The Race for the Future of Energy Storage: Sodium-Oxygen Battery

Battery evolution is targeting always smaller, lighter, and less expensive systems in order to keep up with electronics development. Electric vehicles are starting to spread in many countries and several multinational car corporations, captained by Tesla, are investing in this technology. Moreover, it is just a matter of time before also the electric grid would need powerful batteries to implement the renewable energies, overcoming the issue of discontinuous production. The two main limitations of today Li{ion batteries are the energy density and the high cost. Remarkable improvements are needed to meet future requirements and it is progressively clearer that we are reaching the maximum exploitation of that system. The question is which revolutionary battery will replace Li{ion and become the pivot of the energy storage of tomorrow? Metal-air batteries are considered from lots of scholars as the system of the future. They have an astonishing energy density, one order of magnitude higher than the ones of Me-ion and they are less expensive. Among those new type of batteries, the most studied has been Li-air, yet some complications delayed the obtaining of a practical battery and some researchers started to look around to nd other possible metals to employ as the anode. Sodium turned out to be one of the most promising candidates, thanks to its abundance on the Earth crust (2.83% vs. 0.0018% of Lithium), its low cost (1.7 $=kg vs. 68 $=kg of Lithium), and its high efficiency, due to one{electron transfer reactions. This thesis reports the experimental work done at the Nanomaterials Energy Systems Laboratory at UIC, nalized to the study of Sodium{Oxygen battery. From the preparation of anode and MoS2 nano-flakes coated carbon cathode, to the shallow cycling of the cells. First, we explored different electrolytes and salts, to nd the best combination. Then we performed a systematic study on the influence of current rates and salt concentrations on the performance, and nally we began to analyze the passivation of the anode as protection against side{reactions and poisoning.