Composite electrolyte and lithium battery including the electrolyte

1. A composite electrolyte comprising:

a polymeric ionic liquid; and

an oligomeric electrolyte,

wherein the oligomeric electrolyte consists of at least one oligomer selected from a polyether oligomer, a polyvinyl alcohol oligomer, a polyvinyl lactam oligomer, a polysiloxane oligomer, a polyethylene glycol oligomer, and a polypropylene glycol oligomer,

wherein the polymeric ionic liquid is one selected from the group consisting of Formula 1a or Formula 1b:

wherein, in Formulae 1a and 1b,

 are each independently comprising a 3 to 31 membered group comprising 2 to 30 carbon atoms and optionally at least one heteroatom in addition to X, wherein the 3 to 31 membered group comprises an unsubstituted or substituted C 3 -C 30 cycloalkyl ring, an unsubstituted or substituted C 6 -C 30 aryl ring, or an unsubstituted or substituted C 2 -C 30 heteroaryl ring;

X is S, —N(R 5 )(R 6 ), —N(R 5 ), —P(R 5 ), or —P(R 5 )(R 6 );

R 1 to R 6 are each independently a hydrogen, an unsubstituted or substituted C 1 -C 30 alkyl group, an unsubstituted or substituted C 1 -C 30 heteroalkyl group, an unsubstituted or substituted C 1 -C 30 alkoxy group, an unsubstituted or substituted C 6 -C 30 aryl group, an unsubstituted or substituted C 7 -C 30 arylalkyl group, an unsubstituted or substituted C 6 -C 30 aryloxy group, an unsubstituted or substituted C 6 -C 30 arylthio group, an unsubstituted or substituted C 3 -C 30 heteroaryl group, an unsubstituted or substituted C 4 -C 30 heteroarylalkyl group, an unsubstituted or substituted C 3 -C 30 heteroaryloxy group, an unsubstituted or substituted C 3 -C 30 heteroarylthio group, an unsubstituted or substituted C 3 -C 30 cycloalkyl group, an unsubstituted or substituted C 3 -C 30 heterocycloalkyl group, an unsubstituted or substituted C 3 -C 30 cycloalkyloxy group, or an unsubstituted or substituted C 2 -C 100 alkyleneoxide group;

Y − is an anion;

a and b are each independently an integer of 1 to 5; and

n is an integer of 500 to 2,800, and

wherein the composite electrolyte does not include an ionic liquid other than the polymeric ionic liquid.

2. The composite electrolyte of claim 1 , wherein the oligomer is at least one selected from poly(ethyleneglycol) methacrylate, poly(ethyleneglycol) acrylate, poly(ethyleneglycol) methyl ether methacrylate, poly(ethyleneglycol) phenyl ether acrylate, poly(ethyleneglycol) diacrylate, poly(ethyleneglycol) dimethacrylate, poly(ethyleneglycol) diamine, poly(ethyleneglycol) diglycidyl ether, poly(ethyleneglycol) bis(carboxymethyl) ether, poly(ethyleneglycol) dimethyl ether, poly(ethyleneglycol) dithiol, poly(ethyleneglycol), and poly(ethyleneglycol) methyl ether amine.

3. The composite electrolyte of claim 1 , wherein a molecular weight of the oligomer is 1,000 Daltons or less.

4. The composite electrolyte of claim 1 , wherein an amount of the oligomeric electrolyte is in a range of about 10 parts to about 500 parts by weight based on 100 parts by weight of the polymeric ionic liquid.

5. The composite electrolyte of claim 1 , wherein the polymeric ionic liquid is at least one selected from a cationic polymeric ionic liquid, an anionic polymeric ionic liquid, and a zwitterionic polymeric ionic liquid.

6. The composite electrolyte of claim 1 , wherein

in Formula 1 is represented by Formula 2:

wherein, in Formula 2,

Z denotes N, S, or P; and

(R 5 ) and R 6 are each independently a hydrogen, a C 1 -C 30 alkyl group, a C 1 -C 30 alkoxy group, a C 6 -C 30 aryl group, a C 6 -C 30 aryloxy group, a C 3 -C 30 heteroaryl group, a C 3 -C 30 heteroaryloxy group, a C 3 -C 30 cycloalkyl group, a C 3 -C 30 heterocycloalkyl group, or a C 2 -C 100 alkyleneoxide group,

provided that when Z denotes S, R 5 and R 6 are absent.

7. The composite electrolyte of claim 1 , wherein the polymeric ionic liquid represented by Formula 1 is a polymeric ionic liquid represented by Formula 3:

wherein, in Formula 3,

R 1 to R 8 are each independently a hydrogen, an unsubstituted or substituted C 1 -C 30 alkyl group, an unsubstituted or substituted C 1 -C 30 alkoxy group, an unsubstituted or substituted C 6 -C 30 aryl group, an unsubstituted or substituted C 6 -C 30 aryloxy group, an unsubstituted or substituted C 3 -C 30 heteroaryl group, an unsubstituted or substituted C 3 -C 30 heteroaryloxy group, an unsubstituted or substituted C 3 -C 30 cycloalkyl group, an unsubstituted or substituted C 3 -C 30 heterocycloalkyl group, or an unsubstituted or substituted C 2 -C 100 alkyleneoxide group;

Y − is at least one selected from BF 4 − , PF 6 − , AsF 6 − , SbF 6 − , AlCl 4 − , HSO 4 − , CIO 4 − , CH 3 SO 3 − , CF 3 CO 2 − , (CF 3 SO 2 ) 2 N − , CI − , Br − , I − , BF 4 − , SO 4 − , PF 6 − , CIO 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 − , and (CF 3 SO 2 ) 2 N − ;

a and b are each independently an integer of 1 to 5; and

n is an integer of 500 to 2,800.

8. The composite electrolyte of claim 1 , wherein the composite electrolyte further comprises a plurality of inorganic particles.

9. A lithium battery comprising:

a cathode;

an anode; and

an electrolyte layer disposed between the cathode and the anode,

wherein the electrolyte layer comprises the composite electrolyte of claim 1 .

10. The lithium battery of claim 9 , wherein a thickness of the electrolyte layer is within a range of about 100 nanometers to about 100 micrometers.

11. The lithium battery of claim 9 , wherein the electrolyte layer is adjacent to and in contact with the anode.

12. The lithium battery of claim 9 , wherein the electrolyte layer has a one-layer structure or a multi-layer structure comprising two or more layers, which are the same as or different.

13. The lithium battery of claim 12 , wherein each of the two or more layers independently comprises at least one selected from a liquid electrolyte, a gel electrolyte, and a solid electrolyte.

14. The lithium battery of claim 9 further comprising a liquid electrolyte adjacent to and in contact with the cathode.

15. The lithium battery of claim 14 , wherein the liquid electrolyte comprises an ionic liquid.

16. The lithium battery of claim 15 , wherein the ionic liquid is represented by Formula 4 or Formula 5:

wherein, in Formula 4,

 is a 3 to 31 membered group comprising 2 to 30 carbon atoms and optionally at least one heteroatom in addition to X, wherein the 3 to 31 membered group comprises an unsubstituted or substituted C 3 -C 30 cycloalkyl ring, an unsubstituted or substituted C 6 -C 30 aryl ring, or an unsubstituted or substituted C 2 -C 30 heteroaryl ring;

X in Formula 4 is the same as or different from X in Formulae 1a or 1b and is independently S, —N(R 5 )(R 6 ), —N(R 5 ), —P(R 5 ), or —P(R 5 )(R 6 ); and

Y 31 in Formula 4 is an anion, which is the same as or different from Y − in Formula 1,

wherein, in Formula 5,

X in Formula 5 is the same as or different from X in Formulae 1 and 4 and is independently —N(R 5 )(R 6 ), —N(R 5 ), —P(R 6 ), or —P(R 5 )(R 6 );

R 11 is an unsubstituted or substituted C 1 -C 30 alkyl group, an unsubstituted or substituted C 1 -C 30 heteroalkyl group, an unsubstituted or substituted C 1 -C 30 alkoxy group, an unsubstituted or substituted C 6 -C 30 aryl group, an unsubstituted or substituted C 7 -C 30 arylalkyl group, an unsubstituted or substituted C 6 -C 30 aryloxy group, an unsubstituted or substituted C 6 -C 30 arylthio group, an unsubstituted or substituted C 3 -C 30 heteroaryl group, an unsubstituted or substituted C 4 -C 30 heteroarylalkyl group, an unsubstituted or substituted C 3 -C 30 heteroaryloxy group, an unsubstituted or substituted C 3 -C 30 heteroarylthio group, an unsubstituted or substituted C 3 -C 30 cycloalkyl group, an unsubstituted or substituted C 3 -C 30 cycloalkyloxy group, an unsubstituted or substituted C 3 -C 30 heterocycloalkyl group, or an unsubstituted or substituted C 2 -C 100 alkyleneoxide group;

R 4 and R 5 in Formulae 4 and 5 are the same as or different and are each independently a hydrogen, an unsubstituted or substituted C 1 -C 30 alkyl group, an unsubstituted or substituted C 1 -C 30 heteroalkyl group, an unsubstituted or substituted C 1 -C 30 alkoxy group, an unsubstituted or substituted C 6 -C 30 aryl group, an unsubstituted or substituted C 7 -C 30 arylalkyl group, an unsubstituted or substituted C 6 -C 30 aryloxy group, an unsubstituted or substituted C 6 -C 30 arylthio group, an unsubstituted or substituted C 3 -C 30 heteroaryl group, an unsubstituted or substituted C 4 -C 30 heteroarylalkyl group, an unsubstituted or substituted C 3 -C 30 heteroaryloxy group, an unsubstituted or substituted C 3 -C 30 heteroarylthio group, an unsubstituted or substituted C 3 -C 30 cycloalkyl group, an unsubstituted or substituted C 3 -C 30 heterocycloalkyl group, an unsubstituted or substituted C 3 -C 30 cycloalkyloxy group, or an unsubstituted or substituted C 2 -C 100 alkyleneoxide group; and

Y − in Formula 5 is an anion, which is the same as or different from Y − in Formulae 1 and 4.

17. The lithium battery of claim 16 , wherein

in Formula 4 is a cation represented by Formula 6, and

in Formula 5 is a cation represented by Formula 7:

wherein, in Formula 6,

Z denotes S, N or P; and

R 12 to R 18 are each independently a hydrogen, an unsubstituted or substituted C 1 -C 30 alkyl group, an unsubstituted or substituted C 1 -C 30 alkoxy group, an unsubstituted or substituted C 6 -C 30 aryl group, an unsubstituted or substituted C 6 -C 30 aryloxy group, an unsubstituted or substituted C 3 -C 30 heteroaryl group, an unsubstituted or substituted C 3 -C 30 heteroaryloxy group, an unsubstituted or substituted C 3 -C 30 cycloalkyl group, an unsubstituted or substituted C 3 -C 30 heterocycloalkyl group, or an unsubstituted or substituted C 2 -C 100 alkyleneoxide group,

provided that when Z denotes S, R 5 and R 6 are absent;

wherein, in Formula 7,

Z denotes N or P; and

R 12 to R 15 are each independently a hydrogen, an unsubstituted or substituted C 1 -C 30 alkyl group, an unsubstituted or substituted C 1 -C 30 alkoxy group, an unsubstituted or substituted C 6 -C 30 aryl group, an unsubstituted or substituted C 6 -C 30 aryloxy group, an unsubstituted or substituted C 3 -C 30 heteroaryl group, an unsubstituted or substituted C 3 -C 30 heteroaryloxy group, an unsubstituted or substituted C 3 -C 30 cycloalkyl group, an unsubstituted or substituted C 3 -C 30 heterocycloalkyl group, or an unsubstituted or substituted C 2 -C 100 alkyleneoxide group.

18. The lithium battery of claim 9 further comprising a separator disposed between the cathode and the composite electrolyte layer.

19. The lithium battery of claim 9 further comprising a layer disposed between the cathode and the anode, wherein the layer comprises at least one selected from Cu 3 N, Li 3 N, LiPON, Li 3 PO 4 .Li 2 S.SiS 2 , Li 2 S.GeS 2 .Ga 2 S 3 , Li 2 O.11Al 2 O 3 , Na 2 O.11Al 2 O 3 , (Na,Li) 1+x Ti 2−x Al x (PO 4 ) 3 (wherein 0.1≤x≤0.9), Li 1+x Hf 2−x Al x (PO 4 ) 3 (wherein 0.1≤x≤0.9), Na 3 Zr 2 Si 2 PO 12 , Li 3 Zr 2 Si 2 PO 12 , Na 5 ZrP 3 O 12 , Na 5 TiP 3 O 12 , Na 3 Fe 2 P 3 O 12 , Na 4 NbP 3 O 12 , a Na-Silicate, Li 0.3 La 0.5 TiO 3 , Na 5 MSi 4 O 12 (wherein, M is a rare earth element, such as Nd, Gd, or Dy), Li 5 ZrP 3 O 12 , Li 5 TiP 3 O 12 , Li 3 Fe 2 P 3 O 12 , Li 4 NbP 3 O 12 , Li 1+x (M,Al,Ga) x (Ge 1−y Ti y ) 2−x (PO 4 ) 3 (wherein, 0.1≤x≤0.8, 0≤y≤1.0, and M is Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, or Yb), Li 1+x+y Q x Ti 2−x Si y P 3−y O 12 (wherein, 0<x≤0.4, 0<y≤0.6, and Q is Al or Ga), Li 6 BaLa 2 Ta 2 O 12 , Li 7 La 3 Zr 2 O 12 , Li 5 La 3 Nb 2 O 12 , Li 5 La 3 M 2 O 12 (wherein, M is Nb or Ta), and Li 7+x A x La 3−x Zr 2 O 12 (wherein, 0<x<3, and A is Zn).