Solid polymer electrolyte including crosslinked polymer of lactone/cyclic carbonate, and method of preparing the same

A film of solid polymer electrolyte, comprising:

• a crosslinked polymer network comprising (i) a crosslinked (co)polymer comprising, in ring-opened polymerized form, a lactone with five to eight ring members and/or a cyclic carbonate with five to eight ring members, and (ii) an ionic conductive salt,
• wherein more than 75 wt. % of the solid polymer electrolyte is the crosslinked polymer network, based on total solid electrolyte weight, and
• wherein the (co)polymer is obtained before crosslinking by (co)polymerizing the lactone and/or cyclic carbonate in an environment comprising an organic initiator comprising a first, second, and third hydroxyl function.

A method of preparing an electrochemical system, the method comprising:

• including in the electrochemical system a crosslinked polymer network comprising (i) a crosslinked (co)polymer comprising, in ring-opened polymerized form, a lactone with five to eight ring members and/or a cyclic carbonate with five to eight ring members, and (ii) an ionic conductive salt in the electrochemical system, formed into a solid polymer electrolyte comprising more than 75 wt. % of the crosslinked polymer network, based on total solid electrolyte weight, and
• wherein the (co)polymer in the crosslinked polymer network is obtained before crosslinking by ring-opening (co)polymerizing the lactone and/or cyclic carbonate in an environment comprising an organic initiator comprising a first, second, and third hydroxyl function.

An electrochemical system, comprising:

• a solid polymer electrolyte film comprising a crosslinked polymer network comprising (i) a crosslinked (co)polymer comprising, in ring-opened polymerized form, a lactone with five to eight ring members and/or a cyclic carbonate with five to eight ring members, and (ii) an ionic conductive salt,
• wherein more than 75 wt. % of the solid polymer electrolyte film is the crosslinked polymer network, based on total solid electrolyte weight, and
• wherein the (co)polymer in the crosslinked polymer network is obtained before crosslinking by ring-opening (co)polymerizing the lactone and/or cyclic carbonate in an environment comprising an organic initiator comprising a first, second, and third hydroxyl function.