KR101998119B1 - Method of preparing solid polymer electrolytes comprising polysilsesquioxane polycarbonate diol polymer comprising urethane bond - Google Patents

Abstract

본 발명의 우레탄 결합을 갖는 폴리카보네이트 디올 고분자와 리튬염을 포함하는 고체 고분자 전해질 조성물은 높은 혼용률을 가지며, 누약 및 가스 발생이 없어 안정성이 우수하고, 플렉서블한 특성을 가질 뿐만 아니라, 기계적 물성 및 이온전도도가 우수한 효과가 있다.The present invention relates to a polycarbonate diol (PCD) polymer having a urethane bond represented by the following structural formula (1).
[Formula 1]

The solid polymer electrolyte composition including a polycarbonate diol polymer having a urethane bond and a lithium salt of the present invention has a high mixing ratio, has no leakage and gas generation, and has excellent stability, flexible properties, mechanical properties and ions. The conductivity is excellent.

Description

METHOD OF PREPARING SOLID POLYMER ELECTROLYTES COMPRISING POLYSILSESQUIOXANE POLYCARBONATE DIOL POLYMER COMPRISING URETHANE BOND}

The present invention relates to a polysilsesquioxane (polysilsesquioxane) polycarbonate diol (PCD) polymer comprising a urethane bond, a solid polymer electrolyte composition comprising the same, a method for preparing the same, and a lithium secondary battery comprising the same. Specifically, the present invention relates to a polycarbonate diol polymer matrix and a method for preparing a urethane bond through a condensation polymerization of a polycarbonate diol and an isocyanate silane compound.

With the rapid development of the electric, electronic communication and computer industries, there is an increasing need for secondary batteries having high performance and high stability. In particular, according to the trend of miniaturization and portability of electric and electronic products, the secondary battery, which is an essential component in this field, is required to be thinned and miniaturized.

The lithium polymer secondary battery including a solid electrolyte improves a disadvantage of a lithium ion battery using a conventional liquid electrolyte. That is, the lithium polymer secondary battery has an advantage of excellent stability, low manufacturing cost, and can be used for the manufacture of a large battery, as well as almost no limitation in the size or shape of the battery.

Conventionally, in order to increase the ionic conductivity of the polymer electrolyte, a method of adding a plasticizer lowering the crystallinity is used, but there is a problem in that the plasticizer has low compatibility.

An object of the present invention is to solve the above problems, a solid polymer composition electrolyte comprising a lithium salt and a matrix-type polycarbonate polymer in which silsesquioxane is bonded to a polycarbonate diol polymer chain containing a urethane bond To manufacture.

In addition, the present invention provides a solid polymer electrolyte composition having excellent compatibility and stability, flexible characteristics, excellent mechanical properties and ionic conductivity, and a method for preparing the same.

According to an aspect of the present invention, there is provided a polycarbonate diol (PCD) polymer having a urethane bond represented by the following Structural Formula 1.

 [Formula 1]

In the above formula 1,

Each R ¹ is independently an alkylene group of C1 to C20,

Each R ² is independently an alkylene group of C1 to C20,

R ³ to R ⁵ are the same as or different from each other, and each independently an alkyl group of C1 to C20,

n is any integer of 1-30.

R ¹ is each independently a C4 to C10 alkylene group, R ² is each independently C1 to C6 alkylene group, R ³ to R ⁵ are the same as or different from each other, and each independently C1 to C6 may be an alkyl group have.

N may be any one of an integer of 6 to 20.

The weight average molecular weight (Mw) of the polycarbonate diol polymer may be 2,000 to 200,000.

A matrix comprising a polycarbonate diol polymer gel prepared by sol-gel reaction of a polycarbonate diol (PCD) polymer represented by Structural Formula 1 below; And lithium salts dispersed in the matrix; It provides a solid polymer electrolyte comprising a.

[Formula 1]

In Structural Formula 1,

Each R ¹ is independently an alkylene group of C1 to C20,

R ² are each independently an alkylene group of C1 to C20,

R ³ to R ⁵ are the same or different, are each independently an alkyl group of C1 to C20,

n is any integer of 1-30.

The lithium salt may include at least one selected from Lithium Bis (trifluoromethane) sulfonimide salt, Lithium perchlorate, Lithium hexafluorophosphate, Lithium tetrafluoroborate, and Lithium trifluoromethanesulfonate.

According to another aspect of the present invention, there is provided a lithium secondary battery including the solid polymer electrolyte.

According to another aspect of the invention, (a) a polycarbonate diol having a urethane bond represented by the following structural formula (1) by condensation reaction of the polycarbonate diol represented by the formula (1) and the isocyanate silane represented by the formula (2) preparing a polycarbonate diol (PCD) polymer; (b) preparing a mixture by mixing the polycarbonate diol polymer and a lithium salt; And (c) preparing a solid polymer electrolyte by performing a sol-gel reaction of the polycarbonate diol polymer of the mixture.

[Formula 1]

In Chemical Formula 1,

R ¹ is each independently an alkylene group of C1 to C20,

n is any integer of 1-30.

[Formula 2]

In Chemical Formula 2,

R ² is a C1 to C20 alkylene group,

R ³ to R ⁵ are the same as or different from each other, and are each independently a C1 to C20 alkyl group.

[Formula 1]

In the above formula 1,

Each R ¹ is independently an alkylene group of C1 to C20,

R ² are each independently an alkylene group of C1 to C20,

R ³ to R ⁵ are the same as or different from each other, and each independently an alkyl group of C1 to C20,

n is any integer of 1-30.

The polycarbonate diol is poly (1,6-hexanediol) carbonate, poly (1,5-pentanediol) carbonate, poly (1,4-butanediol) carbonate, poly (1,3-propanediol) carbonate and poly (ethyleneglycol) carbonate It may include one or more selected from.

The isocyanate-based silane is at least one selected from 3- (Triethoxysilyl) propyl isocyanate, 3- (Trimethoxysilyl) ethyl isocyanate, 3- (Trimethoxysilyl) propyl isocyanate, 3- (Trimethoxysilyl) butyl isocyanate, and 3- (Triethoxysilyl) butyl isocyanate It may include.

In step (a), the polycarbonate diol represented by Formula 1 and the isocyanate silane represented by Formula 2 may be reacted in a molar ratio of 1: 2 to 1: 2.5.

In step (b), the mixture may be 20 to 90% by weight of the polycarbonate diol polymer having the urethane bond and 10 to 80% by weight of the lithium salt.

In step (c), the sol-gel reaction may form a matrix comprising a polycarbonate diol polymer having a urethane bond.

According to another aspect of the present invention, there is provided a method of manufacturing a lithium secondary battery including the method of manufacturing the solid polymer electrolyte.

The solid polyelectrolyte composition comprising a lithium salt and a matrix-type polycarbonate polymer having a silsesquioxane bonded to a polycarbonate diol polymer chain including a urethane bond prepared according to the present invention has excellent compatibility and stability. In addition to having flexible properties, mechanical properties and ionic conductivity are excellent.

Figure 1 schematically shows the structure of a sol-gel hybrid matrix for a solid polymer electrolyte prepared according to Examples 2 to 5.
Figure 2 shows a solid polymer electrolyte film prepared according to Examples 2 to 5.
Figure 3 shows the results of nuclear magnetic resonance (NMR) analysis of the polycarbonate diol polymer prepared according to Example 1.
4 shows the results of infrared spectroscopy (IR) analysis of the polycarbonate diol polymer prepared according to Example 1

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, terms including ordinal numbers such as first and second to be used below may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

In addition, when a component is referred to as being "formed" or "laminated" on another component, it may be directly attached to, or laminated to, the front or one side on the surface of the other component, It will be understood that other components may exist in the.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, a polycarbonate diol (PCD) polymer containing silsesquioxane having a urethane bond of the present invention will be described.

It provides a polycarbonate diol (PCD) polymer having a urethane bond represented by the following Structural Formula 1.

[Formula 1]

In Structural Formula 1,

Each R ¹ is independently an alkylene group of C1 to C20,

R ² are each independently a C1 to C20 alkylene group

R ³ to R ⁵ are the same as or different from each other, and each independently an alkyl group of C1 to C20,

n is any integer of 1-30.

Preferably, R ¹ may each independently be an alkylene group of C4 to C10, more preferably may be an alkylene group of C5 to C8.

Preferably, each of R ² may independently be an alkylene group of C1 to C6, more preferably an alkylene group of C2 to C6.

Preferably, R ³ to R ⁵ are the same as or different from each other, and each independently may be an alkyl group of C1 to C6, specifically, may be a methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group or hexyl group It is not limited to this.

n may be any one of integers of 6 to 20, and preferably any of integers of 7 to 15.

The weight average molecular weight (Mw) of the polycarbonate diol polymer may be 2,000 to 200,000, preferably 3,000 to 20,000.

Polysilsesquiionic acid, which acts as a plasticizer to lower crystallinity, may be bonded to the sock end of polycarbonate with a urethane bond, thereby preparing a polymer of Structural Formula 1 in a bridged form.

Hereinafter, the solid polymer electrolyte of the present invention will be described.

A matrix comprising a polycarbonate diol polymer gel prepared by sol-gel reaction of a polycarbonate diol (PCD) polymer represented by Structural Formula 1 of the present invention; And lithium salts dispersed in the matrix; It provides a solid polymer electrolyte comprising a.

[Formula 1]

In the above formula 1,

Each R ¹ is independently an alkylene group of C1 to C20,

Each R ² is independently an alkylene group of C1 to C20,

R ³ to R ⁵ are the same as or different from each other, and each independently an alkyl group of C1 to C20,

n is any integer of 1-30.

The lithium salt may be used Lithium Bis (trifluoromethane) sulfonimide salt, Lithium perchlorate, Lithium hexafluorophosphate, Lithium tetrafluoroborate and Lithium trifluoromethanesulfonate, and preferably may be used Bis (trifluoromethane) sulfonimide lithium salt.

The solid polymer electrolyte of the present invention can be used in a lithium secondary battery.

Figure 1 schematically shows the structure of the matrix obtained by sol-gel reaction of the polycarbonate diol polymer of the present invention.

The matrix has a form in which the polysilsesquiionic acid is connected to the sock end of the polycarbonate diol using a polysilsesquiionic acid as a urethane bond and connected with a bridged polymer.

 FIG. 2 shows a solid polymer electrolyte film prepared by mixing a matrix obtained by sol-gel reaction of a polycarbonate diol polymer prepared according to Example 1 with a lithium salt.

Hereinafter, a method of manufacturing the solid polymer electrolyte of the present invention will be described with reference to FIGS. 1 and 2.

First, the polycarbonate represented by the following formula (1) Dior and  Isocyanate type represented by the following formula (2) Silane Condensation  Polycarbonate having a urethane bond represented by the following formula Dior ( polycarbonate diol , PCD ) To prepare a polymer (step a).

[Formula 1]

In Chemical Formula 1,

Each R ¹ is independently an alkylene group of C1 to C20,

n is any integer of 1-30.

[Formula 2]

In Chemical Formula 2,

R ² is a C1 to C20 alkylene group,

R ³ to R ⁵ are the same as or different from each other, and are each independently a C1 to C20 alkyl group.

[Formula 1]

In Structural Formula 1,

Each R ¹ is independently an alkylene group of C1 to C20,

Each R ² is independently an alkylene group of C1 to C20,

R ³ to R ⁵ are the same as or different from each other, and each independently an alkyl group of C1 to C20,

n is any integer of 1-30.

As the polycarbonate diol, bis (6-hydroxyhexyl) carbonate, bis (2-hydroxyethyl) carbonate, bis (3-hydroxypropyl) carbonate, bis (4-hydroxybutyl) carbonate, bis (5-hydroxypentyl) carbonate, etc. may be used. Preferably, bis (6-hydroxyhexyl) carbonate can be used.

The isocyanate silane may be 3- (Triethoxysilyl) propyl isocyanate, 3- (Trimethoxysilyl) ethyl isocyanate, 3- (Trimethoxysilyl) propyl isocyanate, 3- (Trimethoxysilyl) butyl isocyanate, 3- (Triethoxysilyl) butyl isocyanate, and the like. Preferably 3- (Triethoxysilyl) propyl isocyanate can be used.

Step (a) may be carried out in a nitrogen atmosphere and a vacuum atmosphere, and in detail, alternating between a vacuum atmosphere and a nitrogen atmosphere, which is a process for removing moisture remaining in the flask.

In step (a), the polycarbonate diol represented by Formula 1 and the isocyanate silane represented by Formula 2 may be reacted in a molar ratio of 1: 2 to 1: 2.5.

The isocyanate-based silane compound should be added so as to have a molar ratio of two times or more of the polycarbonate diol in order to react the isocyanate-based yarn with two hydroxyl groups (-OH) groups substituted at the ends of the polycarbonate diol.

Next, the polycarbonate Dior  Polymer and Lithium salt  Mixing to prepare a mixture (step b).

The mixture may be a mixture of 20 to 90% by weight of a polycarbonate diol polymer having a urethane bond and 10 to 80% by weight of a lithium salt.

The ionic conductivity of the solid polymer electrolyte may vary depending on the weight ratio of the polycarbonate diol polymer having a urethane bond of the mixture and the lithium salt.

Finally, the polycarbonate of the mixture Dior  The polymer is subjected to a sol-gel reaction to prepare a solid polymer electrolyte (step c).

The sol-gel reaction may form a matrix including a polycarbonate diol polymer having a urethane bond, and the structure of the matrix is schematically illustrated in FIG. 1.

Referring to FIG. 1, the matrix has a structure in which a polycarbonate diol polymer including a urethane bond is bonded between silsesquioxanes.

Unlike the method of preparing a solid electrolyte composition by adding a plasticizer, the present invention is characterized in that the silsesquioxane is bonded to a polycarbonate diol polymer chain including a urethane bond to form a matrix, thereby improving compatibility.

Provided is a method of manufacturing a lithium secondary battery including the method of manufacturing the solid polymer electrolyte.

Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are merely provided to more easily understand the present invention, and the contents of the present invention are not limited by the examples.

EXAMPLE

Example  1: polycarbonate with urethane bond Dior  Polymer Synthesis

The method for preparing a polycarbonate diol polymer containing silsesquioxane having a urethane bond in Example 1 is shown in Scheme 1 below.

A mixture of polycarbonate diol (PCD) (40.00 g, 0.020 mol) and 3- (Triethoxysilyl) propyl isocyanate (10.88 g, 0.044 mol) in a 100 ml round bottom flask with a molar ratio of 1: 2.2 Was prepared.

The mixture was stirred while heating to 100 ° C. and repeated three times with alternating vaccume and nitrogen (N ₂ ) using a schlenk line to remove moisture remaining in the flask. .

Then, while heating to a temperature of 130 ℃, stirring RPM was fixed to 450 and reacted for 2 hours under a nitrogen stream to obtain a polycarbonate diol polymer having a viscous liquid form of a urethane bond.

Scheme 1

¹ H NMR analysis of the polycarbonate diol polymer having a urethane bond of Example 1 is shown in Figure 3, it was confirmed that the polycarbonate diol polymer having a urethane bond.

Example 2: Preparation of Solid Polymer Electrolyte

A solution of 1 ml of methanol was prepared in 1 ml of a polycarbonate diol polymer having a urethane bond prepared according to Example 1. 0.25 g of lithium salt (Bis (trifluoromethane) sulfonimide lithium salt) was added to the solution to prepare a mixture.

HCl (0.1M, 0.5 ml) was added to the mixture, and the reaction mixture was poured into a petri dish before the reaction solidified, and then heated at a temperature of 70 ° C. for 1 hour to perform a sol-gel reaction, thereby preparing a sol-gel hybrid matrix for a solid polymer electrolyte. Was prepared.

Finally, the solvent was removed in a vacuum oven at 50 ° C. for 24 hours to obtain a solid polymer electrolyte.

Example 3: Preparation of Solid Polymer Electrolyte

A solid polymer electrolyte was prepared in the same manner as in Example 2, except that 0.5 g was added instead of 0.25 g of lithium salt (Bis (trifluoromethane) sulfonimide lithium salt).

Example 4: Preparation of Solid Polymer Electrolyte

A solid polymer electrolyte was prepared in the same manner as in Example 2, except that 1.0 g was added instead of 0.25 g of lithium salt (Bis (trifluoromethane) sulfonimide lithium salt) in Example 2.

Example 5: Preparation of Solid Polymer Electrolyte

A solid polymer electrolyte was prepared in the same manner as in Example 2, except that 2.0 g was added instead of 0.25 g of bis (trifluoromethane) sulfonimide lithium salt (Bis).

[Test Example]

Test Example 1: NMR Analysis

3 is a polycarbonate diol and 3- (Triethoxysilyl) propyl isocyanate and polycarbonate diol polymer having a urethane bond prepared according to Example 1, respectively, dissolved in CDCl ₃ and subjected to NMR analysis. The results are shown in FIG. It was.

According to Figure 3, by checking the amine CH ₂ - NH -C = OO-C at 4.8ppm it was confirmed that the polycarbonate diol polymer having a urethane bond was synthesized.

Test Example 2: IR Analysis

Figure 4 shows the IR analysis results for polycarbonate diol and polycarbonate diol polymer having 3- (Triethoxysilyl) propyl isocyanate and a urethane bond prepared according to Example 1, respectively.

Referring to Figure 4, Wavenumber 500 ~ 4000cm ^-1, make a transmission of the range results, disappears and the isocyanate peak (2200cm ^-1), was confirmed -NH bond peak at 3290cm ^-1, 1611cm ^-1 CN bond in a check for the presence Could. Accordingly, it was confirmed that the polycarbonate diol polymer having a urethane bond was synthesized by the method according to the embodiment of the present invention.

Test Example 3: Ion Conductivity Analysis

 Table 1 below shows the results of analyzing the ionic conductivity of the solid electrolyte according to the amount of lithium salt added.

division Polycarbonate diol polymer amount prepared according to Example 1 (g) Lithium Salt (LiTFSI) Amount (g) Ion Conductivity (S / cm) Example 2 One 0.25 1.4ⅹ10 ^-7 Example 3 One 0.5 2.3ⅹ10 ^-7 Example 4 One 1.0 3.0ⅹ10 ^-5 Example 5 One 2.0 4.1ⅹ10 ^-5

Referring to Table 1, it was confirmed that the ionic conductivity of the solid polymer electrolyte prepared according to Example 5 is the highest.

Therefore, it can be seen that an appropriate ratio of polycarbonate diol polymer and lithium salt should be used to obtain a solid polymer electrolyte having excellent ion conductivity.

As mentioned above, although the preferred embodiment of the present invention has been described in detail, the present invention is not limited to the above embodiment, and various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. It is possible.

Claims (14)

delete delete delete delete delete delete delete (a) condensing a polycarbonate diol represented by Formula 1 with an isocyanate silane represented by Formula 2 to prepare a polycarbonate diol (PC) polymer having a urethane bond represented by Formula 1 below ;
(b) preparing a mixture by mixing the polycarbonate diol polymer and a lithium salt; And
(c) sol-gel reacting the polycarbonate diol polymer of the mixture to prepare a solid polymer electrolyte; Including,
The lithium salt comprises at least one selected from Lithium Bis (trifluoromethane) sulfonimide salt, Lithium perchlorate, Lithium hexafluorophosphate, Lithium tetrafluoroborate and Lithium trifluoromethanesulfonate,
In step (b), the mixture is 20 to 90% by weight of the polycarbonate diol polymer having the urethane bond and 10 to 80% by weight of lithium salt,
In step (c), the sol-gel reaction forms a matrix comprising a polycarbonate diol polymer having a urethane bond,
The solid polymer electrolyte is a method for producing a solid polymer electrolyte for use in a lithium secondary battery.
[Formula 1]

In Chemical Formula 1,
Each R ¹ is independently an alkylene group of C1 to C20,
n is any integer of 2-30.

[Formula 2]

In Chemical Formula 2,
R ² is a C1 to C20 alkylene group,
R ³ to R ⁵ are the same as or different from each other, and are each independently a C1 to C20 alkyl group.

[Formula 1]

In the above formula 1,
Each R ¹ is independently an alkylene group of C1 to C20,
Each R ² is independently an alkylene group of C1 to C20,
R ³ to R ⁵ are the same as or different from each other, and each independently an alkyl group of C1 to C20,
n is any integer of 2-30. The method of claim 8,
The polycarbonate diol is poly (1,6-hexanediol) carbonate, poly (1,5-pentanediol) carbonate, poly (1,4-butanediol) carbonate, poly (1,3-propanediol) carbonate and poly (ethyleneglycol) carbonate Method for producing a solid polymer electrolyte, characterized in that it comprises one or more selected from. The method of claim 8,
The isocyanate-based silane is one or more selected from 3- (Triethoxysilyl) propyl isocyanate, 3- (Trimethoxysilyl) ethyl isocyanate, 3- (Trimethoxysilyl) propyl isocyanate, 3- (Trimethoxysilyl) butyl isocyanate, 3- (Triethoxysilyl) butyl isocyanate Method for producing a solid polymer electrolyte comprising a. The method of claim 8,
In step (a), the polycarbonate diol represented by the formula (1) and the isocyanate-based silane represented by the formula (2) is a method for producing a solid polymer electrolyte, characterized in that the reaction in a molar ratio of 1: 2 to 1: 2.5. delete delete A method of manufacturing a lithium secondary battery comprising the method of manufacturing the solid polymer electrolyte of claim 8.

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