Encapsulated lithium electrochemical device

A lithium electrochemical device comprising a stack of layers suitable for constituting a micro-battery deposited on a substrate and encapsulated using a protective cap sealed onto said substrate, the device comprising two collectors of the current generated by the micro-battery and at least one insulating layer inert as regards lithium, said collectors and the insulating layer or layers being deposited on said substrate, wherein the protective cap is sealed onto the substrate using the layers constituting the current collectors and the insulating layer or layers, said cap having layers of a same nature as said collectors and the insulating layer or layers, positioned in the same order in line with their respective layers deposited on the substrate, so that when the cap is sealed onto the substrate, the respective layers deposited on the cap and on the substrate come into contact with each other so as to provide the actual seal of the cap on the substrate.