Solid polymer electrolyte comprising an alkoxysilane compound having a urethane bond, a method of preparing the electrolyte, and a lithium secondary battery including

Patent metadata

Field	Value
Publication number	US-10797346-B2
Application number	US-201816186624-A
Country	US
Kind code	B2
Filing date	Nov 12, 2018
Priority date	Mar 19, 2018
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

The solid polymer electrolyte composition is configured such that silsesquioxane is linked to a polycarbonate diol-based polymer chain having a urethane bond. The solid polymer electrolyte exhibits superior compatibility, stability, flexibility, mechanical properties and ionic conductivity.

First claim

What is claimed is:

1. A solid polymer electrolyte, comprising:
a matrix prepared by subjecting an alkoxysilane compound having a urethane bone represented by Structural Formula 1 below and an alkoxysilane compound including a compound represented by Structural Formula 2 below to a sol-gel reaction; and
a lithium salt dispersed in the matrix,

wherein R 1 is a C1 to C20 alkylene group, R 2 is a C1 to C20 alkyl group, R 3 is a C1 to C20 alkylene group, R 4 to R 6 are the same as or different from each other, and are each independently a C1 to C20 alkyl group, and m is any one integer of 1 to 20, and

where R 7 is independently a C1 to C20 alkylene group, R 8 is independently a C1 to C20 alkylene group, R 9 to R 11 are the same as or different from each other, and are each independently a C1 to C20 alkyl group, and n is any one integer of 1 to 30.

2. The solid polymer electrolyte of claim 1 , wherein the alkoxysilane compound further includes a compound represented by Structural Formula 3 below:

where R 12 to R 15 are the same as or different from each other, and are each independently a C1 to C20 alkyl group.

3. The solid polymer electrolyte of claim 1 , wherein R 7 is independently a C4 to C10 alkylene group, R 8 is independently a C1 to C6 alkylene group, and R 9 to R 11 are the same as or different from each other, and are each independently a C1 to C6 alkyl group.

4. The solid polymer electrolyte of claim 1 , wherein n is any one integer of 6 to 20.

5. The solid polymer electrolyte of claim 1 , wherein the compound represented by Structural Formula 2 has a weight average molecular weight (Mw) of 2,000 to 200,000.

6. The solid polymer electrolyte of claim 3 , wherein the lithium salt is selected from the group consisting a lithium bis(trifluoromethane)sulfonimide salt, a lithium perchlorate, a lithium hexafluorophosphate, a lithium tetrafluoroborate, a lithium trifluoromethanesulfonate, and combinations thereof.

7. The solid polymer electrolyte of claim 1 , wherein the solid polymer electrolyte comprises:
1 to 30 wt % of the compound represented by Structural Formula 1;
15 to 50 wt % of the compound represented by Structural Formula 2 ; and
10 to 70 wt % of the lithium salt.

8. The solid polymer electrolyte of claim 1 , wherein the solid polymer electrolyte further includes 0.5 to 20 wt % of a compound represented by Structural Formula 3 below:

where R 12 to R 15 are the same as or different from each other, and are each independently a C1 to C20 alkyl group.

9. A lithium secondary battery, comprising the solid polymer electrolyte of claim 1 .

10. A method of preparing a solid polymer electrolyte, comprising:
(a) preparing an alkoxysilane compound having a urethane bond represented by Structural Formula 1 below by reacting an alkoxy alcohol represented by Structural Formula 4 below with an isocyanate-based compound represented by Structural Formula 5 below;
(b) preparing an alkoxysilane compound represented by Structural Formula 2 below by subjecting a polycarbonate diol represented by Structural Formula 6 below and an isocyanate-based silane represented by Structural Formula 7 below to a condensation reaction;
(c) preparing a mixture by mixing the alkoxysilane compound having a urethane bond represented by Structural Formula 1 below, the alkoxysilane compound represented by Structural Formula 2 below, and a lithium salt; and
(d) preparing a solid polymer electrolyte by subjecting the mixture to a sol-gel reaction,

where R 1 is a C1 to C20 alkylene group, R 2 is a C1 to C20 alkyl group, and m is any one integer of 1 to 20,

where R 3 is a C1 to C20 alkylene group, and R 4 to R 6 are the same as or different from each other, and are each independently a C1 to C20 alkyl group,

where R 1 is a C1 to C20 alkylene group, R 2 is a C1 to C20 alkyl group, R 3 is a C1 to C20 alkylene group, R 4 to R 6 are the same as or different from each other, and are each independently a C1 to C20 alkyl group, and m is any one integer of 1 to 20,

where R 7 is independently a C1 to C20 alkylene group, and n is any one integer of 1 to 30,

where R 8 is independently a C1 to C20 alkylene group, and R 9 to R 11 are the same as or different from each other, and are each independently a C1 to C20 alkyl group, and

where R 7 is independently a C1 to C20 alkylene group, R 8 is independently a C1 to C20 alkylene group, R 9 to R 11 are the same as or different from each other, and are each independently a C1 to C20 alkyl group, and n is any one integer of 1 to 30.

11. The method of claim 10 , wherein, in step (c), a compound represented by Structural Formula 3 below is further included:

where R 12 to R 15 are the same as or different from each other, and are each independently a C1 to C20 alkyl group.

12. The method of claim 10 , wherein the alkoxy alcohol is selected from the group consisting of a 2-(2-methoxyethoxy)ethanol, a diethylene glycol methyl ether, a triethylene glycol methyl ether, a monoethylene glycol ethyl ether, a diethylene glycol ethyl ether, a diethylene glycol propyl ether, a diethylene glycol butyl ether and combinations thereof.

13. The method of claim 10 , wherein the isocyanate-based compound is from the group consisting of 3-(triethoxysilyl)propyl isocyanate, 3-(trimethoxysilyl)ethyl isocyanate, 3-(trimethoxysilyl)propyl isocyanate, 3-(trimethoxysilyl)butyl isocyanate, and 3-(triethoxysilyl)butyl isocyanate, and combinations thereof.

14. The method of claim 10 , wherein the polycarbonate diol isselected from the group consisting of poly(1,6-hexanediol)carbonate, poly(1,5-pentanediol)carbonate, poly(1,4-butanediol)carbonate, poly(1,3-propanediol)carbonate, and poly(ethyleneglycol)carbonate, and combinations thereof.

15. The method of claim 10 , wherein, in step (b), the polycarbonate diol represented by Structural Formula 6 and the isocyanate-based silane represented by Structural Formula 7 are reacted at a molar ratio of 1:2 to 1:2.5.

16. The method of claim 10 , wherein, in step (d), a matrix is formed through the sol-gel reaction.

17. A method of manufacturing a lithium secondary battery, including the method of preparing the solid polymer electrolyte of claim 10 .

Assignees

• Korea Inst Ind Tech

Inventors

• Kim Ki Young
• Cho Bong Sang
• Choi Jun
• Jeong Ji San
• Kim Kyung Min
• Kim Seong Kwan
• Lee Yong Pyo

Classifications

• H01M2300/0082

  Organic polymers · CPC title

• H01M10/0565 Primary

  Polymeric materials, e.g. gel-type or solid-type · CPC title

• C08G77/26

  nitrogen-containing groups · CPC title

• C08G18/837

  by silicon containing compounds · CPC title

• C08G18/44

  Polycarbonates · CPC title