JP2000223126A - Electrode and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode that prevents charge/discharge capacity from decreasing and is adequate to a lithium secondary battery by including a cross- linking structure provided by reacting polysiloxane, polyalkyleneoxide, and a specific multifunctional compound. SOLUTION: Polysiloxane represented by a compound in formula I (where, R1 is a univalent hydrocarbon group containing no aliphatic unsaturation, m1 is an integer up to 0-500), polyalkyleneoxide represented by a compound in formula II (where R21 is a univalent hydrocarbon group containing terminal double bond, (a) is an integer of 2-4, n21 is an integer not smaller than 1), and a specific multifunctional compound represented by a compound in formula III (where R31 is H or an alkyl group, R32 is a bivalent organic group or direct bond, I3 is an integer not smaller than 2, Z31 is a substituted group that contains carbon or nitrogen and has the same valent as that of I3) are used. A cross- linking structure is provided by polymerizing them in a hydroxylation reaction from a state of monomer or oligomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrode and a method for manufacturing the electrode.

[0002]

2. Description of the Related Art Lithium secondary batteries have a higher theoretical energy density than many secondary batteries, and have a wide range of applications such as power supplies for portable electronic devices, electric vehicles and power storage. However, even a carbon-based material having a theoretical capacity of 372 mAh / g has practically only a capacity of about 120 to 140 mAh / g, and improvement is urgently needed.

[0003] In recent years, electrode active materials having a larger theoretical capacity have appeared, but as the charge / discharge capacity increases, the amount of lithium ions absorbed and released by the active material increases. This leads to a situation in which the change in volume of the electrode becomes large, the change and collapse of the electrode structure progress, and the repetition characteristics deteriorate.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrode suitable for use in a lithium secondary battery, which does not reduce the charge / discharge capacity even after repeated use, and a method for producing the same.

[0005]

Means for Solving the Problems At least the compound (1)
-1), the polyalkylene oxide represented by the compound (2-1), and the compound (3-
The above problem has been solved by an electrode comprising a crosslinked structure obtained by reacting the polyfunctional compound shown in 1).

[0006]

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In the formula, R ₁ independently represents a monovalent hydrocarbon group containing no aliphatic unsaturation, and m ₁ is 0 to 50
Indicates an integer up to 0.

[0008]

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In the formula, R ₂₁ represents a monovalent hydrocarbon group having a terminal double bond, a represents an integer of 2 to 4, and n ₂₁ represents an integer of 1 or more.

[0010]

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In the formula, R ₃₁ represents a hydrogen atom or an alkyl group, and R ₃₂ represents a divalent organic group or a direct bond. l ₃ is an integer of 2 or more, and Z ₃₁ is a substituent containing carbon or nitrogen and is a group having the same valence as l ₃ .

Further, at least a polysiloxane represented by the compound (1-1), a polyalkylene oxide represented by the compound (2-1), and a polyfunctional compound represented by the compound (3-1) are mixed, The above problem has been solved by a method for producing an electrode, which is characterized by performing heat molding.

[0013]

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In the formula, R ₁ independently represents a monovalent hydrocarbon group containing no aliphatic unsaturation, and m ₁ represents 0 to 50.
Indicates an integer up to 0.

[0015]

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In the formula, R ₂₁ represents a monovalent hydrocarbon group having a terminal double bond, a represents an integer of 2 to 4, and n ₂₁ represents an integer of 1 or more.

[0017]

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In the formula, R ₃₁ represents a hydrogen atom or an alkyl group, and R ₃₂ represents a divalent organic group or a direct bond. l ₃ is an integer of 2 or more, and Z ₃₁ is a substituent containing carbon or nitrogen and is a group having the same valence as l ₃ .

Further, a polysiloxane having at least three or more Si—H groups, a polyalkylene oxide compound (2-1) or (2-2), and a compound (3-1)
The above problem was solved by an electrode characterized by containing a crosslinked structure obtained by the reaction of

[0020]

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In the formula, R ₁ independently represents a monovalent hydrocarbon group containing no aliphatic unsaturation, and m ₁ represents 0 to 50
Indicates an integer up to 0.

[0022]

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In the formula, R ₂₁ represents a monovalent hydrocarbon group having a terminal double bond, a represents an integer of 2 to 4, and n ₂₁ represents an integer of 1 or more.

[0024]

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In the formula, R ₂₂ represents a monovalent hydrocarbon group having a terminal double bond, R ₂₃ represents a hydrogen atom, a monovalent saturated hydrocarbon group or an acyl group, and b is an integer of 2 to 4. And n ₂₂ represents an integer of 1 or more.

[0026]

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In the formula, R ₃₁ represents a hydrogen atom or an alkyl group, and R ₃₂ represents a divalent organic group or a direct bond. l ₃ is an integer of 2 or more, and Z ₃₁ is a substituent containing carbon or nitrogen and is a group having the same valence as l ₃ .

Further, a polysiloxane having at least three or more Si—H groups, a polyalkylene oxide compound (2-1) or (2-2), and a compound (3-1)
The above problem has been solved by a method for producing an electrode, which comprises mixing and heating the mixture as an electrode.

[0029]

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In the formula, R ₁ independently represents a monovalent hydrocarbon group containing no aliphatic unsaturation, and m ₁ represents 0 to 50.
Indicates an integer up to 0.

[0031]

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In the formula, R ₂₁ represents a monovalent hydrocarbon group having a terminal double bond, a represents an integer of 2 to 4, and n ₂₁ represents an integer of 1 or more.

[0033]

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In the formula, R ₂₂ represents a monovalent hydrocarbon group having a terminal double bond, R ₂₃ represents a hydrogen atom, a monovalent saturated hydrocarbon group or an acyl group, and b is an integer of 2 to 4. And n ₂₂ represents an integer of 1 or more.

[0035]

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In the formula, R ₃₁ represents a hydrogen atom or an alkyl group, and R ₃₂ represents a divalent organic group or a direct bond. l ₃ is an integer of 2 or more, and Z ₃₁ is a substituent containing carbon or nitrogen and is a group having the same valence as l ₃ .

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The crosslinked structure according to the present invention is a material capable of forming a higher-order crosslinked structure or a high molecular weight structure in order to gel an electrolyte, and can be an excellent electrode binder. The crosslinked structure according to the present invention is produced by polymerizing from a monomer or oligomer state by a hydrosilylation reaction.

The hydrosilylation reaction is an addition reaction between an alkenyl group such as allyl and vinyl and an Si--H group. As a catalyst, compounds such as platinum, ruthenium, rhodium, palladium, osmium and iridium are known. ing. However, conditions such as rapid progress of the reaction, high activity to complete the reaction, no secondary reaction with the reaction product, and no effect on battery characteristics are required. Compounds are useful.

Examples of platinum compounds include chloroplatinic acid, elemental platinum, solid platinum on a carrier such as alumina, silica, carbon black, platinum-vinylsiloxane complex, platinum-phosphine complex, platinum -Phosphite complexes, platinum alcoholate catalysts and the like can be used. 0.0001% by weight of platinum catalyst during the hydrosilylation reaction
From about 0.1% by weight. In addition, since this reaction has a large temperature dependence of the reaction rate, the reaction can be promoted by heating. This is a great advantage of the hydrosilylation reaction, where the reactants are mixed with moderate viscosity,
If heated after molding, a gel having a desired shape can be obtained at once. Also, at this time, there is almost no other by-product such as water, and there is almost no change in volume immediately after the reaction, which is an excellent method as a gelling method for batteries.

By utilizing the hydrosilylation reaction, a polysiloxane structure and a polyalkylene oxide structure are alternately introduced to obtain a high molecular compound. As a method for synthesizing such a structure, for example, first, a polysiloxane having both ends Si-H groups is synthesized by hydrolysis of dimethyldichlorosilane and dimethylchlorosilane or hydrolysis of dimethoxydimethylsilane and methoxydimethylsilane. Compound (1-1) is obtained. At this time, the molecular weight of the polysiloxane compound can be changed by changing the amount of the monomer having a Si-H group.

[0041]

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Here, R ₁ independently represents a monovalent hydrocarbon group containing no aliphatic unsaturation. m ₁ is from 0 to 5
It is an integer of up to 00, preferably an integer of 2 to 100, more preferably an integer of about 5 to 30.
As a specific example of the compound (1-1), R ₁ is a methyl group,
Compound (1-1-) wherein m ₁ is 20, 12, and 4, respectively.
1), compound (1-1-2) and compound (1-1-3).

[0043]

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Next, when ethylene oxide or the like is chain-polymerized to a dialcohol such as ethylene glycol by a ring-opening reaction of an epoxy group, a polyalkylene glycol having hydroxyl groups at both ends is obtained. For example, the hydroxyl groups at both ends of the polyalkylene glycol thus obtained are substituted with a vinyloxy group, an allyloxy group, a 2-methylallyloxy group, or the like, and the polyalkylene oxide compound having an alkylene group at both ends (2-1) Get) At this time, an oxyethylene unit alone may be used like polyethylene oxide, but units such as an oxyethylene group, a methyloxyethylene group, and an ethyloxyethylene group are polymerized randomly or in a block, and this is used as a polyalkylene oxide compound. You can also.

[0045]

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Here, R ₂₁ represents a monovalent hydrocarbon group having a terminal double bond, a represents an integer of 2 to 4, and n ₂₁
Represents an integer of 1 or more. Specific examples of R ₂₁ include CH ₂
= CHCH _2- , CH ₂ = CHCH ₂ CH _2- , CH ₂ = C
_{H-, CH 2 = C (CH} 3) CH 2 -, CH 2 = CHC 6 H 4
And preferably CH ₂ ＣＨCHCH ₂ —.
The preferable range of n ₂₁ is about 4 to 20. As a specific example of the compound (2-1), the compound (2-1-
1) and compound (2-1-2).

[0047]

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A polyfunctional compound for forming a crosslinked structure with a polyalkylene oxide compound (2-1) having an alkylene group at both ends in a polysiloxane compound (1-1) having Si-H groups at both ends. (3-1) is mixed,
The structure obtained by the hydrosilylation reaction is also a crosslinked structure according to the present invention. At this time, compound (1-1),
The ratio of the compound (2-1) to the compound (3-1) is defined assuming that the Si—H group of the compound (1-1) is 1 and the compound (2-1) is
Having an alkenyl group of about 0.1 to 1.99,
The alkenyl group of -1) is reacted at about 0.01 to 1.9.

The polyfunctional compound (3-1) has two or more unsaturated hydrocarbon groups, and is a compound (1-1) or a reaction product of the compound (1-1) and the compound (2-1). A crosslinked structure is formed by the same hydrosilylation reaction as described above with the Si-H group.

[0050]

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Here, R ₃₁ is a hydrogen atom or a methyl group,
It represents an alkyl group such as an ethyl group, and is preferably a hydrogen atom or a methyl group. R ₃₂ represents a divalent organic group or a direct bond, and examples of the divalent organic group include a methylene group, an ethylene group, and a phenylene group. l ₃ is an integer of 2 or more, preferably 3 or 4. Z ₃₁ is a substituent containing carbon or nitrogen, and is a group having the same valence as l ₃ . Specific examples of the compound (3-1) include the compound (3-1-1), the compound (3-1-2), and the compound (3-
1-3), compound (3-1-4), compound (3-1-
5), compound (3-1-6), compound (3-1-7),
Compound (3-1-8), compound (3-1-9), compound (3-1-10), compound (3-1-11), compound (3-1-12) and the like.

[0052]

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[0053]

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[0054]

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In order to obtain this crosslinked structure, the polysiloxane compound of the compound (1-1), the polyalkylene oxide compound of the compound (2-1), and the polyfunctional compound (3-1) are considered from the viewpoint of molecular weight and the like. In some cases, the compatibility of each compound may be significantly deteriorated. In this case, the compound (1-
The compound (2-1) is reacted by a hydrosilylation reaction in an excess state of 1) to prepare a precursor having an appropriate molecular weight, and the compound (3-1) is acted on the precursor to form a crosslinked structure. You can also get. Specifically, the compound (1-
The precursor is prepared by reacting the alkenyl group of the compound (2-1) with the Si—H group 1 of 1) at a ratio of about 0.1 to 1.99 to prepare a precursor, and further, the alkenyl group of the compound (3-1) It is obtained by reacting groups at a ratio of about 0.01 to 1.9.

As a method for producing the compound (2-2), for example, a compound having an epoxy group such as ethylene oxide in an alcohol such as methanol, ethanol or butanol is polymerized by ring-opening polymerization, and a hydroxyl group is added to one end. To obtain a polyalkylene oxide having the formula: The hydroxyl group at one end of the polyalkylene oxide thus obtained was substituted with a vinyloxy group, an allyloxy group, or a 2-methylallyloxy group, and the other had an alkenyl group and one end was alkoxy-modified. A polyalkylene oxide compound (2-2) is obtained.

[0057]

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Here, R ₂₂ represents a hydrocarbon group having a terminal double bond, R ₂₃ represents a hydrogen atom, a monovalent saturated hydrocarbon group or an acyl group, b represents an integer of 2 to 4, n
₂₂ represents an integer of 1 or more. Specific examples of R ₂₂ is, CH
₂ = CHCH _2- , CH ₂ = CHCH ₂ CH _2- , CH ₂ = C
_{H-, CH 2 = C (CH} 3) CH 2 -, CH 2 = CHC 6 H 4
And preferably CH ₂ ＣＨCHCH ₂ — and CH _{2
= C (CH 3) CH 2} - and the like. Preferred ranges of n _22, is about from 4 20. Examples of the monovalent saturated hydrocarbon group for R ₂₃ include an alkyl group having 1 to 18 carbon atoms such as a methyl group and an ethyl group. R
Preferred examples of ₂₃ include a hydrogen atom, a methyl group, an ethyl group, a butyl group, and an acyl group. Specific examples of the polyalkylene oxide compound (2-2) include the compound (2-2-1).

[0059]

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A structure obtained by reacting a polysiloxane having at least three or more Si—H groups, a polyalkylene oxide compound (2-1) or (2-2), and a compound (3-1) is also included. And a crosslinked structure of the present invention.
The polysiloxane having three or more Si-H groups refers to a linear polysiloxane represented by the following compound (1-2), a cyclic polysiloxane represented by the compound (1-3), and a compound (1- There is a ladder-like polysiloxane represented by 4).

[0061]

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Here, R ₁₂ independently represents a monovalent hydrocarbon group containing no aliphatic unsaturation or a hydrogen atom, and three or more of R _{12 in} the molecule are hydrogen atoms and 50 The following is preferred, and more preferably about 3 to 10. m ₁₂ represents an integer of 0 to 500. The preferable range of m ₁₂ is about 2 to 100, and more preferably about 5 to 30. Specific examples of the compound (1-2) include the compound (1-2-1).

[0063]

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[0064]

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Here, R ₁₃ represents a hydrogen atom or a monovalent hydrocarbon group containing no aliphatic unsaturation independently of each other;
8 3 to R ₁₃ in the molecule are hydrogen atoms. m ₁₃ is 3
Represents an integer from to 8. Specific examples of the compound (1-3) include the compound (1-3-1).

[0066]

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[0067]

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Here, R ₁₄ represents a hydrogen atom or a monovalent hydrocarbon group containing no aliphatic unsaturation independently of each other;
Three or more of R _{14 in} the molecule are hydrogen atoms, and preferably 50 or less. m ₁₄ is an integer of 1 to 50, preferably about 2 to 30, and more preferably about 4 to 20. Specific examples of the compound (1-4) include
There is a compound (1-4-1).

[0069]

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Another crosslinked structure of the present invention is a polysiloxane having three or more Si—H groups.
The ratio of the alkenyl group of the compound (2-1) to the i-H group 1 is about 0.1 to 0.99, and the ratio of the alkenyl group of the compound (2-2) is about 0.1 to 0.9. And the alkenyl group of the compound (3-1) is further reacted at a ratio of about 0.01 to 0.8. As before, a precursor is obtained by reacting a polysiloxane having three or more Si-H groups in advance with the compound (2-1) or the compound (2-2) at such a ratio. It can also be obtained by reacting with (3-1).

The crosslinked structure thus produced is
Very high compatibility with electrolytes and electrolytes used in lithium batteries, high gel strength, and viscoelasticity can be controlled freely. Utilizing this crosslinked structure is particularly advantageous for batteries with variable volumes. Crosslinking also depends on the concentration of precursors and catalysts.
It is carried out by heating from 0 ° C. to 150 ° C. for several minutes to 1 hour.

The lithium battery comprises a positive electrode, a negative electrode, and a partition having a lithium ion conductivity and preventing a short circuit between the two electrodes. The positive electrode includes at least a positive electrode active material, a conductive agent, and a crosslinked structure. The positive electrode active material is LiCoO ₂ ,
LiNiO ₂ , spinel type LiMn ₂ O ₄ , amorphous V ₂ O ₅ , mixture of β-MnO ₂ and Li ₂ MnO ₃ , Li _4/3 Mn _5/3 O ₄ having a spinel superlattice structure, 2,5-dimercapto Organic disulfide compounds such as -3,4-thiadiazole; The conductive agent may be graphite such as natural graphite or synthetic graphite, carbon black, acetylene black, carbon fiber, metal powder, metal fiber, or JP-A-59-209.
Polyphenylene derivatives, polyaniline, polypyrrole, and the like described in JP-A-71 can be used, and acetylene black is preferable.

The negative electrode may be made of metal such as metallic lithium, lithium-aluminum alloy, Li-Pb-Cd-In alloy,
As the negative electrode active material, a lithium / graphite compound, a lithium / graphitizable carbon compound, a lithium / amorphous tin composite oxide, an amorphous cobalt-substituted lithium nitride, or the like is used. The negative electrode active material is composed of at least a conductive agent and a crosslinked structure, similarly to the positive electrode.

The partition has an electrolyte. As the electrolyte, LiClO ₄ , LiBF ₄ , LiPF ₆ , LiAs
F ₆ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li
Lithium salts such as (CF ₃ SO ₂ ) ₃ C and LiBPh ₄ (where Ph represents a phenyl group) can be used.

Further, a solvent for dissolving the lithium salt can also be used. Examples of usable solvents include ester compounds having a carbonyl bond such as propylene carbonate, ethylene carbonate, γ-butyrolactone, dimethyl carbonate, and diethyl carbonate, tetrahydrofuran, 1,2-dimethoxyethane, 1,2-ethoxyethane, and 1,3. -Ether compounds such as dioxane can be used alone or in combination.

Further, polyalkylene oxide compounds such as tetraethylene glycol dimethyl ether and tetrapropylene glycol dimethyl ether, modified polydimethylsiloxane having a polyalkylene oxide in a side chain, modified polyacrylate having a polyalkylene oxide as a structural unit, polyacrylonitrile, and polyfluoroethylene An ionic conductive polymer such as modified polyphosphazene having a structural unit of vinylidene fluoride or polyalkylene oxide can also be mixed.

The crosslinked structure is produced by heating as described above. In addition to forming an electrode and heating it to produce an electrode structure, a partition portion is provided and a battery can be formed. Is formed, and after providing the partition, heating is performed to form a battery structure. In addition, this crosslinked structure can be used for the partition.

[0078]

The present invention will be described in more detail with reference to the following examples, which should not be construed as limiting the scope of the present invention.

Example 1 The following materials were mixed to prepare a negative electrode. Highly crystalline natural graphite 50 parts by weight Acetylene black 33.6 parts by weight Compound (1-1-1) 6.7 parts by weight Compound (2-1-1) 8.4 parts by weight Compound (3-1-1) 1 3 parts by weight ethylene carbonate 5 parts by weight

Further, a small amount of a catalyst is added and kneaded, then the mixture is formed into a film, heated to be gelled, and punched into a circle to form a film.
The mixture was heated at 0 ° C. for 12 hours to obtain a negative electrode pellet.

The following materials were mixed to obtain a positive electrode. LiCoO ₂ 60 parts by weight Acetylene black 23.6 parts by weight Compound (1-1-2) 6.7 parts by weight Compound (2-1-1) 8.4 parts by weight Compound (3-1-1) 1.3 parts by weight Parts ethylene carbonate 5 parts by weight

Further, a small amount of a catalyst was added and kneaded, then the mixture was formed into a film, heated to gel, and punched out into a circular shape to obtain a gel.
It heated at 0 degreeC for 12 hours, and was set as the positive electrode pellet. Next, an equivalent mixture of ethylene carbonate and diethyl carbonate was used as a solvent, and LiClO ₄ was mixed at a concentration of 1 mol / liter to obtain an electrolyte. The negative electrode and the positive electrode prepared above were attached to each other with the separator immersed in the electrolyte interposed therebetween to prepare a battery, and the change in charge / discharge capacity due to repeated use was measured. The current density during charging and discharging is 0.1 mA
/ Cm ² , the initial charge / discharge capacity was 105 mAh / g, and the charge / discharge capacity after 100 cycles was 90% of the initial charge / discharge capacity.

Example 2 The following materials were mixed to prepare a negative electrode. 48 parts by weight of polyacetylene 33.4 parts by weight of acetylene black 4.3 parts by weight of compound (1-2-1) 5.0 parts by weight of compound (2-1-1) 7.2 parts by weight of compound (2-2-1) Compound (3-1-6) 2.1 parts by weight Ethylene carbonate 5 parts by weight

Further, a small amount of a catalyst is added and kneaded, then the mixture is formed into a film, gelled by heating, and punched into a circle to form a film.
The mixture was heated at 0 ° C. for 12 hours to obtain a negative electrode pellet.

The following materials were mixed to obtain a positive electrode. LiMn ₂ O ₄ 58 parts by weight Acetylene black 23.4 parts by weight Compound (1-2-1) 4.3 parts by weight Compound (2-1-2) 5.0 parts by weight Compound (2-2-1) 7. 2 parts by weight Compound (3-1-2) 2.1 parts by weight Ethylene carbonate 5 parts by weight

Further, a small amount of a catalyst was added and kneaded, then the mixture was formed into a film, heated to gel, and punched into a circle to form a film.
It heated at 0 degreeC for 12 hours, and was set as the positive electrode pellet. Next, an equivalent mixture of ethylene carbonate and diethyl carbonate was used as a solvent, and LiClO ₄ was mixed at a concentration of 1 mol / liter to obtain an electrolyte. The negative electrode and the positive electrode prepared above were attached to each other with the separator immersed in the electrolyte interposed therebetween to prepare a battery, and the change in charge / discharge capacity due to repeated use was measured. The current density during charging and discharging is 0.1 mA
/ Cm ² , the initial charge / discharge capacity was 115 mAh / g, and the charge / discharge capacity after 100 cycles was 91% of the initial charge / discharge capacity.

Example 3 The following materials were mixed to prepare a negative electrode. Highly crystalline natural graphite 50 parts by weight Acetylene black 33.6 parts by weight Compound (1-1-3) 6.7 parts by weight Compound (2-1-1) 8.4 parts by weight Compound (3-1-3) 1 3 parts by weight ethylene carbonate 5 parts by weight

Further, a small amount of a catalyst was added and kneaded, then formed into a film, heated to gel, and punched into a circular
The mixture was heated at 0 ° C. for 12 hours to obtain a negative electrode pellet.

The following materials were mixed to obtain a positive electrode. LiCoO ₂ 58 parts by weight Acetylene black 23.4 parts by weight Compound (1-1-1) 4.3 parts by weight Compound (2-1-1) 5.0 parts by weight Compound (3-1-4) 7.2 parts by weight Parts ethylene carbonate 5 parts by weight

Further, a small amount of a catalyst is added and kneaded, then the mixture is formed into a film, heated to be gelled, and punched into a circular shape.
It heated at 0 degreeC for 12 hours, and was set as the positive electrode pellet. Next, an equivalent mixture of ethylene carbonate and diethyl carbonate was used as a solvent, and LiClO ₄ was mixed at a concentration of 1 mol / liter to obtain an electrolyte. The negative electrode and the positive electrode prepared above were attached to each other with the separator immersed in the electrolyte interposed therebetween to prepare a battery, and the change in charge / discharge capacity due to repeated use was measured. The current density during charging and discharging is 0.1 mA
/ Cm ² , the initial charge / discharge capacity was 100 mAh / g, and the charge / discharge capacity after 100 cycles was 92% of the initial charge / discharge capacity.

Example 4 The following materials were mixed to prepare a negative electrode. Highly crystalline natural graphite 58 parts by weight Acetylene black 23.4 parts by weight Compound (1-1-1) 4.3 parts by weight Compound (2-1-1) 5.0 parts by weight Compound (2-2-1) 7 .2 parts by weight Compound (3-1-10) 2.1 parts by weight Ethylene carbonate 5 parts by weight

Further, a small amount of a catalyst is added and kneaded, then the mixture is formed into a film, heated to be gelled, and punched out into a circle to form a film.
The mixture was heated at 0 ° C. for 12 hours to obtain a negative electrode pellet.

The following materials were mixed to obtain a positive electrode. Li _11/6 Cr _1/12 B _1/12 O ₄ 60 parts by weight Acetylene black 23.6 parts by weight Compound (1-1-1) 6.7 parts by weight Compound (2-1-1) 8.4 parts by weight Compound (3-1-12) 1.3 parts by weight Ethylene carbonate 5 parts by weight

Further, a small amount of a catalyst is added and kneaded, then the mixture is formed into a film, heated to be gelled, and punched into a circular shape.
It heated at 0 degreeC for 12 hours, and was set as the positive electrode pellet. Next, an equivalent mixture of ethylene carbonate and diethyl carbonate was used as a solvent, and LiClO ₄ was mixed at a concentration of 1 mol / liter to obtain an electrolyte. The negative electrode and the positive electrode prepared above were attached to each other with the separator immersed in the electrolyte interposed therebetween to prepare a battery, and the change in charge / discharge capacity due to repeated use was measured. The current density during charging and discharging is 0.1 mA
/ Cm ² , the initial charge / discharge capacity was 180 mAh / g, and the charge / discharge capacity after 100 cycles was 90% of the initial charge / discharge capacity.

Example 6 The following materials were mixed to prepare a negative electrode. High crystalline natural graphite 50 parts by weight Acetylene black 33.6 parts by weight Compound (1-1-1) 6.7 parts by weight Compound (2-1-1) 8.4 parts by weight Compound (3-1-9) 1 3 parts by weight ethylene carbonate 5 parts by weight

Further, a small amount of a catalyst is added and kneaded, then the mixture is formed into a film, heated to be gelled, and punched out into a circle to form a film.
The mixture was heated at 0 ° C. for 12 hours to obtain a negative electrode pellet.

The following materials were kneaded and rolled into a film. Li _11/6 Cr _1/12 B _1/12 O ₄ 60 parts by weight Acetylene black 35 parts by weight Polytetrafluoroethylene 5 parts by weight

Next, the resultant was punched into a circle and heated at 110 ° C. for 12 hours to obtain a positive electrode pellet. Next, an equivalent mixture of ethylene carbonate and diethyl carbonate was used as a solvent, and LiClO ₄ was mixed at a concentration of 1 mol / liter to obtain an electrolyte. The negative electrode and the positive electrode prepared above were attached to each other with the separator immersed in the electrolyte interposed therebetween to prepare a battery, and the change in charge / discharge capacity due to repeated use was measured. The current density during charge / discharge was 0.1 mA / cm ² , the initial charge / discharge capacity was 105 mAh / g, and the charge / discharge capacity after 100 cycles was 88% of the first time.

Comparative Example 1 The following materials were kneaded and rolled into a film. High crystalline natural graphite 60 parts by weight Acetylene black 35 parts by weight Polytetrafluoroethylene 5 parts by weight

This was punched out in a circular shape and heated at 110 ° C. for 12 hours to obtain a negative electrode pellet.

The following materials were kneaded and rolled to form a film. LiCoO ₂ 60 parts by weight Acetylene black 35 parts by weight Polytetrafluoroethylene 5 parts by weight

Further, it was punched out in a circular shape and heated at 110 ° C. for 12 hours to obtain a positive electrode pellet. Next, an equivalent mixture of ethylene carbonate and diethyl carbonate was used as a solvent, and LiClO ₄ was mixed at a concentration of 1 mol / liter to obtain an electrolyte. The negative electrode and the positive electrode prepared above were attached to each other with the separator immersed in the electrolyte interposed therebetween to prepare a battery, and the change in charge / discharge capacity due to repeated use was measured. The current density during charge and discharge was 0.1 mA / cm ² , the initial charge and discharge capacity was 105 mAh / g, and the charge and discharge capacity after 100 cycles was 80% of the initial.

[0103]

As described above, according to the electrode of the present invention, a lithium secondary battery having excellent repetition characteristics can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 4/04 H01M 4/04 A 10/40 10/40 Z F term (Reference) 4J002 CH052 CP041 DA117 DD047 EC077 EH076 EU186 EX006 EZ007 FD157 GQ00 5H003 AA04 AA06 BA01 BB11 BD00 5H014 AA02 BB01 EE01 HH00 5H029 AJ05 AJ11 AK03 AK15 AL01 AL03 AL06 AL11 AM00 AM02 AM03 AM07 AM16 BJ03 CJ02 DJ08 EJ12 HJ02

Claims (4)

[Claims] 1. A reaction between at least a polysiloxane represented by the compound (1-1), a polyalkylene oxide represented by the compound (2-1), and a polyfunctional compound represented by the compound (3-1). An electrode comprising the obtained crosslinked structure. Embedded image (In the formula, R ₁ independently represents a monovalent hydrocarbon group containing no aliphatic unsaturation, and m ₁ represents an integer from 0 to 500.) (In the formula, R ₂₁ represents a monovalent hydrocarbon group having a terminal double bond, a represents an integer of 2 to 4, and n ₂₁ represents an integer of 1 or more.) (Wherein, R ₃₁ represents a hydrogen atom or an alkyl group, R ₃₂
Represents a divalent organic group or a direct bond. l ₃ is an integer of 2 or more, and Z ₃₁ is a substituent containing carbon or nitrogen and is a group having the same valence as l ₃ . ) 2. Mixing at least a polysiloxane represented by the compound (1-1), a polyalkylene oxide represented by the compound (2-1), and a polyfunctional compound represented by the compound (3-1), A method for producing an electrode, which is performed by heating. Embedded image (In the formula, R ₁ independently represents a monovalent hydrocarbon group containing no aliphatic unsaturation, and m ₁ represents an integer from 0 to 500.) (In the formula, R ₂₁ represents a monovalent hydrocarbon group having a terminal double bond, a represents an integer of 2 to 4, and n ₂₁ represents an integer of 1 or more.) (Wherein, R ₃₁ represents a hydrogen atom or an alkyl group, R ₃₂
Represents a divalent organic group or a direct bond. l ₃ is an integer of 2 or more, and Z ₃₁ is a substituent containing carbon or nitrogen and is a group having the same valence as l ₃ . ) 3. A crosslink obtained by reacting a polysiloxane having at least three or more Si—H groups, a polyalkylene oxide compound (2-1) or (2-2), and a compound (3-1). An electrode comprising a structure. Embedded image (In the formula, R ₁ independently represents a monovalent hydrocarbon group containing no aliphatic unsaturation, and m ₁ represents an integer of 0 to 500.) (Wherein, R ₂₁ represents a monovalent hydrocarbon group having a terminal double bond, a represents an integer of 2 to 4, and n ₂₁ represents an integer of 1 or more.) (Wherein, R ₂₂ represents a monovalent hydrocarbon group having a terminal double bond, R ₂₃ represents a hydrogen atom, a monovalent saturated hydrocarbon group or an acyl group, and b represents an integer of 2 to 4. , N ₂₂ is 1
The following integers are shown. ) (Wherein, R ₃₁ represents a hydrogen atom or an alkyl group, R ₃₂
Represents a divalent organic group or a direct bond. l ₃ is an integer of 2 or more, and Z ₃₁ is a substituent containing carbon or nitrogen and is a group having the same valence as l ₃ . ) 4. A polysiloxane having at least three or more Si—H groups, a polyalkylene oxide compound (2-1) or (2-2), and a compound (3-1) are mixed and molded by heating. A method for producing an electrode, comprising: Embedded image (In the formula, R ₁ independently represents a monovalent hydrocarbon group containing no aliphatic unsaturation, and m ₁ represents an integer of 0 to 500.) (Wherein, R ₂₁ represents a monovalent hydrocarbon group having a terminal double bond, a represents an integer of 2 to 4, and n ₂₁ represents an integer of 1 or more.) (Wherein, R ₂₂ represents a monovalent hydrocarbon group having a terminal double bond, R ₂₃ represents a hydrogen atom, a monovalent saturated hydrocarbon group or an acyl group, and b represents an integer of 2 to 4. , N ₂₂ is 1
The following integers are shown. ) (Wherein, R ₃₁ represents a hydrogen atom or an alkyl group, R ₃₂
Represents a divalent organic group or a direct bond. l ₃ is an integer of 2 or more, and Z ₃₁ is a substituent containing carbon or nitrogen and is a group having the same valence as l ₃ . )