[3Ep01-07] Surface Science and Energy Storage: Electrode Surface Science Division's Session

[3Ep04] Cathode reaction analysis of Lithium-Air battery by operando XRD measurements

*Toshihiro Kondo¹, Makoto Aoki¹, Dilinigeer Dilixiati¹, Suzumi Yamada¹ (1. Ochanomizu University)

The lithium-air battery (LAB), which has ten times the energy density of conventional lithium-ion batteries (LIB), is one of the promissing candidates for the next-generation storage batteries, and there are great expectations for its development. However, the reaction mechanism of the cathode reaction (2Li⁺+ 2e^- + O₂ --> Li₂O₂) is still unclear, and the type of Li₂O₂ that is the product of the cathode in discharging is still unknown. The main reason for this is considered to be that it was difficult to directly observe the compounds generated at the cathode during LAB operation. By improving the laboratory XRD and the observation cell, we succeeded in operando XRD measurements of the cathode reaction in the LAB. In addition, under general conditions, the cathode product was Li_1.5O₂ with some Li missing from the crystal lattice of Li₂O₂. Here, we describe the details and discuss the reaction mechanism.