Polymer electrolyte, polymer, electrochemical device, and method of preparing the polymer

1. A polymer electrolyte comprising:

a copolymer represented by Formula 1; and

a lithium salt:

wherein, in Formula 1,

each R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , and R 14 , are the same or different, and are each independently a hydrogen atom; a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is substituted or unsubstituted with halogen; a C 2 -C 10 alkenyl group that is substituted or unsubstituted with halogen; a C 2 -C 10 alkynyl group that is substituted or unsubstituted with halogen; a C 6 -C 10 aryl group that is substituted or unsubstituted with halogen; or a C 2 -C 10 heteroaryl group that is substituted or unsubstituted with halogen,

each R 15 is the same or different, and is a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is substituted or unsubstituted with halogen; a C 2 -C 10 alkenyl group that is substituted or unsubstituted with halogen; a C 2 -C 10 alkynyl group that is substituted or unsubstituted with halogen; a C 6 -C 10 aryl group that is substituted or unsubstituted with halogen; or a C 2 -C 10 heteroaryl group that is substituted or unsubstituted with halogen,

each R 16 is the same or different, and is a covalent bond; a C 1 -C 10 linear or branched alkylene group that is substituted or unsubstituted with halogen; -(—R a —O—) k —, wherein k is an integer of 2 to 100, and R a is a C 2 -C 10 alkylene group that is substituted or unsubstituted with halogen; a C 6 -C 10 cycloalkylene group that is substituted or unsubstituted with halogen; a C 6 -C 10 arylene group that is substituted or unsubstituted with halogen; a C 2 -C 10 heteroarylene group that is substituted or unsubstituted with halogen; or a divalent linking group comprising one or more of the foregoing groups,

each R 17 is the same or different, and is a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is substituted or unsubstituted with halogen; a C 2 -C 10 alkenyl group that is substituted or unsubstituted with halogen; a C 2 -C 10 alkynyl group that is substituted or unsubstituted with halogen; a C 6 -C 10 aryl group that is substituted or unsubstituted with halogen; or a C 2 -C 10 heteroaryl group that is substituted or unsubstituted with halogen,

L 1 is a covalent bond or —R b —C(═O)—O—, and L 2 is a covalent bond or —C(═O)—R c —, wherein R b and R c are each independently a linear or branched C 1 -C 20 alkylene group,

n1 is an integer of 2 to 100, and

x, y, and z are each mole fractions in repeating units, wherein 0<x<1, 0<y<1, 0<z<1, and x+y+z=1.

2. The polymer electrolyte of claim 1 , wherein a main chain of the copolymer represented by Formula 1 comprises at least one first block comprising a plurality of first repeating units connected to each other, wherein the first repeating unit is represented by Formula 1a:

wherein, in Formula 1a,

R 4 , R 5 , R 6 , and R 7 are each independently a hydrogen atom; a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen, and

n3 is an integer of 2 to 200.

3. The polymer electrolyte of claim 1 , wherein a main chain of the copolymer represented by Formula 1 comprises at least one second block comprising a second repeating unit represented by Formula 1b and a third repeating unit represented by Formula 1c, wherein the second block is a random copolymer:

wherein, in Formulae 1b and 1c,

R 1 , R 2 , R 3 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , and R 14 are each independently a hydrogen atom; a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen, and

R 15 is a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen,

R 16 is a covalent bond; a linear or branched C 1 -C 10 alkylene group that is unsubstituted or substituted with halogen; -(—R a —O—) k —, wherein k is an integer of 2 to 100, and R a is a C 2 -C 10 alkylene group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkylene group that is unsubstituted or substituted with halogen; a C 6 -C 10 arylene group that is unsubstituted or substituted with halogen; a C 2 -C 10 heteroarylene group that is unsubstituted or substituted with halogen; or a divalent linking group comprising one or more of the foregoing groups, and

R 17 is a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen.

4. The polymer electrolyte of claim 1 , wherein the copolymer represented by Formula 1 is represented by Formula 2:

wherein, in Formula 2,

each R 18 , R 19 , R 20 , R 21 , R 22 , and R 23 are the same or different, and are each independently a hydrogen atom; a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; or a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen,

each R 24 is the same or different, and is a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; or a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen,

each R 25 is the same or different, and is a covalent bond; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; -(—R a —O—) k —, wherein k is an integer of 2 to 100, and R a is a C 2 -C 10 alkylene group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkylene group that is unsubstituted or substituted with halogen; a C 6 -C 10 arylene group that is unsubstituted or substituted with halogen; a C 2 -C 10 heteroarylene group that is unsubstituted or substituted with halogen; or a divalent linking group comprising one or more of the foregoing groups,

each R 26 is a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; or a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen,

L 3 is a covalent bond or —C(CH 3 ) 2 —CH 2 CH 2 —C(═O)—O—,

L 4 is a covalent bond or —C(═O)—CH 2 CH 2 —C(CH 3 ) 2 —,

n1 is an integer of 2 to 100, and

x, y, and z are each mole fractions in repeating units, wherein 0<x<1, 0<y<1, 0<z<1, and x+y+z=1.

5. The polymer electrolyte of claim 1 , wherein the copolymer represented by Formula 1 is represented by Formula 3:

wherein, in Formula 3,

each R 27 and R 28 are the same or different, and are each independently a hydrogen atom; a halogen atom; —C n H 2n+1 (1≤n≤10); —C n F 2n+1 (1≤n≤10); —C n F 2n H (1≤n≤10); or —C n H n (CF 3 ) n+1 (1≤n≤4),

each R 29 is the same or different, and is —C n H 2n+1 (1≤n≤10); —C n F 2n+1 (1≤n≤10); —C n F 2n H (1≤n≤10); or —C n H n (CF 3 ) n+1 (1≤n≤4),

each R 30 is the same or different, and is a covalent bond; a linear or branched C 1 -C 10 alkylene group that is unsubstituted or substituted with halogen; or -(—R a —O—) k —, wherein k is an integer of 2 to 100, and R a is a C 2 -C 10 alkylene group that is unsubstituted or substituted with halogen,

each R 31 is the same or different, and is a halogen atom; —C n H 2n+1 (1≤n≤10); —C n F 2n+1 (1≤n≤10); —C n F 2n H (1≤n≤10); or —C n H n (CF 3 ) n+1 (1≤n≤4),

L 3 is a covalent bond or —C(CH 3 ) 2 —CH 2 CH 2 —C(═O)—O—,

L 4 is a covalent bond or —C(═O)—CH 2 CH 2 —C(CH 3 ) 2 —,

n1 is an integer of 2 to 100, and

x, y, and z are each mole fractions in repeating units, wherein 0<x<1, 0<y<1, 0<z<1, and x+y+z=1.

6. The polymer electrolyte of claim 1 , wherein the copolymer represented by Formula 1 is represented by one of Formulae 4 to 8:

wherein, in Formulae 4 to 8,

L 3 is a covalent bond or —C(CH 3 ) 2 —CH 2 CH 2 —C(═O)—O—,

L 4 is a covalent bond or —C(═O)—CH 2 CH 2 —C(CH 3 ) 2 —,

n1 and n2 are each an integer of 2 to 100, and

x, y, and z are each mole fractions in repeating units, wherein 0<x<1, 0<y<1, 0<z<1, and x+y+z=1.

7. The polymer electrolyte of claim 1 , wherein 0<x<0.5, 0.001<y<0.5, and 0<z<0.75.

8. The polymer electrolyte of claim 1 , wherein the copolymer represented by Formula 1 has an enthalpy of fusion that is about 30% or less of an enthalpy of fusion of a polyethylene oxide having 100% crystallinity, wherein the enthalpy of fusion is obtained by differential scanning calorimetry measurement.

9. The polymer electrolyte of claim 1 , wherein the copolymer represented by Formula 1 has a crystallinity that is about 30% or less of a crystallinity of a polyethylene oxide having 100% crystallinity, wherein the crystallinity is obtained by differential scanning calorimetry measurement.

10. The polymer electrolyte of claim 1 , wherein the polymer has a melting temperature of about 60° C. or less.

11. The polymer electrolyte of claim 1 , wherein the copolymer has a number average molecular weight of about 2,000 Dalton to about 500,000 Dalton.

12. The polymer electrolyte of claim 1 , wherein the lithium salt has a concentration of about 0.01 moles per liter to about 5.0 moles per liter, based on a total volume of the polymer electrolyte.

13. The polymer electrolyte of claim 1 , wherein the lithium salt comprises at least one of LiPF 6 , LiBF 4 , LiCF 3 SO 3 , Li(CF 3 SO 2 ) 2 N, LiC 2 F 5 SO 3 , Li(FSO 2 ) 2 N, LiC 4 F 9 SO 3 , LiN(SO 2 CF 2 CF 3 ) 2 , or a compound represented by one of Formulae 9 to 12:

14. The polymer electrolyte of claim 1 , wherein the polymer electrolyte is liquid at a temperature of about 45° C. or less.

15. The polymer electrolyte of claim 1 , wherein the polymer electrolyte has an ionic conductivity of about 7.5×10 −5 Siemens per centimeter at a temperature of 60° C.

16. The polymer electrolyte of claim 1 , wherein the polymer electrolyte is electrochemically stable in a voltage range of about 4.0 volts to about 4.5 volts with respect to lithium.

17. A copolymer represented by Formula 1:

wherein, in Formula 1,

each R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , and R 14 are the same or different, and are each independently a hydrogen atom; a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen,

each, R 15 , and R 17 is the same or different, and is a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen,

each R 16 is the same or different, and is a covalent bond; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; or -(—R a —O—) k —, wherein k is an integer of 2 to 100, and R a is a C 2 -C 10 alkylene group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkylene group that is unsubstituted or substituted with halogen; a C 6 -C 10 arylene group that is unsubstituted or substituted with halogen; a C 2 -C 10 heteroarylene group that is unsubstituted or substituted with halogen; or a divalent linking group comprising one or more of the foregoing groups,

each R 17 is the same or different, and is a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen,

L 1 is a covalent bond or —R b —C(═O)—O—, and L 2 is a covalent bond or —C(═O)—R c , wherein R b and R c are each independently a linear or branched C 1 -C 20 alkylene group,

n1 is an integer of 2 to 100,

x, y, and z are each mole fractions in repeating units, wherein 0<x<1, 0<y<1, 0<z<1, and x+y+z=1, and

the copolymer has a number average molecular weight of about 2,000 Dalton to about 500,000 Dalton.

18. The copolymer of claim 17 , wherein a main chain of the copolymer comprises a first block comprising a plurality of first repeating units connected to each other and represented by Formula 1a, and the main chain of the polymer further comprises a second block comprising a second repeating unit represented by Formula 1b and a third repeating unit represented by Formula 1c, wherein the second block is a random copolymer:

wherein, in Formulae 1a to 1c,

R 1 , R 2 , R 3 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 and R 14 are each independently a hydrogen atom; a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen,

R 15 is a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen,

R 16 is a covalent bond; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; -(—R a —O—) k —, wherein k is an integer of 2 to 100, and R a is a C 2 -C 10 alkylene group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkylene group that is unsubstituted or substituted with halogen; a C 6 -C 10 arylene group that is unsubstituted or substituted with halogen; a C 2 -C 10 heteroarylene group that is unsubstituted or substituted with halogen; or a divalent linking group comprising one or more of the foregoing groups,

R 17 is a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen, and

n3 is an integer of 2 to 200.

19. The copolymer of claim 17 , wherein the copolymer represented by Formula 1 is represented by one of Formulae 4 to 8:

wherein, in Formulae 4 to 8,

L 3 is a covalent bond or —C(CH 3 ) 2 —CH 2 CH 2 —C(═O)—O—,

L 4 is a covalent bond or —C(═O)—CH 2 CH 2 —C(CH 3 ) 2 —,

n1 and n2 are each independently an integer of 2 to 100,

x, y, and z are each mole fractions in repeating units, wherein 0<x<1, 0<y<1, 0<z<1, and x+y+z=1, and

the copolymer has a number average molecular weight of about 2,000 Dalton to about 500,000 Dalton.

20. The copolymer of claim 17 , wherein the copolymer represented by Formula 1 has enthalpy of fusion that is about 30% or less than an enthalpy of fusion of a polyethylene oxide (PEO) having 100% crystallinity, wherein the enthalpy of fusion is obtained by differential scanning calorimetry measurement, and

wherein the copolymer has a melting temperature of 45° C. or less.

21. An electrochemical device comprising:

a first electrode;

a second electrode; and

an electrolyte disposed between the first electrode and the second electrode,

wherein at least one of the first electrode, the second electrode, and the electrolyte comprises the copolymer of claim 17 .

22. The electrochemical device of claim 21 , wherein the electrochemical device is a lithium battery, a capacitor, or an electrochromic device.

23. A method of preparing a copolymer, the method comprising:

mixing a first monomer comprising an alkylene oxide repeating unit, a second monomer comprising an ester group, and an initiator comprising an alkylene oxide repeating unit to obtain a mixture; and

reacting the first monomer, the second monomer, and the initiator to obtain the copolymer.

24. The method of claim 23 , wherein the first monomer is represented by Formula 1d, the second monomer is represented by Formula 1e, and the initiator is represented by Formula 1f:

wherein, in Formula 1d to Formula 1f,

R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 and R 14 are each independently a hydrogen atom; a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen,

R 15 is a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen,

R 16 is a covalent bond; a linear or branched C 1 -C 10 alkylene group that is unsubstituted or substituted with halogen; -(—R a —O—) k —, wherein k is an integer of 2 to 100, and R a is a C 2 -C 10 alkylene group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkylene group that is unsubstituted or substituted with halogen; a C 6 -C 10 arylene group that is unsubstituted or substituted with halogen; a C 2 -C 10 heteroarylene group that is unsubstituted or substituted with halogen; or a divalent linking group comprising one or more of the foregoing groups,

R 17 is a halogen atom; a linear or branched C 1 -C 10 alkyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 cycloalkyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkenyl group that is unsubstituted or substituted with halogen; a C 2 -C 10 alkynyl group that is unsubstituted or substituted with halogen; a C 6 -C 10 aryl group that is unsubstituted or substituted with halogen; or a C 2 -C 10 heteroaryl group that is unsubstituted or substituted with halogen,

R 32 is a hydrogen atom, or a C 1 -C 10 alkyl group,

R 33 is a C 1 -C 10 alkyl group,

L 1 is a covalent bond or —R b —C(═O)—O—, L 2 is a covalent bond or —C(═O)—R c , wherein R b and R c , are each independently a linear or branched C 1 -C 20 alkylene group, and

n1 is an integer of 2 to 100, n3 is an integer of 2 to 200, and n4 is an integer of 1 to 20.