Solvent autoxidation, electrolyte decomposition, and performance deterioration of the aprotic Li-O2 battery

The electrolyte decomposition is widely recognized as the greatest challenge to the successful development of the aprotic Li-O₂ battery. The decomposition of the organic ethers, which are the commonly used electrolyte solvents in the current studies, can be chemical or electrochemical during discharge or charge. In this paper, the influence of oxygen on the decomposition of the ether-based electrolyte is discussed. Ether solvents are found to be oxidized in contact with oxygen whether the cells operate or not. The solvent autoxidation significantly promotes the electrolyte decomposition during the discharge process of the ether-based Li-O₂ battery. As a result, the oxygen exposure time before battery operation significantly affects the electrochemical performance of the ether-based Li-O₂ battery. After the prolonged exposure to oxygen, both the discharge capacity and the working potential of the battery decrease to some extent. More importantly, the recharge potential of the battery greatly increases with extending the previous oxygen exposure time.