The invention relates to an electrochemical energy source, comprising: a substrate, and at least one stack deposited onto said substrate, the stack comprising: an anode, a cathode, and an intermediate solid-state electrolyte separating said anode and said cathode; and at least one electron-conductive barrier layer being deposited between the substrate and the anode, which barrier layer is adapted to at least substantially preclude diffusion of active species of the stack into said substrate. The invention further relates to a method for manufacturing such an electrochemical energy source, comprising the steps of: A) depositing at least one electron-conductive barrier layer onto the substrate, and B) depositing at least one stack of an anode, an solid-state electrolyte, and a cathode successively onto said electron-conductive barrier layer.