MSU scientists have made another step towards creating a super battery

© A. Khohlovskaya cell, which studies the mechanisms of processes in lithium-air batteriesMSU scientists have made another step towards creating a super battery© Khokhlov

To MSU continues work on the creation of lithium-air battery, the capacity of which is five times more than current lithium-ion batteries. The staff of physical and chemical faculties of the Moscow state University named after M. V. Lomonosov with the assistance of the simulation determined what processes underlie the transfer electrodes of lithium-air battery in an inactive state. The results published in the Journal of Physical Chemistry C.

Lithium-air batteries, a device that produces electricity out of thin air, such batteries are also called Li-flame. Due to the greater energy density is much more effective than lithium-ion competitors. Lithium-air batteries can be very useful, for example, to increase the mileage of electric cars without recharging. But despite all the advantages, the industrial production of lithium-air battery has not yet started: their developers are faced with technological difficulties, which are still can’t decide.

«One of the main problems of development of such batteries is the electrode passivation, i.e. the transition surface of the electrode material in an inactive state. We received new data on the mechanism of the reaction and on the basis of their suggested ways to slow down the passivation of the electrode. Our proposed technique can be used to search for the most suitable solvents for the electrolytes and electrode materials», — said Artem Sergeev, one of the authors, post-graduate student of the Department of physics of polymers and crystals Department of the solid state physics of the physical faculty of MSU named after M. V. Lomonosov.

For normal operation of Li-air batteries require pure oxygen, not air, which is a mixture of atmospheric gases. Carbon dioxide and moisture contained in the air, slowing oxidation-reduction reactions underlying the action of the battery. To circumvent these obstacles, required, according to various estimates, from 5 to 10 years. MSU scientists investigate the processes that impede the smooth operation of lithium-air batteries.

«Generally, in the case of success of development, the battery should be lithium-air, that is, to use air. Unwanted components (moisture, carbon dioxide) needs to be «filtered» special membranes. But now there are more fundamental problems, so their solutions tend to use lithium-oxygen cells, where serves pure oxygen from cylinders,» commented Alexei Khokhlov, one of the authors of the article, academician of RAS, head of chair of physics of polymers and crystals, faculty of physics, Moscow state University named after M. V. Lomonosov, as well as the presidential candidate of Sciences (election of the President of the Russian Academy of Sciences will take place on 25 September).

© RIA Novosti / A. Palaniappan diagram of lithium-air cellsMSU scientists have made another step towards creating a super battery© RIA Novosti / A. Palaniappan diagram of lithium-air akkumulyatorov lithium-air battery cathode (positive electrode) is a porous carbon sponge in the cavities of which there is a containing lithium ions, the electrolyte is in contact with the external gas environment. This is to ensure that the air supplied to the electrolyte is a liquid ionic conductor. Scientists have modeled the boundary between electrode and electrolyte solution in the cathode of lithium-air cells and suggested a way to slow down the passivation of the electrode. For polnotsennogo modeling by the molecular dynamics methods the researchers used a supercomputer complex of Moscow state University.

«We realized that the formation of non-conductive products of the discharge directly on the electrode surface (passivation) occurs only after binding of the intermediate product, the superoxide anion with the lithium ions, which are present in large numbers in close proximity to the electrode. If they are there to displace, it may be that passivation will no longer occur so quickly,» — concluded Alexei Khokhlov.

The work was done in collaboration with scientists from Ulm University, Germany.