At Novosibirsk State Technical University (NETI) is developing electrical insulation materials from domestic raw materials for the energy sector. The work is supported by a grant from the Russian Science Foundation.
Today, one of the most urgent tasks in the energy industry is the development of energy storage systems. Supercapacitors, devices that are used in power grids, power equipment, and electrical engineering applications, have a high storage potential. The supercapacitor consists of two electrodes, an electrolyte and a membrane separator, which ensures the passage of ions during charge and discharge and prevents a short circuit.
According to Nikolay Gromov, Head of the Department of Environmental Engineering at NSTU-NETI, Candidate of Chemical Sciences, Associate Professor, the main suppliers of separators to the world market are Asian countries — China, Japan, South Korea. Separators are mainly made from polyolefins, synthetic polymer compounds obtained from hydrocarbons, which, in turn, are extracted from petroleum raw materials. Production requires a large amount of non-renewable resources, and the disposal of synthetic polymers is accompanied by harmful emissions into the atmosphere. An urgent task arises — to develop materials that would reduce not only the carbon footprint, but also the dependence on imports in general. One of the promising options is to create separators from renewable cellulose.
"We used miscanthus biomass, which is a perennial herbaceous plant that does not require high—quality agricultural land and can be grown in swampy soils. The technology of catalytic fractionation was used to isolate cellulose, this method has environmental advantages — it reduces the amount of waste resulting from processing. The second task of the project was to create the electrical insulation membranes themselves. An eco—friendly approach was also applied here - the casting of membranes from cellulose dissolved in an ionic liquid. Ionic liquids are called "green solvents" because of the possibility of repeated use," said Nikolai Gromov.
The key objective of the project is to verify the effectiveness of the created electrical insulation materials in supercapacitors. For this, a laboratory capacitor with carbon electrodes and an aqueous electrolyte of sodium sulfate solution will be used. As the scientist explained, it is important to check such key parameters of the membrane as wettability, resistance, and resource testing.
Nikolai Gromov added that the resulting cellulose can be modified to produce cellulose esters. They can be used to cast electrical insulating films and make separators for lithium-ion batteries or non-aqueous electrolytes.
Next year, the project will optimize all membrane manufacturing processes with a focus on their electrochemical properties.