Amorphous Li2O2: Chemical Synthesis and Electrochemical Properties

When aprotic Li–O2 batteries discharge, the product phase formed in the cathode often contains two different morphologies, that is, crystalline and amorphous Li2O2. The morphology of Li2O2 impacts strongly on the electrochemical performance of Li–O2 cells in terms of energy efficiency and rate capability. Crystalline Li2O2 is readily available and its properties have been studied in depth for Li–O2 batteries. However, little is known about the amorphous Li2O2 because of its rarity in high purity. Herein, amorphous Li2O2 has been synthesized by a rapid reaction of tetramethylammonium superoxide and LiClO4 in solution, and its amorphous nature has been confirmed by a range of techniques. Compared with its crystalline siblings, amorphous Li2O2 demonstrates enhanced charge‐transport properties and increased electro‐oxidation kinetics, manifesting itself a desirable discharge phase for high‐performance Li–O2 batteries. Ein Hoch auf die Unordnung: Amorphes Li2O2, hergestellt durch schnelle Reaktion von TMAO2 mit LiClO4 in Lösung, übertrifft seine kristallinen Entsprechungen in punkto Ladungstransport und Oxidationskinetik. Dadurch kommt es als wünschenswerte Entladungsphase für leistungsstarke Li‐O2‐Batterien in Betracht.