Ambient Air Operation Rechargeable Lithium-Air Battery with Acetic Acid Catholyte

Lithium-air batteries are expected as next-generation secondary batteries for electric vehicles because of their high energy density. In particular, an aqueous lithium-air battery that uses an aqueous electrolyte has advantages such as a high power density and availability of operation under an air atmosphere. Here, we show the feasibility of an acidic aqueous lithium-air battery that consists of a lithium anode, a lithium-ion conducting liquid interlayer, a solid lithium-ion conductor separator of Li1.4Al0.4Ge0.2Ti1.4(PO4)3, an acetic acid catholyte, and a fuel cell-analogous air electrode. The theoretical energy density of this system based on the masses of the lithium anode, oxygen, and acetic acid is 1340 Wh kg−1. This system was successfully cycled at 0.2 mA cm−2 for 5 h polarization and room temperature under an air atmosphere for 30 cycles.