KR20190037075A - Composite membrane for Lithium battery, a cathode for lithium battery, and lithium battery comprising the same - Google Patents

Abstract

The present invention provides a composite membrane for a lithium battery containing a copolymer including a first repeating unit represented by the following chemical formula 1 and a second repeating unit represented by the following chemical formula 2, a cathode for a lithium battery, and a lithium battery comprising the same.

Description

[0001] The present invention relates to a composite membrane for a lithium battery, a positive electrode for a lithium battery and a lithium battery including the lithium battery,

A composite membrane for a lithium battery, a positive electrode for a lithium battery, and a lithium battery including the same.

With the explosive growth of the reusable energy storage device market applicable to electric vehicles and portable electronic devices, there is a growing demand for high capacity characteristics and stability of lithium batteries, the most representative energy storage device . In response to this demand, a variety of researches have been conducted to increase the amount of charge stored and to utilize the lithium metal electrode as a cathode for a lithium battery for high voltage. The lithium metal electrode has a very high electric capacity per unit mass. The lithium metal electrode may cause a short circuit between the positive electrode and the negative electrode due to the formation of a dendrite structure on the surface of the lithium metal in the process of intercalating / deintercalating lithium ions. Therefore, a method capable of suppressing the generation of dendrites on the surface of lithium metal is required.

One aspect is to provide a novel composite membrane for a lithium battery.

Another aspect is to provide a lithium battery including a composite membrane for a lithium battery.

Another aspect is to provide a positive electrode for a lithium battery.

According to one aspect, there is provided a composite film for a lithium battery, which comprises a copolymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).

[Chemical Formula 1]

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 independently of one another are hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group or an unsubstituted or substituted C 3 -C 30 heteroaryl Lt; / RTI &

A represents a chemical bond or 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 C30 cycloalkylene group, or an unsubstituted or substituted C3-C30 heterocycloalkylene group,

는 2 내지 30개의 탄소 원자를 포함하는 3원 내지 31원 고리(membered ring)이며,

Is a 3 to 31 membered ring comprising 2 to 30 carbon atoms,

X is S, N, N (R) or P (R ^' ),

R and R ^' independently from each other are 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 C7-C30 arylalkyl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted aryl group, Unsubstituted or substituted C3-C30 heteroaryloxy groups, unsubstituted or substituted C3-C30 heteroarylalkyl groups, unsubstituted or substituted C3-C30 cycloalkyl groups, unsubstituted or substituted C2-C30 alkenyl groups, A substituted C3-C30 heterocycloalkyl group or an unsubstituted or substituted C3-C30 alkynyl group,

Y ^- is an anion,

(2)

In Formula 2, R ₄ , R ₅ , and R ₆ are each independently of the other hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group, or an unsubstituted or substituted C3 C30 heteroaryl group,

R ₇ is hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, or an unsubstituted or substituted C 6 -C 20 aryl group,

a is an integer of 1 to 10,

In the general formulas (1) and (2), m and n are molar ratios of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), and the sum thereof is 1,

Anodic according to another aspect; There is provided a lithium battery comprising a negative electrode, and the above-described composite membrane sandwiched between the positive electrode and the negative electrode.

According to another aspect, there is provided a positive electrode for a lithium battery comprising a positive electrode active material, a copolymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).

[Chemical Formula 1]

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 independently of one another are hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group or an unsubstituted or substituted C 3 -C 30 heteroaryl Lt; / RTI &

A represents a chemical bond or 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 C30 cycloalkylene group, or an unsubstituted or substituted C3-C30 heterocycloalkylene group,

는 2 내지 30개의 탄소 원자를 포함하는 3원 내지 31원 고리(membered ring)이며,

Is a 3 to 31 membered ring comprising 2 to 30 carbon atoms,

X is S, N, N (R) or P (R ^' ),

R and R ^' independently from each other are 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 C7-C30 arylalkyl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted aryl group, Unsubstituted or substituted C3-C30 heteroaryloxy groups, unsubstituted or substituted C3-C30 heteroarylalkyl groups, unsubstituted or substituted C3-C30 cycloalkyl groups, unsubstituted or substituted C2-C30 alkenyl groups, A substituted C3-C30 heterocycloalkyl group or an unsubstituted or substituted C3-C30 alkynyl group,

Y ^- is an anion,

(2)

In Formula 2, R ₄ , R ₅ , and R ₆ are each independently of the other hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group, or an unsubstituted or substituted C3 C30 heteroaryl group,

R ₇ is hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group,

Or an unsubstituted or substituted C6-C20 aryl group,

a is an integer of 1 to 10,

In the general formulas (1) and (2), m and n are molar ratios of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), and the sum thereof is 1,

According to one aspect, the use of a negative electrode containing a novel random copolymer suppresses the formation of dendrites on the surface of the negative electrode of the lithium battery, thereby improving the electrochemical stability, high-rate characteristics, and life characteristics of the lithium battery.

Figure 1 schematically depicts the construction of a copolymer according to one embodiment.
2 is an FT-IR spectrum of the random copolymer produced according to Production Example 1. [Fig.
3A is an NMR analysis spectrum of a random copolymer of the formula (6a) obtained according to Preparation Example 1. FIG.
3B is a 2D DOSY (diffusion ordered spectroscopy) NMR spectrum of the random copolymer of formula (6a) obtained according to Preparation Example 1.
4A and 4B are cyclic voltammetry measurement results of a negative electrode manufactured according to Example 1. FIG.
5A is an electrochemical impedance spectrum (EIS) analysis result of a lithium battery manufactured according to Example 1, Comparative Example 2 and Comparative Example 3. FIG.
FIG. 5B shows the charge transfer resistance characteristics for the lithium battery produced according to Example 1, Comparative Examples 2 and 3. FIG.
FIG. 6A shows lithium ion conductivity in a lithium battery produced according to Example 1, Comparative Example 1, and Comparative Example 3. FIG.
6B shows lithium ion mobility characteristics in the lithium battery produced according to Example 1, Comparative Example 1, and Comparative Example 3. FIG.
FIG. 6C shows lithium ion availability in a lithium battery produced according to Example 1, Comparative Example 1 and Comparative Example 3. FIG.
7A shows the electrochemical stability measurement results of a Li / Li symmetric cell fabricated according to Example 1. FIG.
FIG. 7B shows the electrochemical stability measurement result of the Li / Li symmetric cell manufactured according to Comparative Example 2. FIG.
8A is a graph showing lifetime characteristics in a lithium battery manufactured according to Example 4 and Comparative Example 4. FIG.
FIG. 8B shows the potential change according to capacity in the lithium battery manufactured according to Example 4 and Comparative Example 4. FIG.
9 is a schematic view of a lithium battery according to one embodiment.

Hereinafter, a composite membrane for a lithium battery, a positive electrode for a lithium battery, and a lithium battery including the same will be described in more detail.

The composite membrane for a lithium battery according to an embodiment contains a copolymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).

[Chemical Formula 1]

In formula (1), Ar ₁ is a substituted or unsubstituted C6-C30 arylene group or a substituted or unsubstituted C6-C30 heteroarylene group, and R ₁ , R ₂ and R ₃ independently represent hydrogen, A substituted or unsubstituted C1-C20 alkyl group, an unsubstituted or substituted C6-C20 aryl group, or an unsubstituted or substituted C3-C30 heteroaryl group, A represents a chemical bond or an unsubstituted or substituted An unsubstituted or substituted C6-C30 heteroarylene group, an unsubstituted or substituted C4-C30 cycloalkylene group, or an unsubstituted or substituted C6-C30 arylene group, an unsubstituted or substituted C3- C3-C30 < / RTI > heterocycloalkylene group,

는 2 내지 30개의 탄소 원자를 포함하는 3원 내지 31원 고리(membered ring)이며, X는 S, N, N(R) 또는 P(R^’)이고, R 및 R^’은 서로 독립적으로 수소, 비치환된 또는 치환된 C1-C30 알킬기, 비치환된 또는 치환된 C1-C30 헤테로알킬기, 비치환된 또는 치환된 C1-C30 알콕시기, 비치환된 또는 치환된 C6-C30 아릴기, 비치환된 또는 치환된 C7-C30 아릴알킬기, 비치환된 또는 치환된 C6-C30 아릴옥시기, 비치환된 또는 치환된 C3-C30 헤테로아릴기, 비치환된 또는 치환된 C4-C30 헤테로아릴알킬기, 비치환된 또는 치환된 C3-C30 사이클로알킬기, 비치환된 또는 치환된 C2-C30 알케닐기, 비치환된 또는 치환된 C3-C30 헤테로아릴옥시기, 비치환된 또는 치환된 C3-C30 헤테로사이클로알킬기 또는 비치환된 또는 치환된 C3-C30 알키닐기이고, Y^-는 음이온이고,

Is a 3 to 31 membered ring comprising 2 to 30 carbon atoms, X is S, N, N (R) or P (R ^' ), R and R ^' 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, Unsubstituted or substituted C7-C30 arylalkyl groups, unsubstituted or substituted C6-C30 aryloxy groups, unsubstituted or substituted C3-C30 heteroaryl groups, unsubstituted or substituted C4-C30 heteroarylalkyl groups, 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, A substituted or unsubstituted C 3 -C 30 alkynyl group, Y ^- is an anion,

(2)

In Formula 2, R ₄ , R ₅ , and R ₆ are each independently of the other hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group, or an unsubstituted or substituted C3 C30 heteroaryl group,

R ₇ is hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group,

Or an unsubstituted or substituted C6-C20 aryl group,

a is an integer of 1 to 10,

In the general formulas (1) and (2), m and n are molar ratios of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), and the sum thereof is 1,

The 3-to 31-membered ring containing 2 to 30 carbon atoms may be a saturated or unsaturated ring.

In Formula 1, Ar ₁ is a group selected from the group consisting of a phenylene group, a biphenylene group, a naphthalenylene group, a phenanthrenylene group, a triphenylenylene group, an anthracenylene group, a fluorenylene group and a carbazolylene group.

In Formula 1, Ar ₁ may be a group selected from the group consisting of Formula (3).

(3)

Wherein R ₁ to R ₁₉ independently represent hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group, or an unsubstituted or substituted Substituted C3-C30 heteroaryl group.

In the repeating unit represented by the formula (1), Ar1 is an arylene or heteroarylene group as described above. Such a copolymer having a repeating unit represented by the formula (1) having an arylene group and a heteroarylene group is superior in mechanical properties due to the above-described π-π interaction of the arylene group or the heteroarylene group. When in formula (I) Ar ₁ is an aliphatic group such as an alkylene group, a divalent aliphatic chain, the mechanical properties are significantly reduced compared to the case where Ar ₁ an aryl group or a heteroarylene group.

Lithium batteries using a lithium metal electrode as a cathode can provide a theoretically high energy source, but the liquid electrolyte reacts with moisture and oxygen to cause an exothermic reaction, and also has a lower thermal stability than a graphite or carbon-based anode. Also, since the reactivity between the conventional liquid electrolyte and the lithium metal electrode is very high, an irreversible layer is formed, thereby deteriorating the cycle characteristics of the lithium battery. In order to solve such a problem, a lithium ion conductive polymer electrolyte is applied to the upper portion of the lithium metal electrode. As the lithium ion conductive polymer electrolyte, an ether type electrolyte such as a polyethylene oxide electrolyte is generally used. However, the ether-based electrolyte has relatively low lithium ion mobility as compared with the liquid electrolyte, and its mechanical properties are insufficient, so that the electrochemical performance may be deteriorated.

When the temperature of the lithium battery is raised, it is difficult to maintain the film shape of the ether-based electrolyte in the free standing state, so that the mechanical properties may be further lowered and a short circuit may occur. And the cycle characteristics of the lithium battery may be deteriorated due to the formation and growth of lithium dendrite on the surface of the lithium negative electrode.

Accordingly, the present inventors provide a novel composite membrane capable of improving electrochemical stability through inhibition of side reactions with a lithium negative electrode. Such a composite membrane can be used as a protective film and electrolyte for a lithium negative electrode, and a protective film and electrolyte for a lithium negative electrode.

The composite membrane for a lithium battery according to an embodiment includes a first repeating unit having a polymerized ionic liquid (PIL) which is excellent in lithium ion mobility and is electrochemically very stable and a second repeating unit having a lithium ion conductive second repeating unit Lt; / RTI > The second repeating unit is a polyoxyethylene methacrylate (POEM) repeating unit. The copolymer improves the electrochemical characteristics of the lithium battery by improving the low mechanical properties of the second repeating unit.

FIG. 1 schematically shows a composition of a copolymer comprising a first repeating unit (PIL) represented by the following formula (1) and a second repeating unit (POEM) represented by the following formula (2) constituting a composite membrane for a lithium battery according to an embodiment .

The first repeating unit of the copolymer provides structural rigidity and has a group inhibiting lithium dendrite growth, and the second repeating unit of the copolymer has a POEM group which is a lithium ion conductive group. As shown in FIG. 1, the copolymer having the first repeating unit and the second repeating unit may be a heterogeneous polymer containing a first repeating unit (PIL) and an ion-conducting second repeating unit (POEM). By having such a heterogeneous state, the effect of suppressing the growth of lithium dendrite is superior to the case of using a polymer having a homogenized state.

As used herein, the term " heterogeneous polymer " refers to a polymer in which the first repeating unit (PIL) and the ionic conductive second repeating unit (POEM) are irregular or nonuniform, as shown in FIG.

The copolymer may be a random copolymer or a block copolymer.

The random copolymer contains the first repeating unit (PIL) and the second repeating unit (POEM) in an inhomogeneous state. In the random copolymer, the first repeating unit and the second repeating unit exist in a non-homogenized state and the interaction between the first repeating units is reduced as compared with the case where the block copolymer is used, so that the first repeating unit moves to the lithium region of the lithium negative electrode surface And it is possible to effectively block the periphery of the lithium dendrite. As a result, it provides a charge delocalization effect of uniform charge throughout the copolymer, so lithium ions on the lithium metal surface can more effectively inhibit dendrite formation due to local increase.

Also, the random copolymer is easier to synthesize and less expensive to manufacture than a block copolymer. The random copolymers can exhibit similar physical properties to the polymer backbone as compared with the block copolymers.

For example, in the block copolymer containing the first repeating unit and the second repeating unit, the first repeating unit and the second repeating unit not containing an ionic liquid moiety are locally present , It may be difficult to uniformly suppress the growth of lithium dendrites on the surface of the lithium negative electrode. Also, the block copolymer is liable to localization of charges in the polymer block portion composed of the second repeating unit which does not include the ionic liquid moiety, so that the dendrite by the local reduction of lithium ions on the lithium metal surface It may be difficult to effectively suppress growth. In addition, due to the self-interaction between the first repeating units, it is relatively difficult to move to the lithium dendrite site as compared with the random copolymer, thereby reducing the chance of blocking the lithium dendrite. Therefore, the lithium dendrite inhibiting effect of the random copolymer can be further improved as compared with the block copolymer.

The composite membrane according to one embodiment includes a copolymer having an ionic liquid unit capable of reducing the lithium metal dendrites with excellent mechanical properties and has excellent mechanical properties at a high temperature and a large amount of lithium salt . Therefore, the lithium ion transfer ability is further improved and a lithium battery improved in cycle characteristics can be produced.

The composite membrane for a lithium battery can be used as a cathode protection film of a lithium battery or as an electrolyte. The composite membrane can be used as a cathode protective film and an electrolyte.

는 지방족 고리 또는 질소 함유 방향족 고리인 이미다졸 고리일 수 있다.In formula (1)

May be an aliphatic ring or an imidazole ring which is a nitrogen containing aromatic ring.

는 지방족 고리일 수 있다. 공중합체가 포함하는

가 지방족 고리를 형성함에 의하여 방향족 고리를 포함하는 이온성 액체 고분자에 비하여 더 넓은 전압 범위에서 안정하므로 보다 넓은 전기화학적 창(window)을 제공할 수 있다. 예를 들어, 리튬 금속에 대하여 보다 넓은 환원 전위를 제공할 수 있다. 예를 들어, 랜덤 공중합체가 리튬 금속에 대하여 음의 전압 범위에서도 전기화학적으로 안정할 수 있다. 본 명세서에서 "전기화학적으로 안정하다"는 의미는 공중합체 자체의 산화 또는 환원에 기인한 전류가 리튬의 산화/환원에 기인한 전류에 비하여 1/2 이하라는 의미이다.

May be an aliphatic ring. Copolymer Containing

Is more stable in a wider voltage range than an ionic liquid polymer containing an aromatic ring by forming an aliphatic ring, so that a wider electrochemical window can be provided. For example, it is possible to provide a wider reduction potential for the lithium metal. For example, the random copolymer may be electrochemically stable even in the negative voltage range with respect to the lithium metal. In the present specification, the term " electrochemically stable " means that the current due to the oxidation or reduction of the copolymer itself is 1/2 or less of the current due to the oxidation / reduction of lithium.

The aliphatic ring included in the copolymer is not particularly limited and can be any one capable of acting as a moiety corresponding to the cation of the ionic liquid in the technical field.

가 하기 화학식 4로 표시되는 그룹 및 화학식 4a로 표시되는 그룹 중에서 선택될 수 있다.(1)

May be selected from the group represented by the following general formula (4) and the group represented by the general formula (4a).

[Chemical Formula 4]

Wherein Z is S, N or P and R ₁₁ to R ₂₅ are independently of each other 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 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,

Provided that if Z is S then R ₁₁ is absent.

[Chemical Formula 4a]

In formula (4a), R ₂₂ to R ₂₆ are defined as R ₁₁ to R _{25 in} formula (4), and Z is N.

가 하기 화학식 5로 표시되는 그룹 중에서 선택되고, In the formula 1

Is selected from the group represented by the following formula (5)

Y of the formula ^- is _{^{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 -, (FSO 2}} ) 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 -, and _{- (O (CF 3) 2} C 2 (CF 3) 2 O) 2 PO - from selected May be one or more anions.

[Chemical Formula 5]

In Formula 5, R ₂₀ to R ₂₈ independently represent 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, Unsubstituted or substituted C6-C30 aryloxy groups, unsubstituted or substituted C3-C30 heteroaryl groups, unsubstituted or substituted C3-C30 heteroaryloxy groups, unsubstituted or substituted C4-C30 cyclo An alkyl group or an unsubstituted or substituted C3-C30 heterocycloalkyl group.

The composite membrane comprises a lithium salt. The content of the lithium salt is 1 to 90 parts by weight, for example 20 to 60 parts by weight, based on 100 parts by weight of the composite membrane.

In the copolymer containing the first repeating unit of Formula 1 and the second repeating unit of Formula 2, the molar ratio of the first repeating unit represented by Formula 1 to the second repeating unit represented by Formula 2 is preferably from 1:99 to 99 : May be one. In the copolymer, the molar ratio of the first repeating unit represented by Formula 1 to the second repeating unit represented by Formula 2 may be 1: 1 to 4: 1. When the content of the first repeating unit represented by the general formula (1) is within the range described above, a composite membrane having excellent ionic conductivity can be produced without deteriorating the mechanical strength of the copolymer and the composite membrane containing the copolymer.

The copolymer according to one embodiment may be a copolymer represented by the following formula (6).

[Chemical Formula 6]

In the formula (6), Ar ₁ is a substituted or unsubstituted C6-C30 arylene group,

R ₁ , R ₂ and R ₃ independently of one another are hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group or an unsubstituted or substituted C 3 -C 30 heteroaryl Lt; / RTI &

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

는 하기 화학식 5로 표시되는 그룹이며,

Is a group represented by the following formula (5)

[Chemical Formula 5]

In Formula 5, R ₂₀ to R ₂₈ independently represent 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, Unsubstituted or substituted C6-C30 aryloxy groups, unsubstituted or substituted C3-C30 heteroaryl groups, unsubstituted or substituted C3-C30 heteroaryloxy groups, unsubstituted or substituted C4-C30 cyclo An alkyl group or an unsubstituted or substituted C3-C30 heterocycloalkyl group, * represents a bonding region,

Y ^- is _{^{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 _{^{-, (FSO 2) 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 -, and _{(O (CF 3) 2 C} 2 (CF 3) 2 O) 2 PO - , and one or more anions selected from the group consisting of ,

m and n are each from 0.01 to 0.99, and the sum thereof is 1.

The copolymer may be at least one selected from compounds represented by the following formulas (6a), (6b), (6c), and (6d).

[Formula 6a] [Formula 6b]

[Chemical Formula 6c] [Chemical formula 6d]

Of formula 6a to 6d, Y ^- is _{^{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 -, (FSO 2)}} 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 -, and _{(O (CF 3) 2 C} 2 (CF 3) 2 O) 2 PO - at least one selected among A is an integer of 1 to 10, R ₂₄ is a C 1 -C 10 alkyl group, m and n are each in the range of 0.01 to 0.99, the sum of these is 1, and the degree of polymerization is 10 to 5000.

The copolymer may be, for example, a copolymer represented by the following formula 6e, 6f or 6g.

[Chemical Formula 6e] [Chemical Formula 6f]

[Chemical Formula 6g]

In the above formulas (6e), (6f) and (6g), a is an integer of 1 to 10, m and n each are 0.01 to 0.99, the sum thereof is 1, and the degree of polymerization is 10 to 5000.

The degree of polymerization of the copolymer is 10 to 5,000. And the weight average molecular weight of the copolymer is from 3,000 Dalton to 400,000 Dalton, for example from 5,000 to 200,000 Dalton. When the degree of polymerization and the weight average molecular weight of the copolymer are in the ranges described above, the mechanical strength of the copolymer is excellent and the growth of the lithium dendrite can be effectively suppressed, thereby further improving the performance of the lithium battery. The weight average molecular weight was measured for polymethylmethacylate (PMMA) standard samples using GPC (Gel Permeation Chromatography).

For example, the polydipersity index (PDI) of the copolymer can be from 1 to 3, for example from 1 to 2.0, for example from 1.2 to 2.8. The performance of the lithium battery can be further improved by including the copolymer having the polydispersity index range.

The glass transition temperature (T _g ) of the copolymer can be from 30 to 90. [ For example, a number of 55 at a weight average molecular weight of 37,000 Dalton copolymer glass transition temperature (T _g). By including the copolymer having the glass transition temperature in the above range, the performance of the lithium battery can be further improved.

The copolymer may be electrochemically stable to -0.4 V with respect to lithium. That is, the copolymer can neglect the reduction current due to the side reaction of the random copolymer to -0.4 V with respect to lithium. For example, the copolymer may be in the range of -0.4 V to 6.2 V relative to the lithium metal, for example, in the range of -0.4 V to 5.5 V, for example, in the range of -0.4 V to 5.0 V, To provide a wide electrochemically stable voltage window of < RTI ID = 0.0 > 4.5V. ≪ / RTI >

The composite membrane according to one embodiment is available as an electrolyte. An electrolyte having enhanced durability and ionic conductivity can be obtained by including the above-mentioned copolymer in the electrolyte. In addition, the charge / discharge characteristics of a lithium battery including such an electrolyte can be improved.

The electrolyte comprising the copolymer may additionally comprise a lithium salt. The lithium salt can be, for example, LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ , LiN (SO ₂ C ₂ F ₅ ) ₂ , Li (CF ₃ SO ₂ ) ₂ N, Li (FSO ₂ ) ₂ N, LiC ₄ F _{9 SO 3, LiClO 4, LiAlO} 2, LiAlCl 4, LiN (C x F 2x + 1 SO 2) (C y F 2y + 1 SO 2) ( where, x and y is 1 to 30), LiF, LiBr, _{LiCl, LiI, LiB (C 2} O 4) 2 ( lithium bis oxalate reyito borate: lithium bis (oxalato) borate; LiBOB), LiTFSI one or two selected from the group consisting of (lithium bis (Trifluoromethanesulfonyl) Imide) and LiNO ₃ , But it is not limited thereto and any lithium salts can be used in the art.

In addition, the electrolyte comprising the random copolymer may additionally comprise another polymer. The polymer to be added is not particularly limited and can be used as an electrolyte in the art. For example, the electrolyte may further include polyethylene oxide, polyvinyl alcohol (PVA), and the like.

In addition, the electrolyte containing the copolymer may be a liquid electrolyte or a solid electrolyte.

For example, the liquid electrolyte containing the copolymer may be liquid at room temperature, further comprising at least one selected from an organic solvent and an ionic liquid.

The organic solvent may comprise an aprotic solvent. As aprotic solvents, for example, carbonate, ester, ether, ketone, or alcohol solvents may be used. Examples of the carbonate solvent include dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC) EC), propylene carbonate (PC), and butylene carbonate (BC) can be used. As the ester solvent, methyl acetate, ethyl acetate, n-propyl acetate, butyl acetate, methyl propionate, ethyl propionate Natta, gamma butyrolactone, decanolide, valerolactone, mevalonolactone, caprolactone and the like can be used. Examples of the ether solvent include dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, and tetrahydrofuran. As the ketone solvent, cyclohexanone may be used have. As the alcoholic solvent, ethyl alcohol, isopropyl alcohol, etc. may be used, but not limited thereto, and any protonic solvent that can be used in the art can be used. As the organic solvent, for example, tetraethylene glycol Dimethyl ether (TEGDME) and the like can be used.

An ionic liquid is an ionic liquid which is in a molten state at room temperature (25 ° C), and can be used without limitation as long as it contains cations and anions. The ionic liquid includes, but is not limited to, a cation, including but not limited to imidazolium, ammonium, pyrrolidinium or piperidinium, and anions include, but are not limited to, bis (Fluorosulfonyl) imide, fluorosufonylamide, fluoroborate, or fluorophosphate. The term " fluorosulfonyl " Specific examples of the cation include, for example, alkylammonium such as triethylammonium, imidazolium such as ethylmethylimidazolium and butylmethylimidazolium, and pyrrolidinium such as 1-methyl-1-propylpyrrolidinium . Specific examples of the anion include bis (trifluoromethylsulfonyl) imide (TFSI), bis (pentafluoroethylsufonyl) imide (BETI), bis Tetrafluoroborate (BF ₄ ), or hexafluorophosphate (PF ₆ ).

Ionic liquids Specific example _{[emim] Cl / AlCl 3 (} emim = ethyl methyl imidazolium), [bmpyr] NTf2 (bppyr = butyl methyl pyridinium), [bpy] Br / AlCl 3 (bpy = 4, 4'- bipyridine, [choline] Cl / CrCl ₃ .6H ₂ O, [Hpy (CH ₂ ) ₃ pyH] [NTf ₂ ] ₂ (NTf ₂ = bistrifluoromethanesulfonimide), [emim] OTf / [hmim] I (hmim = hexyl methyl imidazolium ), [choline] Cl / HOCH ₂ CH ₂ OH, [Et ₂ MeN (CH ₂ CH ₂ OMe)] BF ₄ (Et = ethyl, Me = octyl, Hex = hexyl), [ Bu 3 PCH 2 CH 2 C 8 F 17] OTf (OTf = trifluoromethane sulfonate), [bmim] PF 6 (bmim = butyl methyl imidazolium), [bmim] BF 4, [omim] PF _{6 (omim = octyl methyl imidazolium)} , [Oct 3 PC 18 H 37] I, [NC (CH 2) 3 mim] NTf 2 (mim = methyl imidazolium), [Pr 4 N] [B (CN) 4], [Me ₃ NCH (Me) CH (OH) Ph] NTf ₂ , [bmim] NTf ₂ , [bmim] Cl, [bmim] [Me (OCH ₂ CH ₂ ) ₂ OSO ₃ ], [PhCH ₂ mim] [bmim] [Cu ₂ Cl ₃ ], [C ₁₈ H (PO ₄ ) ₂ ], [(6-Me) b quin] NTf ₂ (bquin = butyl quinolinium, ₃₇ OCH ₂ mim] _{BF 4 (mim = methyl imidazolium)} , [heim] PF 6 (heim = hexyl ethyl imidazolium), [mim (CH 2 CH 2 O) 2 CH 2 CH 2 mim] [NTf 2] 2 (mim = methyl imidazolium), _{[obim] PF 6 (obim =} octyl butyl imidazolium), [oquin] NTf 2 (oquin = octyl quinolinium), [hmim] [PF 3 (C 2 F 5) 3], [C 14 H 29 mim] Br (mim _{= methyl imidazolium), [Me 2} N (C 12 H 25) 2] NO 3, [emim] BF 4, [mm (3-NO 2) im] [dinitrotriazolate], [MeN (CH 2 CH 2 OH) 3 ] [[MeOSO ₃ ], [Hex ₃ PC ₁₄ H ₂₉ ] NTf ₂ , [emim] [EtOSO ₃ ], [choline] [ibuprofenate], [emim] NTf ₂ , [emim] [(EtO) ₂ PO ₂ ] [emim] Cl / CrCl ₂ , [Hex ₃ PC ₁₄ H ₂₉ ] N (CN) ₂ , and the like, but is not limited thereto and can be used as an ionic liquid in the related art.

The solid electrolyte containing the copolymer is solid at room temperature and may contain no organic solvent.

The solid electrolyte may be heated to a temperature below 50 ° C, for example below 30 ° C, for example below 25 ° C

It can be solid. According to one embodiment, the solid electrolyte may have a solidification temperature of 0 to 50 占 폚, for example 5 to 40 占 폚, for example 10 to 30 占 폚. The electrolyte may be a solid at room temperature by including a copolymer. The solid electrolyte may be a solvent free electrolyte. The solid electrolyte may not contain a solvent. For example, the solid electrolyte may be a solid polymer electrolyte comprising only a copolymer and a lithium salt without containing a solvent. Since the electrolyte does not contain a solvent, it is possible to prevent problems such as side reactions and leakage of the solvent.

The solvent-free solid electrolyte is distinguished from the polymer gel electrolyte in which the solid polymer contains a small amount of solvent. The polymer gel electrolyte can have a further improved ionic conductivity, for example, by including a small amount of solvent in the ion conductive polymer.

When the composite membrane according to one embodiment is used as a lithium cathode protection film, the protection film includes a copolymer, thereby suppressing dendrite formation on the surface of the cathode during charging and discharging in the lithium battery, thereby improving the charge / discharge characteristics of the lithium battery .

The negative electrode includes a lithium metal, a lithium-metal-based alloy, or a material capable of absorbing and releasing lithium, but is not limited thereto. The negative electrode may be used as a negative electrode in the related art. Any material is possible. The cathode may be, for example, lithium metal. The lithium metal-based alloy may be, for example, an alloy of aluminum, tin, magnesium, indium, calcium, titanium, vanadium and the like and lithium.

The protective layer may further include a lithium salt. By additionally including the lithium salt, the ionic conductivity of the protective film is increased, so that the interface resistance between the cathode and the electrolyte can be reduced. The lithium salt may be the same as the lithium salt contained in the electrolyte containing the above-mentioned copolymer.

The thickness of the composite membrane may be from 1 nm to 1000 탆, for example from 0.1 탆 to 100 탆, for example from 0.5 to 70 탆, for example from 1 to 50 탆, for example from 1 to 20 탆. The composite membrane having the above thickness range is excellent in the function of protecting the lithium negative electrode, and the lithium ion can be easily transferred, so that the charge / discharge characteristics of the lithium battery can be improved.

The composite membrane may be disposed on one or both surfaces of the cathode, and the composite membrane may be cathode coated. By the composite film covering the entire cathode, the generation of dendrite on the entire surface of the cathode can be effectively suppressed.

The composite membrane may have a single-layer structure or a multi-layer structure. The composite membrane has a multi-layer structure, so that the physical properties of the entire composite membrane can be easily controlled by varying the composition of each layer in a plurality of layers. In a composite membrane having a multi-layer structure, at least one of the layers may comprise a copolymer.

The lithium ion conductivity of the composite membrane at 25 캜 is 0.001 mS / cm or more, for example, 0.01 to 0.5 mS / cm.

According to another aspect, the lithium battery comprises a positive electrode; cathode; And a composite membrane disposed therebetween.

The composite membrane may be an electrolyte disposed between an anode and a cathode in a lithium battery. For example, the lithium battery may further include a liquid electrolyte or a solid electrolyte. The lithium battery may be a lithium ion battery or a lithium air battery. The lithium battery may be a primary battery or a secondary battery.

The lithium battery may be a lithium negative electrode including a lithium metal or a lithium alloy electrode as a negative electrode. A lithium battery employing a lithium negative electrode is a lithium metal battery.

The negative electrode is a lithium metal or lithium metal alloy electrode; Alternatively, the negative electrode may be formed of a carbon-based material, silicon, silicon oxide, silicon-based alloy, silicon-carbon based material composite, tin, tin-based alloy, tin-carbon composite material, metal / And may include one or more selected anode active materials.

Wherein the cathode is a lithium metal or lithium metal alloy electrode, and the composite membrane is a cathode protection film or a cathode protection film and electrolyte.

The composite membrane can be used as an electrolyte.

The lithium battery may further include at least one selected from a liquid electrolyte, a solid electrolyte, a gel electrolyte, and a polymer ionic liquid.

The positive electrode may contain a positive electrode active material and a copolymer including the first repeating unit represented by the formula (1) and the second repeating unit represented by the formula (2). When the positive electrode contains a copolymer containing the first repeating unit represented by the formula (1) and the second repeating unit represented by the formula (2), the lithium ion mobility is excellent, the electrochemical stability is improved, and the mechanical properties are improved The electrochemical characteristics of the lithium battery can be improved.

The operating voltage of the lithium battery is 4.0 V or more.

According to another aspect, there is provided a positive electrode for a lithium battery comprising a positive electrode active material, a copolymer comprising a first repeating unit represented by the formula (1) and a second repeating unit represented by the formula (2).

The lithium battery can be produced, for example, in the following manner.

First, the anode is prepared. As the anode, a cathode according to one embodiment may be used, or a general anode may be used.

For example, a cathode active material composition in which a cathode active material, a conductive agent, a binder and a solvent are mixed is prepared. The positive electrode active material composition is coated directly on the metal current collector and dried to produce a positive electrode. The positive electrode active material composition may further include a copolymer including a first repeating unit represented by the formula (1) and a second repeating unit represented by the formula (2). Alternatively, the cathode active material composition may be cast on a separate support, and then the film peeled off from the support may be laminated on the metal current collector to produce a cathode plate.

The positive electrode active material may include at least one selected from the group consisting of lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, and lithium manganese oxide. However, May be used.

For example, Li _a A _{1 - b} B _b D ₂ , where 0.90? A? 1.8, and 0? B? 0.5; Li _a E _{1 -b} B _b O _{2 -c} D _c wherein, in the formula, 0.90? A? 1.8, 0? B? 0.5, 0 _{? C?} 0.05; LiE _{2 - b} B _b O _{4 - c} D _{c where} 0? B? 0.5, 0 _{? C?} 0.05; Li _a Ni _{1 -b- c} Co _b B _c D _? Wherein, in the formula, 0.90 _{? A?} 1.8, 0 _? B _? 0.5, 0 _? C _? 0.05, 0? Li _a Ni _{1 -b- c} Co _b B _c O _{2 - ?} F _? Wherein, in the formula, 0.90? A? 1.8, 0 _? B _? 0.5, 0 _? C _? 0.05, 0 <? Li _a Ni _{1 -b- c} Co _b B _c O _{2 - ?} F ₂ wherein 0.90? A? 1.8, 0 _? B _? 0.5, 0? C? 0.05, 0 <? Li _a Ni _{1 -bc} Mn _b B _c D _? Wherein, in the formula, 0.90 _{? A?} 1.8, 0 _? B _? 0.5, 0 _? C _? 0.05, 0? _{? A ?} 1.8, 0 _? B _? 0.5, 0 _? C _? 0.05, 0?? <2), Li _a Ni _{1 -bc} Mn _b B _c O _{2 -?} F _? Li _a Ni _{1 -b- c} Mn _b B _c O _{2 - ?} F ₂ wherein 0.90? A? 1.8, 0 _? B _? 0.5, 0? C? 0.05, 0 <? Li _a Ni _b E _c G _d O ₂ wherein, in the formula, 0.90? A? 1.8, 0? B? 0.9, 0? C? 0.5, and 0.001? D? Li _a Ni _b Co _c Mn _d GeO ₂ wherein 0.90? A? 1.8, 0? B? 0.9, 0? C? 0.5, 0? D? 0.5, and 0.001? E? 0.1. Li _a NiG _b O ₂ (in the above formula, 0.90? A? 1.8, and 0.001? B? 0.1); Li _a CoG _b O ₂ (in the above formula, 0.90? A? 1.8, 0.001? B? 0.1); Li _a MnG _b O ₂ (in the above formula, 0.90? A? 1.8, and 0.001? B? 0.1); Li _a Mn ₂ G _b O ₄ (in the above formula, 0.90? A? 1.8, 0.001? B? 0.1); QO _2; QS ₂ ; LiQS ₂ ; V ₂ O ₅ ; LiV ₂ O ₅ ; LiIO ₂ ; LiNiVO _4; Li _(3-f) J ₂ (PO ₄ ) ₃ (0 _{? F? 2} ); _{(0≤f≤2) Li (3-f} ) Fe 2 (PO 4) 3; In the formula of LiFePO ₄ may be used a compound represented by any one:

In the above formula, A is Ni, Co, Mn, or a combination thereof; B is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element or a combination thereof; D is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or combinations thereof; Q is Ti, Mo, Mn, or a combination thereof; I is Cr, V, Fe, Sc, Y, or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

Of course, a compound having a coating layer on the surface of the compound may be used, or a compound having a coating layer may be mixed with the compound. The coating layer may comprise an oxide, a hydroxide of the coating element, an oxyhydroxide of the coating element, an oxycarbonate of the coating element, or a coating element compound of the hydroxycarbonate of the coating element. The compound constituting these coating layers may be amorphous or crystalline. The coating layer may contain Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr or a mixture thereof. The coating layer forming step may be any coating method as long as it can coat the above compound by a method that does not adversely affect physical properties of the cathode active material (for example, spray coating, dipping, etc.) by using these elements, It will be understood by those skilled in the art that a detailed description will be omitted.

For _{example, LiNiO 2, LiCoO 2, LiMn} x O 2x (x = 1 or _{2), LiNi 1 - x Mn} x O 2 (0 <x <1), LiNi 1 -xy Co x Mn y O 2 (0 ? 0.5, 0? Y? 0.5), LiFeO ₂ , V ₂ O ₅ , TiS, MoS and the like can be used.

Examples of the conductive agent include carbon black, graphite fine particle natural graphite, artificial graphite, acetylene black, Ketjen black, carbon fiber; Metal powders or metal fibers or metal tubes such as carbon nanotubes, copper, nickel, aluminum, and silver; Conductive polymers such as polyphenylene derivatives, and the like can be used, but the present invention is not limited thereto, and any conductive polymer may be used as the conductive polymer in the art.

Examples of the binder include vinylidene fluoride / hexafluoropropylene copolymer, polyvinylidene fluoride, polyimide, polyethylene, polyester, polyacrylonitrile, polymethylmethacrylate, polytetrafluoroethylene (PTFE) A carboxymethyl cellulose-styrene-butadiene rubber (SMC / SBR) copolymer, a styrene butadiene rubber-based polymer, or a mixture thereof may be used.

As the solvent, N-methylpyrrolidone, acetone or water may be used.

But not limited to, all of those which can be used in the technical field.

The content of the composite cathode active material, the conductive agent, the binder, and the solvent is a level commonly used in a lithium battery. At least one of the conductive agent, the binder and the solvent may be omitted depending on the use and configuration of the lithium battery.

The negative electrode can be obtained by carrying out almost the same method except that the negative electrode active material is used instead of the positive electrode active material in the positive electrode manufacturing process described above.

As the negative electrode active material, a carbon-based material, silicon, a silicon oxide, a silicon-based alloy, a silicon-carbon-based material composite, a tin, a tin alloy, a tin-carbon composite or a metal oxide or a combination thereof is used.

The carbon-based material may be crystalline carbon, amorphous carbon or a mixture thereof. The crystalline carbon may be graphite such as natural graphite or artificial graphite in the form of amorphous, plate-like, flake, spherical or fibrous type, and the amorphous carbon may be soft carbon or hard carbon carbon fiber, carbon fiber, mesophase pitch carbide, fired cokes, graphene, carbon black, fullerene soot, carbon nanotubes, and carbon fiber, and the like, Anything that can be used is possible.

The negative electrode active material may be selected from the group consisting of Si, SiOx (0 <x <2, for example, 0.5 to 1.5), Sn, SnO ₂ or a silicon-containing metal alloy and mixtures thereof. At least one of Al, Sn, Ag, Fe, Bi, Mg, Zn, In, Ge, Pb and Ti can be used as the metal for forming the silicon alloy.

The negative electrode active material may include a metal / metalloid alloy that is alloyable with lithium, an alloy thereof, or an oxide thereof. Al, Ge, Pb, Bi, Sb, and Si-Y alloy (Y is an alkali metal, an alkali earth metal, or an alloy thereof) (Wherein Y is an alkali metal, an alkaline earth metal, a Group 13 to Group 16 element, a transition metal, a rare earth element or a rare earth element, or a combination thereof) Or a combination thereof, but not Sn), MnOx (0 < x? 2), and the like. The element Y may be at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Se, Te, Po, or a combination thereof. For example, the oxide of the metal / metalloid capable of alloying with lithium may be lithium titanium oxide, vanadium oxide, lithium vanadium oxide, SnO ₂ , SiO _x (0 <x <2) and the like.

For example, the negative electrode active material may include one or more elements selected from the group consisting of Group 13 elements, Group 14 elements, and Group 15 elements of the Periodic Table of the Elements. For example, the negative electrode active material may include at least one element selected from the group consisting of Si, Ge, and Sn.

The content of the negative electrode active material, the conductive agent, the binder and the solvent is a level commonly used in a lithium battery.

Next, a separator may be inserted between the positive electrode and the negative electrode.

The separator is interposed between the positive electrode and the negative electrode, and an insulating thin film having high ion permeability and mechanical strength is used.

The pore diameter of the separator is generally 0.01 to 10 mu m and the thickness is generally 5 to 20 mu m. Examples of such a separator include olefin-based polymers such as polypropylene and polyethylene; A sheet or nonwoven fabric made of glass fiber, polyethylene or the like is used. When a solid polymer electrolyte is used as the electrolyte, the solid polymer electrolyte may also serve as a separator.

Of the above separators, specific examples of the olefin-based polymer include polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more thereof. The polyethylene / polypropylene double layer separator, polyethylene / polypropylene / A multi-layered film such as a separator, a polypropylene / polyethylene / polypropylene three-layer separator, or the like can be used.

Next, the electrolyte is prepared. The electrolyte may be in a liquid or gel state. The electrolyte may comprise the random copolymer described above.

For example, the electrolyte may be an organic liquid electrolyte. The organic liquid electrolyte can be prepared by dissolving a lithium salt in an organic solvent. As the organic solvent, the above-mentioned aprotic solvent may be used. Lithium salt The lithium salt contained in the electrolyte described above can also be used.

Alternatively, the electrolyte may be a solid. For example, boron oxide, lithium oxynitride, and the like, but not limited thereto, and any of them can be used as long as they can be used as solid electrolytes in the art. The solid electrolyte may be formed on the cathode by a method such as sputtering.

As shown in FIG. 9, the lithium battery 91 includes an anode 93, a cathode 92, and a composite membrane 94. The anode 93, the cathode 92 and the composite membrane 94 described above are wound or folded and housed in the battery case 95. An organic electrolyte is then injected into the battery case 95 and sealed with a cap assembly 96 to complete the lithium battery 91. The battery case may have a cylindrical shape, a rectangular shape, a thin film shape, or the like. For example, the lithium battery may be a thin film battery.

For example, the lithium battery may be a lithium ion polymer battery. In the lithium ion polymer battery, a separator is disposed between the positive electrode and the negative electrode to form a battery structure, and then the battery structure is laminated or wound in a bi-cell structure, then impregnated with the organic electrolyte solution, do.

In addition, a plurality of battery structures are stacked to form a battery pack, and such a battery pack can be used for all devices requiring high capacity and high output. For example, a notebook, a smart phone, an electric vehicle, and the like.

Particularly, the lithium battery is suitable for an electric vehicle (EV) because it has excellent thermal stability and provides good battery characteristics. For example, it is suitable for a hybrid vehicle such as a plug-in hybrid electric vehicle (PHEV).

Alternatively, the lithium battery may be a lithium air battery.

The lithium air cell can be prepared, for example, as follows.

First, an air electrode is prepared as an anode. For example, the air electrode may be manufactured as follows. As the electrode member, a conductive agent and a binder are mixed and then an appropriate solvent is added or a solvent is not added to prepare an air electrode slurry. Then, the air electrode slurry is coated and dried on the current collector surface, For example, by compression molding. The current collector may be a gas diffusion layer. Alternatively, the air electrode slurry may be coated and dried on the surface of a separator or a solid electrolyte membrane, or alternatively, compression-molded into a separator or a solid electrolyte membrane to improve electrode density.

The conductive material contained in the air electrode slurry may be porous. Accordingly, any material having porosity and conductivity can be used without limitation, and for example, a carbon-based material having porosity can be used. Examples of such carbon-based materials include carbon blacks, graphites, graphenes, activated carbons, and carbon fibers.

Catalysts for oxidation / reduction of oxygen may be added to the air electrode slurry. Examples of such catalysts include noble metal catalysts such as platinum, gold, silver, palladium, ruthenium, rhodium and osmium, manganese oxides, iron oxides, cobalt oxides, nickel Oxides and the like, or organometallic catalysts such as cobalt phthalocyanine may be used. However, the present invention is not limited thereto, and any catalyst that can be used as an oxidation / reduction catalyst for oxygen in the related art can be used.

In addition, the catalyst may be supported on the carrier. The carrier may be an oxide, zeolite, clay minerals, carbon, or the like. The oxide may include one or more oxides such as alumina, silica, zirconium oxide, and titanium dioxide. Or an oxide comprising at least one metal selected from Ce, Pr, Sm, Eu, Tb, Tm, Yb, Sb, Bi, V, Cr, Mn, Fe, Co, Ni, Cu, . The carbon may be carbon black such as Ketjen black, acetylene black, channel black or lamp black, graphite such as natural graphite, artificial graphite or expanded graphite, activated carbon, carbon fiber or the like, but is not limited thereto, Anything that can be used as a carrier in the field is possible.

The air electrode slurry may comprise a binder. The binder may include a thermoplastic resin or a thermosetting resin. For example, it is possible to use polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene-butadiene rubber, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride- Vinylidene fluoride copolymer, fluoroethylene copolymer, fluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, vinylidene fluoride-pentafluoropropylene copolymer, Ethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene copolymer, ethylene- Acrylic acid copolymer and the like can be used singly or in combination, but they are not limited to these, Anything that can be used as a binder in the technical field is possible.

The current collector may use a porous material such as a mesh or mesh in order to accelerate the diffusion of oxygen, and a porous metal plate such as stainless steel, nickel, or aluminum may be used. However, the present invention is not limited thereto, As long as it can be used as an electronic device. The current collector may be coated with an oxidation-resistant metal or alloy coating.

The air electrode slurry may optionally include conventional conventional oxygen oxidation / reduction catalysts and conductive materials. In addition, the air electrode slurry may optionally include lithium oxide.

And the composite membrane for a lithium battery described above is disposed between the air electrode and the cathode. And may further include a separator used in a lithium battery.

Further, in the lithium air battery, an oxygen barrier film impervious to oxygen may be additionally disposed between the air electrode and the cathode. A lithium air cell having an oxygen barrier membrane that is impervious may not contain a general separator. The oxygen barrier layer may serve as a protective layer for protecting impurities such as oxygen contained in the air electrode from directly reacting with the lithium metal anode, as a lithium ion conductive solid electrolyte membrane. Examples of the lithium ion conductive solid electrolyte film forming material that is impermeable to oxygen in this way include inorganic materials containing lithium ion conductive glass, lithium ion conductive crystals (ceramic or glass-ceramic), or mixtures thereof. , It is possible to use a solid electrolyte membrane which has lithium ion conductivity and is impermeable to oxygen and can protect the cathode, as long as it can be used in the technical field. On the other hand, in consideration of chemical stability, the lithium ion conductive solid electrolyte membrane may be exemplified by an oxide.

For example, the oxygen barrier film containing lithium ion conductive crystals may include Li _{1 + x + y} Al _x (Ti, Ge) _2-x Si _y P _3-y O _1, 0? X? 2, ), And is, for example, a solid electrolyte membrane containing LATP (Li _1.4 Ti _1.6 Al _0.4 P ₃ O ₁₂ ).

Next, an electrolyte is injected between the air electrode and the cathode. The electrolyte may be the same as that used for the lithium battery.

The shape of the lithium air battery is not particularly limited and may be, for example, a coin shape, a button shape, a sheet shape, a laminate shape, a cylindrical shape, a flat shape, a horn shape or the like. It can also be applied to large-sized batteries used in electric vehicles and the like.

As used herein, the term " air " is not meant to be limited to atmospheric air, but may include a combination of gases containing oxygen, or pure oxygen gas. The broad definition of this term " air " can be applied to all applications, such as air cells, air air poles, and the like.

The copolymer according to one embodiment can produce a random copolymer or a block copolymer according to a synthesis method. For example, the block copolymer may be prepared by anionic polymerization, chain transfer agent (CTA), or the like.

Hereinafter, the synthesis process of the copolymer will be described in more detail.

The first monomer represented by the following general formula (7) and the second monomer represented by the following general formula (8) are subjected to a polymerization reaction to obtain a copolymer represented by the general formula (9).

[Chemical Formula 7]

In the formula (7), R ₁ to R ₃ , Ar 1 and A are as defined in the formula (1), and X is a halogen atom. The halogen atom is, for example, Cl, Br, or I.

In formula (8), R ₄ to R ₇ , a are as defined in formula (2).

[Chemical Formula 9]

Wherein R ₁ to R ₃ , Ar 1 and A are as defined in the formula (1), R ₄ to R ₇ , a are as defined in the formula (2), m and n are each a repeat The sum of the mole fractions of the units is 1, and is a number of 0.1 to 0.99.

X^-로 변화된다. 이어서, 상기 결과물에 Y^-를 함유한 화합물을 부가 및 반응하여 목적하는 공중합체를 얻을 수 있다.The copolymer represented by the formula (9) is reacted with the compound represented by the formula (10) so that X at the terminal of the copolymer

X ^- . &Lt; / RTI &gt; Then, a compound containing Y ^- is added to and reacted with the resultant product to obtain the desired copolymer.

[Chemical formula 10]

는 2 내지 30개의 탄소 원자를 포함하는 3원 내지 31원 고리(membered ring)이며, X는 S, N, N(R) 또는 P(R')이고, R, R'은 화학식 1에서 정의된 바와 같다.In formula (10)

Is a 3 to 31 membered ring comprising 2 to 30 carbon atoms, X is S, N, N (R) or P (R ') and R, R' Same as.

The compound represented by Formula 10 is a 3-membered to 31-membered ring compound containing 2 to 30 carbon atoms, and X is as defined in Formula (1).

Examples of the compound represented by formula (10) include N-methylpyrrolidine, N-methylimidazole, and the like. As the compound containing Y ^- , for example, lithium bis (trifluoromethylsulfonyl) imide, lithium bis (fluorosulfonyl) imide and the like are used.

The polymerization method in the copolymer production method is not limited to them but solution polymerization may be used, and any method can be used as a method for producing a polymer in the art. The polymerization temperature and the polymerization time are not particularly limited and can be appropriately changed.

Y^- 는 화학식 9로 표시되는 공중합체를 먼저 합성한 후, 이를 상기 화학식 10으로 표시되는 화합물 및 상기 Y^-를 함유한 화합물과 순차적으로 반응하여 공중합체의 말단에 존재하는 X를

Y^-로 변화되어 목적하는 공중합체를 제조할 수 있다. 다르게는 일구현예에 따른 공중합체는 하기 화학식 7a로 표시되는 제1모노머와 상기 화학식 8로 표시되는 제2모노머를 공중합하여 제조하는 것도 가능하다.The copolymer according to one embodiment has a structure in which in the first repeating unit

Y ^- is prepared by first synthesizing a copolymer represented by the formula (9), and then sequentially reacting the compound represented by the formula (10) and the compound containing the Y ^- to form X at the end of the copolymer

Y ^- , so that the desired copolymer can be produced. Alternatively, the copolymer according to one embodiment may be prepared by copolymerizing a first monomer represented by the following formula (7a) and a second monomer represented by the following formula (8).

[Formula 7a]

는 화학식 1에서 정의된 바와 같다.In formula (7a), R ₁ to R ₃ , Ar ₁ , A, Y ^- ,

Is as defined in formula (1).

According to another aspect, there is provided a copolymer comprising the first repeating unit represented by the formula (1) and the second repeating unit represented by the formula (2). This copolymer may be a random copolymer as described above.

The definitions of substituents used in the formulas of the present specification are as follows.

Alkyl groups refer to groups of fully saturated branched or unbranched (or straight chain or linear) hydrocarbons. Non-limiting examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, neopentyl, n- , 2-dimethylpentyl, 2,3-dimethylpentyl, n-heptyl and the like. At least one of the hydrogen atoms of the alkyl is an alkyl group of a halogen atom, halogen-substituted C1-C20 (for _{example: CF 3, CH 3 CF 2} , CH 2 F, CCl 3 , etc.), C1-C20 alkoxy group, C2-C20 A sulfamoyl group, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a sulfonic acid group, a sulfonic acid group or a salt thereof, a sulfonic acid group or a salt thereof, , Or a C1-C20 alkyl group, a C2-C20 alkenyl group, a C2-C20 alkynyl group, a C1-C20 heteroalkyl group, a C6-C20 aryl group, a C7-C20 arylalkyl group, a C6-C20 heteroaryl group , A C7-C20 heteroarylalkyl group, a C6-C20 heteroaryloxy group, a C6-C20 heteroaryloxyalkyl group, or a C6-C20 heteroarylalkyl group.

The alkenyl group means an aliphatic hydrocarbon containing one or more double bonds, and the alkynyl group means an aliphatic hydrocarbon containing one or more triple bonds.

A cycloalkyl group means an aliphatic hydrocarbon containing one or more rings. Wherein the alkyl group is as described above. Heterocycloalkyl means a cycloalkyl group containing at least one heteroatom selected from N, O, P or S. Wherein the cycloalkyl group is as described above.

The halogen atom includes fluorine, bromine, chlorine, iodine and the like.

The alkoxy group represents an alkyl group -O-, wherein the alkyl group is as described above. Non-limiting examples of the alkoxy group include methoxy, ethoxy, propoxy, 2-propoxy, butoxy, tert-butoxy, pentyloxy, . At least one hydrogen atom of the alkoxy group may be substituted with the same substituent as the alkyl group described above.

The cycloalkyloxy group represents a cycloalkyl group -O-, wherein the cycloalkyl group is as described above. The heterocycloalkyloxy group represents a heterocycloalkyl group -O-, wherein the heterocycloalkyl group is as described above.

The aryl group, alone or in combination, means an aromatic hydrocarbon containing one or more rings. The aryl group also includes a group in which the aromatic ring is fused to one or more cycloalkyl rings. Non-limiting examples of the aryl group include a phenyl group, a naphthyl group, and a tetrahydronaphthyl group. Further, at least one hydrogen atom in the aryl group may be substituted with the same substituent as in the case of the above-mentioned alkyl group.

The alkyl group and the aryl group in the arylalkyl group are as described above.

The aryloxy group represents an aryl group -O-, wherein the aryl group is as described above.

The arylthio group represents an aryl group -S-, wherein the aryl group is as described above.

Heteroaryl means a monocyclic or bicyclic organic compound having at least one heteroatom selected from N, O, P or S and the remaining ring atoms carbon. The heteroaryl group may contain, for example, 1 to 5 hetero atoms, and may include 5 to 10 ring members. The S or N may be oxidized to have various oxidation states.

The monocyclic heteroaryl group includes, for example, thienyl, furyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, 1,2,3-oxadiazolyl, , 4-oxadiazolyl group, 1,2,5-oxadiazolyl group, 1,3,4-oxadiazolyl group, 1,2,3-thiadiazolyl group, 1,2,4-thiadiazolyl Thiadiazolyl group, a 1,3,4-thiadiazolyl group, an isothiazol-3-yl group, an isothiazol-4-yl group, an isothiazol- An isoxazol-4-yl group, an isoxazol-5-yl group, an 1,2,4-triazole group, Yl group, a 1,2,3-triazol-5-yl group, a tetrazolyl group, a p-toluenesulfonyl group, Pyrazin-2-yl group, a pyrimidin-2-yl group, a pyrimidin-2-yl group, Or a 5-pyrimidin-2-yl group.

Heteroaryl includes those where the heteroaromatic ring is fused to one or more aryl, cyclyaliphatic, or heterocycle.

Examples of bicyclic heteroaryls include, but are not limited to, indolyl, isoindolyl, indazolyl, indolizinyl, purinyl, quinolizinyl, quinolyl, Quinolinyl, isoquinolinyl, and the like. At least one hydrogen atom in such heteroaryl may be substituted with the same substituent as in the case of the above-mentioned alkyl group.

The aryl group in the heteroarylalkyl group is as described above. The heteroaryloxy group represents a heteroaryl group -O-, wherein the heteroaryl group is as described above. And the heteroarylthio group represents a heteroaryl group -S-, wherein the heteroaryl group is as described above.

Alkylene, arylene, heteroarylene, cycloalkylene, heterocycloalkylene means a substituent wherein one hydrogen is removed from alkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl.

Will be explained in more detail through the following examples and comparative examples. However, the embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

Manufacturing example  One: Random copolymer  synthesis

10 g of 1-chloromethyl-4-vinylbenzene (manufactured by Oakwood Chemical Company) and polyoxyethylene methacrylate (A) were added to the inside of the reactor, and AIBN (Azobisisobutyronitrile) 0.075 g, and the polymerization reaction was carried out while stirring at 60 DEG C for 15 hours. The molar ratio of 1-chloromethyl-4-vinylbenzene to polyoxyethylene methacrylate was 4: 1. After completion of the polymerization reaction, the solvent was removed by evaporation under reduced pressure, and the residue was precipitated with n-hexane to obtain a random copolymer (B) as a polymerization product.

[Reaction Scheme 1]

In Scheme 1, m and n are mole ratios respectively, the sum of which is 1, m is 0.8, n is 0.2, a is 10, and the degree of polymerization of the random copolymer is controlled to be about 300,000 Dalton do.

6.13 g of n-methylpyrrolidine (97%, manufactured by Sigma-Aldrich) dissolved in 100 ml of dichloroethane was added to the random copolymer (B) The reaction was carried out to prepare a random copolymer (C).

             (C)

Wherein m is 0.8, n is 0.2, and a is 10.

A random copolymer composition was prepared by adding lithium bis (trifluoromethylsulfonyl) imide (LiTFSI, manufactured by PANAX) and acetone to the random copolymer (C). The random copolymer (C) and LiTFSI were mixed at a molar ratio of 1: 1.2, and the content of acetone was controlled so that the content of the random copolymer (C) was about 10% by weight based on the total weight of the random copolymer composition. The reaction mixture was stirred at room temperature (25 ° C) for 6 hours to synthesize a random copolymer of the formula (6e) in which the Cl ^- anion of the random copolymer (C) was substituted with TFSI ^- anion.

[Formula 6e]

In the formula (6e), m and n are each a molar fraction, and the sum thereof is 1, m is 0.8, n is 0.2, a is 10, and the degree of polymerization of the random copolymer of formula (6e) is 300,000 Dalton Respectively.

Manufacturing example  2: Preparation of random copolymer

The procedure of Production Example 1 was repeated except that the molar ratio of 1-chloromethyl-4-vinylbenzene and polyoxyethylene methacrylate was changed to 1: 1 in the preparation of the random copolymer (B) Was prepared. &Lt; tb &gt; &lt; TABLE &gt; In formula 6e, both m and n were 0.5.

Manufacturing example  3: Preparation of random copolymer

The procedure of Production Example 1 was repeated except that the molar ratio of 1-chloromethyl-4-vinylbenzene to polyoxyethylene methacrylate was changed to 2: 1 in the preparation of the random copolymer (B) Was prepared. &Lt; tb &gt; &lt; TABLE &gt; In the formula (6e), m and n were 0.67 and 0.23, respectively.

Manufacturing example  4: Random copolymer  synthesis

Lithium bis (fluorosulfonyl) imide (LiFSI, manufactured by PANAX) was used instead of lithium bis (trifluoromethylsulfonyl) imide added to the random copolymer (C) , A random copolymer represented by the following formula (6f) was prepared.

(6f)

In formula (6f), m and n are each a molar fraction, and the sum thereof is 1, m is 0.8, n is 0.2, a is 10, and the degree of polymerization is such that the random copolymer of formula (6f) has a weight average molecular weight of 300,000 Dalton Respectively.

Manufacturing example  5: Preparation of random copolymer

The procedure of Preparation Example 1 was repeated except that chloromethyl-4-vinylbenzene was used instead of the compound of Formula 11 to prepare a random copolymer represented by Formula 6g.

[Chemical Formula 11] [Chemical Formula 6g]

In the formula (6g), m is 0.8, n is 0.2, a is 10, and the degree of polymerization of the random copolymer of formula (6g) is controlled so that the weight average molecular weight is 300,000 Dalton.

Comparative Manufacturing Example  One: Random copolymer  Produce

10 g of 1-chloromethyl-4-vinylbenzene (manufactured by Oakwood Chemical Company) was introduced into the inside of the reactor, and 6.13 g of n-methylpyrrolidone dissolved in 100 ml of dichloroethane (N-methylpyrrolidine, 97%, manufactured by Sigma-Aldrich) was added thereto, and the reaction was allowed to proceed at 70 ° C for 9 hours to obtain a solution of N-methylpyrrolidinium To obtain an intermediate product having a nitrogen atom bonded thereto.

A composition was prepared by adding lithium bis (trifluoromethylsulfonyl) imide, LiTFSI, PANAX) and acetone to the intermediate product. The intermediate product and LiTFSI were mixed in a molar ratio of 1: 1.2 and the acetone content was controlled to be about 10% by weight based on the total weight of the composition. To the reaction mixture was stirred for 6 hours at room temperature (25 ℃) Cl ^- ethylamine The TFSI anion ^{monomer-vinyl} substituted with anion-benzyl-4-methyl-pyrrolidin pyridinium TFSI ^{+ - - (+} mVBMPYR TFSI).

Then, to the reactor a styrene (styrene) and 20g of 4-vinylbenzyl prepared in methyl-pyrrolidin pyridinium ⁺ TFSI ^{- (+} mVBMPYR TFSI ^-) input of the monomer 10.74g: the (82 molar ratio), and initiator AIBN (Azobisisobutyronitrile), and the polymerization reaction was carried out while stirring at 60 ° C for 15 hours. After completion of the polymerization reaction, the solvent was removed using a rotary evaporator and precipitated with methanol to recover the random copolymer (D) as a polymerization product.

      (D)

In the above formula, m was 0.8, n was 0.2, and the degree of polymerization of the random copolymer was controlled such that the weight average molecular weight of the obtained random copolymer (D) was 37,000 Dalton. The polydispersion index (PDI) of the random copolymer (D) was 1.55.

Example  1: Lithium battery ( Li / Li Symmetric cell )

0.4 g of the random polymer of the formula 6e prepared in Preparation Example 1 was dissolved in 4 ml of a mixed solvent of dimethylformamide (DMF) and tetrahydrofuran (THF) (5: 5 by volume) to obtain a polymer solution. The lithium salt LiTFSI was dissolved in 0.2 g, and the solution was coated on a lithium foil having a thickness of 20 탆 by using a doctor blade. The solution was dried at room temperature (25 캜) for 2 days and vacuum dried (60 캜 overnight) A 5 占 퐉 -thick random copolymer was formed on the lithium negative electrode and a lithium negative electrode was laminated on the other side of the protective film to prepare a Li / Li symmetric cell. Since the protective layer includes a random copolymer and a lithium salt, which are polymeric ionic liquids, the protective layer may act as an electrolyte.

Example  2-3: Lithium battery ( Li / Li Symmetric cell )

A Li / Li symmetric cell was prepared in the same manner as in Example 1 except that the random copolymer of the formula (6e) prepared in Preparation Examples 2 and 3 was used instead of the random copolymer of the formula (6e) prepared in Preparation Example 1, .

Example  4: Lithium battery ( Full cell )

A protective film containing a random copolymer having a thickness of 5 탆 was formed on the lithium negative electrode in accordance with Example 1. The positive electrode was laminated on the other side of the protective film to prepare a full cell.

The anode is LiN _{0 . 6} Co _{0 . 2 Mn 0 .2 (3.5mAh / cm} 2, LiNCM, Samsung SDI), a conductive agent (Super-P; Timcal Ltd.) , Preparation 1 mixture of copolymer and N- methyl-pyrrolidone of the formula obtained according to 6e To obtain a positive electrode composition. The mixing ratio by weight of LiNCM in the positive electrode composition, the conductive agent, and the copolymer of Formula 6e obtained in Production Example 1 was 70: 5: 25. The above cathode composition was coated on an aluminum foil (thickness: about 15 탆), dried at 25 캜, and dried at a temperature of about 110 캜 under vacuum to prepare a full cell.

Example  5-6: Lithium battery ( Full cell )

The procedure of Example 4 was repeated except that the copolymer of Preparation Example 4 and the copolymer of Preparation Example 5 were used in place of the copolymer of Preparation Example 1, respectively.

Comparative Example  1: Lithium battery ( Li / Li Symmetric cell )

A Li / Li symmetric cell was prepared in the same manner as in Example 1, except that a POEM membrane was formed using polyoxyethylene methacrylate (POEM) instead of the random polymer prepared in Preparation Example 1. It is very difficult to form a free standing film in the POEM film, and an O-ring type short prevention film having a thickness of about 15 mu m is used together with the POEM film. A 12 μm thick Celgard membrane was used as the short-circuiting film. Thus, it was found that the POEM membrane was insufficient in mechanical properties to such an extent that it could not be used as a single membrane.

Comparative Example  2: Lithium battery ( Li / Li Symmetric cell )

A Li / Li symmetric cell was prepared in the same manner as in Example 1, except that the random copolymer (D) prepared in Comparative Preparation Example 1 was used instead of the random polymer prepared in Production Example 1.

Comparative Example  3: Manufacture of lithium battery (Li / Li symmetric cell)

A Li / Li symmetric cell was prepared in the same manner as in Example 1, except that polyethylene oxide (weight average molecular weight: 60,000 Daltons) was used in place of the random polymer prepared in Preparation Example 1.

Comparative Example  4: Lithium battery ( Full cell )

The procedure of Example 4 was repeated to prepare a full cell, except that the cathode protecting film obtained by the following procedure was used as the cathode protecting film.

The negative electrode protective film was prepared in the same manner as in Example 1, except that the random copolymer (D) prepared in Comparative Preparation Example 1 was used instead of the random copolymer produced in Production Example 1.

Evaluation example  1: FT-IR analysis

FT-IR was measured on the random copolymer (B) and (C) of the formula (6e) prepared in Production Example 1, and the results are shown in FIG. 2, polyoxyethylene methacrylate-poly (vinylbenzyl chloride) (POEM-PVBCl), POEM-PVBMPryCl (polyoxyethylene methacrylate-poly), and POEM-PVBMPryTFSI (polyoxyethylene methacrylate- pyrrolidinium (trifluoromethanesulfonyl) imide) copolymer represents a random copolymer (B), a random copolymer (C) and a random copolymer of formula (6e).

As a result, peaks corresponding to C = C bonds and C-H (sp2 orbital) bonds derived from the vinyl group of polystyrene were not observed. In addition, no peak corresponding to the C-Cl bond of 1-chloromethyl-4-vinylbenzene was observed. Thus, it was confirmed that the polymerization proceeded completely and the random copolymer was synthesized.

Evaluation example  2: Nuclear magnetic resonance spectrum (NMR)

NMR analysis was conducted on the random copolymer of the formula (6e) obtained in Production Example 1, and the result is shown in FIG. 3A. The 2D DOSY (diffusion ordered spectroscopy) NMR spectrum of the random copolymer of the formula (6e) Respectively.

3A, the structure of the monomer constituting the random copolymer was confirmed, and it was found that the random copolymer had a heterogeneous copolymer molecular structure. As shown in FIG. 3B. Through this NMR analysis, the mixing ratio of the first repeating unit and the second repeating unit constituting the random copolymer can be confirmed.

Evaluation example  3: Evaluation of electrochemical stability

In the Li / Li symmetric cell of Example 1, one of the lithium negative electrodes was changed to a bare aluminum thin film (thickness 10 mu m) to prepare a Li / Al symmetric cell. In the Li / Al symmetric cell, a lithium negative electrode was used as a reference electrode, and an aluminum thin film protected with a protective film containing a random copolymer (hereinafter, protective aluminum electrode) was used as a working electrode.

The Li / Al cell was scanned at a rate of 5 mV / sec between -1.5 and 6.0 V relative to the lithium metal by the cyclic voltammetric method to observe whether a reduction current was generated by the side reaction of the protective film. A potentiometer (electrochemical interface (1287 ECI), manufactured by Solartron analytical) was used in the experiment.

The results of the cyclic voltammetry measurement are shown in Figs. 4A and 4B.

The protective aluminum electrode shows only the reduction current of deposition of lithium ions at a voltage lower than 0 V compared to the lithium metal and the oxidation current at which lithium reduced at a voltage of 0 V or more compared to the lithium metal is lower than the lithium metal. The reduction current was not shown.

Therefore, the protective film showed electrochemical stability to -0.5 V against lithium metal. It was also found that the protective film is electrochemically stable against lithium metal even at a high voltage. From these results, the electrochemical stability of the electrolyte was confirmed in the operating voltage range of the lithium battery.

Evaluation example  4: Impedance measurement

The impedance of the lithium battery of Comparative Examples 2 and 3 and the lithium battery of Example 1 was measured at 25 ° C by using an impedance analyzer (Solartron 1260A Impedance / Gain-Phase Analyzer). The amplitude was 10 mV, and the frequency range was 0.1 Hz to 1 MHz.

The Nyquist plot of the impedance measurement results for each lithium battery is shown in FIG. 5A. The interfacial resistance for each lithium battery is shown in FIG. 5B.

Referring to FIG. 5A, the difference between the left x side fragment and the right x side fragment of the semicircle represents the interface resistance at the electrode. The area specific resistance (ASR) of the lithium battery of Example 1 was 18% lower than that of the lithium battery of Comparative Example 3.

As shown in FIG. 5B, the charge transfer resistance of the lithium battery of Example 1 was reduced by about 80% as compared with the lithium battery of Comparative Example 3.

Evaluation example  5: Lithium ion availability measurement

The lithium ion transfer mobility (lithium transference rate), lithium ion conductivity and lithium mobility of the lithium battery prepared according to Example 1 and Comparative Examples 1 and 3 were measured and shown in FIGS. 6A to 6C, respectively. . The lithium transfer probability is defined by Equation 1 below.

[Formula 1]

Lithium ion availability = lithium ion conductivity X Lithium ion mobility

6A, the lithium battery of Example 1 has superior lithium ion conductivity as compared with the lithium batteries of Comparative Examples 1 and 3, and the lithium ion mobility of the lithium battery of Example 1 is higher than that of Comparative Example 1 1, it was improved by about 100%, and it was found to be remarkably improved as compared with the case of Comparative Example 3. As shown in FIG. 6C, the lithium ion battery of Example 1 was improved by about 120% in lithium ion availability as compared with the lithium batteries of Comparative Examples 1 and 3.

Evaluation example  6: Charging and discharging  characteristic

Example 1 and compares the lithium cell (Li / Li symmetric cells) prepared according to Example ² 0.2 mA / cm 2 Li ion deposition and peeling behavior were evaluated by charging and discharging at a charging and discharging rate of 1 hour, and the electrochemical stability of each battery was measured. The results of the electrochemical stability measurement of the lithium battery produced according to Example 1 and Comparative Example 2 are shown in FIGS. 7A and 7B, respectively.

As shown in FIG. 7B, when applying Polystyrene (PS) and copolymer PS-PIL (Comparative Example 2) having good mechanical strength as compared with POEM, the over-potential of about 1 V is shown and shot occurs after 120 cycles, As shown in FIG. 7A, the lithium battery of Example 1 maintained a relatively low over-potential and exhibited a stable deposition / peeling behavior until a cycle of 270 or more cycles was reached, indicating that the cycle characteristics were improved by about 125%.

Evaluation example  7: Charging and discharging  characteristic

The lithium battery prepared in Example 4 and Comparative Example 4 was charged at a constant current of 0.7 C rate from 2.7 V to 4.2 V at 25 캜 with lithium metal and then charged at a constant voltage until the current decreased to 0.025 C at 4.2 V And then discharged at a constant current of 0.5C. Subsequently, the charge-discharge cycle was repeated to charge and discharge a total of 80 times. Some of the experimental results are shown in Figs. 8A and 8B. The capacity retention rate is calculated from the following equation (2).

<Formula 2>

Capacity retention rate (%) = [80th cycle discharge capacity / 1st cycle discharge capacity] × 100

Referring to FIGS. 8A and 8B, it was confirmed that the cycle characteristics of the battery of Example 4 were improved by about 115% as compared with Comparative Example 4. POEM-PIL, which consists of POEM, which is a lithium ion conductive polymer, and PIL, which improves lithium ion mobility and improves mechanical properties, is applied as a polymer electrolyte for a lithium battery using lithium metal, thereby improving electrochemical performance .

The cycle characteristics of the lithium batteries produced in Examples 5 and 6 were evaluated in the same manner as in the evaluation method of cycle characteristics of the lithium battery of Example 4 described above.

As a result of the evaluation, it was found that the lithium batteries of Examples 5 and 6 exhibited the same cycle characteristics as those of the lithium battery of Example 4.

Evaluation example  8: Composite membrane Free standing  Check whether

The composite membranes prepared in Examples 1 to 4 and the composite membranes prepared in Comparative Examples 1 to 4 were confirmed to be free standing at 25 ° C.

The composite membranes prepared according to Examples 1 to 4 had a film form capable of being freed up at 25 DEG C, whereas the composite membranes of Comparative Example 1 were not capable of free standing and had poor film forming properties. The composite membranes of Comparative Examples 2 and 4 were free standing, but had a lithium ion conductivity of about 0.005 mS / cm, which was difficult to apply practically.

The composite membrane of Comparative Example 3 had good lithium ion conductivity, but free standing was not easy as in the case of the composite membrane of Comparative Example 1.

91: Lithium battery 92: cathode
93: anode 94: separator
95: Battery case 96: Cap assembly

Claims (25)

A composite membrane for a lithium battery, comprising a copolymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).
[Chemical Formula 1]

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 independently of one another are hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group or an unsubstituted or substituted C 3 -C 30 heteroaryl Lt; / RTI &
A represents a chemical bond or 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 C30 cycloalkylene group, or an unsubstituted or substituted C3-C30 heterocycloalkylene group,

Is a 3 to 31 membered ring comprising 2 to 30 carbon atoms,
X is S, N, N (R) or P (R ^' ),
R and R ^' independently from each other are 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 C7-C30 arylalkyl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted aryl group, Unsubstituted or substituted C3-C30 heteroaryloxy groups, unsubstituted or substituted C3-C30 heteroarylalkyl groups, unsubstituted or substituted C3-C30 cycloalkyl groups, unsubstituted or substituted C2-C30 alkenyl groups, A substituted C3-C30 heterocycloalkyl group or an unsubstituted or substituted C3-C30 alkynyl group,
Y ^- is an anion,
(2)

In Formula 2, R ₄ , R ₅ , and R ₆ are each independently of the other hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group, or an unsubstituted or substituted C3 C30 heteroaryl group,
R ₇ is hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group,
Or an unsubstituted or substituted C6-C20 aryl group,
a is an integer of 1 to 10,
In the general formulas (1) and (2), m and n are molar ratios of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), and the sum thereof is 1, The method according to claim 1,
In the above formula (1), Ar ₁ is a lithium group which is selected from the group consisting of a phenylene group, a biphenylene group, a naphthalenylene group, a phenanthrenylene group, a triphenylenylene group, an anthracenylene group, a fluorenylene group and a carbazolylene group Composite membrane. The method according to claim 1,
Wherein Ar ₁ in Formula ₁ is selected from the group consisting of the following Formula 3:
(3)

Wherein R ₁ to R ₁₉ independently represent hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group, or an unsubstituted or substituted Substituted C3-C30 heteroaryl group. The method according to claim 1,
In the formula 1

Is selected from the group consisting of the following Chemical Formula 4 or Chemical Formula 4a:
[Chemical Formula 4]

Wherein Z is S, N or P and R ₁₁ to R ₂₅ are independently of each other 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 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,
Provided that if Z is S then R ₁₁ is absent.
[Chemical Formula 4a]

In formula (4a), R ₂₂ to R ₂₆ are defined as R ₁₁ to R _{25 in} formula (4), and Z is N. The method according to claim 1,
In the formula 1

And Y ^- in the formula (1) is selected from the group consisting of BF ₄ ^- , PF ₆ ^- , AsF ₆ ^- , SbF ₆ ^- , AlCl ₄ ^- , HSO ₄ ^- , CH ₃ SO ₃ ^- , ^{_{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 -, _{3 C, (CF 3 SO 2} ) - - (C 2 F 5 SO 2) (CF 3 SO 2) N -, (FSO 2) 2 N -, NO 3 -, Al 2 Cl 7 -, CH 3 COO, ^{_{(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 -, and _{(O (CF 3) 2 C} 2 ( CF ₃ ) ₂ O) ₂ PO ^- .
[Chemical Formula 5]

In Formula 5, R ₂₀ to R ₂₈ independently represent 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, Unsubstituted or substituted C6-C30 aryloxy groups, unsubstituted or substituted C3-C30 heteroaryl groups, unsubstituted or substituted C3-C30 heteroaryloxy groups, unsubstituted or substituted C4-C30 cyclo An alkyl group or an unsubstituted or substituted C3-C30 heterocycloalkyl group. The method according to claim 1,
Wherein the copolymer is a random copolymer. The method according to claim 1,
Wherein the composite membrane comprises a lithium salt. 8. The method of claim 7,
Wherein the content of the lithium salt is 1 to 90 parts by weight based on 100 parts by weight of the total weight of the composite membrane. The method according to claim 1,
Wherein the copolymer has a degree of polymerization of 10 to 5,000. The method according to claim 1,
Wherein m is from 0.45 to 0.8 in the formula (1). The method according to claim 1,
Wherein the copolymer is a copolymer represented by the following Chemical Formula 6 and the degree of polymerization of the copolymer is 10 to 5,000:
[Chemical Formula 6]

In the formula (6), Ar ₁ is a substituted or unsubstituted C6-C30 arylene group,
R ₁ , R ₂ and R ₃ independently of one another are hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group or an unsubstituted or substituted C 3 -C 30 heteroaryl Lt; / RTI &
A is a chemical bond or an unsubstituted or substituted C1-C30 alkylene group, or an unsubstituted or substituted C6-C30 arylene group,
Y ^- is ^{_{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 ^{_{-, (FSO 2) 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 -, and _{(O (CF 3) 2 C} 2 (CF 3) 2 O) 2 PO - , and one or more anions selected from the group consisting of ,
m and n are each from 0.01 to 0.99 and the sum of them is 1,
R ₇ is hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, or an unsubstituted or substituted C 6 -C 20 aryl group,

Is a group represented by the following general formula (4)
[Chemical Formula 5]

In Formula 5, R ₂₀ to R ₂₈ independently represent 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, Unsubstituted or substituted C6-C30 aryloxy groups, unsubstituted or substituted C3-C30 heteroaryl groups, unsubstituted or substituted C3-C30 heteroaryloxy groups, unsubstituted or substituted C4-C30 cyclo An alkyl group or an unsubstituted or substituted C3-C30 heterocycloalkyl group, and * represents a bonding region. The method according to claim 1,
Wherein the copolymer is at least one selected from the compounds represented by the following general formulas (6a), (6b), (6c) and (6d)
[Formula 6a] [Formula 6b]

[Chemical formula 6c] [Chemical formula 6d]

Y ^- is _{^{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 -, (FSO _{^{2) 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 and at least one selected _{^{among, - -, (CF 3 SO}} 2) 2 CH -, (SF 5) 3 C -, and _{(O (CF 3) 2 C} 2 (CF 3) 2 O) 2 PO
a is an integer of 1 to 10,
R ₂₄ is a C 1 -C 10 alkyl group;
m and n are each from 0.01 to 0.99 and the sum of them is 1,
The polymerization degree of the copolymer is 10 to 5000. The method according to claim 1,
Wherein the composite membrane has a thickness of 1 nm to 1000 占 퐉. The method according to claim 1,
Wherein the copolymer has a weight average molecular weight of 3,000 to 400,000 Dalton. The method according to claim 1,
Wherein the composite membrane retains a free standing film at 25 to 60 占 폚. The method according to claim 1,
Wherein the copolymer is electrochemically stable up to -0.4 V with respect to lithium. The method according to claim 1,
Wherein the composite membrane has a lithium ion conductivity of 0.001 mS / cm or more at 25 캜. anode;
cathode; And
17. A lithium battery comprising the composite membrane according to any one of claims 1 to 17 interposed therebetween. 19. The method of claim 18,
The negative electrode is a lithium metal or lithium metal alloy electrode; or
Wherein the anode is selected from the group consisting of a carbon-based material, silicon, a silicon oxide, a silicon-based alloy, a silicon-carbon based material composite, a tin-tin alloy, a tin-carbon composite, a metal / A lithium battery comprising at least one negative electrode active material. 19. The method of claim 18,
Wherein the cathode is a lithium metal or a lithium metal alloy electrode, and the composite membrane is a cathode protection film or a cathode protection film and electrolyte. 19. The method of claim 18,
Wherein the composite membrane is an electrolyte. 19. The method of claim 18,
Wherein the lithium battery further comprises at least one selected from a liquid electrolyte, a solid electrolyte, a gel electrolyte, and a polymer ionic liquid. 19. The method of claim 18,
Wherein the lithium battery has an operating voltage of 4.0 V or more. 19. The method of claim 18,
Wherein the positive electrode comprises a positive electrode active material and a copolymer comprising a first repeating unit represented by the following formula 1 and a second repeating unit represented by the following formula 2:
[Chemical Formula 1]

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 independently of one another are hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group or an unsubstituted or substituted C 3 -C 30 heteroaryl Lt; / RTI &
A represents a chemical bond or 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 C30 cycloalkylene group, or an unsubstituted or substituted C3-C30 heterocycloalkylene group,

Is a 3 to 31 membered ring comprising 2 to 30 carbon atoms,
X is S, N, N (R) or P (R ^' ),
R and R ^' independently from each other are 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 C7-C30 arylalkyl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted aryl group, Unsubstituted or substituted C3-C30 heteroaryloxy groups, unsubstituted or substituted C3-C30 heteroarylalkyl groups, unsubstituted or substituted C3-C30 cycloalkyl groups, unsubstituted or substituted C2-C30 alkenyl groups, A substituted C3-C30 heterocycloalkyl group or an unsubstituted or substituted C3-C30 alkynyl group,
Y ^- is an anion,
(2)

In formula (2), R ₄ , R ₅ , and R ₆ independently of one another are hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group, A C3-C30 heteroaryl group,
R ₇ is hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group,
Or an unsubstituted or substituted C6-C20 aryl group,
a is an integer of 1 to 10,
In the general formulas (1) and (2), m and n are molar ratios of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), and the sum thereof is 1, A positive electrode for a lithium battery comprising a positive electrode active material, a copolymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2)
[Chemical Formula 1]

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 independently of one another are hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group or an unsubstituted or substituted C 3 -C 30 heteroaryl Lt; / RTI &
A represents a chemical bond or 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 C30 cycloalkylene group, or an unsubstituted or substituted C3-C30 heterocycloalkylene group,

Is a 3 to 31 membered ring comprising 2 to 30 carbon atoms,
X is S, N, N (R) or P (R ^' ),
R and R ^' independently from each other are 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 C7-C30 arylalkyl group, an unsubstituted or substituted C6-C30 aryloxy group, an unsubstituted or substituted C3-C30 heteroaryl group, an unsubstituted or substituted aryl group, Unsubstituted or substituted C3-C30 heteroaryloxy groups, unsubstituted or substituted C3-C30 heteroarylalkyl groups, unsubstituted or substituted C3-C30 cycloalkyl groups, unsubstituted or substituted C2-C30 alkenyl groups, A substituted C3-C30 heterocycloalkyl group or an unsubstituted or substituted C3-C30 alkynyl group,
Y ^- is an anion,
(2)

In formula (2), R ₄ , R ₅ , and R ₆ independently of one another are hydrogen, an unsubstituted or substituted C 1 -C 20 alkyl group, an unsubstituted or substituted C 6 -C 20 aryl group, A C3-C30 heteroaryl group,
R ₇ is independently selected from the group consisting of hydrogen, unsubstituted or substituted C 1 -C 20 alkyl groups,
Or an unsubstituted or substituted C6-C20 aryl group,
a is an integer of 1 to 10,
In the general formulas (1) and (2), m and n are molar ratios of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), and the sum thereof is 1,

Images