Electrolyte for secondary battery, method of preparing electrolyte, and secondary battery including electrolyte

A secondary battery, comprising:

• a positive electrode;
• a negative electrode comprising a lithium metal or a lithium metal alloy;
• and
• an electrolyte, wherein the electrolyte is disposed between the positive electrode and the negative electrode, and wherein the electrolyte is disposed on at least one portion of the negative electrode as a layer, a film, or a sheet,
• wherein the electrolyte comprise an ionic polymer comprising a repeating unit represented by Formula 1:
• wherein, in Formula 1,
• CY is selected from a substituted or unsubstituted non-fused 6-membered aromatic ring, a substituted or unsubstituted fused C10-C30 6-membered aromatic ring, and a combination of at least two of the foregoing aromatic rings, wherein the at least two of the foregoing aromatic rings are linked through a single bond or a C1-C20 alkylene group;
• R1, R2, and R3 are each independently selected from a hydrogen atom, a halogen atom, a cyano group, a hydroxy group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C1-C20 heteroalkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C3-C20 cycloalkyloxy group, a substituted or unsubstituted C3-C30 heterocycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, an unsubstituted C7-C30 arylalkyl group, a substituted or unsubstituted C6-C30 aryloxy group, a substituted or unsubstituted C3-C30 heteroaryl group, a substituted or unsubstituted C4-C30 heteroarylalkyl group, a substituted or unsubstituted C3-C30 heteroaryloxy group, and a C2-C20 alkylene oxide group, and a combination thereof, provided that R3 is not an arylalkyl group substituted with a C2 alkene;
• n is an integer up to 5,000, and m is an integer selected from 1 to 1,000, wherein the ionic polymer has a weight average molecular weight from about 500 Daltons to about 1,000,000 Daltons;
• and
• X1− is at least one anion selected from BF4−, PF6−, AsF6−, SbF6−, AlCl4−, HSO4−, CH3SO3−, (CF3SO2)2N−, Cl−, Br−, I−, SO4−, PF6−, ClO4−, CF3SO3−, CF3CO2−, (C2F5SO2)2N−, (C2F5SO2)(CF3SO2)N−, (CF3SO2)2N−, NO3−, Al2Cl7−, AsF6−, SbF6−, CH3COO−, (CF3SO2)3C−, (CF3)2PF4−, (CF3)3PF3−, (CF3)4PF2−, (CF3)5PF−, (CF3)6P−, SF5CF2SO3−, SF5CHFCF2SO3−, CF3CF2(CF3)2CO−, (CF3SO2)2CH−, (SF5)3C−, and (O(CF3)2C2(CF3)2O)2PO−.