Advances and Challenges on Cathode Catalysts for Lithium–Oxygen Batteries
Aprotic lithium-oxygen batteries (LOBs) with high theoretical energy density have received considerable attention over the past years. However, the oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) at cathodes suffer from slow kinetics for large overvoltages in LOBs. Significant advances catalysts have been achieved to accelerate cathode kinetics, but understanding on the formation/decomposition processes of Li2O2 is limited. Herein, this review highlights the fundamental understanding of the correlation between catalysts and formation/decomposition of Li2O2. Various types of cathode catalysts are discussed to reveal the mechanism of formation/decomposition of Li2O2, aiming to present the prerequisites for the design of highly efficient cathode catalysts. Further prospects of comprehensive consideration on introduction of light or magnetism, protection of Li metal anode, and electrolyte engineering are presented for the further development of LOBs.