TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method further comprises: contacting the membrane with a first solution containing the first material; contacting the membrane with a second solution containing the second material; contacting the membrane with a third solution containing the third material; and contacting the membrane with a fourth solution containing the fourth material. The pH of the first solution, the second solution, the third solution, and the fourth solution is adjusted for hydrogen bonding between materials in the bilayers. The lithium bis(oxalate) borate is dissolved in the first, second, third or fourth solution. Preferred Components: The first material and the third material are the same. The first material and the third material are different. The second material and the fourth material are the same. The second material and the fourth material are different. The substrate includes a membrane. The membrane includes polypropylene. The substrate is plasma treated or is glass. The first, second, third or fourth solution includes polyethylene oxide, graphene oxide, or polyacrylic acid. The first material is polyethylene oxide, the second material is graphene oxide, the third material is polyethylene oxide, and the fourth material is polyacrylic acid. The pair of bilayers is formed on a polypropylene membrane. The tetralayer is on a substrate. The tetralayer includes graphene oxide, polyethylene oxide or polyacrylic acid. The tetralayer or electrode protective structure includes a first polyethylene oxide layer, a graphene oxide layer adjacent to the first polyethylene oxide layer, a second polyethylene oxide layer adjacent to the graphene oxide layer and opposite the first polyethylene oxide layer, and a polyacrylic acid layer adjacent to the second polyethylene oxide layer. The tetralayer is on a polypropylene membrane. The surface of the tetralayer is more hydrophilic than a surface of the substrate. The thickness of the structure increases as the number of tetralayers increases. In the structure, increasing the thickness of the tetralayer changes the ionic conductivities of the structure. The electrolyte permeability is repressed with increasing thickness of the tetralayer. The graphene oxide lowers the permeability. The electrode protective structure contacts a surface of an anode. The electrode protective structure includes ion-conductive polymer, a barrier layer, polyethylene oxide, or polyacrylic acid. The electrode protective layers are formed on a polypropylene membrane. The electrode protective layers suppress dendritic growth on an electrode. The electrode protective layers suppress dendritic growth on a lithium anode. EXAMPLE - No suitable example given.