Researchers at the Federal Research Center "Institute of Catalysis” SB RAS (IC) has created carbon materials for supercapacitors based on pine nut shells, the only ones harvested in Russia on an industrial scale. The properties of these materials make it possible to obtain elements with a high density of stored energy. This is necessary for uninterrupted power supplies, alternative energy, electric transport, and the space industry.
Petr Yeletsky, Candidate of Chemical Sciences and Senior Researcher at the IC Engineering Center, provided more details,
The nut shell has a high density that is, to a certain extent, transferred to the final product. To achieve high energy capacity per unit volume of a supercapacitor, the electrode material must be dense and have a high specific surface area. The denser the material, the less volume it occupies, and the large surface provides a high capacity.
To achieve activated carbon, the shell is first crushed and carbonized in a fluidized catalyst bed. Then, the biochar obtained in the first stage is mixed with an alkali solution, treated at a temperature of 600-1000 °C, washed, and dried. The maximum nutshell coal specific surface area that scientists achieved is 2,200 square meters per gram. The materials obtained were tested in the IC-NSU "Institute of Chemical Technologies” that is based at NSU in the recently created youth laboratory of composite materials for electronics.
Marina Lebedeva, Candidate of Chemical Sciences and Laboratory Head, explained,
We form thin tablets from the carbon material obtained and press these into the metal cases of flat batteries. This allows you to test materials in conditions that are as close to real as possible. The tests conducted demonstrate that activated charcoal from walnut shells shows promise for practical use.
A review of such promising materials and methods for obtaining them was published by experts in the Journal of Energy Storage. The scientists plan to improve the process of activated carbon synthesis so that its properties become optimal for use in a supercapacitor with the highest possible energy intensity. The next step will be the creation of a prototype of a powerful ionistor.
Based on material from IC SB RAS
