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

Abstract

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 degrees 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 cm(2) at 60 degrees 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.