Patent ID: 7700019

Claim:
A process of co-extrusion of a thin electrode sheet with a thin electrolyte polymer sheet directly onto a current collector sheet to form a bi-face assembly for a lithium polymer battery, said process comprising the steps of: (a) mixing a polymer with electrochemically active material, lithium salt and electronic conductive material in a first mixing chamber to form a first electrode slurry; (b) mixing a polymer with a lithium salt in a second mixing chamber to form a first electrolyte slurry; (c) feeding said first electrode slurry through a first flow channel and said first electrolyte slurry through a second flow channel; (d) mixing a polymer with electrochemically active material, lithium salt and electronic conductive material in a third mixing chamber to form a second electrode slurry; (e) mixing a polymer with a lithium salt in a fourth mixing chamber to form a second electrolyte slurry; (f) feeding said second electrode slurry through a third flow channel and said second electrolyte slurry through a fourth flow channel; (g) extruding said first electrode slurry in the form of a first thin electrode sheet through a first slot die opening connected to said first flow channel directly onto a first side of a moving current collector sheet; (h) concurrently extruding said first electrolyte slurry in the form of a first thin electrolyte sheet through a second slot die opening adjacent to said first die opening and connected to said second flow channel, said first thin electrolyte sheet being extruded directly onto said first thin electrode sheet; (j) extruding said second electrode slurry in the form of a second thin electrode sheet through a third slot die opening connected to said third flow channel directly onto a second side of the moving current collector sheet; (k) concurrently extruding said second electrolyte slurry in the form of a second thin electrolyte sheet through a fourth slot die opening adjacent to said third die opening and connected to said fourth flow channel, said second thin electrolyte sheet being extruded directly onto said second thin electrode sheet; wherein, the moving current collector sheet is guided in between the first and third slot die openings and between the second and fourth slot die openings; wherein said first and second thin electrode sheets and said first and second thin electrolyte sheets are extruded through a multiple slot die having four flow channels and four slot openings; and wherein said multiple slot die comprises a central channel adapted to guide said current collector between said four slot openings such that said first thin electrode sheet and said first thin electrolyte sheet are extruded on the first side of said moving current collector and said second thin electrode sheet and said second thin electrolyte sheet are extruded on the second side of said moving current collector thereby forming a bi-face electrochemical assembly.