A rechargeable aqueous lithium-air battery with a water-stable high lithium-ion conductivity and an excellent bending strength solid electrolyte as a separator between the lithium metal anode and aqueous electrolyte was developed. The cell consists of a lithium metal anode, a buffer layer of 4 M lithium bis(fluorosulfonyl)imide in ethylene glycol dimethyl ether, a lithium-ion conducting solid electrolyte separator of Li1.3Al0.5Nb0.2Ti1.3(PO4)(3 )(LANTP), a 10 M LiCl aqueous solution with 1.5 M LiOH, and an activated MnO2 air electrode. The tape-cast water-impermeable LANTP film with a small amount of epoxy resin was used as the separator between the lithium anode and aqueous electrolyte. The conductivity and 3-point bending strength of the ca 0.2 min thick film was 9.1 x 10(-4) S cm(-1) at 25 degrees C and 100 MPa, respectively. The cell with the LANTP film was operated successfully at 0.26 mA cm(-2) for more than 30 cycles at room temperature in air.