Polyether polymer, process for producing the same, composition for solid polymer electrolyte, and use thereof

摘要

A composition for solid polymer electrolyte which comprises a polyether polymer and an electrolyte salt compound soluble in the polyether polymer; wherein said polyether polymer is either (1) a polyether polymer having a toluene insoluble content of not larger than 5 weight %, or (2) a polyether polymer having a Mooney viscosity of 3 to 190, which has been prepared by applying a shearing force under heated conditions using an extruder to a polyether polymer having a Mooney viscosity of 10 to 200 so that the Mooney viscosity is reduced by 5 or more. This composition exhibits good film-forming property, and gives a solid polymer electrolyte exhibiting good and uniform ionic conductivity, and having high mechanical strength and surface smoothness. The solid polymer electrolyte is suitable for batteries and capacitors, especially for a lithium ion secondary battery.