Influence of 12-Crown-4 on oxygen electrode of aprotic Li-O2 battery

Abstract

One of the major challenges with Li-O2 batteries is that the discharge product, Li2O2, blocks the gas pathway because of its poor solubility in aprotic solvents. In this work, 12-crown-4 ether was used as an additive to capture Li+, and its influence on the solubility of the discharge products of the oxygen electrode was investigated. Multiple electrochemical methods, including cyclic voltammetry and rotatingring disk electrode, were used. The results show that the addition of only 5% of 12-crown-4 ether significantly improves the stability of the oxygen reduction product O2‑, and decreases the formation of solid Li2O2. We used a combination of the hard-soft-acid-base theory and ab initio calculations to explain these observations.