Review of Electrolytes in Nonaqueous Lithium-Oxygen Batteries

Based on an inexhaustible and ubiquitous source of oxygen, the lithium-oxygen batteries are currently the subject of much scientific investigation because of their potential for extremely high energy density. The electrocatalytic materials for them have been extensively researched during the past decade. Even though they are a key component in the lithium-oxygen batteries, however, the study of electrolytes is still in its primary stage. Electrolytes have an important influence on the electrochemical performance of lithium-oxygen batteries, especially on their cycling stability and rate capacity. Therefore, it is important to select an ideal electrolyte with excellent stability against attack by reaction intermediates, along with excellent oxygen solubility and diffusivity. In this review, the physicochemical and electrochemical properties of organic electrolytes for lithium-oxygen batteries are discussed and compared. Furthermore, possible research directions are proposed for the development of an ideal electrolyte for enhanced electrochemical performance.