Abstract:
Li-O2 batteries have become a promising candidate in the scientific world and can be a better replacement for the existing energy storage devices because of their theoretical high specific capacity. However, they suffer from poor rechargeability, high charging voltages, low efficiency, accumulation of side products like Li2CO3, HCOOLi etc. Here, we tried to study the possible mechanisms that can occur during their cycling and also the parasitic reactions associated with it. We found from the pressure measurements that the disproportionation reaction occurs during charge in addition to discharge. Moreover, the number of e- per mole of O2 deviate from the ideal value of 2 because of the parasitic reactions and many other factors still unknown. A method based on Mass Spectrometry has been developed to quantify those carbonaceous side products along with the discharge products for Li-O2 and Na-O2 batteries. Based on that method, discharge products like Li2O2, NaO2 and KO2 can be quantitatively determined using aq.FeCl3 and side products with the acid and Fenton’s reagent. But there many factors still unknown about this method like the reactivity of different ions in the solutions.
