Implementations of the present disclosure generally relate to separators, high performance electrochemical devices, such as, batteries and capacitors, including the aforementioned separators, and methods for fabricating the same. In one implementation, a method of forming a separator for a battery is provided. The method comprises exposing a metallic material to be deposited on a surface of an electrode structure positioned in a processing region to an evaporation process. The method further comprises flowing a reactive gas into the processing region. The method further comprises reacting the reactive gas and the evaporated metallic material to deposit a ceramic separator layer on the surface of the electrode structure.