NOVELTY - Forming ceramic lithium-ion electrolyte membrane (100) involves: fabricating lithium-ion electrolyte sheet, and cutting at least one edge of lithium-ion electrolyte sheet with ablative laser to form ablative edge (110).    USE - For forming ceramic lithium-ion electrolyte membrane (claimed) which is useful for battery or fuel cell.    ADVANTAGE - The ceramic lithium-ion electrolyte membrane produced is mechanically strong, dense, hermetic, flat, wrinkle-free, thin, pore-free, fine-grained, and comprises at least one defect-free, high quality edge, particularly in comparison to pre-cut lithium ion electrolyte membranes. The large grains are considered to be defects in certain applications, and may degrade mechanical properties of membrane. The size of microstructural features introduced from cutting process may be less than 1/3 thickness of membrane, such as less than 1/10 thickness of membrane. The ceramic lithium-ion electrolyte membrane is less than 200 mu m thick, is comprised of grains having average grain size of less than 5 mu m, and has relative density of greater than 90%.    DETAILED DESCRIPTION - Forming ceramic lithium-ion electrolyte membrane (100) involves: fabricating lithium-ion electrolyte sheet, and cutting at least one edge of lithium-ion electrolyte sheet with ablative laser to form ablative edge (110). The step of fabricating lithium-ion electrolyte sheet involves tape-casting process; which involves mixing starting materials, treating mixed starting materials to form powder, further processing powder to particle size of less than 5 mu m and casting powder to form tape. The process further involves adding phosphate additive. The ablative laser has wavelength of less than 2 mu m, fluence of less than 250 Joules/cm2, repetition rate of 20 Hz to 100 MHz, and cutting speed over 10 mm/second. The ablative edge is outer edge. The ablative edge is enriched with lithium relative to bulk of membrane. The ablative edge has depth of less than 5 mu m. An INDEPENDENT CLAIM is included for the ceramic lithium-ion electrolyte membrane comprising at least one ablative edge.    DESCRIPTION OF DRAWING(S) - The figure shows 1500x scanning electron micrograph (SEM) of ablative edge of the lithium ion electrolyte membrane.    Lithium aluminum titanium phosphate electrolyte membrane (100)    Ablative edge (110)    Thickness of ablative edge (120)