In-situ Three-dimensional Visualization of Precipitation Behavior in a Porous Air Electrode for Aqueous Lithium-air Battery

Abstract

The aqueous lithium-air battery is receiving considerable research attention because of its high theoretical energy density; however, discharge products tend to precipitate and inhibit the chemical reaction in the battery. To clarify the precipitation mechanism, the precipitated discharge products in a carbon-based porous air electrode were visualized three-dimensionally by oblique soft X-ray computed tomography. As a result, precipitation of the discharge products was observed clearly. The precipitate did not dissolve entirely and bubbles emerged in the air electrode during the charging process. This indicates that the charge/discharge products degrade the cycling performance of the aqueous lithium-air battery.