Advancements in in situ characterization techniques for lithium-oxygen batteries
The remarkable energy density of lithium-oxygen batteries has gained considerable attention among researchers. Nevertheless, the insufficient stability of the lithium metal anode and the high charging overpotential pose substantial obstacles to the advancement of lithium-oxygen batteries, negatively impacting cycling performance and round-trip efficiency. With the evolving techniques, an expanding array of advanced in situ characterization methods is employed for mechanism research and battery structure optimization in lithium-oxygen batteries. In situ characterization techniques offer static insights into various components of lithium-oxygen batteries while enabling precise monitoring of the dynamic electrochemical behavior and structural evolution of the battery throughout the cycling process with remarkable accuracy. Thus, in situ characterization techniques play a pivotal role in driving the progress of lithium-oxygen batteries. The study comprehensively reviews recent advancements in in situ characterization techniques for lithium-oxygen batteries, encompassing in situ microscopic, in situ X-ray, and in situ mass spectrometry characterizations. Through the analysis of specific cases, we elucidate the functionalities of various in situ characterization techniques, outline their specific applications in lithium-oxygen batteries, and unveils the deeper reaction mechanisms of lithium-oxygen batteries. Furthermore, we explore and anticipate advanced in situ characterization techniques for future research on lithium-oxygen batteries.