Ultra‐Thin Layer Inside Separator Deposited by Spray Pyrolysis Using Methylaluminoxane Solution

Abstract Depositions are conducted on monolayer porous membrane at 50 °C by spray pyrolysis using methylaluminoxanes diluted with N ‐methylpyrrolidone. The solution penetrates the film during spraying and the ultra‐thin layers are deposited on the side wall of internal pores. It is suggested that these layers are fine polycrystalline of Al 2 O 3 . In the obtained film, most of the pores are exposed on the surface and there is no increase in film thickness. Further, the ionic conductivity is the same as that of the received film, and the thermal stability is improved. This method can be an effective technique for improving the function of the separator used in the lithium‐ion batteries.