, perform steps 3 and 4 continuously until the batteries cannot power the electrolysis – Record the total amount of time the car runs – Hook up the third AA battery to the motor wires using electrical tape Record the total amount of time the car runs – Compare the time the car runs when two batteries are use to charge the fuel cell compared to one battery powering the motor directly

Control Group and Variable Control Group: Car running in air without friction Variable: Power source: (a) batteries or (b) fuel cell using hydrogen and oxygen produced from batteries

Data

Analysis of Data The car ran over twice as long on batteries as it did using batteries to separate hydrogen and power the fuel cell It takes more energy to separate hydrogen than the hydrogen creates in a fuel cell Batteries used to separate hydrogen and oxygen Batteries used to power car directly

Analysis of Data The oxygen cylinder took twice as long to fill as the hydrogen The car ran three times longer on the wood floor than on the rug It took more energy to run on the carpet because of friction

Analysis of Data The experiment tested my hypothesis because I was able to test the amount of time the car ran on batteries alone compared to running on a hydrogen powered fuel cell. Since the batteries were used to separate the hydrogen I could tell which used more battery power, running the car or creating hydrogen to run the car. The batteries alone were able to run the car for 21 hours and 38 minutes while the fuel cell was only able to run the car for 9 hours and 15 minutes using the same amount of battery power. I also noticed that the car could only run for less than half as long on carpet than a wood floor or air because of the friction. I believe the experiment tested my hypothesis because there were no malfunctions with the experiment and the car operated the way the manual explained. Almost every time I used the fuel cell to separate the hydrogen it took just about a minute and filled up in about half the time as the oxygen. This makes sense because there is twice as much hydrogen in water as oxygen.

Conclusion My hypothesis was correct because it took more energy to make the hydrogen than the hydrogen created in the fuel cell. Therefore the battery by itself was a more efficient form of energy than when used to charge the fuel cell. The batteries ran the car for over twice as long as the fuel cell and hydrogen using the same amount of battery power. This is because it takes a lot of energy to make the hydrogen. This is probably why fuel cells aren't used more often. If I changed the experiment I would like to find out if there are more efficient ways to make hydrogen than by using the fuel cell. Maybe by trying solar power so the energy would be free. That would make the fuel cell more efficient than the batteries. Questions I would have are: What is the best way to get hydrogen? How expensive is it to make fuel cells? If cars all ran on fuel cells where would people get the hydrogen?

Fuel Cell Experiment Pictures

Bibliography

Any Questions??? Thank you for watching The End