NOVELTY - The device comprises a strip (100) made of an electrically insulating material comprising polyolefin and a regular meshing grid or an embossed sheet (101) forming a current collector (10) and housed in the strip by leveling on its both faces. A periphery (100P) of the strip is devoid of the grid or embossed sheet. The two leveling parts of the grid or embossed sheet are covered with an electrode made of a lithium insertion material. The strip comprises a polymer inserted between the polyolefin and the current collector, and an adhesion promoter.    USE - The device is useful in a lithium electrochemical generator and a bipolar battery (claimed).    ADVANTAGE - The device provides good seal with respect to the electrolytes between adjacent electrochemical cells thus improving the performance, energy density and electrical resistance of the battery.    DETAILED DESCRIPTION - The device comprises a strip (100) made of an electrically insulating material comprising polyolefin and a regular meshing grid or an embossed sheet (101) forming a current collector (10) and housed in the strip by leveling on its both faces. A periphery (100P) of the strip is devoid of the grid or embossed sheet. The two leveling parts of the grid or embossed sheet are covered with an electrode made of a lithium insertion material. The strip comprises a polymer inserted between the polyolefin and the current collector, and an adhesion promoter. The adhesion promoter is interposed between the polyolefin and the current collector to improve the adherence between them. The polymer forming the strip is a two-component resin. The current collector is a grid or embossed metal sheet on a surface of another metal, and is shaped as a frame centered in the insulating material strip. INDEPENDENT CLAIMS are included for:    (1) a bipolar battery; and    (2) a process for manufacturing a bipolar battery.    DESCRIPTION OF DRAWING(S) - The diagram shows a side view of a device devoid of the electrode.    Current collector (10)    Strip (100)    Periphery of the strip (100P)    Embossed sheet. (101)