Green Ideas #15:

Quando le auto elettriche

andranno a gusci d’uovo

“Ideario” per un futuro

sostenibile…

Uno dei problemi delle auto elettriche è la capacità di ricarica:

senza condensatori sufficientemente efficienti, “fare il pieno” è

un’operazione lunga e logisticamente impegnativa.

Sembra che gli scienziati abbiano trovato una soluzione: i gusci

d’uovo. La loro microstruttura li renderebbe, dopo una tostatura a

800 gradi, perfetti condensatori. Per fare un esempio: con un

condensatore a gusci, un cellulare si ricaricherebbe da zero in 45

secondi. Resta solo da capire come integrarli nelle batterie.

(segue articolo originale in lingua inglese)

The Electric Car Of The Future Will Be Powered By Eggshells

It’s a question that’s puzzled electric car makers for decades--how do you

effectively store enough electrical energy that will power them over long

distances?

Turns out, it might be as simple as making an omelet.

Batteries store the bulk of the electrical energy that powers electric vehicles

today, but they’re limited by how quickly they wear out.

Batteries are helped along by capacitors--electrical devices that charge up

and drain quickly and can be recharged over and over again, but hold

comparatively much less charge.

So for some years now, the hunt’s been on for an ideal crossbreed of batteries

and capacitors--an electrical device that will store a lot of charge, like a deep

bowl of soup, but is also swift to fill up and drain.

Scientists found it--they just had to break a few eggs.

That’s because, it turns out, chicken eggshells may offer a solution.

A group of Canadian scientists have tested and shown that the membranes

from eggshells, toasted to 800 degrees, make for surprisingly efficient

supercapacitors that could one day be used in electric vehicles, maybe even

in cell phone and laptops.

"What we were able to achieve is [a capacitor] that looks a lot more battery-

esque," said David Mitlin, the lead on the eggs-periment. "What we showed is

our material can hold three times as much charge as activated carbon but

last just as long."

That’s three to four times as much charge as a commercial electrode.

And, unlike expensive carbon nanotubes and graphene sheets that are also

being turned into capacitors, eggshells are usually thrown away as trash.

"People will actually pay us to take them away." Mitlin says.

It has to do with the atomic and microstructure of the heated eggshell

membranes. The membrane’s chock full of nitrogen groups which can soak up

and store extra charge. Plus, the interconnected mesh of carbon fibers make

for a great conducting highway, letting the charge flow in and out of the

capacitor rapidly.

Oddly enough, other chicken bits have been found to be suited to the task of

energy storage.

A little over years ago, scientists at the University of Delaware discovered that

roasted chicken feathers made great hydrogen storage materials for fuel

cells, again, because of their unique porous micro architecture.

Mitlin’s group has plans to develop their discovery towards commercial

application. After all, high storage capacitors in our electronics could make a

world of difference to our daily lives.

"If your cell phone ran on a capacitor you could charge it in 45 seconds," Mitlin

says.

Just make sure your capacitor is cage free.

Fonti: Italic News e Co.Exist

E’ un’iniziativa

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