Electrolyte composition, method for producing the same and non-aqueous electrolyte secondary cell

An electrolyte composition that contains a molten salt having a specific structure, a silicon polymer, and a salt of a metal ion of Group 1 or 2 of the Periodic Table; and a non-aqueous electrolyte secondary cell containing the electrolyte composition. Also disclosed are an electrolyte composition that contains a polymer compound having repetitive units of a structure of the following formula (1), and a salt of a metal ion of Group 1 or 2 of the Periodic Table; a method for producing the electrolyte composition; and a non-aqueous electrolyte secondary cell containing the electrolyte composition.