Hemp Based Supercapacitors
A capacitor is an electronic component which can store electrical charge. A supercapacitor is one which can store up to 10-100 times more charge than a traditional capacitor. Two conductor plates standing parallel to each other and a dielectric material (an electrical insulator that can be polarized by an applied electric field) in between make up a capacitor. The smaller the distance between plates, the larger their area, or the quality of the insulator determines the capacitor’s capacitance.
As superconductor technology advances, we have bateries which are lighter in weight, have more battery life, are faster to charge or discharge, and are less costly to produce. Such techonologies are used in mobile phones, electrical cars, computers and more.
This is where hemp fibre comes into play. Currently, a carbon based material, graphene is used in supercapacitors. Graphene is quite expensive to produce, it costs $2000 per gram.
Researchers led by Professor David Mitlin, developed graphene-like nano-material that outperformed graphene with nearly twice more storage capacity. According to Prof. Mitlin hemp supercapacitors have been able to store 12 watt-hours of energy per kilogram.
And this material made from hemp fibre costs less than $5000 per ton. It is made from the plant’s raw hurds going through a thermal and chemical process. Hemp waste is made into nanosheets of supercapacitors.
Supercapacitors vs Batteries
Like batteries, supercapacitors are able to store energy. Lithium-ion batteries for example, are able to hold large amounts of electricity, and are inexpensive to produce. They work well as rechargeable batteries. Yet they have drawbacks: they have a limited lifespan and they can release a limited amount of electricity in an instant.
Comparatively speaking, supercapacitors can charge in seconds, their lifecycle is much longer and can release much larger amounts of charge in an isntant. However, their capacity is much less compared to batteries. Overall, making them a poor choice for energy storage. With the advance of hemp based supercapacitors, this might revolutionize our energy storage technologies. If supercapacitors can be made at a low enough cost, they might eventually replace li-ion batteries.