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.