Composite membrane for lithium battery, cathode for lithium battery, and lithium battery comprising the composite membrane

1. A composite membrane for a lithium battery, the composite membrane comprising:

a random copolymer of a first repeating unit represented by Formula 1 and a second repeating unit represented by Formula 2

Formula 1

wherein, in Formula 1, Ar 1 is a substituted or unsubstituted C6-C30 arylene group or a substituted or unsubstituted C6-C30 heteroarylene group,

R 1 , R 2 , and R 3 are each independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, an unsubstituted or substituted C6-C20 aryl group, or an unsubstituted or substituted C3-C30 heteroaryl group,

A is a chemical bond, an unsubstituted or substituted C1-C30 alkylene group, an unsubstituted or substituted C6-C30 arylene group, an unsubstituted or substituted C3-C30 heteroarylene group, an unsubstituted or substituted C4-C30 cycloalkylene group, or an unsubstituted or substituted C3-C30 heterocycloalkylene group,

is a 3-membered to 31-membered ring system comprising 2 to 30 carbon atoms,

X is S, N, N(R), or P(R′), wherein R and R′ are each independently hydrogen, an unsubstituted or substituted C1-C30 alkyl group, an unsubstituted or substituted C1-C30 heteroalkyl group, an unsubstituted or substituted C1-C30 alkoxy group, an unsubstituted or substituted C6-C30 aryl group, an unsubstituted or substituted C7-C30 arylalkyl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted C4-C30 heteroarylalkyl group, an unsubstituted or substituted C3-C30 cycloalkyl group, an unsubstituted or substituted C2-C30 alkenyl group, an unsubstituted or substituted C3-C30 heteroaryloxy group, an unsubstituted or substituted C3-C30 heterocycloalkyl group, or an unsubstituted or substituted C3-C30 alkynyl group, and

Y − is an anion,

wherein, in Formula 2, R 4 , R 5 , and R 6 are each independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, an unsubstituted or substituted C6-C20 aryl group, or an unsubstituted or substituted C3-C30 heteroaryl group,

each R 7 is independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, or unsubstituted or substituted C6-C20 aryl group, and

a is an integer of 1 to 10, and

in Formulae 1 and 2, m and n are mole fractions of the first repeating unit represented by Formula 1 and the second repeating unit represented by Formula 2, respectively, wherein the sum of m and n is 1, and m and n are each independently greater than 0 and less than 1.

2. The composite membrane of claim 1 , wherein, in Formula 1, Ar 1 comprises a phenylene group, a biphenylene group, a naphthalenylene group, a phenanthrenylene group, a triphenylenylene group, an anthracenylene group, a fluorenylene group, or a carbazolylene group.

3. The composite membrane of claim 1 , wherein, in Formula 1, Ar 1 comprises a group represented by Formula 3-1, Formula 3-2, Formula 3-3, Formula 3-3, or Formula 3-4:

wherein in Formula 3-1, Formula 3-2, Formula 3-3, Formula 3-4, and Formula 3-5, * indicates a point of attachment, and R 11 to R 19 are each independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, an unsubstituted or substituted C6-C20 aryl group, or an unsubstituted or substituted C3-C30 heteroaryl group.

4. The composite membrane of claim 1 , wherein, in Formula 1,

comprises a group represented by Formula 4-1, Formula 4-2, Formula 4-3, Formula 4-4, or Formula 4a:

wherein, in Formula 4-1, Formula 4-2, Formula 4-3, Formula 4-4, Z is sulfur, nitrogen, or phosphorous, and R 11 to R 25 are each independently hydrogen, an unsubstituted or substituted C1-C30 alkyl group, an unsubstituted or substituted C1-C30 alkoxy group, an unsubstituted or substituted C6-C30 aryl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted C3-C30 heteroaryloxy group, an unsubstituted or substituted C4-C30 cycloalkyl group, or an unsubstituted or substituted C3-C30 heterocycloalkyl group, wherein R 11 is absent if Z is S

wherein, in Formula 4a, R 22 to R 26 are defined the same as R 11 to R 25 in Formula 4-1, Formula 4-2, Formula 4-3, and Formula 4-4, and Z is N.

5. The composite membrane of claim 1 , wherein

in Formula 1 comprises a group represented by Formula 5-1 or Formula 5-2, and

Y − in Formula 1 comprises BF 4 − , PF 6 − , AsF 6 − , SbF 6 − , AlCl 4 − , HSO 4 − , CH 3 SO 3 − , (CF 3 SO 2 ) 2 N − , Cl − , Br − , I − , SO 4 2 , ClO 4 − , CF 3 SO 3 − , CF 3 CO 2 − , (C 2 F 5 SO 2 ) 2 N − , (C 2 F 5 SO 2 )(CF 3 SO 2 )N − , NO 3 − , Al 2 Cl 7 − , CH 3 COO − , (CF 3 SO 2 ) 3 C − , (CF 3 ) 2 PF 4 − , (CF 3 ) 3 PF 3 − , (CF 3 ) 4 PF 2 − , (CF 3 ) 5 PF − , (CF 3 ) 6 P − , SF 5 CF 2 SO 3 − , SF 5 CHFCF 2 SO 3 − , CF 3 CF 2 (CF 3 ) 2 CO − , (CF 3 SO 2 ) 2 CH − , (SF 5 ) 3 C − , (O(CF 3 ) 2 C 2 (CF 3 ) 2 O) 2 PO − , or a combination thereof

wherein, in Formula 5-1 and Formula 5-2, R 20 to R 28 are each independently hydrogen, an unsubstituted or substituted C1-C30 alkyl group, an unsubstituted or substituted C1-C30 alkoxy group, an unsubstituted or substituted C6-C30 aryl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted C3-C30 heteroaryloxy group, an unsubstituted or substituted C4-C30 cycloalkyl group, or an unsubstituted or substituted C3-C30 heterocycloalkyl group.

6. The composite membrane of claim 1 , further comprising a lithium salt.

7. The composite membrane of claim 6 , wherein an amount of the lithium salt is about 1 part to about 90 parts by weight, based on 100 parts by weight of a total weight of the composite membrane.

8. The composite membrane of claim 1 , wherein the random copolymer has a degree of polymerization of about 10 to about 5,000.

9. The composite membrane of claim 1 , wherein, in Formula 1, m is about 0.45 to about 0.8.

10. The composite membrane of claim 1 , wherein the random copolymer is represented by Formula 6, and the random copolymer has a degree of polymerization of about 10 to about 5,000

wherein, in Formula 6, Ar 1 is a substituted or unsubstituted C6-C30 arylene group,

R 1 , R 2 , and R 3 are each independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, an unsubstituted or substituted C6-C20 aryl group, or an unsubstituted or substituted C3-C30 heteroaryl group,

A is a chemical bond, an unsubstituted or substituted C1-C30 alkylene group, or an unsubstituted or substituted C6-C30 arylene group,

Y − comprises BF 4 − , PF 6 − , AsF 6 − , SbF 6 − , AlCl 4 − , HSO 4 − , CH 3 SO 3 − , (CF 3 SO 2 ) 2 N − , Cl − , Br − , I − , SO 4 − , ClO 4 − , CF 3 SO 3 − , CF 3 CO 2 − , (C 2 F 5 SO 2 ) 2 N − , (C 2 F 5 SO 2 )(CF 3 SO 2 )N − , NO 3 − , Al 2 Cl 7 − , CH 3 COO − , (CF 3 SO 2 ) 3 C − , (CF 3 ) 2 PF 4 − , (CF 3 ) 3 PF 3 − , (CF 3 ) 4 PF 2 − , (CF 3 ) 5 PF − , (CF 3 ) 6 P − , SF 5 CF 2 SO 3 − , SF 5 CHFCF 2 SO 3 − , CF 3 CF 2 (CF 3 ) 2 CO − , (CF 3 S 02 ) 2 CH − , (SF 5 ) 3 C − , (O(CF 3 ) 2 C 2 (CF 3 ) 2 O) 2 PO − , or a combination thereof,

m and n are each independently 0.01 to 0.99, wherein the sum of m and n is 1,

each R 7 is independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, or unsubstituted or substituted C6-C20 aryl group,

a is an integer of 1 to 10, and

comprises a group represented by Formula 5-1 or Formula 5-2,

wherein, in Formula 5-1 and Formula 5-2, R 20 to R 28 are each independently hydrogen, an unsubstituted or substituted C1-C30 alkyl group, an unsubstituted or substituted C1-C30 alkoxy group, an unsubstituted or substituted C6-C30 aryl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted C3-C30 heteroaryloxy group, an unsubstituted or substituted C4-C30 cycloalkyl group, or an unsubstituted or substituted C3-C30 heterocycloalkyl group; and * indicates a point of attachment.

11. The composite membrane of claim 1 , wherein the random copolymer comprises a compound represented by Formula 6a, Formula 6b, Formula 6c, Formula 6d, or a combination thereof

wherein, in Formulae 6a to 6d, Y comprises PF 6 − , AsF 6 − , SbF 6 − , AlCl 4 − , HSO 4 − , CH 3 SO 3 − , (CF 3 SO 2 ) 2 N − , Cl − , Br − , I − , SO 4 − , ClO 4 − , CF 3 SO 3 − , CF 3 CO 2 − , (C 2 F 5 SO 2 ) 2 N − , (C 2 F 5 SO 2 )(CF 3 SO 2 )N − , NO 3 − , Al 2 Cl 7 − , CH 3 COO − , (CF 3 SO 2 ) 3 C − , (CF 3 ) 2 PF 4 − , (CF 3 ) 3 PF 3 − , (CF 3 ) 4 PF 2 − , (CF 3 ) 5 PF − , (CF 3 ) 6 P − , SF 5 CF 2 SO 3 − , SF 5 CHFCF 2 SO 3 − , CF 3 CF 2 (CF 3 ) 2 CO − , (CF 3 S 02 ) 2 CH − , (SF 5 ) 3 C − , (O(CF 3 ) 2 C 2 (CF 3 ) 2 O) 2 PO − , or a combination thereof,

a is an integer from 1 to 10,

R 24 is a C1-C10 alkyl group,

m and n are each independently 0.01 to 0.99, and the sum of m and n is 1, and

the random copolymer has a degree of polymerization of about 10 to 5,000.

12. The composite membrane of claim 1 , wherein the composite membrane has a thickness of about 1 nanometer to about 1,000 micrometers.

13. The composite membrane of claim 1 , wherein the random copolymer has a weight average molecular weight of about 3,000 Daltons to about 200,000 Daltons.

14. The composite membrane of claim 1 , wherein the composite membrane maintains a form of a free-standing film at a temperature of about 25° C. to 60° C.

15. The composite membrane of claim 1 , wherein the random copolymer is electrochemically stable at up to −0.4 Volts with respect to Li/Li + .

16. The composite membrane of claim 1 , wherein the composite membrane has a lithium ion conductivity of about 0.001 millisiemens/centimeter or greater at about 25° C.

17. A lithium battery comprising:

a cathode;

an anode; and

the composite membrane of claim 1 disposed between the cathode and the anode.

18. The lithium battery of claim 17 , wherein the anode comprises lithium metal or a lithium metal alloy; or

the anode comprises an active material comprising a carbonaceous material, silicon, a silicon oxide, a silicon alloy, a silicon-carbonaceous material composite, tin, a tin alloy, a tin-carbon composite, a metal or a metalloid alloyable with lithium, an alloy comprising the metal or metalloid alloyable with lithium, an oxide of the metal or metalloid alloyable with lithium, or a combination thereof.

19. The lithium battery of claim 17 , wherein the anode comprises lithium metal or a lithium metal alloy,

and the composite membrane comprises an anode protection layer, or an anode protection layer and an electrolyte.

20. The lithium battery of claim 17 , wherein the composite membrane comprises an electrolyte.

21. The lithium battery of claim 17 , wherein the lithium battery further comprises a liquid electrolyte, a solid electrolyte, a gel electrolyte, a polymer ionic liquid, or a combination thereof.

22. The lithium battery of claim 17 , wherein an operating voltage of the lithium battery is about 4 Volts or greater.

23. The lithium battery of claim 17 , wherein the cathode comprises a cathode active material and a copolymer, the copolymer comprising a first repeating unit represented by Formula 1 and a second repeating unit represented by Formula 2

wherein, in Formula 1, Ar 1 is a substituted or unsubstituted C6-C30 arylene group or a substituted or unsubstituted C6-C30 heteroarylene group,

R 1 , R 2 , and R 3 are each independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, an unsubstituted or substituted C6-C20 aryl group, or an unsubstituted or substituted C3-C30 heteroaryl group,

A is a chemical bond, an unsubstituted or substituted C1-C30 alkylene group, an unsubstituted or substituted C6-C30 arylene group, an unsubstituted or substituted C3-C30 heteroarylene group, an unsubstituted or substituted C4-C30 cycloalkylene group, or an unsubstituted or substituted C3-C30 heterocycloalkylene group,

is a 3-membered to 31-membered ring system comprising 2 to 30 carbon atoms,

X is S, N, N(R), or P(R′),

R and R′ are each independently hydrogen, an unsubstituted or substituted C1-C30 alkyl group, an unsubstituted or substituted C1-C30 heteroalkyl group, an unsubstituted or substituted C1-C30 alkoxy group, an unsubstituted or substituted C6-C30 aryl group, an unsubstituted or substituted C7-C30 aryl alkyl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted C4-C30 heteroarylalkyl group, an unsubstituted or substituted C3-C30 cycloalkyl group, an unsubstituted or substituted C2-C30 alkenyl group, or an unsubstituted or substituted C3-C30 alkynyl group, and

Y − is an anion,

wherein, in Formula 2, R 4 , R 5 , and R 6 are each independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, an unsubstituted or substituted C6-C20 aryl group, or an unsubstituted or substituted C3-C30 heteroaryl group,

each R 7 is independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, or an unsubstituted or substituted C6-C20 aryl group, and

a is an integer of 1 to 10,

and in Formulae 1 and 2, m and n are mole fractions of the first repeating unit represented by Formula 1 and the second repeating unit represented by Formula 2, respectively, wherein the sum of m and n is 1, and m and n are each independently greater than 0 and less than 1.

24. A cathode for a lithium battery, comprising:

a cathode active material; and

a random copolymer of a first repeating unit represented by Formula 1 and a second repeating unit represented by Formula 2

wherein, in Formula 1, Ar 1 is a substituted or unsubstituted C6-C30 arylene group or a substituted or unsubstituted C6-C30 heteroarylene group,

R 1 , R 2 , and R 3 are each independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, an unsubstituted or substituted C6-C20 aryl group, or an unsubstituted or substituted C3-C30 heteroaryl group,

A is a chemical bond, an unsubstituted or substituted C1-C30 alkylene group, an unsubstituted or substituted C6-C30 arylene group, an unsubstituted or substituted C3-C30 heteroarylene group, an unsubstituted or substituted C4-C30 cycloalkylene group, or an unsubstituted or substituted C3-C30 heterocycloalkylene group,

is a 3-membered to 31-membered ring system including 2 to 30 carbon atoms,

X is S, N, N(R), or P(R′),

R and R′ are each independently hydrogen, an unsubstituted or substituted C1-C30 alkyl group, an unsubstituted or substituted C1-C30 heteroalkyl group, an unsubstituted or substituted C1-C30 alkoxy group, an unsubstituted or substituted C6-C30 aryl group, an unsubstituted or substituted C7-C30 aryl alkyl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted C4-C30 heteroarylalkyl group, an unsubstituted or substituted C3-C30 cycloalkyl group, an unsubstituted or substituted C2-C30 alkenyl group, an unsubstituted or substituted C3-C30 heteroaryloxy group, an unsubstituted or substituted C3-C30 heterocycloalkyl group or an unsubstituted or substituted C3-C30 alkynyl group, and

Y − is an anion

wherein, in Formula 2, R 4 , R 5 , and R 6 are each independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, an unsubstituted or substituted C6-C20 aryl group, or an unsubstituted or substituted C3-C30 heteroaryl group,

each R 7 is independently hydrogen, an unsubstituted or substituted C1-C20 alkyl group, or unsubstituted or substituted C6-C20 aryl group, and

a is an integer of 1 to 10,

and in Formulae 1 and 2, m and n are mole fractions of the first repeating unit represented by Formula 1 and the second repeating unit represented by Formula 2, respectively, wherein the sum of m and n is 1, and m and n are each independently greater than 0 and less than 1.