One-Electron Mechanism in a Gel–Polymer Electrolyte Li–O₂ Battery

Development of better energy storage media is vital in the adoption of renewable energy technologies, and lithium–air (O 2 ) batteries have spurred great interest. However, current Li–O 2 batteries are plagued by unwanted side reactions, flammable electrolytes, and slow kinetics attributed to the 2 mol e – /mol O 2 peroxide chemistry. In this work, we show that a gel polymer electrolyte consisting of a polymer, ionic liquid, and salt can control the oxygen reduction chemistry in a Li–O 2 cell (switching from a 2 e – to a 1 e – superoxide chemistry), support the formation of ionic liquid–superoxide complexes, and reduce the number of reactive species present in the cell. A one electron process could allow for newer energy-dense Li–O 2 batteries with faster kinetics and higher energy efficiencies typical of superoxide-dominant Na–O 2 and K–O 2 batteries.