Yuta Shimonishi

Stability of a Water-Stable Lithium Metal Anode for a Lithium–Air Battery with Acetic Acid–Water Solutions

The stability of water-stable lithium metal in aqueous acetic acid solution was examined as an anode in a lithium-air rechargeable battery. The water-stable lithium anode consisted of a water-stable glass-ceramic Li 1+x+y Ti 2-x Al x Si y P 3-y O 12 (LTAP), a poly(ethylene oxide) (PEO)-based electrolyte with Li(CF 3 SO 2 ) 2 N (LiTFSI), and lithium metal. The LTAP immersed in CH 3 COOH (HAc)-H 2 O-saturated CH 3 COOLi (LiAc) solutions at 50°C for several weeks showed no change in the X-ray diffraction pattern and showed a slight decrease in the electrical conductivity. The water-stable lithium anode, Li/PEO 18 LiTFSI/LTAP, showed a total resistance of 164 Ω cm 2 at 60°C after being immersed in HAc (90 vol %)-H 2 O (10 vol %)-saturated LiAc for 1 week. The Li/PEO 18 LiTFSI/LTAP/HAc-H 2 O-LiAc/Pt black air cell had a low polarization for lithium dissolution and deposition at a current density of 1 mA cm -2 . A prototype lithium-air cell using a carbon air electrode with a platinum catalyst showed a good charge and discharge cycle performance, and about 30% of acetic acid in the cell was consumed and recovered in the charge and discharge process.