Social protection issues, the environment and the effectiveness of the acquisition and use of energy are currently being hotly debated. Deal with them as experts from academics and scientists. They are compiled by specialized teams that deal with materials research and solve current problems in the field of electrochemical power sources, solar cells and other alternative power sources. One such is addressed to the Faculty of Electrical Engineering and Communication BUT – the safety of lithium-ion batteries.
Lithium (and now especially the version known as lithium – ion) batteries are the power source particularly suitable for mobile use and for balancing the difference between the floating production and consumption of such energy from alternative sources. Electric passenger demand performance of tens of kW backup daily fluctuations in the production of alternative sources of hundreds of kW to MW units. The bulk of their application to the phenomenon, with other unknown chemical power sources, and question their safety.
Each element lithium – ion battery contains a number of substances with different properties in terms of ignition. Positive electrode materials are substances with a high proportion of chemically bound oxygen and thereby promoting burning. Negative electrode materials themselves are often flammable and pyrophoric in air. This accesses the electrolyte solution consisting of lithium salts in organic and therefore usually flammable liquid. In fact we know several ways, which can cause burning and the fire system. This may be an excessive load current, both during charging and discharging, overheating or mechanical damage causing internal short circuit. This last reason is particularly important for applications in military (puncturing and subsequent short circuit caused by penetration).
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Defense against fire is basically threefold. As a base must be compliance with the prescribed working conditions. Above all, the prescribed method of charging. Furthermore, in the compilation of articles for batteries, we make sure that the articles in both the nominal battery capacity or immediate varied as possible. Of course we must exclude the improper manipulation and arbitrary dismantling both cells and batteries from them assembled.
Active protection is to use the battery protection circuit. Battery cell for mobile phones contains at least two electronic circuits, one of which is the governing and the other works as a power switch. Articles include power battery protection circuit, which in addition to voltage and current extra police and excessive temperature rise and exceeded the article unplugged. Output voltage is always governed by power electronic system. Loss of large battery voltage, for example, composed of hundreds of articles, is compensated electronic control, and therefore jeopardize the entire system.
** One of the teams of the Institute of Electrical and Electronic Engineering FEEC BUT **, ** which maintains Assoc. Ing. ** Mary Sedlaříková solves the passive protection on finding materials for lithium – ion batteries, which have significantly lower ignitability and increased resistance to elevated temperatures. Currently focused on solvents and polymers for the preparation of electrolytes. As solvents are investigated substances such as sulfones, a flash point less than about 50 ° to 60 ° C higher than the value currently used solvents. The staff of that team then verifies and develops polymers containing organic silicates. Also, these substances are less incendiary, and in addition, electrical conductivity of composite polymer made on this basis is higher than the conductivity of electrolytes used yet.
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It is at the Institute of Electrical Research in the field of electrochemical power sources a long tradition (40 years). The research is focused on the area of lead-acid batteries, alkaline batteries, both types of advanced lithium-ion batteries and supercapacitors. This issue will also have completed projects, namely: the Ministry of Education Research Grant project („Resources, Accumulation and Optimization of energy use in terms of sustainable development“), Grant GA ("increased safety lithium-ion batteries) and has also obtained a European project CVVOZE Regional Centre (Centre for Research and utilization of renewable energy sources).
These topics will also be part of the forthcoming international conference ** Advanced Batteries, Fuel Cells and accumulators ** (ABAF). This conference traditionally held in Glasgow from 19th ** – 22 September 2010 **. "It will be 11th Conference series, and was attended by scientists from the already more than 27 countries worldwide. Traditional is also interested scientists from Eastern countries and the Far East, "said the main organizer of the Assoc. Sedlaříková. More information about the upcoming conference can be found at www.aba-brno.cz.
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** ** For information about the faculty:
Electrotechnical disciplines were first at the technical university, BUT the first time in 1905. Since 1959, when it was founded as an independent faculty of energy, which later transformed into the Faculty of Electrical Engineering, has successfully completed engineering studies at our faculty over 23 000 graduates. In 2001 she received the present name of Science – Faculty of Electrical Engineering and Communication Technology (FIT) and a year later she conceived the accreditation of new advanced degree programs in a structured study. The faculty has more than 4,400 students in bachelor's, master's and doctoral degree programs.
Studying at the faculty is focused on a wide range of scientific areas: control technology and robotics, biomedical engineering, power electronics and electrical engineering, electrotechnology and electronics, microelectronics, and Radioelectronics Teleinformatics.
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