Lithium-oxygen cells

Jung H-G, Kim H-S, Park J-B et al (2012) A transmission electron microscopy study of the electrochemical process of lithium-oxygen cells. Nano Lett 1 2. doi 10.1021/nl302066d... 

Figure 22.18 Schematic of the lithium-oxygen cell and its component materials. The electrolyte laminate is composed of PC/LI20), GC, and polymer composite (PC/BN) membranes. (Reproduced from Kumar et al. [36].)...

All these issues are very critical for the proper operation of lithium-oxygen cells. The electrolyte instability severely affects the cycle life. Indeed, the poor cycling performance observed in the first prototypes was due to this factor. With the formation of lithium peroxide 2Li + 02 LijOj, the overall oxygen electrochemical process proceeds via a sequence of intermediates steps O2 + e —> O2 + 2Li —> Li202, including a radical anion O2 that readily decomposes most electrolytes [62], in particular the organic carbonate solutions commonly used in lithium-ion batteries (see Figure 3.33). 

B. Kumar and J. Kumar, Cathodes for solid-state lithium-oxygen cells Roles of Nasicon glass-ceramics, J. Electrochem. Soc. 157,2010, A611-A616. 

Imanishi and co-workers of Mie University, Japan, [68] have examined the charge discharge performance of an aqueous lithium-air cell with 0-LATP and saturated LiOH with 10 M LiCl aqueous solution with a third electrode for the OER, as proposed by Stevens [50]. Rechargeable hthium-air batteries require a bi-functional air electrode for the oxygen reduction reaction (ORR) and the OER. When an air electrode is used for the OER, it is exposed to a highly corrosive potential. Arai et al. [69] examined a high surface area carbon black (Ketjen black KB) electrode for the ORR and OER in aqueous 8 M KOH and observed electrode deterioration during the OER, which they claimed was due to a loss of the electrochemicaUy active surface... 

Theoretically with unlimited oxygen, the capacity of the battery is limited by the amount of lithium metal present in the anode. The theoretical specific energy of the Li-oxygen cell. 

FIGURE 1.5 A lithium-air cell s discharge is depicted here in pure oxygen gas using a manganese oxide catalyst. The cell could provide additional energy past tlie 1.5 V cutoff. 

FIGURE 1.6 Different specific capacities are determined by the catalysts present in the air cathodes. These were lithium-air cells run in oxygen gas with variables constant except the catalyst present. 

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