After decades of bans on its cultivation, hemp is making its comeback in the US and according to scientists, its fibers can contain as much energy and power as graphene which has long been the model material for supercapacitators.
Though hemp and marijuana come from similar plant species, they’re distinct and hemp is indeed one of the most universally-useful plants on the planet. The use of hemp goes way back to the time between 5000 and 7000 BC.
Could hemp batteries become the future? Let’s find out…
Hemp Batteries more Powerful than Graphene & Lithium?
According to experts in the field, industrial hemp and hemp seed may help change the economy in a positive way and thus, we need to use it in its full potential, particularly in the area of energy storage.
David Mitlin, Ph.D., points out that supercapacitors are devices for energy storing that have immense potential to change the way in which electronics are powered.
Namely, unlike the rechargeable batteries today that sip up energy over a couple of hours, the supercapacitators are able to charge and discharge within seconds.
However, normally, they don’t store as much energy as batteries do, which is a crucial characteristic known as energy density.
Researchers are trying to better the energy density of supercapacitators by designing better electrodes.
Mitlin together with his team have discovered how to do this from specific hemp fibers which can hold up as much energy as the top contender currently, i.e. graphene.
Graphene: The Ideal Supercapacitator?
The creation of the best supercapacitator has mostly been focused on graphene, a strong and light material made from atom-thick carbon layers. When stacked, they can be made into electrodes.
Currently, the scientists are testing how to benefit from the one-of-a-kind characteristics of graphene to make better solar cells, systems for filtration of water, touch-screen tech, and supercapacitators and batteries.
But, this isn’t cheap. So, they may turn to a less expensive, yet potent enough variant, that is, hemp.
Could Hemp Be the Key?
Mitlin’s team decided to find out if they can create graphene-like carbons from hemp fibers that are acquired from the inside bark of the plant.
They’re often discarded from the fast-growing industries in Canada where hemp is used for clothing, construction materials, and other products.
For the purposes of the research, they heated up the hemp fibers for 24 hours at 350 degrees Fahrenheit. The hemp-based devices produced energy density as high as 122 Watt-hours per kilo, two to three times higher than commercial counterparts.
Moreover, they also operate over a vast temperature range, from freezing to higher than 200 degrees Fahrenheit. The small-scale production of hemp-based supercapacitators is expected to start soon.