RUDN: RUDN University chemist creates carbon “flower” for zinc-ion supercapacitors

A RUDN University chemist has created an unusual carbon structure that can be used as a cathode in zinc-ion supercapacitors. The batteries obtained on its basis have a higher capacity and energy density than existing analogues.
СуперконденсатSupercapacitorsры can store up to 100 times more energy, than conventional batteries, charge faster, and withstand more recharge cycles. One of the most promising supercapacitors is zinc — ion. However, its real capacities, which are still possible to achieve experimentally, are significantly less than those calculated theoretically. This is due to the limitations of the characteristics of carbon compounds that are used as cathodes. In an attempt to find the best carbon structure, scientists are investigating carbon nanotubes, chemically activated graphene, layered porous carbon, and hollow уuranium spheres. A RUDN University chemist has proposed a new 3D-structurethat will improve the properties of zinc-ion supercapacitors.

“Hybrid суперконденсаторыion-based supercapacitorshave attracted considerable attention as перспективнpromising platformsа for optimizing energy storage devices. However, limited by the insufficientquality of carbon cathodes, the energy capabilities of zinc-ion supercapacitors are inferior to those expected, especially at high power output, ” Raphael Luque, Professor at the RUDN University Center for Molecular Design and Synthesis of Innovative Compounds for Medicine.

To get a new 3-Dstructure, chemists mixed melamine, boric acid and flour in water. The mixture was placed in an autoclave at 180 ° C for 15 hours. The result is structures similar in structure to carnation or hydrangea flowers — uneven balls with a large number of pores. This” bouquet ” chemists subjected to pyrolysis-for 2 hours heated, gradually increasing the temperature to 900 degrees. During pyrolysis, the auxiliary compounds in the” flowers ” disintegrated, and only the carbon frame remained. Chemists performed similar procedures using flour and melamine, as well as only flour, as the starting compounds. All the resulting structures were studied using a scanning electron microscope. Then,using the resulting” flower ” carbon (BCF), chemists made zinc-ion суперкондеsuperconductors and measured its characteristics.

After comparing the structure of the obtained compounds, chemists came to the conclusion that boric acid did not affect the formation of the “flower” structure, and in fact оmelamine crystals and flour became the basis for it. It alsoturned out that BCF consists of many “nanolipes” — thin sheets connected to each other in a single ball structure. These bound nanolipes provided fast charge transfer within the flower and low resistance. The capacity аккумулятора на основе of the BCF-based battery was larger than that of other similar devices — 133.5,5 mAh/ gram. The energy density (that is, the amount of energy that 1 kg of battery can store) also exceeded existing zinc-ion analogues.

“Suitable pores of the resulting carbon and the structure of its nanolobes ensure the penetration and exchange of electrolyte ions. Our research paves the way for creating carbon structures from individual carbon segments for устройствenergy storage devices, ” Raphael Luque, Professor at the RUDN University Center for Molecular Design and Synthesis of Innovative Compounds for Medicine.

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