Methods of manufacturing electrochromic devices containing a solid-state electrolyte

A method of providing an electrochromic (EC) device, comprising:

• providing a solid-state polymer electrolyte layer comprising a polymer network, a plasticizer and an electrolyte salt containing at least one of lithium or sodium ions, wherein the free-standing polymer electrolyte layer excludes tetraglyme;
• and
• after providing the solid-state polymer electrolyte layer, laminating the solid-state polymer electrolyte layer between a working electrode and a counter electrode form the EC device.

A free-standing polymer electrolyte for an electrochromic device comprising a polymer network, a plasticizer comprising dihydrolevoglucosenone, and an electrolyte salt containing at least one of lithium or sodium ions.