A Regular Biporous Model of the Cathode Active Layer Structure of a Lithium-Oxygen Battery. Calculation of Overall Characteristics of the Cathode Active Layer

• Published in: Protection of metals and physical chemistry of surfaces 2020-07, Vol.56 (4), p.716-724
• Main Authors: Chirkov, Yu. G., Rostokin, V. I., Andreev, V. N., Bogdanovskaya, V. A., Korchagin, O. V.
• Format: Article
• Language: English
• Subjects: Capacitance; Cathodes; Channels; Characterization and Evaluation of Materials; Chemistry and Materials Science; Clusters; Corrosion and Coatings; Current density; Discharge; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Lithium; Lithium batteries; Lithium ions; Materials Science; Metallic Materials; Oxygen; Physicochemical Processes at the Interfaces; Tribology
• ISSN: 2070-2051; 2070-206X
• DOI: 10.1134/S2070205120030119

The active layer of a lithium-oxygen battery (LOB) cathode must have a complex structure consisting of two types of pores (macropores and mesopores). For successful operation of the cathode active layer during the LOB discharge, attempts are being made to create two types of pore clusters: a macropore cluster that provides the transport of oxygen to a zone, where the final product, lithium peroxide, is formed, and a mesopore cluster that guarantees the delivery of lithium ions. The structure of the cathode active layer composed of two types of clusters is optimized in model calculations. However, it from the experimental data, even after the actual implementation of these theoretical recommendations, that the LOB dimensional characteristics during the discharge (in particular, current density I , mA/cm 2 , and cathodic capacitance C , C/cm 2 ) remain low. In the present work, a new type of cathode active layer structure was suggested: a regular biporous model. In this model, the channels for the supply with oxygen and lithium ions are separated from each other. This fact allows one to simultaneously and independently improve the operation of each of the two channels. The calculations showed a clear advantage of the active layers with this new structure. In particular, the current density i and cathode capacitance С raised to tens of mA/cm 2 and about of a thousand of C/cm 2 .