Performance characteristics of lithium-ion cells using in situ polymerized electrolytes

Complete lithium-ion cells have been cycled to demonstrate the effectiveness of a new type of solid polymer electrolyte (SPE). The polymer electrolyte was developed with a eye toward manufacturability and reliability. Monomers are reacted in place, either on a thin supporting fabric or directly onto one electrode surface, just prior to assembly. This approach leads to an interface between the electrolyte and electrodes 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 also shown some tolerance to moderate (600%) overcharge and can be cycled at a wide range of current densities.