Hemp nanosheets could be better than graphene for making ideal supercapacitor

[Seaniebawn]

_http://www.kurzweilai.net/could-hemp-nanosheets-topple-graphene-for-making-the-ideal-supercapacitor

As hemp makes a comeback in the U.S. after a decades-long ban on its cultivation, scientists are reporting that fibers from the plant can pack as much energy and power as graphene, long-touted as the model material for supercapacitors, according to David Mitlin, Ph.D.

Supercapacitors are energy storage devices that have huge potential to transform the way future electronics are powered. Unlike today’s rechargeable batteries, which sip up energy over several hours, supercapacitors can charge and discharge within seconds. But they normally can’t store nearly as much energy as batteries, an important property known as energy density.

One approach researchers are taking to boost supercapacitors’ energy density is to design better electrodes. Mitlin’s team has figured out how to make them from certain hemp fibers — and they can hold as much energy as the current top contender: graphene.

“The key advantage is that our electrodes are made from biowaste using a simple process, and therefore, are much cheaper than graphene.”

His process uses hemp bast fibers. The fibers come from the inner bark of the plant and often are discarded from Canada’s fast-growing industries that use hemp for clothing, construction materials and other products. The US could soon become another supplier of bast.

His team found that if they heated the fibers for 24 hours at a little over 350 degrees Fahrenheit, and then blasted the resulting material with more intense heat, it would exfoliate into carbon nanosheets.

Mitlin’s team built their supercapacitors using the hemp-derived carbons as electrodes and an ionic liquid as the electrolyte. Fully assembled, the devices performed far better than commercial supercapacitors in both energy density and the range of temperatures over which they can work. The hemp-based devices yielded energy densities as high as 12 Watt-hours per kilogram, two to three times higher than commercial counterparts. They also operate over an impressive temperature range, from freezing to more than 200 degrees Fahrenheit.

They’re presenting their research, which a Canadian start-up company is working on scaling up, at the 248th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society.

Mitlin, who conducted the research while at the University of Alberta, received funding from Alberta Innovates Technology Futures, National Institute for Nanotechnology (Canada) and Alberta Livestock and Meat Agency.

 

[MusicMan]

Thanks, Seaniebawn for another great discovery.
Hemp would be a good material to have available when SHTF, so versatile.

 

[Seaniebawn]

Thanks, Seaniebawn for another great discovery.
Hemp would be a good material to have available when SHTF, so versatile.

No Problem MusicMan, my friend Neil and I were looking into building our own supercapacitors using graphene oxide as a possible way for energy storage, there is a video on youtube from a Professor at UCLA describing the process

_https://www.youtube.com/watch?v=_oEFwyoWKXo

from the video description

Imagine having an energy storage device that stores as much energy as a conventional battery, yet, can be charged 100 to 1000 times faster. Supercapacitors store charge in electrochemical double layers whereas batteries store charge through electrochemical reactions. Although supercapacitors can charge and discharge much faster than batteries, they are still limited by low energy densities and slow rate capabilities. Researchers at UCLA have successfully used an inexpensive precursor (graphite oxide) to produce high-performance graphene-based supercapacitors using a computerized LightScribe DVD drive. These devices exhibit ultrahigh energy density values in different electrolytes approaching those of batteries, yet they can be charged in seconds. The devices can be charged and discharged for more than 10,000 cycles without losing much in performance compared with a normal life-time of less than 1000 cycles typical for batteries. Additionally, the devices are completely flexible and maintain excellent performance under high mechanical stress.

we aren't engineer's but that doesn't stop us from trying :), and to be honest the method seems easy enough and fairly inexpensive, but alas it sort of got dropped on the way side when we started building our 3D printer, we must get back to that "experiment"

 

[dredger]

Hi,
I found this article and searched on the forum to know if this was already mentionned (on terms "hemp batteries"), and yes, i found this old 2015 post.
Here's a new article from 5/1/2022 about, I thought this was good to link it somewhere here on the forum :

Hemp Batteries Last 8X Longer than Lithium, Outperforming Graphene for 1000th of the Cost

Replacing lithium batteries with hemp would make electric cars (and all our other gadgets) WAY more sustainable! Is there anything hemp can’t do? A year after hemp became legal to grow in the United States, we’ve seen its power to make better clothing, better buildings and better medicine. Now...

returntonow.net

Bonus for french, as i discovered it initially in french, so here's the translated article in french.