| 초록 |
Metal-oxygen batteries have been paid attention to one of the promising next-generation batteries applied for electric vehicles, thanks to higher energy density than current lithium-ion batteries. In particular, sodium-oxygen (Na-O2) batteries give a promise for little overpotentials for charge and less side reactions in comparison with lithium-oxygen (Li-O2) batteries. Nevertheless, poor cycling performance is still measured, which have not yet fully understood. Here we demonstrate one of the critical reasons for low cycling stability from Na metal as the negative electrode. We observed nanometer size of uneven precipitates that passivate the positive carbon electrode surface before and after galvanostatic tests. These precipitates are ascribed to soluble solid electrolyte interphase (SEI) that fell away from the Na metal interphase and deposited on the positive electrode. In the presentation, I will discuss improving stability of Na metal from selective electrolytes and the correlated Na-O2 battery performance in detail. |
