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What materials/combination

of materials make the best supercapacitor?

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6th grade

Nativity Catholic School

2024 San Mateo County Office of Education STEM Fair

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Abstract

The purpose of this experiment was to try to improve supercapacitors. Supercapacitors are a lot less toxic and are a lot less flammable than lithium batteries. While supercapacitors do store less energy than lithium batteries they have many pros, such as the ones mentioned above and also that they can charge and discharge very quickly which more or less makes up for their low energy capacity, at least in my opinion. This is why I chose to do this experiment.

I believe that a supercapacitor with electrodes with high surface area will be best. I believe this because the high surface area allows more ions to stick to the electrodes, the more ions can stick the more electrons can be held. I also believe that an electrolyte with many ions will be best. I believe this because the more ions can stick to the electrodes the more electrons can be held.

The variables that were tested were the electrode as well as the electrolyte. The way that these would be tested would be by changing one of these variables. Then they would be measured by charging the supercapacitor and seeing how long it would last before fully discharging.

The results of this experiment were that the supercapacitor did not work. Only one supercapacitor was made and tested as the one trait they did share was likely the cause of failure. The point of failure was electrodes as the binder in the electrode material was not conductive and there was too much of it not allowing electricity to flow.

In conclusion even though the supercapacitors did not work, a lot of information was learned on how they could be improved for future experiments.

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Abstract

I believe that a supercapacitor with electrodes with high surface area will be best. I believe this because the high surface area allows more ions to stick to the electrodes, the more ions can stick the more electrons can be held. I also believe that an electrolytes with may ions will be best. I believe this because the more ions can stick to the electrodes the more electrons can be held.

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Purpose Statement

The purpose of this experiment is to take one of many more step to a sustainable future. From your smartphone to your laptop they probably use lithium-ion batteries. Lithium batteries might seem like a good battery, and to be fair it is, however not only do lithium mines harm the environment, lithium is also very toxic and flammable as well as expensive. Unlike lithium batteries supercapacitors are a lot less toxic and are a lot less flammable than than lithium batteries, if even. While supercapacitors do store less energy than lithium batteries they have many pros, such as the ones mentioned above and that they can charge and discharge very quickly which more or less makes up for their low energy capacity, at least in my opinion. This is why I chose to do this experiment.

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Hypothesis

I believe that a supercapacitor with electrodes with high surface area will be best. I believe this because the high surface area allows more ions to stick to the electrodes, the more ions can stick the more electrons can be held. I also believe that an electrolyte with many ions will be best. I believe this because the more ions can stick to the electrodes the more electrons can be held.

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Experimental Procedures and

Materials

  • Distilled Water
  • Tissue Paper
  • Aluminum/Tin Foil
  • Multimeter
  • 100 ohm resistor
  • Small Motor with Fan
  • Elmers Multipurpose Glue
  • Activated Carbon
  • Graphite Powder
  • Sea Salt
  • Baking Soda
  • Citric Acid
  • Vinegar
  • Acetone
  • Sodium Nitrate
  • Lactic Acid
  • Potassium Chloride

Materials

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Experimental Procedures and

Materials

  • Cut 32 3x2 cm of aluminum/tin foil and 16 2.5x2.5 squares of tissue paper
  • Add a drop of glue onto a square of foil and dip a brush into either the carbon or graphite and spread it and the glue over the square evenly with the brush. Repeat this 15 times with whichever material (graphite or carbon) you used on 15 other square foils
  • Repeat step 2 with the material you did not use
  • Get a foil square and on the side with the electrode place a square of tissue on top
  • In a small container add some of the powder used in the electrolyte solution then add some distilled water.
  • Add a few drops of electrolyte to the tissue paper from step 4 without any powder going into the tissue other than the one that is dissolved in the distilled water

Procedure

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Experimental Procedures and

Materials

7. Add another foil square with the electrode side facing down make sure it has the same electrode material

8. Repeat steps 4 -7 with different foil squares and tissues. Also make sure to use every electrolyte type once for every type of electrode material. And use different beakers for each electrolyte

9. To test the supercapacitors connect them to the battery with the resistor then connect the supercapacitor to the motor and record for how long it powers the motor

10. Use the data to find which supercapacitor has the highest capacitance

Procedure

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Experimental Results

The result of this experiment was that the supercapacitor that was built did not work. The supercapacitor was tested to see if it simply didn’t have enough capacity to power a small motor, it was tested by wiring it in series with a functional battery and it still didn’t power the motor. The plates that the electrodes were on were conductive and the electrolyte was saturated with the potassium chloride and didn’t have any extra undissolved potassium chloride(I used potassium chloride for the electrode)

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Analysis of Experimental

Results

Since we used a non conductive binder I should have used around ten percent of the total electrode however it would not bind the electrode material so I used more. The issue of using a non conductive binder is that the electrons and ions cannot “stick” to the electrode as the electrons cannot flow due to the electric insulation. The supercapacitor was tested to see if to simply didn’t have enough capacity to power a small motor, it was tested by wiring it in series with a functional battery and it still didn’t power the motor giving another reason that’s the binder was an electric insulator.

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Analysis of Experimental

Results

The plates that the electrodes were on were conductive so that shouldn’t have been a problem and the electrolyte was saturated with the potassium chloride but didn’t have any extra undiscovered potassium chloride.The solution for the binder would have been to use the materials from the video that inspired this experiment, but they were very expensive or another solution would have been to use a conductive binder or ten percent of another binder.

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Conclusions

In conclusion of this experiment it is not possible to affirm the hypothesis of this experiment as the result was a non functional, however some new questions have formed as well as changes that would be made to the experiment to continue to explore this topic. A change that would be made would be made would be to test another variable, the binder (glue) used for the electrolyte.

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Acknowledgements

I would like to thank my dad for helping me setup and test my experiment as well as for purchasing the supplies.

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Bibliography and

Sources

Byjus. (2024). Supercapacitors

https://byjus.com/physics/supercapacitors/

Wikipedia (2024). Supercapacitors

https://en.wikipedia.org/wiki/Supercapacitor

The Thought Emporium. (2018). How to Make a Basic Supercapacitor

https://www.youtube.com/watch?v=Lqj2zJbztbM&t=454s

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Bibliography and

Sources

Byjus. (2024). Supercapacitors

https://byjus.com/physics/supercapacitors/

MIT News. (2023). MIT engineers create an energy-storing supercapacitor from ancient materials.

https://news.mit.edu/2023/mit-engineers-create-supercapacitor-ancient-materials-0731