Supercapacitors are electrical energy storage devices that recharge and discharge much faster than normal rechargeable batteries. They’re used for things like capturing the energy from regenerative braking in hybrid cars to providing power for static random access memory units. Supercapacitors use double-layer electrodes to store their charges, and can use activated carbon (carbon with micropores) for that purpose. That said, one of the challenges with carbon-based supercapacitors can be finding an environmentally friendly and sustainable carbon source.

Now, researchers at the Boreskov Institute of Catalysis and the Novosibirsk State University (both in Novosibirsk, Russia) have demonstrated a technique for fabricating activated carbon from waste rice husk, and have tested this material in supercapacitors. What Marina V. Lebedeval, Petr M. Yeletsky, Artem B. Ayupov, Aleksey N. Kuznetsov,Vadim A. Yakovlev, and Valentin N. Parmon report in their article, “Micro-mesoporous carbons from rice husks as active materials for supercapacitors” published in Materials for Renewable and Sustainable Energy, is that they fabricated and tested supercapacitors made from rice husks.

Now, researchers at the Boreskov Institute of Catalysis and the Novosibirsk State University (both in Novosibirsk, Russia) have demonstrated a technique for fabricating activated carbon from waste rice husk, and have tested this material in supercapacitors.

Typically, rice husk, as a bulk agricultural waste product, has had no viable commercial application. Because the husk contains high amounts of amorphous silica in addition to its carbon (organic) content, processing this waste has been difficult. What Lebedeval et al. did was to prepare activated carbon using sodium and potassium carbonates and bases in a fluidized catalyst bed reaction (a technique about which they had previously published) and then tested this carbon in supercapacitors. They prepared and tested a range of carbons, with surface area (magnified by the microporous “activation” process) from 540 to 3,600 square meters per gram. While each material demonstrated different electrical properties, they conclude that “utilization of the rice husk as [a] template-containing precursor allows [us] to prepare materials with [the] textual characteristics for… application in… supercapacitors.”

You can read the entire article here.