| Popis: |
Today, more and more attention is paid to non-traditional rechargeable sources of electric current, which are able to quickly charge and discharge (in a few seconds or minutes), have high power (kW/kg) and a long service life (tens of thousands of charge-discharge cycles). Such current sources include electrochemical capacitors (EC), which in the special literature are called supercapacitors, ultracapacitors, ionistors, or molecular storage devices. The principle of operation of such current sources is based on their ability to store and release electrical energy at a given time through the internal redistribution of electrolyte ions in a double electric layer (DEL). The rate of redistribution of ions in the DEL is several orders of magnitude higher than the rate of ion transfer through the “electrode-electrolyte” phase boundary during classical redox transformations in batteries. That is why ECs are non-traditional current sources, they have significant advantages over batteries in terms of their specific power, the rate of charge-discharge processes and service life, although they are inferior to batteries in terms of their capacity and energy density. Particular attention has been paid to EC in connection with the start of production in many countries of the world of environmentally friendly cars and buses with electric motors that require high power at the time of engine start. In addition to being used in transport, ECs are widely used in military and space technology, in energy storage systems at peak loads, for regulating wind generator turbines, etc. The production of electrochemical capacitors requires fairly large capital investments. This is due to the requirements for the environmental friendliness of the production itself, where a significant amount of costs is spent on ensuring safe working conditions for personnel, on capturing harmful substances and their disposal. That is why the issue of developing EC to reduce the cost of production through the use of new materials and the improvement of technological processes becomes especially relevant. The main scientific research in recent years in the field of EC has been associated with the study of new electrochemical systems, electrode materials and electrolytes. To a certain, but insufficient extent, attention was also paid to the improvement of the technology of combining the active material and the current collector. Even less research work is related to the development of environmentally friendly technologies for the production of composite active materials for capacitors, although the development of these components can potentially provide high electrical performance of capacitors and significantly reduce the cost of their production. These circumstances put forward the research and development of environmentally friendly methods for obtaining composite materials for electrochemical capacitors into the category of complex, but relevant scientific and technical problems. |
