Development of ion‐conducting polymer electrolytes for use in high‐energy lithium rechargeable batteries

Abstract

AbstractPolymers based on poly(thylene oxide) (PEO) are a very promising new type of stable electrolytes for lithium rechargeable batteries. Their relatively low ionic conductivities can be more than compensated by the very small electrolyte thicknesses that can be used. Specific energies of 100 Wh/kg at sustained specific powers of 70 W/kg, have been obtained at Hydro‐Québec with 100 μm of PEO electrolyte at 100°C. In an electric vehicle, this would give a driving range of over 300 km at 80 km/h, more than three times as much as lead‐acid batteries. PEO‐related polymers have been developed for lower temperature applications such as computers or portable appliances. Advantages over competitive Ni‐Cd batteries are higher energy densities and absence of self‐discharge, with expected shell lifes of 10 years. Laboratory prototypes (3600 cm2, 10 Wh) demonstrate the absence of scale‐up effects and excellent cycling capability (over 300 charge‐discharge cycles).