Patent ID: 7700018
Filing Date: 2010-04-20
Classification: B29C,B29K,B29L,B32B,H01M,Y02E,Y02P

Abstract:
1. A process for extruding a positive electrode sheet having at least 40%/wt of solid content for a solid polymer battery through a single or twin screw extruder, said process comprising: a) mixing an ionically conductive electrolyte including a polyethylene oxide based polymer and a lithium salt, an active cathode material, water in a proportion ranging from 0.005% to 5%/wt, and an electronic conductive material into a single or twin screw section of said extruder; b) melting the materials mixed in step a) through the single or twin screw section of the extruder to form an homogenous slurry and thereafter eliminating the water contained in the slurry by evaporation and dissipation of the water vapor in a decompression zone defined by a greater thread pitch of the screw or screws through a vent aligned with the decompression zone of the extruder; c) extruding a positive electrode material through a die opening in the form of a sheet having a thickness within a range of 40 to 200 microns and a porosity of less than 10%; d) feeding said positive electrode material in sheet form directly between a pair of rollers maintained at a temperature ranging from about −5° C. to about −30° C., without a substrate; and e) depositing said positive electrode material onto a substrate traveling near said rollers.