Water-Stable Lithium Anode with the Three-Layer Construction for Aqueous Lithium-Air Secondary Batteries

A water-stable multilayer Li-metal electrode consisting of a lithium metal, a PEO(18)LiN(SO(2)CF(3))(2)-BaTiO(3) composite polymer, and a lithium-conducting glass ceramic Li(1.35)Ti(1.75)Al(0.25)P(0.9)Si(0.1)O(12) (LTAP) was proposed as the lithium anode for aqueous lithium-air secondary batteries. The addition of finely dispersed nanosize BaTiO(3) in the polymer electrolyte greatly reduced the interfacial resistance between the Li anode and the polymer electrolyte. A Li/PEO(18)LiN(SO(2)CF(3))(2)-10 wt % BaTiO(3)/LTAP electrode showed a total resistance of 175 Omega cm(2) in a 1 M aqueous LiCl solution at 60 degrees C, with no change in the electrode resistance over a month. The Li/PEO(18)LiN(SO(2)CF(3))(2)-10 wt % BaTiO(3)/LTAP/aqueous 1 M LiCl/Pt air cell had a stable open-circuit voltage of 3.80 V, which was equivalent to that calculated from the cell reaction of 2Li+1/2O(2)+H(2)O=2LiOH. The cell exhibited a stable and reversible discharge/charge performance of 0.5 mA cm(-2) at 60 degrees C, suggesting excellent reversibility of the lithium oxidation reduction reaction for the Li/PEO(18)LiN(SO(2)CF(3))(2)-10 wt % BaTiO(3)/LTAP electrode.