Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision Next revisionBoth sides next revision | ||
| michka:research:supercapacitors [2014-07-01 14:15] – michka | michka:research:supercapacitors [2014-07-01 14:29] – michka | ||
|---|---|---|---|
| Line 9: | Line 9: | ||
| We ended the workshop having no functional supercapacitor, | We ended the workshop having no functional supercapacitor, | ||
| - | ===Best design=== | + | ====Best design==== |
| Our best design was very simple. It was a sandwich design, which means that it was just a stack of dry material layers we taped all together. It contained three layers: | Our best design was very simple. It was a sandwich design, which means that it was just a stack of dry material layers we taped all together. It contained three layers: | ||
| Line 24: | Line 24: | ||
| These characteristics are not outstanding, | These characteristics are not outstanding, | ||
| - | ===How to build the best design ?=== | + | ====How to build the best design ?==== |
| - | ==Step 1 - Find at least one dead computer battery== | + | ===Step 1 - Find at least one dead computer battery=== |
| We ended up opening three of them: | We ended up opening three of them: | ||
| Line 43: | Line 43: | ||
| This step of the process is, in my opinion, the most hazardous. If the battery is still a little bit charged, you will end up with heat and sparks. Gloves could be useful. Even when it is not, you will have a strange smell coming out: this is the electrolyte evaporating. As we do not really know what the electrolyte is made of, it may be smart to wear a mask. | This step of the process is, in my opinion, the most hazardous. If the battery is still a little bit charged, you will end up with heat and sparks. Gloves could be useful. Even when it is not, you will have a strange smell coming out: this is the electrolyte evaporating. As we do not really know what the electrolyte is made of, it may be smart to wear a mask. | ||
| - | ==Step 2 - Clean up the graphene from the copper layers & some insulating layers== | + | ===Step 2 - Clean up the graphene from the copper layers & some insulating layers=== |
| Scrap with your nails or whatever soft tools which will not make holes in the plastic or copper layer. | Scrap with your nails or whatever soft tools which will not make holes in the plastic or copper layer. | ||
| - | ==Step 3 - Assemble the layers== | + | ===Step 3 - Assemble the layers=== |
| * Put the layer of insulating material coated with graphene at the bottom, with the graphene-coated side facing you. | * Put the layer of insulating material coated with graphene at the bottom, with the graphene-coated side facing you. | ||
| Line 53: | Line 53: | ||
| * Tape a layer of cleaned-up copper on top of the second one, making sure to avoid any copper to graphene contact. | * Tape a layer of cleaned-up copper on top of the second one, making sure to avoid any copper to graphene contact. | ||
| - | ==Step 4 - Measure the initial voltage== | + | ===Step 4 - Measure the initial voltage=== |
| Measure the voltage between the copper layer and the graphene layer. There was an initial voltage every time we assembled such a sandwich. This step allows you to see what the polarity of the design is and charge it adequately. Our negative pole was the graphene layer. | Measure the voltage between the copper layer and the graphene layer. There was an initial voltage every time we assembled such a sandwich. This step allows you to see what the polarity of the design is and charge it adequately. Our negative pole was the graphene layer. | ||
| - | ==Step 5 - Charge it== | + | ===Step 5 - Charge it=== |
| Put the + of the power source on your + pole, and - on -. Check the current flow on your power source screen. We used small voltage to charge, from 1 V to 5 V. Start small. | Put the + of the power source on your + pole, and - on -. Check the current flow on your power source screen. We used small voltage to charge, from 1 V to 5 V. Start small. | ||
| - | ==Step 6 - Measure the charge== | + | ===Step 6 - Measure the charge=== |
| Once the current is back to 0 A and stable, measure the voltage between the copper layer and the graphene layer. | Once the current is back to 0 A and stable, measure the voltage between the copper layer and the graphene layer. | ||
| - | ==Step 7 - Test it== | + | ===Step 7 - Test it=== |
| You can tape several of these and connect them in series by soldering contacts from one to another. For graphene contacts, we used a small bit of copper that we taped and tried to maintain with pressure against graphene. | You can tape several of these and connect them in series by soldering contacts from one to another. For graphene contacts, we used a small bit of copper that we taped and tried to maintain with pressure against graphene. | ||
| Line 71: | Line 71: | ||
| Once you reach a sufficiently interesting voltage, try to connect a LED and see what happens. | Once you reach a sufficiently interesting voltage, try to connect a LED and see what happens. | ||
| - | ===Other | + | ====Other |
| Except for our sandwich designs, we also had some sushi designs - which are nothing else than wrapped sandwiches. We also made some waffle designs, which are square sushis - not cylindrical. | Except for our sandwich designs, we also had some sushi designs - which are nothing else than wrapped sandwiches. We also made some waffle designs, which are square sushis - not cylindrical. | ||
| Line 88: | Line 88: | ||
| We however encourage you to try anything, as it seems that every battery type is different, and even avery battery, as the damage they overcome makes each of them quite singular in behavior. | We however encourage you to try anything, as it seems that every battery type is different, and even avery battery, as the damage they overcome makes each of them quite singular in behavior. | ||
| - | ===Wet Designs=== | + | ====Wet Designs==== |
| We also tried some wet designs, which means designs with a liquid electrolyte. | We also tried some wet designs, which means designs with a liquid electrolyte. | ||
| Line 99: | Line 99: | ||
| We used two different designs to apply the electrolyte: | We used two different designs to apply the electrolyte: | ||
| * Dipping a whole sushi in the electrolyte | * Dipping a whole sushi in the electrolyte | ||
| - | * Intercalating a sandwich layer made of printer paper dipped into the electrolyte between copper & graphene, thus replacing the insulating layer from the the dead battery | + | * Intercalating a sandwich layer made of printer paper dipped into the electrolyte between copper & graphene, thus replacing the insulating layer from the the dead battery |
| - | ====Information Sources==== | + | Our wet designs were no success. |
| + | |||
| + | A sushi dipped in sulfuric acid was severly attacked. Current kept on flowing, it was bubbling slightly, the solution started to become dark. It did hold voltage and quite a good charge, but after opening it up, we saw huge corrosion spots on the copper layer. | ||
| + | |||
| + | Sushi dipped in salted water and demineralized water showed a strange charging behavior: current was slightly increasing, before being stable around 100 mA. They ended up not charging, or having a low and evanescent charge. | ||
| + | |||
| + | Our sandwich with salted-water-wet paper had a similar charging behavior, and copper also ended up corroded. | ||
| + | |||
| + | Our sandwich with demineraliued-water-wet paper had a similar charging behavior, and a low and evanescent charge. | ||
| + | |||
| + | ====Conclusion & Future Research==== | ||
| + | |||
| + | Our best dry sandwich design seems interesting. However, we are not sure wether this behavior is a consequence of some remanent electrolyte from the dead battery still present in the graphene layer. Moreover, it proved to be unstable to design change: sushis & waffles could not hold the charge as well, and the voltage stored was highly sensitive to finger pressure. | ||
| + | |||
| + | On our next session, we have to focus on electrolytes, | ||
| + | |||
| + | ====Preliminary | ||
| * [[https:// | * [[https:// | ||
| * [[https:// | * [[https:// | ||
| - | * Robert Murray Smith - Supercapacitor 101 - A home Inventor' | + | |
michka