PERFORMANCE-CHARACTERISTICS OF LITHIUM-ION CELLS CASING IN-SITU POLYMERIZED ELECTROLYTES

Complete lithium-ion cells have been cycled to demonstrate the effecti veness of a new type of solid polymer electrolyte (SPE). The polymer e lectrolyte was developed with a eye toward manufacturability and relia bility. Monomers are reacted in place, either on a thin supporting fab ric or directly onto one electrode surface, just prior to assembly. Th is approach leads to an interface between the electrolyte and electrod es which permits excellent ion transport during charge and discharge. When combined with a disordered carbon lithium-ion anode and a metal, oxide lithium intercalation cathode, the new electrolyte supports over 500 cycles of reliable capacity down to 80% of the initial capacity. The cell load voltage averages 3.3 V at C/1 rate. These cells have als o shown some tolerance to moderate (600%) overcharge and can be cycled at a wide range of current densities. (C) 1997 Elsevier Science S.A.