ИСТИНА

Lithium-oxygen chemistry can potentially enable devel-opment of rechargeable batteries demonstrating a few-fold in-creased specific energy in comparison to lithium-ion ones. The practical implementation of this idea, however, faces a number of significant challenges. The first one is the problem of posi-tive electrode material stability during cycling. During lithi-um-air battery (LAB) operation oxygen reduction reaction oc-curs at the positive electrode – oxygen dissolved in the electro-lyte is reduced to superoxide (O2-), which forms ionic pairs with Li+ (LiO2). Such intermediates are then converted to a final discharge product lithium peroxide (Li2O2) after transfer of second electron from the electrode or by chemical dispro-portionation reaction. Unfortunately, oxygen reduction prod-ucts and intermediates are highly reactive species that can at-tack both electrolyte solvents and electrode materials. Among others, carbon materials received major attention as a positive electrode in Li–O2 cells as they are freely available, porous, highly conductive and lightweight. The requirements for po-rous positive electrodes and their chemical stability would be discussed in the talk using carbon materials and Ti-based con-ductive compounds as examples. Application of a number of neutron and synchrotron- based tools (neutron reflectometry, XPS/NAP XPS and others) for monitoring the interfacial pro-cesses at positive electrodes will be demonstrated.