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Aerogel from fruit biowaste produces ultracapacitors
- dalf 7y agoAn article that sums up the idea: https://www.popularmechanics.com/technology/design/a31114696/durian-fruit-stinky-electric-chargers/ https://www.popularmechanics.com/technology/design/a31114696...
- aero- 7y agoHow does the storage capacity of these biowaste supercapicitors compare to that of a synthesized or inorganic material? Is the Jackfruit and Durian selected because its spongy properties after being autoclaved?
- mrfusion 7y agoGeneral capacitor question If you take a charged parallel plate capacitor and pull the plates farther apart does the energy in the system go up or down? The equations seem to be geared to how distance affects how much you can charge a capacitor. But if it’s already holding a given charge, I don’t think the basic equation applies.
- bananabiscuit 7y agoStored energy goes up. That energy comes from the work done to pull the plates apart (since there is a static electric force attracting them to each other)
- marcosdumay 7y agoIf you hold the charge constant and capacitance goes down, voltage will go up (U = QC). The energy is (E = U^2C/2), so yes the energy will increase. That extra energy is coming from your mechanic effort of separating two plates that attract each other.
- mrfusion 7y agoOk wow that makes sense. So I’d actually have a hard time pulling them apart? What’s the limit? What happens 1 meter apart? 20 meters?
- hwc 7y agoAs long the capacitors have a width much larger than the distance between them, the energy stored is (if I recall correctly) linear. this is because the electric field is a constant vector field between the plates. Once that is not true, you will transition to just separating two charged objects. Use Coulombs law to figure out the force. (Work energy is integral of force over distance).
- raverbashing 7y agoThe practical limit is not having electrons flying off due to the photoelectric effect or discharging due to conductive material in the environment. So do it in a vacuum, in complete darkness.
- stevefolta 7y agoMuch shorter distances can be useful: https://en.wikipedia.org/wiki/Microphone#Condenser_microphone https://en.wikipedia.org/wiki/Microphone#Condenser_microphon...
- viggity 7y agoTitle sounds like it was created by an HN article generator.
- csours 7y agoHN Mad Titles, now you can play at home! ___tech_thing___ FROM ___mundane_trash___ PRODUCES ___space_magic_thing___!
- markrages 7y agohttps://twitter.com/HNTitles https://twitter.com/HNTitles
- BubRoss 7y agoThe article seems like it was written for a high school news paper. It's a shame because it seems like there is real research going on that doesn't depend on the smell of durian or what Anthony Bourdain thought of it.
- westurner 7y ago> "Aerogel from fruit biowaste produces ultracapacitors with high energy density and stability" (2020) https://www.sciencedirect.com/science/article/pii/S2352152X19309077 https://www.sciencedirect.com/science/article/pii/S2352152X1... Years ago, I remember reading about supercapacitor electrodes made from what would be waste hemp bast fiber. They used graphene as a control. And IIRC, the natural branching structure in hemp (the strongest natural fiber) was considered ideal for an electrode. "Hemp Carbon Makes Supercapacitors Superfast" https://www.asme.org/topics-resources/content/hemp-carbon-makes-supercapacitors-superfast https://www.asme.org/topics-resources/content/hemp-carbon-ma... How do the costs and performance compare? Graphene, hemp, durian, jackfruit While graphene production costs have fallen due to lots of recent research, IIUC all graphene production is hazardous due to graphene's ability to cross the lungs and the blood-brain barrier?
- agumonkey 7y agodamn if hemp doesn't make a come back.. from cbd to ultracaps..
- virmundi 7y agoHopefully but it’s only been legal to grow hemp in the US since 2018. https://www.vox.com/the-goods/2018/12/13/18139678/cbd-industry-hemp-legalization-farm-bill https://www.vox.com/the-goods/2018/12/13/18139678/cbd-indust...
- westurner 7y agoTechnically, the 2013 farm bill (signed into law in 2014) authorized growing hemp for state-registered research purposes. https://www.votehemp.com/laws-and-legislation/federal-legislation/sec-7606-of-the-farm-bill/ https://www.votehemp.com/laws-and-legislation/federal-legisl... Turns out UC Berkeley's got an approach for brewing cannabinoids (and I think terpenes) from yeast, and a company in Germany has a provisional patent application to brew cannabinoids from bacteria. We could be absorbing carbon ("sequestering" carbon) and coal ash acid rain with mostly fields of industrial hemp for which there are indeed thousands of uses.
- sitzkrieg 7y agowonder if any smell remains from the durian
- mizunooto 7y agoHence “Duracell“
- nirav72 7y agoI'd like to see aerogel batteries one day.