NOVELTY - A lithium metal-air battery (10) includes a polymeric barrier layer (26) comprising a mixture of alkali-hydroxide modified polyvinylidene fluoride, polyethylene oxide, and lithium hexafluorophosphate, which allows a passage of lithium ions and oxygen ions to the metal foil anode. The alkali-hydroxide modified polyvinylidene fluoride is 75-85 wt.%. The polyethylene oxide is 5-10 wt.%. The lithium hexafluorophosphate is 10-15 wt.%.    USE - Lithium metal-air battery for small portable electronic devices.    ADVANTAGE - The lithium metal-air battery is moisture-resistant.    DETAILED DESCRIPTION - A lithium metal-air battery (10) comprises:    (1) a housing (14) having an aperture to permit the passage of air;    (2) two electrodes extending from the housing;    (3) an air cathode (20) interconnected with one of the electrodes;    (4) a metal foil anode interconnected with another one electrode;    (5) a separator (22) interposed between the air cathode and the metal foil anode;    (6) a polymeric barrier layer (26) surrounds the metal foil anode;    (7) a first wire-mesh layer disposed adjacent the air cathode; and    (8) a second wire-mesh layer interposed between the metal foil anode and the polymeric barrier layer.    The polymeric barrier layer comprising a mixture of alkali-hydroxide modified polyvinylidene fluoride, polyethylene oxide, and lithium hexafluorophosphate, allows a passage of lithium ions and oxygen ions to the metal foil anode. The alkali-hydroxide modified polyvinylidene fluoride is 75-85 wt.%. The polyethylene oxide is 5-10 wt.%. The lithium hexafluorophosphate is 10-15 wt.%. The passage of lithium ions and oxygen ions through the polymeric barrier layer to the metal foil anode causes oxidation reactions and reduction reactions while reducing unwanted contact between external moisture and the metal foil anode to generate electrical energy at an increased level of stability.    DESCRIPTION OF DRAWING(S) - The drawing shows an exploded view of a metal-air battery.    Lithium metal-air battery (10)    Housing (14)    Air cathode (20)    Separator (22)    Polymeric barrier layer (26)