Decomposition of Lithium Peroxide in Lithium–Oxygen Battery: Mechanisms, Strategies, and Prospectives

Lithium–oxygen batteries (LOBs) have been widely investigated as one of the next generations of potential energy storage devices due to their high theoretical energy density (3500 Wh kg ⁻¹ ), low cost, and small size. However, the performance of LOBs in practical applications is still not ideal. One of the vital bottlenecks is that the discharge product lithium peroxide (Li ₂ O ₂ ) is insoluble in organic electrolytes and self‐insulation and cannot be completely decomposed during the charging process. In addition, the incompletely decomposed Li ₂ O ₂ blocks the electrode channel and covers the active site of the catalyst, eventually leading to fatal problems such as an increase in overpotential and a decrease in the cycle life of the battery. To solve the difficulties in the decomposition of Li ₂ O ₂ in LOBs, this work systematically reviewed the strategies for promoting Li ₂ O ₂ decomposition by developing a new electrolyte to improve the solubility of Li ₂ O ₂ , designing a new system or an efficient catalyst to boost the kinetics of the oxygen reduction/oxygen evolution reaction (ORR/OER), and regulating the morphology of the formed Li ₂ O ₂ . This review provides guidance and ideas for the design of a new generation of high‐performance LOBs.