A lithium ion conducting protective film is produced using a layer-by-layer assembly process. The lithium ion conducting protective film is assembled on a substrate by a sequential exposure of the substrate to a first poly(ethylene oxide) (PEO) layer including a cross-linking silane component on the first side of the substrate, a graphene oxide (GO) layer on the first PEO layer, a second poly(ethylene oxide) (PEO) layer including a cross-linking silane component on the GO layer and a poly(acrylic acid) (PAA) layer on the second PEO layer, The film functions as a lithium ion conducting protective film that isolates the lithium anode from the positive electrochemistry of the cathode in a lithium-air battery, thereby preventing undesirable lithium dendrite growth.