Binder composition for nonaqueous secondary battery electrode, slurry composition for nonaqueous secondary battery electrode, electrode for nonaqueous secondary battery, and nonaqueous secondary battery

Abstract

The purpose of the present invention is to provide a binder composition for a nonaqueous secondary battery electrode with which the viscosity stability of a slurry composition can be enhanced. The present invention is a binder composition for a nonaqueous secondary battery electrode, the binder composition containing a polymer X and water, in which the polymer X is water-soluble and includes a conjugated diene monomer unit and / or an alkylene structural unit and a hydroxyl group-containing (meth)acrylic acid ester monomer unit, the total proportion of the conjugated diene monomer unit and the alkylene structural unit in the polymer X is 30.0-55.0 mass%, and the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer unit in the polymer X is 27.0-40.0 mass%.

Description

Binder composition for non-aqueous secondary battery electrodes, slurry composition for non-aqueous secondary battery electrodes, electrodes for non-aqueous secondary batteries and non-aqueous secondary batteries

[0001] The present invention relates to a binder composition for non-aqueous secondary battery electrodes, a slurry composition for non-aqueous secondary battery electrodes, an electrode for a non-aqueous secondary battery, and a non-aqueous secondary battery.

[0002] Non-aqueous secondary batteries, such as lithium-ion batteries (hereinafter sometimes abbreviated as "secondary batteries"), are small, lightweight, have high energy density, and can be repeatedly charged and discharged, making them suitable for a wide range of applications. Therefore, in recent years, improvements to battery components such as electrodes have been considered with the aim of further enhancing the performance of non-aqueous secondary batteries.

[0003] Here, electrodes for secondary batteries typically include an electrode composite layer. The electrode composite layer is formed by, for example, dispersing an electrode active material and a non-aqueous secondary battery electrode binder composition containing a polymer acting as a binder in a dispersion medium, and then applying a slurry composition (non-aqueous secondary battery electrode slurry composition) onto a current collector and drying it.

[0004] Therefore, in recent years, attempts have been made to improve the binder composition used in forming the electrode composite layer in order to achieve further performance improvements in secondary batteries.

[0005] For example, Patent Document 1 describes the formulation of a copolymer containing units derived from (meth)acrylonitrile and units derived from a conjugated diene monomer as a dispersant for compounding into a conductive material dispersion, wherein the copolymer contains 15 to 50% by mass of units derived from (meth)acrylonitrile and has a weight-average molecular weight of 5,000 to 400,000.

[0006] Japanese Patent Publication No. 2020-187866

[0007] In this context, from the viewpoint of improving the productivity and performance of secondary batteries, binder compositions are required to enhance the viscosity stability of the slurry composition prepared using such binder compositions.

[0008] However, when using a composition containing the copolymer described above, there was room for improvement in the viscosity stability of the resulting slurry composition.

[0009] Therefore, the present invention aims to provide a binder composition for non-aqueous secondary battery electrodes that can improve the viscosity stability of the slurry composition. The present invention also aims to provide a slurry composition for non-aqueous secondary battery electrodes that has excellent viscosity stability. The present invention also aims to provide an electrode for a non-aqueous secondary battery comprising an electrode composite layer formed using the above-mentioned slurry composition for non-aqueous secondary battery electrodes. The present invention also aims to provide a non-aqueous secondary battery comprising the above-mentioned electrode for a non-aqueous secondary battery.

[0010] The inventors conducted diligent research to achieve the above objectives. They then discovered that the above problems can be solved by using a polymer in the binder composition that is water-soluble and contains a predetermined proportion of conjugated diene monomer units and / or alkylene structural units and a predetermined proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units, and thus completed the present invention.

[0011] In other words, the present invention aims to advantageously solve the above problems, and [1] the present invention is a binder composition for a non-aqueous secondary battery electrode comprising a polymer X and water, wherein the polymer X is water-soluble and contains conjugated diene monomer units and / or alkylene structural units and hydroxyl group-containing (meth)acrylic acid ester monomer units, the total proportion of the conjugated diene monomer units and the alkylene structural units in the polymer X is 30.0% by mass or more and 55.0% by mass or less, and the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer units in the polymer X is 27.0% by mass or more and 40.0% by mass or less, and is a binder composition for a non-aqueous secondary battery electrode. With a binder composition for a non-aqueous secondary battery electrode as described above, the viscosity stability of the slurry composition for a non-aqueous secondary battery electrode can be improved. In this specification, a polymer is said to be "water-soluble" if, when 0.5 g (in terms of solid content) of the polymer is dissolved in 100 g of water at a temperature of 25°C, the amount of insoluble content is less than 5.0% by mass. In this specification, "monomer unit" of a polymer means "a repeating unit derived from the monomer contained in the polymer obtained using that monomer." Furthermore, the content ratio of various repeating units (monomer units and structural units) in the polymer is as follows: １ It can be measured using nuclear magnetic resonance (NMR) methods such as 1H-NMR. In this specification, (meth)acrylic means acrylic and / or methacrylic.

[0012] [2] In the binder composition for non-aqueous secondary battery electrodes described in [1] above, the hydroxyl group-containing (meth)acrylic acid monomer unit comprises a hydroxyl group-containing (meth)acrylic acid monomer unit A, in which a hydroxyl group-containing hydrocarbon group having 2 to 3 carbon atoms is bonded to a non-carbonyl oxygen atom, and a hydroxyl group-containing (meth)acrylic acid monomer unit B, in which a hydroxyl group-containing hydrocarbon group having 4 or more carbon atoms is bonded to a non-carbonyl oxygen atom. Preferably, the proportion of the hydroxyl group-containing (meth)acrylic acid monomer unit A in the polymer X is 2.0% by mass or more and 20.0% by mass or less, and the proportion of the hydroxyl group-containing (meth)acrylic acid monomer unit B in the polymer X is 15.0% by mass or more and 35.0% by mass or less. Using the polymer X described above, the viscosity stability of the slurry composition for non-aqueous secondary battery electrodes can be effectively improved.

[0013] [3] In the binder composition for non-aqueous secondary battery electrodes according to [1] or [2] above, it is preferable that the polymer X further contains acidic group-containing monomer units. If the polymer X contains acidic group-containing monomer units, the viscosity stability of the slurry composition for non-aqueous secondary battery electrodes can be improved.

[0014] [4] In any of the binder compositions for non-aqueous secondary battery electrodes described in [1] to [3] above, it is preferable that the polymer X further contains hydroxyl group-free (meth)acrylic acid ester monomer units. If the polymer X contains hydroxyl group-free (meth)acrylic acid ester monomer units, the viscosity stability of the slurry composition for non-aqueous secondary battery electrodes can be improved.

[0015] [5] In any of the non-aqueous secondary battery electrode binder compositions described in [1] to [4] above, the weight-average molecular weight of the polymer X is preferably 10,000 or more and 100,000 or less. If the weight-average molecular weight of the polymer X is within the above range, the viscosity stability of the non-aqueous secondary battery electrode slurry composition can be effectively improved. Here, the weight-average molecular weight of the polymer X can be measured according to the method described in the examples of this specification.

[0016] Moreover, the present invention aims to advantageously solve the above problems, and [6] the present invention is a slurry composition for a non-aqueous secondary battery electrode, comprising an electrode active material and the binder composition for a non-aqueous secondary battery electrode according to any one of [1] to [5] above. The slurry composition for a non-aqueous secondary battery electrode as described above has excellent viscosity stability.

[0017] [7] The slurry composition for a non-aqueous secondary battery electrode according to [6] above preferably further contains a particulate polymer Y containing a hydrophilic group. If the particulate polymer Y containing a hydrophilic group is further contained, the adhesion of the electrode mixture layer formed using the slurry composition for a non-aqueous secondary battery electrode to the current collector can be improved.

[0018] [8] In the slurry composition for a non-aqueous secondary battery electrode according to [7] above, the content ratio of the particulate polymer Y is preferably 0.1% by mass or more and 5.0% by mass or less when the total solid content contained in the slurry composition for a non-aqueous secondary battery electrode is 100% by mass. If the content ratio of the particulate polymer Y is at least the above lower limit, the adhesion of the electrode mixture layer formed using the slurry composition for a non-aqueous secondary battery electrode to the current collector can be effectively improved. On the other hand, if the content ratio of the particulate polymer Y is at most the above upper limit, the output characteristics of the secondary battery can be effectively improved.

[0019] [9] In the slurry composition for a non-aqueous secondary battery electrode according to any one of [6] to [8] above, the electrode active material preferably contains a lithium-containing composite metal oxide having an olivine-type structure. If olivine-type lithium iron phosphate is used as the electrode active material, the stability of the secondary battery against overcharging can be improved.

[0020]

[10] The slurry composition for a non-aqueous secondary battery electrode according to any one of [6] to [9] above preferably further contains a conductive material containing at least one of a particulate conductive material and carbon nanotubes. If the conductive material contains at least one of a particulate conductive material and carbon nanotubes, the output characteristics of the non-aqueous secondary battery can be improved.

[0021] Furthermore, this invention aims to advantageously solve the above problems, and

[11] the present invention is an electrode for a non-aqueous secondary battery comprising an electrode composite layer formed using any of the non-aqueous secondary battery electrode slurry compositions of [6] to

[10] above. Such a non-aqueous secondary battery electrode can enable the secondary battery to exhibit excellent battery characteristics.

[0022] Furthermore, this invention aims to advantageously solve the above problems, and

[12] the present invention is a non-aqueous secondary battery equipped with the electrodes for non-aqueous secondary batteries described in

[11] above. Such a non-aqueous secondary battery has excellent battery characteristics.

[0023] The present invention provides a binder composition for non-aqueous secondary battery electrodes that can improve the viscosity stability of the slurry composition. Furthermore, the present invention provides a slurry composition for non-aqueous secondary battery electrodes that exhibits excellent viscosity stability. Furthermore, the present invention provides an electrode for a non-aqueous secondary battery comprising an electrode composite layer formed using the above-mentioned slurry composition for non-aqueous secondary battery electrodes. Furthermore, the present invention provides a non-aqueous secondary battery comprising the above-mentioned electrode for non-aqueous secondary battery.

[0024] Each component disclosed herein, as well as preferred embodiments, numerical ranges, and thresholds defining such numerical ranges, can be independently combined with each other in any manner.

[0025] Embodiments of the present invention will be described in detail below. Here, the binder composition for non-aqueous secondary battery electrodes of the present invention (hereinafter sometimes simply referred to as "binder composition") can be used to prepare the slurry composition for non-aqueous secondary battery electrodes of the present invention (hereinafter sometimes simply referred to as "slurry composition"). Furthermore, the slurry composition for non-aqueous secondary battery electrodes of the present invention can be used when manufacturing electrodes for non-aqueous secondary batteries such as lithium-ion secondary batteries. In addition, the non-aqueous secondary battery of the present invention is characterized by using an electrode for a non-aqueous secondary battery (hereinafter sometimes simply referred to as "electrode") formed using the slurry composition for non-aqueous secondary battery electrodes of the present invention. It is preferable that the binder composition for non-aqueous secondary battery electrodes be a binder composition for a positive electrode of a non-aqueous secondary battery, as it can particularly enhance the viscosity stability of the slurry composition containing the positive electrode active material, which will be described later.

[0026] (Binder composition for non-aqueous secondary battery electrodes) The binder composition for non-aqueous secondary battery electrodes of the present invention comprises polymer X and water, wherein polymer X is water-soluble and contains conjugated diene monomer units and / or alkylene structural units and hydroxyl group-containing (meth)acrylic acid ester monomer units. Furthermore, in the binder composition of the present invention, the total proportion of conjugated diene monomer units and alkylene structural units in polymer X is 30.0% by mass or more and 55.0% by mass or less, and the proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units in polymer X is 27.0% by mass or more and 40.0% by mass or less. With a binder composition as described above, the viscosity stability of the slurry composition can be improved. The reason for this is presumed to be that by using polymer X as described above, polymer X is adsorbed onto the surface of the electrode active material contained in the slurry composition and effectively covers the surface, thereby effectively suppressing aggregation of the electrode active materials. Furthermore, with the binder composition described above, the electrode composite layer formed using the resulting slurry composition can be given the desired adhesion to the current collector. Moreover, with the binder composition described above, the resulting secondary battery can be given the desired output characteristics and cycle characteristics. The binder composition of the present invention may optionally further contain components other than polymer X and water (hereinafter sometimes referred to as "other components"). In addition, the binder composition of the present invention usually does not contain electrode active material.

[0027] <Polymer X> Polymer X is a water-soluble component that can function as a dispersant for effectively dispersing components such as electrode active materials and conductive materials in a slurry composition prepared using the binder composition. Polymer X can also function as a binder in the electrode composite layer formed using the slurry composition.

[0028] <<Composition of Polymer X>> Polymer X contains a predetermined proportion of conjugated diene monomer units and / or alkylene structural units, and a predetermined proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units. Furthermore, polymer X preferably further contains acidic group-containing monomer units, as described later, as this can improve the viscosity stability of the slurry composition. Furthermore, polymer X preferably further contains hydroxyl group-free (meth)acrylic acid ester monomer units, as described later, as this can improve the viscosity stability of the slurry composition. Polymer X may optionally contain monomer units other than the above-mentioned conjugated diene monomer units, alkylene structural units, hydroxyl group-containing (meth)acrylic acid ester monomer units, acidic group-containing monomer units, and hydroxyl group-free (meth)acrylic acid ester monomer units (hereinafter sometimes referred to as "other monomer units").

[0029] [Conjugated diene monomer units, alkylene structural units] Conjugated diene monomer units can be formed from conjugated diene monomers. Examples of conjugated diene monomers include conjugated diene compounds such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene. These can be used individually or in combination of two or more. Among these, 1,3-butadiene and isoprene are preferred, and 1,3-butadiene is more preferred. That is, the conjugated diene monomer unit is preferably at least one of a 1,3-butadiene unit and an isoprene unit, and is preferably a 1,3-butadiene unit.

[0030] The alkylene structural unit has the general formula: -C ｎ H ２ｎ - [where n is an integer greater than or equal to 2] is a repeating unit composed solely of alkylene structures.

[0031] The alkylene structural unit may be linear or branched, but it is preferable that it be linear, i.e., a linear alkylene structural unit. Furthermore, the number of carbon atoms in the alkylene structural unit is four or more (i.e., the general formula above: -C) ｎ H ２ｎ It is preferable that the negative n is an integer of 4 or greater.

[0032] The method for introducing alkylene structural units into polymer X is not particularly limited, but examples include the following methods (1) or (2): (1) a method of preparing a polymer from a monomer composition containing a conjugated diene monomer and converting the conjugated diene monomer units into alkylene structural units by hydrogenation (hydrogenation) of the polymer; and (2) a method of preparing a polymer from a monomer composition containing a 1-olefin monomer. Among these, method (1) is preferred because it is easy to produce polymer X.

[0033] In other words, the alkylene structural unit is preferably a structural unit (conjugated diene hydride unit) obtained by hydrogenating (hydrogenating) the conjugated diene monomer unit as described above. Examples of 1-olefin monomers include 1-butene and 1-hexene. These conjugated diene monomers and 1-olefin monomers can be used individually or in combination of two or more.

[0034] Furthermore, the conjugated diene monomers that can be used in the method described in (1) above are the conjugated diene monomers described above, and among them, the 1,3-butadiene monomer is preferred. That is, the alkylene structural unit is preferably a structural unit obtained by hydrogenating a conjugated diene monomer unit (conjugated diene hydride unit), and more preferably a structural unit obtained by hydrogenating a 1,3-butadiene unit (1,3-butadiene hydride unit). The hydrogenation can be carried out using a known method as described later.

[0035] Furthermore, if the conjugated diene monomer units are not completely hydrogenated when alkylene structural units are introduced into polymer X via the method described in (1) above, conjugated diene monomer units may remain in polymer X. In other words, polymer X may optionally contain conjugated diene monomer units as repeating units.

[0036] In one embodiment of the present invention, polymer X may contain at least one of conjugated diene monomer units and alkylene structural units, but it is preferable that it contains conjugated diene monomer units.

[0037] The total proportion of conjugated diene monomer units and alkylene structural units in polymer X must be 30.0% by mass or more, preferably 32.5% by mass or more, more preferably 35.0% by mass or more, and must be 55.0% by mass or less, preferably 50.0% by mass or less, and more preferably 45.0% by mass or less, based on the total repeating units (sum of structural units and monomer units) contained in polymer X being 100% by mass. If the total content of conjugated diene monomer units and alkylene structural units in polymer X is above the above lower limit, the decrease in hydrophobicity of polymer X can be effectively suppressed, and the viscosity stability of the resulting slurry composition can be effectively improved. Furthermore, the adhesion of the electrode composite layer formed using the slurry composition to the current collector can be effectively improved. In addition, the cycle characteristics of the resulting secondary battery can be effectively improved. On the other hand, if the total content ratio of alkylene structural units and conjugated diene monomer units in polymer X is below the above upper limit, the decrease in water solubility of polymer X can be effectively suppressed, and the viscosity stability of the resulting slurry composition can be effectively improved. Furthermore, the output characteristics and cycle characteristics of the resulting secondary battery can be effectively improved.

[0038] Furthermore, the total proportion of the conjugated diene monomer units and alkylene structural units described above is the ratio of present monomer units to structural units if either the conjugated diene monomer units or the alkylene structural units are not contained in polymer X. For example, if the conjugated diene monomer units are completely hydrogenated in method (1) above, or if the polymer is produced by method (2) above (and no additional conjugated diene monomer units are introduced), polymer X will not contain conjugated diene monomer units but will contain alkylene structural units. Alternatively, if the conjugated diene monomer units are not completely hydrogenated in method (1) above, polymer X will contain both conjugated diene monomer units and alkylene structural units.

[0039] [Hydroxyl Group-containing (Meth)acrylate Monomer Unit] The hydroxyl group-containing acrylic ester monomer that can form the hydroxyl group-containing (meth)acrylate monomer unit in Polymer X includes alkanol esters of (meth)acrylic acid such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-(hydroxymethyl)cyclohexylmethyl (1,4-cyclohexanedimethanol mono(meth)acrylate) (also referred to as "hydroxyalkyl (meth)acrylate monomer"); esters of polyalkylene glycol represented by the general formula: CH ２ =CH-COO-(C ｑ H ２ｑ O) ｐ -H (where p represents an integer from 2 to 9 and q represents an integer from 2 to 4) and (meth)acrylic acid (also referred to as "(meth)acrylate polyalkylene glycol ester monomer"); and the like. These may be used alone or in combination of two or more in any ratio, but it is preferable to use two or more. In this specification, (meth)acrylate means acrylic and / or methacrylic.

[0040] Among the above, (meth)acrylate hydroxyalkyl monomers are preferred, (meth)acrylate 2-hydroxyethyl, (meth)acrylate 2-hydroxypropyl, (meth)acrylate 4-hydroxybutyl, (meth)acrylate 2-hydroxybutyl, and (meth)acrylate 4-(hydroxymethyl)cyclohexylmethyl are more preferred, acrylate 2-hydroxyethyl, methacrylate 2-hydroxyethyl, methacrylate 2-hydroxypropyl, acrylate 2-hydroxybutyl, acrylate 4-hydroxybutyl, and acrylate 4-(hydroxymethyl)cyclohexylmethyl are even more preferred, and methacrylate 2-hydroxyethyl and acrylate 4-hydroxybutyl are even more preferred. That is, the hydroxyl group-containing (meth)acrylic acid ester monomer unit is preferably a (meth)acrylate hydroxyalkyl ester monomer unit, more preferably at least one monomer unit selected from the group consisting of (meth)acrylate 2-hydroxyethyl unit, (meth)acrylate 2-hydroxypropyl unit, (meth)acrylate 4-hydroxybutyl unit, (meth)acrylate 2-hydroxybutyl unit, and (meth)acrylate 4-(hydroxymethyl)cyclohexylmethyl unit, even more preferably at least one monomer unit selected from the group consisting of acrylate 2-hydroxyethyl unit, methacrylate 2-hydroxyethyl unit, acrylate 2-hydroxypropyl unit, methacrylate 2-hydroxypropyl unit, acrylate 2-hydroxybutyl unit, acrylate 4-hydroxybutyl unit, and acrylate 4-(hydroxymethyl)cyclohexylmethyl unit, and even more preferably at least one of methacrylate 2-hydroxyethyl unit and acrylate 4-hydroxybutyl unit.

[0041] In one embodiment of the present invention, the hydroxyl group-containing (meth)acrylic acid monomer unit includes hydroxyl group-containing (meth)acrylic acid monomer unit A (hereinafter sometimes simply referred to as "hydroxyl group-containing (meth)acrylic acid monomer unit A"), in which a hydroxyl group-containing hydrocarbon group having 2 to 3 carbon atoms is bonded to a non-carbonyl oxygen atom, and hydroxyl group-containing (meth)acrylic acid monomer unit B (hereinafter sometimes simply referred to as "hydroxyl group-containing (meth)acrylic acid monomer unit B"), in which a hydroxyl group-containing hydrocarbon group having 4 or more carbon atoms, preferably 4 to 12 carbon atoms, more preferably 4 to 8 carbon atoms, is bonded to a non-carbonyl oxygen atom. If the hydroxyl group-containing (meth)acrylic acid monomer unit includes hydroxyl group-containing (meth)acrylic acid monomer unit A and hydroxyl group-containing (meth)acrylic acid monomer unit B, the viscosity stability of the slurry composition for non-aqueous secondary battery electrodes can be improved.

[0042] Examples of hydroxyl group-containing (meth)acrylic acid ester monomer A that can form hydroxyl group-containing (meth)acrylic acid ester monomer unit A include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate. These may be used individually or in any ratio of two or more. Among these, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate are preferred, with 2-hydroxyethyl methacrylate being more preferred. That is, hydroxyl group-containing (meth)acrylic acid ester monomer unit A is preferably at least one monomer unit selected from the group consisting of 2-hydroxyethyl acrylate unit, 2-hydroxyethyl methacrylate unit, and 2-hydroxypropyl methacrylate unit, and is more preferably a 2-hydroxyethyl methacrylate unit.

[0043] Examples of hydroxyl group-containing (meth)acrylic acid ester monomer B that can form hydroxyl group-containing (meth)acrylic acid ester monomer unit B include 4-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-(hydroxymethyl)cyclohexylmethyl (meth)acrylate. These may be used individually or in any ratio of two or more. Among these, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, and 4-(hydroxymethyl)cyclohexylmethyl acrylate are preferred, with 4-hydroxybutyl acrylate being more preferred. That is, hydroxyl group-containing (meth)acrylic acid ester monomer unit B is preferably at least one selected from the group consisting of 2-hydroxybutyl acrylate unit, 4-hydroxybutyl acrylate unit, and 4-(hydroxymethyl)cyclohexylmethyl acrylate unit, and is more preferably 4-hydroxybutyl acrylate unit.

[0044] The proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units in polymer X must be 27.0% by mass or more, preferably 28.5% by mass or more, more preferably 30.0% by mass or more, and must be 40.0% by mass or less, preferably 38.5% by mass or less, and more preferably 37.0% by mass or less, based on the total repeating units (sum of structural units and monomer units) contained in polymer X being 100% by mass. If the proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units in polymer X is above the above lower limit, the viscosity stability of the slurry composition can be effectively improved. This is presumed to be because polymer X is well adsorbed to electrode active materials and conductive materials when used as a slurry composition. Furthermore, the output characteristics and cycle characteristics of the resulting secondary battery can be effectively improved. On the other hand, if the proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units in polymer X is below the above upper limit, the viscosity stability of the slurry composition can be effectively improved. This is presumably because it effectively suppresses the aggregation of electrode active materials and conductive materials via polymer X. Furthermore, it effectively improves the adhesion of the electrode composite layer formed using the slurry composition to the current collector. In addition, it effectively improves the cycle characteristics of the resulting secondary battery.

[0045] When polymer X contains hydroxyl group-containing (meth)acrylic acid ester monomer units A and hydroxyl group-containing (meth)acrylic acid ester monomer units B, the proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units A in polymer X is preferably 2.0% by mass or more, more preferably 4.0% by mass or more, even more preferably 6.0% by mass or more, preferably 20.0% by mass or less, more preferably 18.0% by mass or less, and even more preferably 16.0% by mass or less, based on a total of 100% by mass of all repeating units (sum of structural units and monomer units) contained in polymer X. If the proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units A in polymer X is within the above range, the viscosity stability of the slurry composition can be effectively improved.

[0046] When polymer X contains hydroxyl group-containing (meth)acrylic acid ester monomer units A and hydroxyl group-containing (meth)acrylic acid ester monomer units B, the proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units B in polymer X is preferably 15.0% by mass or more, more preferably 18.0% by mass or more, even more preferably 21.0% by mass or more, preferably 35.0% by mass or less, more preferably 32% by mass or less, and even more preferably 29.0% by mass or less, based on the total repeating units (sum of structural units and monomer units) contained in polymer X being 100% by mass. If the proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units B in polymer X is within the above range, the viscosity stability of the slurry composition can be effectively improved.

[0047] When polymer X contains hydroxyl group-containing (meth)acrylic acid ester monomer units A and hydroxyl group-containing (meth)acrylic acid ester monomer units B, the mass ratio of hydroxyl group-containing (meth)acrylic acid ester monomer units A to hydroxyl group-containing (meth)acrylic acid ester monomer units B in polymer X (hydroxyl group-containing (meth)acrylic acid ester monomer unit A / hydroxyl group-containing (meth)acrylic acid ester monomer unit B in polymer X) is preferably 0.02 or higher, more preferably 0.10 or higher, even more preferably 0.25 or higher, preferably 1.80 or lower, more preferably 0.90 or lower, and even more preferably 0.50 or lower. If the above mass ratio is within the above range, the viscosity stability of the slurry composition can be effectively improved.

[0048] When polymer X contains hydroxyl group-containing (meth)acrylic acid ester monomer units A and hydroxyl group-containing (meth)acrylic acid ester monomer units B, the total proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units A and hydroxyl group-containing (meth)acrylic acid ester monomer units B in polymer X must be 27.0% by mass or more, preferably 28.5% by mass or more, more preferably 30.0% by mass or more, and must be 40.0% by mass or less, preferably 38.5% by mass or less, and more preferably 37.0% by mass or less, based on the total repeating units (sum of structural units and monomer units) contained in polymer X being 100% by mass. If the total proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units A and hydroxyl group-containing (meth)acrylic acid ester monomer units B in polymer X is above the above lower limit, the viscosity stability of the slurry composition can be effectively improved. Furthermore, the output characteristics and cycle characteristics of the resulting secondary battery can be effectively improved. On the other hand, if the total proportion of hydroxyl group-containing (meth)acrylic acid ester monomer unit A and hydroxyl group-containing (meth)acrylic acid ester monomer unit B in polymer X is less than or equal to the above upper limit, the viscosity stability of the slurry composition can be effectively improved. Furthermore, the adhesion of the electrode composite layer formed using the slurry composition to the current collector can be effectively improved. Moreover, the cycle characteristics of the resulting secondary battery can be effectively improved.

[0049] [Acid group-containing monomer units] Examples of acid group-containing monomers that can form any acid group-containing monomer unit include carboxylic acid group-containing monomers, sulfonic acid group-containing monomers, and phosphate group-containing monomers.

[0050] Examples of monomers containing carboxylic acid groups include monocarboxylic acids and their derivatives, dicarboxylic acids and their acid anhydrides, and their derivatives. Examples of monocarboxylic acids include acrylic acid, methacrylic acid, and crotonic acid. Examples of monocarboxylic acid derivatives include 2-ethylacrylic acid, isocrotonic acid, α-acetoxyacrylic acid, β-trans-aryloxyacrylic acid, α-chloro-β-E-methoxyacrylic acid, and β-diaminoacrylic acid. Examples of dicarboxylic acids include maleic acid, fumaric acid, and itaconic acid. Examples of dicarboxylic acid derivatives include methylmaleic acid, dimethylmaleic acid, phenylmaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, and maleic acid esters such as methylallyl maleate, diphenyl maleate, nonyl maleate, decyl maleate, dodecyl maleate, octadecyl maleate, and fluoroalkyl maleate. Examples of dicarboxylic acid acid anhydrides include maleic anhydride, acrylic anhydride, methyl maleic anhydride, and dimethyl maleic anhydride. Furthermore, as monomers containing a carboxylic acid group, acid anhydrides that generate a carboxyl group through hydrolysis can also be used. In addition, the hydrogen atoms in the carboxylic acid group of the above-mentioned carboxylic acid group-containing monomers may be substituted with inorganic or organic ions, resulting in the form of an inorganic or organic salt. That is, the carboxylic acid group-containing monomer may also exist in the form of a carboxylic acid salt.

[0051] Examples of sulfonic acid group-containing monomers include vinyl sulfonic acid, methyl vinyl sulfonic acid, (meth)allyl sulfonic acid, styrene sulfonic acid, ethyl (meth)acrylate-2-sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, and 3-alyloxy-2-hydroxypropanesulfonic acid. In addition, the sulfonic acid group in the above-mentioned sulfonic acid group-containing monomers may be replaced by an inorganic or organic ion, resulting in the form of an inorganic salt or organic salt. That is, the sulfonic acid group-containing monomer may also be in the form of a sulfonate salt.

[0052] Examples of phosphate group-containing monomers include 2-(meth)acryloyloxyethyl phosphate, methyl-2-(meth)acryloyloxyethyl phosphate, and ethyl-(meth)acryloyloxyethyl phosphate. In the phosphate group of the above-mentioned phosphate group-containing monomers, the hydrogen atom may be substituted with an inorganic or organic ion, and the monomer may be in the form of an inorganic salt or organic salt. That is, the phosphate group-containing monomer may be in the form of a phosphate salt. In this specification, (meth)acryloyl means acryloyl and / or methacryloyl.

[0053] These acidic group-containing monomers may be used individually or in any ratio of two or more.

[0054] Furthermore, from the viewpoint of further improving the adhesion of the formed electrode composite layer to the current collector, it is preferable to use a carboxylic acid group-containing monomer or a sulfonic acid group-containing monomer as the acid group-containing monomer, more preferably a carboxylic acid group-containing monomer, even more preferably (meth)acrylic acid, and even more preferably methacrylic acid. That is, the acid group-containing monomer unit is preferably at least one of a carboxylic acid group-containing monomer unit and a sulfonic acid group-containing monomer unit, more preferably a carboxylic acid group-containing monomer unit, even more preferably a (meth)acrylic acid unit, and even more preferably a methacrylic acid unit.

[0055] The proportion of acidic group-containing monomer units in polymer X is preferably 10.0% by mass or more, more preferably 15.0% by mass or more, even more preferably 20.0% by mass or more, preferably 35.0% by mass or less, more preferably 32.5% by mass or less, and even more preferably 30.5% by mass or less, based on the total repeating units (sum of structural units and monomer units) contained in polymer X being 100% by mass. If the proportion of acidic group-containing monomer units in polymer X is above the lower limit, the viscosity stability of the slurry composition can be effectively improved. On the other hand, if the proportion of acidic group-containing monomer units in polymer X is below the upper limit, the hardening of polymer X can be effectively suppressed, and the adhesion of the electrode composite layer to the current collector can be improved.

[0056] [Hydroxygroup-free (meth)acrylate monomer units] Examples of arbitrary hydroxygroup-free (meth)acrylate monomer units include hydroxygroup-free (meth)acrylate alkyl monomer units. While the hydroxygroup-free (meth)acrylate alkyl monomer units will be explained in detail below, hydroxygroup-free (meth)acrylate monomer units are not limited to hydroxygroup-free (meth)acrylate alkyl monomer units.

[0057] As hydroxyl group-free alkyl (meth)acrylate monomers that can form hydroxyl group-free alkyl (meth)acrylate monomer units, alkyl (meth)acrylates that do not contain hydroxyl groups, such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, can be used. These may be used individually or in any ratio of two or more. Among these, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate are more preferred, and butyl acrylate is even more preferred. In other words, the hydroxyl group-free alkyl (meth)acrylate monomer unit is preferably at least one monomer unit selected from the group consisting of ethyl (meth)acrylate units, butyl (meth)acrylate units, and 2-ethylhexyl (meth)acrylate units, more preferably at least one monomer unit selected from the group consisting of ethyl acrylate units, butyl acrylate units, and 2-ethylhexyl acrylate units, and even more preferably a butyl acrylate unit.

[0058] The proportion of hydroxyl group-free (meth)acrylic acid ester monomer units in polymer X is preferably 0.5% by mass or more, more preferably 0.75% by mass or more, even more preferably 0.9% by mass or more, preferably 10.0% by mass or less, more preferably 8.0% by mass or less, and even more preferably 6.0% by mass or less, when the total repeating units (sum of structural units and monomer units) contained in polymer X are taken as 100% by mass. If the proportion of hydroxyl group-free (meth)acrylic acid ester monomer units in polymer X is above the lower limit above, the flexibility of the resulting electrode composite layer can be effectively improved. On the other hand, if the content of hydroxyl group-free (meth)acrylic acid ester monomer units in polymer X is below the upper limit above, excessive swelling of polymer X in the electrolyte can be effectively suppressed, and the cycle characteristics of the secondary battery can be effectively improved.

[0059] [Other Monomer Units] There are no particular limitations on the monomers that can form any other monomer units, and examples include nitrile group-containing monomers and aromatic vinyl monomers. These monomers may be used individually or two or more in any ratio.

[0060] The proportion of other monomer units in polymer X is preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less, even more preferably 2% by mass or less, and even more preferably 1% by mass or less, when the total repeating units (sum of structural units and monomer units) in the polymer are taken as 100% by mass. Of course, the content of other monomer units in polymer X may be 0% by mass, that is, polymer X may not contain any other monomer units.

[0061] <<Method for Preparing Polymers>> The method for producing the polymer X described above is not particularly limited, and any of the following methods can be used, for example, solution polymerization, suspension polymerization, bulk polymerization, emulsion polymerization, etc. Furthermore, addition polymerization methods such as ionic polymerization, radical polymerization, and living radical polymerization can be used as polymerization methods. Also, known polymerization initiators can be used as polymerization initiators.

[0062] In the production of polymer X, it is preferable to use a molecular weight modifier (chain transfer agent) having a sulfur-containing group such as a mercapto group during polymerization. Examples of compounds having a mercapto group that can be used as molecular weight modifiers include compounds having 8 to 12 carbon atoms such as octyl mercaptan, 2,2,4,6,6-pentamethyl-4-heptanethiol, 2,4,4,6,6-pentamethyl-2-heptanethiol, 2,3,4,6,6-pentamethyl-2-heptanethiol, 2,3,4,6,6-pentamethyl-3-heptanethiol, t-dodecyl mercaptan, and n-dodecyl mercaptan; and compounds having a mercapto group such as 2,2,4,6,6-pentamethyl-4-octanthiol, 2,2,4,6,6,8,8-heptamethyl-4-nonanthiol, bis(2-mercaptoethyl) sulfide, methyl 3-mercaptopropionate, and 1-butanethiol. Among these, compounds having a mercapto group with 8 to 12 carbon atoms are preferred, and t-dodecyl mercaptan is more preferred.

[0063] When polymer X is produced by the method described in (1) above (method for introducing alkylene structural units into polymer X), after emulsion polymerization, hydrogenation is performed on the resulting polymer before hydrogenation (i.e., the polymer precursor). Hydrogenation can be carried out using known hydrogenation methods such as oil-layer hydrogenation or aqueous-layer hydrogenation. Furthermore, any known selective hydrogenation catalyst can be used without limitation as the catalyst for hydrogenation, and palladium-based catalysts or rhodium-based catalysts can be used. Two or more of these may be used in combination.

[0064] <<Properties of Polymer X>> The weight-average molecular weight of polymer X is preferably 10,000 or more, more preferably 15,000 or more, even more preferably 20,000 or more, preferably 100,000 or less, more preferably 80,000 or less, and even more preferably 60,000 or less. If the weight-average molecular weight of polymer X is within the above range, the viscosity stability of the slurry composition can be effectively improved. Furthermore, if the weight-average molecular weight is above the lower limit, the adhesion of the resulting electrode composite layer to the current collector can be effectively improved. Note that the weight-average molecular weight of polymer X can be controlled, for example, by adjusting the amount of molecular weight adjusting agent added during polymerization.

[0065] The molecular weight distribution of polymer X is preferably 1.5 or higher, more preferably 1.8 or higher, even more preferably 2.2 or higher, preferably 10 or lower, more preferably 7 or lower, and even more preferably 4 or lower. The molecular weight distribution of polymer X can be calculated according to the method described in the examples below.

[0066] <Solvent> The binder composition contains water as a solvent. The binder composition may further contain an organic solvent other than water. Examples of organic solvents include N-methylpyrrolidone (NMP), N,N-dimethylformamide, and acetone.

[0067] <Other Components> In addition to the components mentioned above, the binder composition of the present invention may also contain components such as reinforcing agents, leveling agents, viscosity modifiers, and electrolyte additives. These are not particularly limited as long as they do not affect the battery reaction, and known components, such as those described in International Publication No. 2012 / 115096, can be used. Furthermore, these components may be used individually or in combination of two or more components in any ratio.

[0068] <Method for preparing a binder composition for non-aqueous secondary battery electrodes> The binder composition of the present invention can be prepared, for example, by mixing polymer X and other components in water using a known method. Alternatively, for example, an aqueous solution or aqueous dispersion of polymer X obtained by the above-described method for preparing polymer X can be used as is as the binder composition of the present invention. Furthermore, for example, the preparation of the binder composition and the preparation of the slurry composition described later can be carried out simultaneously by mixing polymer X and electrode active material and then adding other components such as particulate polymers as desired.

[0069] (Slurry composition for non-aqueous secondary battery electrodes) The slurry composition for non-aqueous secondary battery electrodes of the present invention comprises an electrode active material and the binder composition for non-aqueous secondary battery electrodes of the present invention described above. Because the slurry composition of the present invention contains the binder composition of the present invention described above, it has excellent viscosity stability. Here, the slurry composition of the present invention may optionally further contain particulate polymers, conductive materials, dispersion media, and other components in addition to the electrode active material and the binder composition.

[0070] The slurry composition of the present invention may be a slurry composition for the positive electrode of a non-aqueous secondary battery containing a positive electrode active material as the electrode active material, or it may be a slurry composition for the negative electrode of a non-aqueous secondary battery containing a negative electrode active material as the electrode active material. Here, the slurry composition of the present invention is preferably a slurry composition for the positive electrode of a non-aqueous secondary battery because it has particularly excellent viscosity stability when containing a positive electrode active material.

[0071] The following describes in detail the case where the non-aqueous slurry composition for secondary battery electrodes of the present invention is a slurry composition for lithium-ion secondary battery cathodes, but the present invention is not limited to the following example.

[0072] <Electrode Active Material (Positive Electrode Active Material)> Here, the positive electrode active material for the lithium-ion secondary battery is not particularly limited, and known positive electrode active materials can be used. Specifically, as the positive electrode active material, compounds containing transition metals, such as transition metal oxides, transition metal sulfides, and composite metal oxides of lithium and transition metals can be used. Examples of transition metals include Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Mo.

[0073] Here, examples of transition metal oxides include MnO, MnO ２ , V ２ O ５ , V ６ O １３ , TiO ２ ,Cd ２ V ２ O ３ Amorphous V ２ O-P ２ O ５ Amorphous MoO ３ Amorphous V ２ O ５ Amorphous V ６ O １３ Examples include TiS ２ TiS ３ Amorphous MoS ２ Examples include FeS. Examples of composite metal oxides of lithium and transition metals include lithium-containing composite metal oxides having a layered structure, lithium-containing composite metal oxides having a spinel-type structure, and lithium-containing composite metal oxides having an olivine-type structure. In particular, it is preferable that the electrode active material contains a lithium-containing composite metal oxide having an olivine-type structure. If the electrode active material contains a lithium-containing composite metal oxide having an olivine-type structure, the stability of the secondary battery against overcharging can be improved.

[0074] Examples of lithium-containing composite metal oxides having an olivine-type structure include olivine-type lithium iron phosphate (LiFePO4). ４ ), olivine-type lithium manganese phosphate (LiMnPO ４ ), olivine-type manganese iron lithium (LiMn １－ｘ Fe ｘPO ４ Li such as 0 < x < 1 ｙ MdPO ４ Examples of olivine-type lithium phosphate compounds are given by the formula: Here, Md represents one or more transition metals with an average oxidation state of 3+, such as Mn, Fe, Co, etc. Also, y represents a number satisfying 0 ≤ y ≤ 2. Furthermore, Li ｙ MdPO ４ The olivine-type lithium phosphate compound represented by may have Md partially substituted with another metal. Examples of substituted metals include Cu, Mg, Zn, V, Ca, Sr, Ba, Ti, Al, Si, B, and Mo. Here, as the olivine-type lithium iron phosphate, carbon-coated olivine-type lithium iron phosphate particles can also be used, in which at least a portion of the surface of the olivine-type lithium iron phosphate particles is coated with a carbon coating layer.

[0075] The particle size of the positive electrode active material is not particularly limited and can be adjusted as appropriate within the range in which the desired effects of the present invention can be obtained. However, for example, it is preferable that the median diameter of the positive electrode active material is 2 μm or less. In the present invention, the median diameter of the positive electrode active material refers to the particle size D50 at which the cumulative volume calculated from the smallest diameter side in the particle size distribution (volume basis) measured by a laser diffraction particle size analyzer manufactured by Malvern Corporation becomes 50%.

[0076] Furthermore, the content ratio of the electrode active material in the slurry composition is preferably 90% by mass or more and 99% by mass or less, for example, when the total solid content in the slurry composition is taken as 100% by mass.

[0077] <Binder Composition> The binder composition of the present invention described above can be used as the binder composition.

[0078] The amount of binder composition added when preparing the slurry composition can be appropriately adjusted within the range in which the desired effects of the present invention can be obtained. For example, when the total solid content in the slurry composition is 100% by mass, the amount of binder composition added can be adjusted so that the content of polymer X is preferably 0.1% by mass or more and 5% by mass or less, more preferably 0.1% by mass or more and 3% by mass or less, and even more preferably 0.1% by mass or more and 2% by mass or less. The slurry composition contains polymer X and optionally particulate polymer, but the total content of polymer X and the optional particulate polymer in the slurry composition can satisfy the same preferred content range as above, specifically preferably 0.1% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less.

[0079] <Conductive Material> The conductive material that may be optionally included in the slurry composition is a component that has the function of contributing to electrical contact between electrode active materials in the electrode composite layer.

[0080] The conductive material can improve the output characteristics of non-aqueous secondary batteries, and therefore it is preferable to contain at least one of carbon nanotubes and particulate conductive materials, and more preferably carbon nanotubes and particulate conductive materials. However, conductive materials other than carbon nanotubes and particulate conductive materials (other conductive materials) may also be used as the conductive material. Examples of other conductive materials include fibrous conductive materials other than carbon nanotubes.

[0081] <<Carbon Nanotubes>> Carbon nanotubes can improve the output characteristics of secondary batteries by forming conductive paths in the electrode composite layer. Furthermore, the use of carbon nanotubes can also improve the cycle characteristics and low-temperature characteristics of secondary batteries. The carbon nanotubes are not particularly limited as long as they are carbon nanotubes that can obtain the desired effects of the present invention (hereinafter sometimes abbreviated as "CNT"). Depending on the type of layer, examples of carbon nanotubes include single-walled (SW) carbon nanotubes and multi-walled (MW) carbon nanotubes. The carbon nanotubes that can be used as conductive materials may be single-walled carbon nanotubes, multi-walled carbon nanotubes, or a combination thereof.

[0082] The average number of layers of the CNT is preferably 10 or less, more preferably 9 or less, even more preferably 8 or less, even more preferably 2 or less, and even more preferably 1.5 or less. If the average number of layers of the CNT is below the above upper limit, the cycle characteristics of the secondary battery can be further improved. The lower limit of the average number of layers of the CNT is not particularly limited, and is usually 1 or more.

[0083] The average diameter of the CNTs is preferably 0.5 nm or more, more preferably 1 nm or more, even more preferably 1.5 nm or more, even more preferably 2 nm or more, even more preferably 2.5 nm or more, preferably 20 nm or less, more preferably 12 nm or less, even more preferably 8 nm or less, even more preferably 6 nm or less, and even more preferably 4 nm or less. If the average diameter of the CNTs is above the lower limit, the aggregation of CNTs can be sufficiently suppressed, and the dispersibility of the CNTs as a conductive material can be improved. On the other hand, if the average diameter of the CNTs is below the upper limit, good conductive paths can be formed in the electrode composite layer, further improving the output characteristics of the secondary battery and further improving the cycle characteristics of the secondary battery.

[0084] The ratio of the G-band peak intensity to the D-band peak intensity in the Raman spectrum of CNTs (G / D ratio) is preferably 0.6 or higher, more preferably 1.2 or higher, even more preferably 2.1 or higher, even more preferably 3.0 or higher, and even more preferably 3.6 or higher. If the G / D ratio of the CNTs is above the lower limit mentioned above, the cycle characteristics of the secondary battery can be further improved. The upper limit of the G / D ratio of the CNTs is not particularly limited, but for example, it is 200 or lower.

[0085] The BET specific surface area of ​​CNT is 100 m². ２ Preferably, it is 1 / g or more, and 200m ２ It is more preferable that the amount is 250m or more per gram. ２ It is even more preferable that the amount is 1200m or more. ２ It is preferable that the amount is less than or equal to 1100m ２ It is more preferable that it be less than or equal to 1000m ２ It is even more preferable that the amount is less than or equal to / g. If the BET specific surface area of ​​the CNT is within the above predetermined range, the output characteristics of the secondary battery can be further improved. In this invention, the "BET specific surface area" of the CNT refers to the nitrogen adsorption specific surface area measured using the BET method.

[0086] [Method for Manufacturing Carbon Nanotubes] CNTs having the above-described properties can be manufactured using known methods such as arc discharge, laser ablation, and supergrowth, without any particular limitations.

[0087] [Carbon Nanotube Content] The content of any CNT in the slurry composition can be adjusted as appropriate within the range in which the desired effects of the present invention can be obtained. For example, when the total solid content in the slurry composition is 100% by mass, it is preferable to have a content of 0.01% by mass or more and 0.5% by mass or less. If the content of CNT in the slurry composition is above the lower limit, the internal resistance of the secondary battery can be effectively reduced, and the output characteristics of the secondary battery can be further improved. On the other hand, if the content of CNT in the slurry composition is below the upper limit, the flexibility of the electrode composite layer can be increased.

[0088] <<Particulate Conductive Material>> Particulate conductive material is a component that can function as a conductive material in the electrode composite layer and can also improve the flexibility of the electrode composite layer. The particulate conductive material is not particularly limited as long as it is a conductive material having a shape other than fibrous (for example, spherical, plate-shaped, etc.), and examples include carbon black (for example, acetylene black, Ketjenblack®, Farnest Black, etc.) and graphene. These particulate conductive materials may be used individually or in combination of two or more types in any ratio.

[0089] [Content ratio of particulate conductive material] The content ratio of any particulate conductive material in the slurry composition can be appropriately adjusted within the range in which the desired effects of the present invention can be obtained. For example, when the total solid content in the slurry composition is 100% by mass, it is preferable to have a content ratio of 0.1% by mass or more and 5% by mass or less. If the content ratio of particulate conductive material in the slurry composition is above the lower limit above, the flexibility of the electrode composite layer can be further improved. On the other hand, if the content ratio of particulate conductive material in the slurry composition is below the upper limit above, the adhesion of the electrode composite layer to the current collector can be improved.

[0090] <<Mixing ratio of CNTs and particulate conductive material>> The mixing ratio of CNTs and particulate conductive material is not particularly limited, but for example, the proportion of CNTs in the total content of CNTs and particulate conductive material in the slurry composition is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, preferably 30% by mass or less, and more preferably 25% by mass or less. If the proportion of CNTs in the total content of CNTs and particulate conductive material is above the lower limit above, the internal resistance of the secondary battery can be effectively reduced and the output characteristics of the secondary battery can be further improved. On the other hand, if the proportion of CNTs in the total content of CNTs and particulate conductive material is below the upper limit above, the flexibility of the electrode composite layer can be improved.

[0091] <Particulate Polymer> The particulate polymer, together with the polymer X described above, is a component that can function as a binder in the electrode composite layer. The particulate polymer is a polymer that has a different composition and / or physical properties from the polymer X described above. Here, the particulate polymer is usually water-insoluble. In this invention, a polymer is "water-insoluble" if, when 0.5 g of the polymer (in terms of solid content) is dissolved in 100 g of water at a temperature of 25°C, the amount of insoluble content is 90% by mass or more.

[0092] The particulate polymer is preferably a particulate polymer Y containing hydrophilic groups (hereinafter sometimes simply referred to as "particulate polymer Y"), as it can improve the adhesion of the electrode composite layer formed using the slurry composition to the current collector. That is, the slurry composition of the present invention preferably further contains particulate polymer Y.

[0093] Here, the method for introducing hydrophilic groups into particulate polymer Y is not particularly limited, but for example, a method can be employed in which hydrophilic group-containing monomers are used during the polymerization of particulate polymer Y to form hydrophilic group-containing monomer units in the resulting particulate polymer Y. In the following, monomer units that can constitute particulate polymer Y will be described, but the particulate polymers that can be included in the slurry composition of the present invention are not limited thereto.

[0094] <<Hydrophilic Group-Containing Monomer Units>> Examples of hydrophilic group-containing monomers that can form hydrophilic group-containing monomer units in particulate polymer Y include the various monomers mentioned above, hydroxyl group-containing monomers, etc., which can be used as acidic group-containing monomers to introduce acidic group-containing monomer units into polymer X.

[0095] As the acidic group-containing monomer (carboxylic acid group-containing monomer, sulfonic acid group-containing monomer, phosphate group-containing monomer, etc.), various acidic group-containing monomers that can be used in the preparation of polymer X described above can be used. These may be used individually or two or more in any ratio.

[0096] As hydroxyl group-containing monomers, for example, the various compounds described as monomers that can be used to introduce hydroxyl group-containing (meth)acrylic acid ester monomer units into polymer X, and other hydroxyl group-containing monomers listed below can be used.

[0097] Other hydroxyl group-containing monomers include mono(meth)acrylic acid esters of dihydroxy esters of dicarboxylic acids such as 2-hydroxyethyl-2'-(meth)acryloyl oxyphthalate and 2-hydroxyethyl-2'-(meth)acryloyl oxysuccinate; vinyl ethers such as 2-hydroxyethyl vinyl ether and 2-hydroxypropyl vinyl ether; and mono(meth)alkylene glycols such as (meth)allyl-2-hydroxyethyl ether, (meth)allyl-2-hydroxypropyl ether, (meth)allyl-3-hydroxypropyl ether, (meth)allyl-2-hydroxybutyl ether, (meth)allyl-3-hydroxybutyl ether, (meth)allyl-4-hydroxybutyl ether, and (meth)allyl-6-hydroxyhexyl ether. Examples include allyl ethers; polyoxyalkylene glycol mono(meth)allyl ethers such as diethylene glycol mono(meth)allyl ether and dipropylene glycol mono(meth)allyl ether; mono(meth)allyl ethers of halogen and hydroxy-substituted (poly)alkylene glycols such as glycerin mono(meth)allyl ether, (meth)allyl-2-chloro-3-hydroxypropyl ether, and (meth)allyl-2-hydroxy-3-chloropropyl ether; mono(meth)allyl ethers of polyhydric phenols such as eugenol and isoeugenol and their halogen-substituted derivatives; and (meth)allyl thioethers of alkylene glycols such as (meth)allyl-2-hydroxyethyl thioether and (meth)allyl-2-hydroxypropyl thioether. In this specification, "(meth)allyl" means allyl and / or methallyl.

[0098] Furthermore, as the hydrophilic group-containing monomer, it is preferable to use an acidic group-containing monomer (carboxylic acid group-containing monomer, sulfonic acid group-containing monomer, phosphate group-containing monomer, etc.) from the viewpoint of further improving the viscosity stability of the slurry composition and the adhesion of the formed electrode composite layer to the current collector. From the viewpoint of further improving the adhesion of the formed electrode composite layer, it is more preferable to use an acidic group-containing monomer and a hydroxyl group-containing monomer in combination, and even more preferable to use a carboxylic acid group-containing monomer and a hydroxyl group-containing monomer in combination.

[0099] The content of hydrophilic group-containing monomer units in particulate polymer Y is preferably 10% by mass or less, when the total amount of monomer units contained in particulate polymer Y is taken as 100% by mass. If the content of hydrophilic group-containing monomer units in particulate polymer Y is within the above predetermined range, the viscosity stability of the slurry composition, as well as the adhesion and flexibility of the formed electrode composite layer to the current collector, can be further improved.

[0100] When particulate polymer Y contains both acidic group-containing monomer units (carboxylic acid-containing monomer units, sulfonic acid-containing monomer units, phosphate-containing monomer units, etc.) and hydroxyl group-containing monomer units as hydrophilic group-containing monomer units, the content ratio of hydrophilic group-containing monomer units in particulate polymer Y (i.e., the total content ratio of acidic group-containing monomer units and hydroxyl group-containing monomer units) is more preferably 2% by mass or more, even more preferably 3% by mass or more, more preferably 5% by mass or less, and even more preferably 4% by mass or less, when the total monomer units contained in particulate polymer Y are taken as 100% by mass. If the total content ratio of acidic group-containing monomer units and hydroxyl group-containing monomer units in particulate polymer Y is within the above predetermined range, the viscosity stability of the slurry composition, as well as the adhesion and flexibility of the formed electrode composite layer to the current collector, can be further improved.

[0101] When particulate polymer Y contains acidic group-containing monomer units (carboxylic acid group-containing monomer units, sulfonic acid group-containing monomer units, phosphate group-containing monomer units, etc.) as hydrophilic group-containing monomer units, the content of acidic group-containing monomer units in particulate polymer Y is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 1.5% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2.5% by mass or less, based on the total monomer units contained in particulate polymer Y being 100% by mass. If the content of acidic group-containing monomer units in particulate polymer Y is above the lower limit above, the viscosity stability of the slurry composition and the adhesion of the formed electrode composite layer to the current collector can be further improved. On the other hand, if the content of acidic group-containing monomer units in particulate polymer Y is below the upper limit above, the flexibility of the formed electrode composite layer can be sufficiently ensured.

[0102] When particulate polymer Y contains hydroxyl group-containing monomer units as hydrophilic group-containing monomer units, the content of hydroxyl group-containing monomer units in particulate polymer Y is preferably 0.5% by mass or more, more preferably 1% by mass or more, preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably 1.5% by mass or less, based on the total monomer units contained in particulate polymer Y being 100% by mass. If the content of acidic group-containing monomer units in particulate polymer Y is above the above lower limit, the flexibility of the formed electrode composite layer can be further improved. On the other hand, if the content of acidic group-containing monomer units in particulate polymer Y is below the above upper limit, the viscosity stability of the slurry composition and the adhesion of the formed electrode composite layer to the current collector can be sufficiently ensured.

[0103] <<Types of particulate polymer Y>> For particulate polymer Y containing hydrophilic groups, it is preferable to use, for example, a hydrophilic group-containing acrylic polymer or a hydrophilic group-containing conjugated diene polymer.

[0104] [Hydrophilic Group-Containing Acrylic Polymers] Hydrophilic group-containing acrylic polymers are copolymers that contain at least (meth)acrylic acid ester monomer units in addition to the hydrophilic group-containing monomer units described above. Preferably, hydrophilic group-containing acrylic polymers further contain aromatic vinyl monomer units. Furthermore, hydrophilic group-containing acrylic polymers may further contain monomer units other than hydrophilic group-containing monomer units, (meth)acrylic acid ester monomer units, and aromatic vinyl monomer units.

[0105] Furthermore, the content ratio of hydrophilic group-containing monomer units in the hydrophilic group-containing acrylic polymer can be within the same range as the preferred range for the content ratio of hydrophilic group-containing monomer units in the polymer described above.

[0106] As (meth)acrylic acid ester monomers that can form (meth)acrylic acid ester monomer units in hydrophilic group-containing acrylic polymers, alkyl (meth)acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and 2-ethylhexyl acrylate can be used. These may be used individually or in any ratio of two or more types.

[0107] Here, the content of (meth)acrylic acid ester monomer units in the hydrophilic group-containing acrylic polymer is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, when the total monomer units contained in the hydrophilic group-containing acrylic polymer are taken as 100% by mass. If the content of (meth)acrylic acid ester monomer units in the hydrophilic group-containing acrylic polymer is within the above predetermined range, the adhesion and flexibility of the formed electrode composite layer to the current collector can be further improved.

[0108] Aromatic vinyl monomers that can form aromatic vinyl monomer units in hydrophilic group-containing acrylic polymers include styrene, α-methylstyrene, vinyltoluene, and divinylbenzene. These may be used individually or in any ratio of two or more. Styrene is particularly preferred.

[0109] The content of aromatic vinyl monomer units in a hydrophilic group-containing acrylic polymer is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 17% by mass or more, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 25% by mass or less, when the total monomer units contained in the hydrophilic group-containing acrylic polymer are taken as 100% by mass.

[0110] [Hydrophilic group-containing conjugated diene polymers] Hydrophilic group-containing conjugated diene polymers are copolymers that contain conjugated diene monomer units in addition to the hydrophilic group-containing monomer units described above.

[0111] Specific examples of conjugated diene polymers include, but are not limited to, copolymers containing hydrophilic group-containing monomer units, aromatic vinyl monomer units, and aliphatic conjugated diene monomer units, such as hydrophilic group-containing styrene-butadiene copolymer (hydrophilic group-containing SBR); hydrophilic group-containing butadiene rubber (hydrophilic group-containing BR) (a copolymer containing hydrophilic group-containing monomer units and butadiene units); hydrophilic group-containing acrylic rubber (hydrophilic group-containing NBR) (a copolymer containing hydrophilic group-containing monomer units, acrylonitrile units, and butadiene units); and their hydrides. These may be used individually or in any ratio of two or more. In particular, from the viewpoint of further improving the adhesion and flexibility of the formed electrode composite layer to the current collector, it is preferable to use copolymers containing hydrophilic group-containing monomer units, aromatic vinyl monomer units, and aliphatic conjugated diene monomer units, such as hydrophilic group-containing styrene-butadiene copolymer (hydrophilic group-containing SBR).

[0112] The content ratio of hydrophilic group-containing monomer units in the hydrophilic group-containing conjugated diene polymer can be within the same range as the preferred range for the content ratio of hydrophilic group-containing monomer units in the polymer described above.

[0113] Examples of conjugated diene monomer units that can form conjugated diene monomer units in hydrophilic group-containing conjugated diene polymers include the various compounds listed above that can be used to introduce conjugated diene monomer units into polymer X. These may be used individually or in any ratio of two or more. Among these, 1,3-butadiene is preferred.

[0114] The content of conjugated diene monomer units in a hydrophilic group-containing conjugated diene polymer is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less, based on 100% by mass of all monomer units contained in the hydrophilic group-containing conjugated diene polymer. If the content of conjugated diene monomer units in a hydrophilic group-containing conjugated diene polymer is within the above predetermined range, the adhesion and flexibility of the formed electrode composite layer to the current collector can be further improved.

[0115] Aromatic vinyl monomers that can form aromatic vinyl monomer units in hydrophilic group-containing conjugated diene polymers include styrene, α-methylstyrene, vinyltoluene, and divinylbenzene. These may be used individually or in any ratio of two or more. Among these, styrene is preferred.

[0116] The content of aromatic vinyl monomer units in the hydrophilic group-containing conjugated diene polymer is preferably 30% by mass or more, more preferably 45% by mass or more, even more preferably 56% by mass or more, preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 71% by mass or less, based on 100% by mass of all monomer units contained in the hydrophilic group-containing conjugated diene polymer. If the content of aromatic vinyl monomer units in the hydrophilic group-containing conjugated diene polymer is within the above predetermined range, the adhesion and flexibility of the formed electrode composite layer to the current collector can be further improved.

[0117] <<Method for preparing particulate polymer Y>> The polymerization method of particulate polymer Y is not particularly limited, and any of the following methods may be used, for example, solution polymerization, suspension polymerization, bulk polymerization, emulsion polymerization, etc. Addition polymerization such as ionic polymerization, radical polymerization, and living radical polymerization can be used as the polymerization reaction. The emulsifiers, dispersants, polymerization initiators, chain transfer agents, etc. that can be used in polymerization can be those that are commonly used, and the amounts used can also be those that are commonly used.

[0118] <<Content of particulate polymer Y>> The content of particulate polymer Y in the slurry composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1.5% by mass or less, when the total solid content in the slurry composition is taken as 100% by mass. If the content of particulate polymer Y is above the lower limit above, the adhesion of the electrode composite layer formed using the non-aqueous secondary battery electrode slurry composition to the current collector can be effectively improved. On the other hand, if the content of particulate polymer Y is below the upper limit above, the output characteristics of the secondary battery can be effectively improved.

[0119] <<Median diameter of particulate polymer Y>> The median diameter of particulate polymer Y is preferably 100 nm or more, more preferably 110 nm or more, even more preferably 120 nm or more, preferably 250 nm or less, more preferably 230 nm or less, and even more preferably 210 nm or less. In this specification, the "median diameter" of particulate polymer Y means the particle diameter (D50) at which the cumulative volume calculated from the smallest diameter side becomes 50% in the particle size distribution (volume basis) measured by laser diffraction, and can be measured in more detail using the method described in the examples of this specification.

[0120] <Dispersion medium> Water and the organic solvents listed in the <Solvent> section above can be used as the dispersion medium.

[0121] <Other Components> Other components that can be incorporated into the slurry composition are not particularly limited and include those similar to the other components that can be incorporated into the binder composition of the present invention. In addition, one type of other component may be used alone, or two or more types may be used in any ratio.

[0122] <Method for Producing Slurry Composition> The slurry composition described above can be prepared by dissolving or dispersing each of the above components in a dispersion. For example, it is preferable to prepare the slurry composition of the present invention by adding a positive electrode active material, a solvent, and optional components to the binder composition described above and mixing them using the known method described above. In particular, when CNTs are incorporated as a conductive material, it is preferable to prepare a CNT dispersion by mixing CNTs with a dispersant such as carboxymethylcellulose and a dispersion medium, and then perform a multi-stage mixing process in which the CNT dispersion is further mixed with the positive electrode active material, etc.

[0123] (Electrodes for non-aqueous secondary batteries) The electrode of the present invention comprises an electrode composite layer formed using the slurry composition of the present invention described above, and usually has a structure in which the electrode composite layer is formed on a current collector. Therefore, the electrode composite layer contains at least an electrode active material and polymer X, and optionally further contains particulate polymer, conductive material, etc.

[0124] Here, since the electrode composite layer of the electrode of the present invention is formed using the slurry composition of the present invention, it can enable secondary batteries to exhibit excellent battery characteristics. More specifically, since the electrode composite layer of the electrode of the present invention is formed using the slurry composition of the present invention, which has excellent viscosity stability, it has a uniform structure and can reduce the internal resistance of secondary batteries. Furthermore, since the slurry composition of the present invention exhibits particularly excellent viscosity stability when it contains a positive electrode active material, and can enable secondary batteries to exhibit excellent battery characteristics, it is preferable that the electrode of the present invention is a positive electrode.

[0125] The electrode active material, polymer X, particulate polymer, conductive material, and other components contained in the electrode composite layer are those that were contained in the slurry composition described above, and the preferred content ratio of each component is the same as the preferred content ratio of each component when the total solid content in the slurry composition is taken as 100% by mass.

[0126] Furthermore, the electrode of the present invention may further include a conductive adhesive layer between the current collector and the electrode composite layer, the adhesive layer comprising at least a conductive material and an adhesive.

[0127] <Current Collector> The current collector is made of a material that is electrically conductive and electrochemically durable. Specifically, the current collector can be made of metal materials such as iron, copper, aluminum, nickel, stainless steel, titanium, tantalum, gold, or platinum. These materials may be used individually or in combination of two or more materials in any ratio.

[0128] Furthermore, for example, when manufacturing an electrode further comprising the conductive adhesive layer described above between the electrode composite layer and the current collector, a current collector with a conductive adhesive layer can be used, wherein the conductive adhesive layer is formed on a current collector substrate. As the current collector substrate, for example, a current collector made of the metal material described above can be used. The method for forming the conductive adhesive layer on the current collector substrate is not particularly limited. For example, a slurry composition (also referred to as "conductive adhesive") in which a conductive material and an adhesive are dispersed or dissolved in a dispersion medium or solvent such as water, and optionally a dispersant is further dispersed or dissolved, can be applied to the current collector substrate and then dried to form the conductive adhesive layer. The conductive material is not particularly limited, and for example, a conductive material that may be included in the slurry composition described above can be used. Also, the adhesive is not particularly limited, and particulate polymers that may be included in the slurry composition described above can be used. Furthermore, the dispersant is not particularly limited, and for example, known dispersants such as carboxymethylcellulose and its salts can be used. Furthermore, the method for applying the conductive adhesive onto the substrate for the current collector and the method for drying the applied conductive adhesive are not particularly limited, and known methods can be used.

[0129] <Electrode Mixture Layer> The electrode mixture layer is formed, for example, through a process of applying a slurry composition onto the current collector (coating process) and a process of drying the slurry composition applied onto the current collector (drying process). The electrode mixture layer formed in this way can usually take the form of a dried film.

[0130] <<Coating Process>> The method for coating the slurry composition onto the current collector is not particularly limited, and known methods can be used. Specifically, the coating methods can include the doctor blade method, dip method, reverse roll method, direct roll method, gravure method, extrusion method, brush coating method, etc. In this case, the slurry composition may be coated on only one side of the current collector or on both sides. Furthermore, the thickness of the slurry composition film on the current collector before drying after coating can be appropriately set according to the thickness of the electrode composite layer obtained after drying.

[0131] <<Drying Process>> The method for drying the slurry composition applied to the current collector is not particularly limited and known methods can be used, such as drying with hot air, hot air, or low-humidity air, vacuum drying, or drying by irradiation with infrared rays or electron beams. By drying the slurry composition applied to the current collector in this way, an electrode composite layer is formed on the current collector, and an electrode having a current collector and an electrode composite layer can be obtained. After the drying process, the electrode composite layer may be subjected to pressure treatment using a die press or roll press or the like. Pressure treatment can improve the peel strength of the electrode.

[0132] (Non-aqueous secondary battery) The secondary battery of the present invention is equipped with the electrodes of the present invention as described above. For example, the secondary battery of the present invention is equipped with a positive electrode, a negative electrode, a separator, and an electrolyte, and at least one of the positive electrode and the negative electrode is the electrode of the present invention as described above. In other words, the secondary battery of the present invention may have the electrode of the present invention as the positive electrode and a known negative electrode as the negative electrode, or the electrode of the present invention and a known positive electrode as the negative electrode, or both the positive electrode and the negative electrode may be the electrode of the present invention. However, the slurry composition of the present invention is particularly excellent in viscosity stability and excellent in battery characteristics when it contains a positive electrode active material, so it is preferable that at least the positive electrode of the secondary battery of the present invention is the electrode of the present invention. Furthermore, since the secondary battery of the present invention is equipped with the electrodes of the present invention as described above, the internal resistance is reduced, the output characteristics are excellent, and the cycle characteristics are excellent. In the following, the case in which the non-aqueous secondary battery is a lithium-ion secondary battery will be described as an example, but the present invention is not limited to the following example.

[0133] <Positive Electrode> The positive electrode is not particularly limited and can be the electrode of the present invention as described above. That is, for example, the positive electrode can be a positive electrode comprising a positive electrode composite layer formed from the slurry composition of the present invention and a current collector. Also, if the electrode of the present invention is not used as the positive electrode, a known positive electrode can be used.

[0134] <Negative Electrode> The negative electrode is not particularly limited and can be the electrode of the present invention as described above. That is, for example, the negative electrode can be a negative electrode comprising a negative electrode composite layer formed from the slurry composition of the present invention and a current collector. If the electrode of the present invention is not used for the negative electrode, a known negative electrode can be used.

[0135] <Separator> The separator is not particularly limited, but examples include microporous membranes using polyolefin resins (polyethylene, polypropylene, polybutene, polyvinyl chloride), microporous membranes using resins such as polyethylene terephthalate, polycycloolefin, polyethersulfone, polyamide, polyimide, polyimidamide, polyaramid, polycycloolefin, nylon, and polytetrafluoroethylene, woven or nonwoven fabrics using polyolefin fibers, and aggregates of particles made of insulating materials. Among these, microporous membranes using polyolefin resins (polyethylene, polypropylene, polybutene, polyvinyl chloride) are preferred because they allow for a thinner overall film thickness of the separator, thereby increasing the ratio of the electrode composite layer in the secondary battery and thus increasing the capacity per unit volume.

[0136] <Electrolyte> As the electrolyte, an electrolyte solution obtained by dissolving an electrolyte in a solvent can be used. Here, an organic solvent capable of dissolving the electrolyte can be used as the solvent. Specifically, suitable solvents include carbonates such as dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), butylene carbonate (BC), and ethyl methyl carbonate (EMC); esters such as γ-butyrolactone and methyl formate; ethers such as 1,2-dimethoxyethane and tetrahydrofuran; sulfur-containing compounds such as sulfolane and dimethyl sulfoxide; etc. A mixture of these solvents may also be used. In addition, known additives, such as vinylene carbonate (VC), fluoroethylene carbonate (FEC), and ethyl methyl sulfone, may be added to the solvent. As the electrolyte, a lithium salt can be used. As a lithium salt, for example, the compound described in Japanese Patent Publication No. 2012-204303 can be used. Among these lithium salts, LiPF is preferred as an electrolyte due to its easy solubility in organic solvents and high degree of dissociation. ６ LiClO ４ CF ３ SO ３ Li is preferred. Note that one type of electrolyte may be used alone, or two or more types may be used in any ratio. Generally, lithium ion conductivity tends to increase as the degree of dissociation of the supporting electrolyte increases; therefore, lithium ion conductivity can be adjusted by the type of supporting electrolyte.

[0137] Furthermore, the secondary battery of the present invention can be manufactured using known assembly methods without particular limitations. Specifically, the secondary battery of the present invention can be manufactured, for example, by winding, folding, etc., the negative electrode, positive electrode, and separator obtained above into a battery shape as needed, placing them in a battery container, injecting electrolyte into the battery container, and sealing it. Here, in order to prevent the occurrence of an increase in the internal pressure of the secondary battery, overcharging and discharging, etc., an overcurrent prevention element such as a fuse or PTC element, expanded metal, lead plates, etc. may be provided as needed. The shape of the secondary battery may be, for example, coin type, button type, sheet type, cylindrical type, rectangular type, flat type, etc. The battery components such as the positive electrode, negative electrode, and separator of the secondary battery are usually arranged so that the positive electrode is in contact with one side of the separator and the negative electrode is in contact with the other side of the separator. More specifically, the positive electrode composite layer is arranged so that it is in contact with one side of the separator and the negative electrode composite layer is in contact with the other side of the separator.

[0138] (Exemplary Embodiments) The present invention is further illustrated by the following exemplary embodiments [1] to

[22] . However, the present invention is not limited to the following embodiments [1] to

[22] .

[0139] [1] A binder composition for non-aqueous secondary battery electrodes comprising polymer X and water, wherein polymer X is water-soluble and contains conjugated diene monomer units and / or alkylene structural units and hydroxyl group-containing (meth)acrylic acid ester monomer units, the total proportion of the conjugated diene monomer units and the alkylene structural units in polymer X is 30.0% by mass or more and 55.0% by mass or less, and the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer units in polymer X is 27.0% by mass or more and 40.0% by mass or less.

[0140] [2] The binder composition for non-aqueous secondary battery electrodes according to [1], wherein the hydroxyl group-containing (meth)acrylic acid ester monomer unit comprises a hydroxyl group-containing (meth)acrylic acid ester monomer unit A, in which a hydroxyl group-containing hydrocarbon group having 2 to 3 carbon atoms is bonded to a non-carbonyl oxygen atom, and a hydroxyl group-containing (meth)acrylic acid ester monomer unit B, in which a hydroxyl group-containing hydrocarbon group having 4 or more carbon atoms is bonded to a non-carbonyl oxygen atom, wherein the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer unit A in the polymer X is 2.0% by mass or more and 20.0% by mass or less, and the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer unit B in the polymer X is 15.0% by mass or more and 35.0% by mass or less.

[0141] [3] The binder composition for non-aqueous secondary battery electrodes according to [2], wherein the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer unit A in the polymer X is 4.0% by mass or more and 18.0% by mass or less.

[0142] [4] The binder composition for non-aqueous secondary battery electrodes according to [2] or [3], wherein the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer unit A in the polymer X is 6.0% by mass or more and 16.0% by mass or less.

[0143] [5] The binder composition for non-aqueous secondary battery electrodes according to any one of [2] to [4], wherein the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer unit B in the polymer X is 18.0% by mass or more and 32.0% by mass or less.

[0144] [6] The binder composition for non-aqueous secondary battery electrodes according to any one of [2] to [5], wherein the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer unit B in the polymer X is 21.0% by mass or more and 29.0% by mass or less.

[0145] [7] The binder composition for non-aqueous secondary battery electrodes according to any one of [2] to [6], wherein the hydroxyl group-containing (meth)acrylic acid ester monomer unit A is at least one monomer unit selected from the group consisting of 2-hydroxyethyl acrylate units, 2-hydroxyethyl methacrylate units, and 2-hydroxypropyl methacrylate units.

[0146] [8] A binder composition for non-aqueous secondary battery electrodes according to any one of [2] to [7], wherein the hydroxyl group-containing (meth)acrylic acid ester monomer unit A is a 2-hydroxyethyl methacrylate unit.

[0147] [9] The binder composition for non-aqueous secondary battery electrodes according to any one of [2] to [8], wherein the hydroxyl group-containing (meth)acrylic acid ester monomer unit B is at least one selected from the group consisting of 2-hydroxybutyl acrylate unit, 4-hydroxybutyl acrylate unit, and 4-(hydroxymethyl)cyclohexylmethyl acrylate unit.

[0148]

[10] A binder composition for non-aqueous secondary battery electrodes according to any one of [2] to [9], wherein the hydroxyl group-containing (meth)acrylic acid ester monomer unit B is a 4-hydroxybutyl acrylate unit.

[0149]

[11] A binder composition for non-aqueous secondary battery electrodes according to any one of [1] to

[10] , wherein the polymer X further contains an acidic group-containing monomer unit.

[0150]

[12] A binder composition for non-aqueous secondary battery electrodes according to any one of [1] to

[11] , wherein the polymer X further contains hydroxyl group-free (meth)acrylic acid ester monomer units.

[0151]

[13] A binder composition for non-aqueous secondary battery electrodes according to any one of [1] to

[12] , wherein the weight-average molecular weight of the polymer X is 10,000 or more and 100,000 or less.

[0152]

[14] A binder composition for non-aqueous secondary battery electrodes according to any one of [1] to

[13] , wherein the weight-average molecular weight of the polymer X is 15,000 or more and 80,000 or less.

[0153]

[15] A binder composition for non-aqueous secondary battery electrodes according to any one of [1] to

[14] , wherein the weight-average molecular weight of the polymer X is 20,000 or more and 60,000 or less.

[0154]

[16] A slurry composition for non-aqueous secondary battery electrodes, comprising an electrode active material and a binder composition for non-aqueous secondary battery electrodes described in any of [1] to

[15] .

[0155]

[17] The slurry composition for non-aqueous secondary battery electrodes according to

[16] , further comprising a particulate polymer Y containing a hydrophilic group.

[0156]

[18] The non-aqueous secondary battery electrode slurry composition according to

[17] , wherein the content of the particulate polymer Y is 0.1% by mass or more and 5.0% by mass or less when the total solid content contained in the non-aqueous secondary battery electrode slurry composition is 100% by mass.

[0157]

[19] A slurry composition for non-aqueous secondary battery electrodes according to any one of

[16] to

[18] , wherein the electrode active material contains a lithium-containing composite metal oxide having an olivine-type structure.

[0158]

[20] A slurry composition for non-aqueous secondary battery electrodes according to any one of

[16] to

[19] , further comprising a conductive material containing at least one of particulate conductive material and carbon nanotubes.

[0159] An electrode for a non-aqueous secondary battery comprising an electrode composite layer formed using the slurry composition for non-aqueous secondary battery electrodes described in any of

[21] ,

[16] , to

[20] .

[0160] A non-aqueous secondary battery comprising electrodes for non-aqueous secondary batteries as described in

[22] and

[21] .

[0161] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. In the following description, "%" and "parts" representing quantities refer to mass unless otherwise specified. In addition, in polymers produced by copolymerizing multiple types of monomers, the proportion of monomer units formed by polymerization of a certain monomer in the polymer is usually equal to the ratio of that monomer to the total monomers used in the polymerization of the polymer (charging ratio), unless otherwise specified. Furthermore, in the case of a hydrogenated polymer obtained by hydrogenating a polymer containing conjugated diene monomer units, the total content ratio of unhydrogenated conjugated diene monomer units and alkylene structural units as hydrogenated conjugated diene monomer units in the hydrogenated polymer is equal to the ratio of conjugated diene monomers to the total monomers used in the polymerization of the polymer (charging ratio). Various measurements and evaluations were performed in the examples and comparative examples using the following methods.

[0162] <Weight-average molecular weight of polymer X> The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polymer X were measured by gel permeation chromatography (GPC) using a 10 mM LiBr-DMF solution as the eluent under the following measurement conditions: ・Separation column: Shodex KD-806M (Showa Denko K.K.) ・Detector: Differential refractometer detector RID-10A (Shimadzu Corporation) ・Eluent flow rate: 0.3 mL / min ・Column temperature: 40°C ・Standard polymer: TSK standard polystyrene (Tosoh Corporation) The measurement sample was prepared as follows: First, polymer X was added to 5 mL of the above eluent so that the solid content concentration was 0.45% by mass. The mixture was then stirred at 25°C with a stirring bar and a magnetic stirrer at 300 rpm for 30 minutes. The resulting solution was filtered through a 0.22 μm membrane filter and used as the measurement sample. The molecular weight distribution (Mw / Mn) was calculated from the weight-average molecular weight (Mw) and number-average molecular weight (Mn) measured according to the above procedure.

[0163] <Median diameter D50 of particulate polymer Y> For each particulate polymer produced in the examples and comparative examples, the particle size distribution (volume basis) of an aqueous dispersion solution adjusted to a solid content concentration of 0.1% by mass was measured using a laser diffraction particle size distribution analyzer (Beckman Coulter, product name "LS-230"). The median diameter D50 of particulate polymer Y was determined as the particle size (nm) at which the cumulative volume calculated from the smallest diameter side reached 50%.

[0164] <Viscosity Stability> The viscosity of the positive electrode slurry composition was measured using a Brookfield B-type viscometer (60 rpm, 25°C), and the viscosity η0 immediately after preparation was measured. Next, the slurry composition whose viscosity was measured was left to stand for 24 hours, and the viscosity η1 after 24 hours of storage was measured using the same B-type viscometer (rotation speed: 60 rpm). The viscosity retention rate Δη of the slurry composition before and after storage was calculated as η1 / η0 × 100 (%), and the viscosity stability of the slurry composition was evaluated according to the following criteria. The closer the viscosity retention rate Δη is to 100%, the better the viscosity stability of the slurry composition. A: Viscosity retention rate Δη is 100% or more and less than 200% B: Viscosity retention rate Δη is 200% or more and less than 300% C: Viscosity retention rate Δη is 300% or more and less than 400% D: Viscosity retention rate Δη is 400% or more

[0165] <Adhesion of Electrode Mixture Layer to Current Collector> The positive electrodes manufactured in the examples and comparative examples were cut into rectangles measuring 1.0 cm wide x 10 cm long to serve as test specimens. Cellophane tape (as specified in JIS Z1522) was attached to the positive electrode mixture layer side surface of these test specimens. The stress was measured when the cellophane tape was peeled off from one end of the test specimen at a speed of 50 mm / min in a 90° direction. The measurement was performed a total of three times, and the average value was calculated and defined as the peel strength (N / m). A higher peel strength indicates that the positive electrode mixture layer has excellent adhesion and is firmly attached to the current collector.

[0166] <Output Characteristics> The lithium-ion secondary batteries prepared in the examples and comparative examples were left to stand for 5 hours at 25°C after electrolyte injection. Next, they were charged to a State of Charge (SOC) of 20% using a constant current method at 25°C and 0.1C, and then aged for 12 hours at 60°C. Then, they were discharged to a cell voltage of 2.6V using a constant current method at 25°C and 0.2C. After that, CC-CV charging (upper limit cell voltage 3.6V) was performed with a constant current of 0.2C, and CC discharge was performed to a cell voltage of 2.6V with a constant current of 0.2C. This charging and discharging at 0.2C was repeated three times. The discharge capacity of the third discharge at 0.2C was defined as the initial capacity CX. Subsequently, CC-CV charging was performed at a constant current of 0.2C (maximum cell voltage 3.6V), and CC discharge was performed at a constant current of 2.0C until the cell voltage reached 2.6V. The discharge capacity at this time was defined as CY. The 2.0C / 0.2C discharge capacity retention rate, expressed as (CY / CX) × 100 (%), was calculated. Note that a higher discharge capacity retention rate indicates better output characteristics of the lithium-ion secondary battery.

[0167] <Cycle Characteristics> The lithium-ion secondary batteries prepared in the examples and comparative examples were left standing at 25°C for 5 hours after electrolyte injection. Next, they were charged to a State of Charge (SOC) of 20% using a constant current method at 0.1C at 25°C, and then aged for 12 hours at 60°C. Then, they were discharged to a cell voltage of 2.6V using a constant current method at 0.2C at 25°C. After that, CC-CV charging (upper limit cell voltage 3.6V) was performed with a constant current of 0.2C, and CC discharge was performed to a cell voltage of 2.6V with a constant current of 0.2C. This charging and discharging at 0.2C was repeated three times. After that, under conditions of 45°C, the charging and discharging operation was performed 100 times with a cell voltage of 3.60-2.60V, a constant current of 0.2C, CC-CV charging (upper limit cell voltage 3.6V), and a discharge rate of 1.0C. In this process, the discharge capacity of the first cycle was defined as X1, and the discharge capacity of the 100th cycle was defined as X2. Using the discharge capacities X1 and X2, the capacity retention rate, expressed as ΔC = (X2 / X1) × 100 (%), was calculated. A larger value of this capacity retention rate ΔC indicates that the lithium-ion secondary battery has superior cycle characteristics.

[0168] (Example 1) <Preparation of Polymer X (Binder Composition)> In a reactor, 200 parts of deionized water, 8.5 parts of a 30% aqueous solution of sodium dodecyldiphenyl ethersulfonate, 10.0 parts of 2-hydroxyethyl methacrylate, 25.0 parts of 4-hydroxybutyl acrylate, 24.0 parts of methacrylic acid, 1.0 part of butyl acrylate, and 2.5 parts of t-dodecyl mercaptan as a molecular weight modifier (chain transfer agent) were charged in order. Next, the gas inside was replaced with nitrogen three times, and then 40.0 parts of 1,3-butadiene was charged. The reactor was kept at 18°C, and 0.3 parts of cumene hydroperoxide as a polymerization initiator, appropriate amounts of a reducing agent and a chelating agent were charged. The polymerization reaction was continued while stirring, and when the polymerization conversion rate reached 85%, 0.1 parts of a 10% aqueous hydroquinone solution as a polymerization termination agent was added to stop the polymerization reaction. Next, residual monomers were removed using an evaporator at a water temperature of 80°C to obtain an aqueous dispersion of the polymer precursor. Then, the dispersion was concentrated using an evaporator until the solid content concentration reached 40%. Next, an 8.0% NaOH aqueous solution and deionized water were added to the concentrated aqueous dispersion of the polymer to adjust the pH to 8.5 and the solid content concentration to 8% to obtain polymer X. Polymer X was a water-soluble polymer according to the definition described herein. The weight-average molecular weight and molecular weight distribution of the obtained polymer X were obtained according to the above procedure. The results are shown in Table 1.

[0169] <Preparation of Particulate Polymer Y> Particulate polymer Y (hydrophilic group-containing acrylic polymer) was prepared as a binder according to the following procedure. 90 parts of deionized water and 0.5 parts of sodium lauryl sulfate as an emulsifier were added to a 1 L flask with a septum equipped with a stirrer (reaction vessel). The gas phase was replaced with nitrogen gas, and the temperature was raised to 60°C. Then, 0.3 parts of ammonium persulfate (APS) was dissolved in 20.0 parts of deionized water and added as a polymerization initiator. Meanwhile, in a separate container (emulsion container), 30 parts of deionized water, 0.5 parts of sodium lauryl sulfate as an emulsifier, 78.0 parts of butyl acrylate as a (meth)acrylic acid ester monomer, 2.5 parts of itaconic acid and 1.0 part of 2-hydroxyethyl acrylate as hydrophilic group-containing monomers, and 18.5 parts of styrene as an aromatic vinyl monomer were mixed to obtain a monomer composition. This monomer composition was continuously added to a 1 L flask with a septum over 3 hours to carry out polymerization. The reaction was carried out at 60°C during the addition. After the addition was complete, the mixture was stirred at 80°C for 2 hours to obtain an aqueous dispersion of particulate polymer Y. To the aqueous dispersion of particulate polymer Y thus obtained, an 8% sodium hydroxide aqueous solution was added to adjust the pH to 8 to obtain an aqueous dispersion of particulate polymer Y. The obtained particulate polymer Y was water-insoluble according to the definition herein. The median diameter of particulate polymer Y was measured according to the above and was found to be 135 nm.

[0170] <Preparation of slurry composition for positive electrode> Lithium iron phosphate (LiFePO) olivine type as positive electrode active material ４96.5 parts of polymer Y (median diameter: 1 μm) and 1.5 parts of acetylene black as a conductive material were mixed in a planetary mixer (15 rpm, 15 minutes). Then, 1.0 part (equivalent to solid content) of an aqueous solution of polymer X as a binder composition and deionized water were added to adjust the solid content concentration to 78%, and the mixture was mixed in a planetary mixer (60 rpm, 50 minutes). Next, water was added to adjust the viscosity of the slurry composition to be in the range of 3000 mPa·s to 4000 mPa·s. Next, 1.0 part (equivalent to solid content) of an aqueous dispersion of particulate polymer Y was added and mixed in a planetary mixer (40 rpm, 10 minutes) to prepare the slurry composition for the positive electrode. Finally, water was added to adjust the viscosity of the slurry composition to be in the range of 1000 mPa·s to 2000 mPa·s. The viscosity stability of the obtained cathode slurry composition was evaluated according to the above. The results are shown in Table 1. During the preparation of the cathode slurry composition, the viscosity of the obtained cathode slurry composition was measured using a single-cylinder rotational viscometer (Brookfield B-type viscometer) in accordance with JIS Z8803:1991. The measurement conditions were a temperature of 25°C and a rotational speed of 60 rpm.

[0171] <Preparation of Current Collector with Conductive Adhesive Layer> A current collector with a conductive adhesive layer prepared by the following method was used as the current collector for the manufacture of the positive electrode. 70 parts of conductive carbon (graphite / acetylene black = 70 / 30 (mass ratio)) and 8 parts of carboxymethylcellulose (Daicel 1220, manufactured by Daicel Corporation) as a dispersant were added, and the mixture was stirred at 3000 rpm for 60 minutes using a disperser. Then, 22 parts of an aqueous dispersion of particulate polymer equivalent to the solid content were added, and the mixture was further stirred at 1500 rpm for 10 minutes using a disperser to prepare a conductive adhesive. The conductive adhesive was applied to aluminum foil, which was to be used as the substrate for the current collector, using a casting method with a roll bar at a molding speed of 20 m / min, and dried at 80°C to form a conductive adhesive layer with a thickness of 1 μm. This obtained a current collector with a conductive adhesive layer formed on the substrate for the current collector.

[0172] <Preparation of positive electrode for lithium-ion secondary battery> The positive electrode slurry composition obtained as described above is applied to the conductive adhesive layer side of the current collector with a conductive adhesive layer, and the basis weight after drying is 25 mg / cm² using a comma coater. 2 The material was applied to obtain a cathode base by drying at 90°C for 20 minutes, then at 120°C for another 20 minutes, and finally at 60°C for 10 hours. This cathode base was rolled using a roll press to obtain a density of 2.5 g / cm³. 3 A sheet-like positive electrode was fabricated consisting of a positive electrode composite layer, a conductive adhesive layer, and aluminum foil. The sheet-like positive electrode was then cut to a width of 48.0 mm and a length of 47 cm to be used as a positive electrode for a lithium-ion secondary battery. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was found to be good.

[0173] <Preparation of anode for lithium-ion secondary battery> In a 5 MPa pressure vessel equipped with a stirrer, 65.0 parts of styrene as an aromatic vinyl monomer, 35.0 parts of 1,3-butadiene as an aliphatic conjugated diene monomer, 2.0 parts of itaconic acid and 1.0 part of 2-hydroxyethyl acrylate as hydrophilic group-containing monomers, 0.3 parts of t-dodecyl mercaptan as a molecular weight modifier, 5 parts of sodium dodecylbenzenesulfonate as an emulsifier, 150 parts of deionized water as a solvent, and 1 part of potassium persulfate as a polymerization initiator were added and thoroughly stirred. Polymerization was started by heating to 55°C. When the monomer consumption reached 95.0%, the mixture was cooled and the reaction was stopped. A 5% sodium hydroxide aqueous solution was added to the aqueous dispersion containing the polymer obtained in this way to adjust the pH to 8. Unreacted monomers were then removed by heated vacuum distillation. After that, the mixture was cooled to below 30°C to obtain an aqueous dispersion of particulate polymer to be used as a binder for the anode. In a planetary mixer, 48.75 parts of artificial graphite and 48.75 parts of natural graphite as negative electrode active materials, and 1 part of carboxymethylcellulose (equivalent to solid content) as a thickener were added. Furthermore, the mixture was diluted with deionized water to a solid content concentration of 60%, and then kneaded at a rotation speed of 45 rpm for 60 minutes. Next, 1.5 parts (equivalent to solid content) of the aqueous dispersion of particulate polymer as a negative electrode binder, obtained as described above, was added, and the mixture was kneaded at a rotation speed of 40 rpm for 40 minutes. Finally, deionized water was added to achieve a viscosity of 3000 ± 500 mPa·s (measured with a B-type viscometer at 25°C and 60 rpm) to prepare the negative electrode slurry composition. The above negative electrode slurry composition was then coated onto the surface of a 15 μm thick copper foil current collector using a comma coater at a rate of 12.5 ± 0.5 mg / cm². ２ The material was applied in this manner. Subsequently, the copper foil coated with the negative electrode slurry composition was transported at a speed of 400 mm / min in an oven at 80°C for 2 minutes, and then in an oven at 110°C for another 2 minutes, thereby drying the negative electrode slurry composition on the copper foil and obtaining a negative electrode base roll with a negative electrode composite layer formed on the current collector. This negative electrode base roll was rolled in a roll press to obtain a density of 1.6 g / cm³. 3A sheet-like negative electrode was fabricated consisting of a negative electrode composite layer and copper foil. The sheet-like negative electrode was then cut to a width of 50.0 mm and a length of 52 cm to be used as a negative electrode for a lithium-ion secondary battery.

[0174] <Fabrication of Lithium-ion Secondary Battery> The fabricated positive electrode and negative electrode for the lithium-ion secondary battery were placed with their electrode composite layers facing each other, and a 15 μm thick separator (microporous polyethylene membrane) was interposed between them. The materials were then wound around a 20 mm diameter core to obtain a wound body. The resulting wound body was then compressed from one direction at a speed of 10 mm / second until its thickness reached 4.5 mm. The compressed wound body was elliptical in plan view, and its ratio of major axis to minor axis (major axis / minor axis) was 7.7. A 1.0 M LiPF 4 solution was used as the electrolyte. ６ A solution (solvent: mixed solvent of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) = 3 / 7 (volume ratio), additive: containing 2 vol% vinylene carbonate (solvent ratio)) was prepared. Then, the compressed coil was placed in an aluminum laminate case along with 3.2 g of electrolyte. Nickel lead wires were connected to the designated locations on the negative electrode for the secondary battery, and aluminum lead wires were connected to the designated locations on the positive electrode for the lithium-ion secondary battery. The opening of the case was then sealed with heat to obtain a lithium-ion secondary battery. This lithium-ion secondary battery was a pouch type with a width of 35 mm, a height of 60 mm, and a thickness of 5 mm, and the nominal capacity of the battery was 700 mAh. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0175] (Example 2) The same operations, measurements, and evaluations as in Example 1 were performed, except that the particulate polymer Y was prepared as described below. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0176] <Preparation of Particulate Polymer Y> Particulate polymer Y (hydrophilic group-containing conjugated diene polymer) was prepared as a binder according to the following procedure. In a 5 MPa pressure vessel equipped with a stirrer, 63.0 parts of styrene as an aromatic vinyl monomer, 34.0 parts of 1,3-butadiene as an aliphatic conjugated diene monomer, 2.0 parts of itaconic acid and 1.0 part of 2-hydroxyethyl acrylate as hydrophilic group-containing monomers were added, 0.3 parts of t-dodecyl mercaptan as a molecular weight adjuster, 5 parts of sodium dodecylbenzenesulfonate as an emulsifier, 150 parts of ion-exchanged water as a solvent, and 1 part of potassium persulfate as a polymerization initiator were added, and after thorough stirring, polymerization was started by heating to 55°C. When the monomer consumption reached 95.0%, the mixture was cooled and the reaction was stopped. To the aqueous dispersion containing the polymer thus obtained, a 5% sodium hydroxide aqueous solution was added to adjust the pH to 8. Subsequently, unreacted monomers were removed by heated vacuum distillation. Furthermore, the mixture was cooled to below 30°C to obtain an aqueous dispersion of the particulate polymer. The obtained particulate polymer Y was water-insoluble according to the definition herein. The median diameter of the particulate polymer Y was measured according to the above procedure and was found to be 150 nm.

[0177] (Example 3) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 4-hydroxybutyl acrylate was changed from 25.0 parts to 27.0 parts, 1,3-butadiene was changed from 40.0 parts to 34.0 parts, methacrylic acid was changed from 24.0 parts to 25.0 parts, and butyl acrylate was changed from 1.0 part to 4.0 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0178] (Example 4) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 7.0 parts, 4-hydroxybutyl acrylate was changed from 25.0 parts to 23.0 parts, 1,3-butadiene was changed from 40.0 parts to 47.0 parts, methacrylic acid was changed from 24.0 parts to 22.5 parts, and butyl acrylate was changed from 1.0 part to 0.5 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained positive electrode for lithium-ion secondary batteries, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0179] (Example 5) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 6.0 parts, 4-hydroxybutyl acrylate was changed from 25.0 parts to 22.5 parts, 1,3-butadiene was changed from 40.0 parts to 44.0 parts, methacrylic acid was changed from 24.0 parts to 25.0 parts, and butyl acrylate was changed from 1.0 part to 2.5 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were evaluated, and the cycle characteristics were good.

[0180] (Example 6) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 13.0 parts, 4-hydroxybutyl acrylate was changed from 25.0 parts to 27.0 parts, 1,3-butadiene was changed from 40.0 parts to 35.0 parts, methacrylic acid was changed from 24.0 parts to 22.5 parts, and butyl acrylate was changed from 1.0 part to 2.5 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were evaluated, and the cycle characteristics were good.

[0181] (Example 7) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 17.0 parts and the amount of 4-hydroxybutyl acrylate was changed from 25.0 parts to 18.0 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0182] (Example 8) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 3.0 parts and the amount of 4-hydroxybutyl acrylate was changed from 25.0 parts to 32.0 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0183] (Example 9) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that 10.0 parts of 2-hydroxyethyl methacrylate was replaced with 10.0 parts of 2-hydroxyethyl acrylate, the amount of methacrylic acid was changed from 24.0 parts to 23.0 parts, and the amount of butyl acrylate was changed from 1.0 part to 2.0 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0184] (Example 10) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that 10.0 parts of 2-hydroxyethyl methacrylate was replaced with 9.0 parts of 2-hydroxyethyl acrylate, 25.0 parts of 4-hydroxybutyl acrylate was replaced with 21.0 parts of 4-(hydroxymethyl)cyclohexylmethyl acrylate, and the amount of methacrylic acid was changed from 24.0 parts to 29.0 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0185] (Example 11) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that 10.0 parts of 2-hydroxyethyl methacrylate was replaced with 10.0 parts of 2-hydroxypropyl methacrylate. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0186] (Example 12) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that 25.0 parts of 4-hydroxybutyl acrylate were replaced with 25.0 parts of 2-hydroxybutyl acrylate. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0187] (Example 13) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 1.0 part, the amount of 4-hydroxybutyl acrylate was changed from 25.0 parts to 28.0 parts, the amount of methacrylic acid was changed from 24.0 parts to 22.0 parts, and the amount of butyl acrylate was changed from 1.0 part to 9.0 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0188] (Example 14) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 22.0 parts, 4-hydroxybutyl acrylate was changed from 25.0 parts to 13.0 parts, methacrylic acid was changed from 24.0 parts to 22.0 parts, and butyl acrylate was changed from 1.0 part to 3.0 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0189] (Example 15) The same operations, measurements, and evaluations as in Example 1 were performed, except that polymer X was prepared as described below. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0190] <Preparation of Polymer X> First, an aqueous dispersion of the polymer precursor was obtained in the same manner as in Example 1. Then, the aqueous dispersion of the polymer precursor and a palladium catalyst (a solution of 1% palladium acetate acetone solution mixed with an equal weight of ion-exchanged water) were added to an autoclave so that the palladium content relative to the weight of solids contained in the obtained aqueous dispersion of the polymer precursor was 3,000 ppm. A hydrogenation reaction was carried out at a hydrogen pressure of 3 MPa and a temperature of 55°C for 3 hours to obtain the aqueous dispersion of the target polymer X. After that, the contents were returned to room temperature, the system was subjected to a nitrogen atmosphere, and the dispersion was concentrated using an evaporator until the solid content concentration reached 40%. Next, an 8.0% NaOH aqueous solution and ion-exchanged water were added to the concentrated aqueous dispersion of polymer X to adjust the pH to 8.5 and the solid content concentration to 8% to obtain polymer X. Polymer X contains units in which almost all monomer units derived from 1,3-butadiene have been hydrogenated, and therefore contains 1,3-butadiene hydride units as alkylene structural units. Furthermore, polymer X was a water-soluble polymer according to the definition described herein. The weight-average molecular weight and molecular weight distribution of the obtained polymer X were obtained according to the above procedure. The results are shown in Table 1.

[0191] (Example 16) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of t-dodecyl mercaptan was changed from 2.5 parts to 1.5 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were also evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0192] (Example 17) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of t-dodecyl mercaptan was changed from 2.5 parts to 3.5 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0193] (Example 18) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of t-dodecyl mercaptan was changed from 2.5 parts to 0.6 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were also evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0194] (Example 19) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of t-dodecyl mercaptan was changed from 2.5 parts to 5 parts. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were also evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0195] (Example 20) In preparing the slurry composition for the positive electrode, a CNT dispersion was prepared as described below, and then this CNT dispersion was used to prepare the slurry composition for the positive electrode. Otherwise, the same operations, measurements, and evaluations as in Example 1 were performed. The results are shown in Table 1. The adhesion of the positive electrode composite layer to the current collector was evaluated using the obtained lithium-ion secondary battery positive electrode, and the adhesion was good. The output characteristics of the obtained lithium-ion secondary battery were evaluated, and the output characteristics were good. The cycle characteristics of the obtained lithium-ion secondary battery were also evaluated, and the cycle characteristics were good.

[0196] <Preparation of CNT dispersion> Carbon nanotubes as conductive material (BET specific surface area: 250 m²) 2 A CNT dispersion with a solid content of 1% by mass was prepared by stirring 0.4 parts ( / g) of carboxymethylcellulose (Daicel 1220, manufactured by Daicel Corporation) and 99 parts of deionized water using a disperser (3000 rpm, 10 minutes), and then mixing for 1 hour at a peripheral speed of 8 m / s using a bead mill with 1 mm diameter zirconia beads.

[0197] <Preparation of slurry composition for positive electrode> Lithium iron phosphate (LiFePO) olivine type as positive electrode active material ４96.5 parts of polymer Y (median diameter: 1 μm) and 1.5 parts of acetylene black as a conductive material were mixed in a planetary mixer (15 rpm, 15 minutes). Then, 1.0 part (equivalent to solid content) of an aqueous solution of polymer X as a binder composition and deionized water were added to adjust the solid content concentration to 78%, and the mixture was mixed in a planetary mixer (60 rpm, 50 minutes). Next, a CNT dispersion was added so that the amount of carbon nanotubes added was 0.1 parts, and the mixture was mixed in a planetary mixer (60 rpm, 10 minutes). Next, water was added to adjust the viscosity of the slurry composition so that it was in the range of 3000 mPa·s to 4000 mPa·s. Next, 1.0 part (equivalent to solid content) of an aqueous dispersion of particulate polymer Y was added, and the mixture was mixed in a planetary mixer (40 rpm, 10 minutes) to prepare the slurry composition for the positive electrode. Finally, water was added to adjust the viscosity of the slurry composition to a range of 1000 mPa·s to 2000 mPa·s. The viscosity stability of the obtained cathode slurry composition was evaluated. The results are shown in Table 1. During the preparation of the cathode slurry composition, the viscosity of the obtained cathode slurry composition was measured using a single-cylinder rotational viscometer (Brookfield B-type viscometer) in accordance with JIS Z8803:1991. The measurement conditions were a temperature of 25°C and a rotational speed of 60 rpm.

[0198] (Comparative Example 1) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 11.0 parts, 4-hydroxybutyl acrylate was changed from 25.0 parts to 24.0 parts, 1,3-butadiene was changed from 40.0 parts to 28.0 parts, methacrylic acid was changed from 24.0 parts to 30.0 parts, and butyl acrylate was changed from 1.0 part to 7.0 parts. The results are shown in Table 1.

[0199] (Comparative Example 2) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 9.0 parts, 4-hydroxybutyl acrylate was changed from 25.0 parts to 18.0 parts, 1,3-butadiene was changed from 40.0 parts to 56.5 parts, methacrylic acid was changed from 24.0 parts to 16.0 parts, and butyl acrylate was changed from 1.0 part to 0.5 parts. The results are shown in Table 1.

[0200] (Comparative Example 3) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 4.0 parts, 4-hydroxybutyl acrylate was changed from 25.0 parts to 21.0 parts, 1,3-butadiene was changed from 40.0 parts to 45.0 parts, methacrylic acid was changed from 24.0 parts to 27.0 parts, and butyl acrylate was changed from 1.0 part to 3.0 parts. The results are shown in Table 1.

[0201] (Comparative Example 4) In the preparation of polymer X (binder composition), the same operations, measurements, and evaluations as in Example 1 were performed, except that the amount of 2-hydroxyethyl methacrylate was changed from 10.0 parts to 12.0 parts, 4-hydroxybutyl acrylate was changed from 25.0 parts to 30.0 parts, 1,3-butadiene was changed from 40.0 parts to 35.0 parts, and methacrylic acid was changed from 24.0 parts to 22.0 parts. The results are shown in Table 1.

[0202] In the table below, "2-3 carbon atoms" refers to hydroxyl group-containing (meth)acrylic acid ester monomer unit A, in which a hydroxyl group-containing hydrocarbon group with 2-3 carbon atoms is bonded to a non-carbonyl oxygen atom; "4 or more carbon atoms" refers to hydroxyl group-containing (meth)acrylic acid ester monomer unit B, in which a hydroxyl group-containing hydrocarbon group with 4 or more carbon atoms is bonded to a non-carbonyl oxygen atom; "2HEMA" refers to 2-hydroxyethyl methacrylate unit; "2HEA" refers to 2-hydroxyethyl acrylate unit; "2HPMA" refers to 2-hydroxypropyl methacrylate unit; "4HBA" refers to 4-hydroxybutyl acrylate unit; "CHDMMA" refers to 4-(hydroxymethyl)cyclohexylmethyl acrylate unit; "2HBA" refers to 2-hydroxybutyl acrylate unit; and "BD" refers to 1,3-butadiene unit. "H-BD" represents a 1,3-butadiene hydride unit, "MAA" represents a methacrylic acid unit, "BA" represents a butyl acrylate unit, "LFP" represents olivine-type lithium iron phosphate, "ACR" represents a hydrophilic group-containing acrylic polymer, "SBR" represents a hydrophilic group-containing conjugated diene polymer, "AcB" represents acetylene black, and "CNT" represents carbon nanotube.

[0203]

[0204] As is clear from Table 1, the binder composition of the example can be used to improve the viscosity stability of the slurry composition.

[0205]

[0206] As is clear from Table 2, it can be seen that the viscosity stability of the slurry composition can be effectively improved by keeping the proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units in polymer X within a predetermined range.

[0207]

[0208] As is clear from Table 3, it can be seen that the viscosity stability of the slurry composition can be effectively improved by keeping the total proportion of conjugated diene monomer units and alkylene structural units in polymer X within a predetermined range.

[0209]

[0210] As is clear from Table 4, by setting the proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units A, in which hydroxyl group-containing hydrocarbon groups having 2 to 3 carbon atoms in polymer X are bonded to non-carbonyl oxygen atoms, within a predetermined range, and setting the proportion of hydroxyl group-containing (meth)acrylic acid ester monomer units B, in which hydroxyl group-containing hydrocarbon groups having 4 or more carbon atoms in polymer X are bonded to non-carbonyl oxygen atoms, within a predetermined range, it can be seen that the viscosity stability of the slurry composition can be effectively improved.

[0211]

[0212] As is clear from Table 5, the viscosity stability of the slurry composition can be improved regardless of whether polymer X contains a hydroxyl group-containing (meth)acrylic acid ester monomer unit A in which any of the hydroxyl group-containing hydrocarbon groups having 2 to 3 carbon atoms is bonded to a non-carbonyl oxygen atom.

[0213]

[0214] As is clear from Table 6, the viscosity stability of the slurry composition can be improved even when polymer X contains any hydroxyl group-containing (meth)acrylic acid ester monomer unit B in which a hydroxyl group-containing hydrocarbon group having 4 or more carbon atoms is bonded to a non-carbonyl oxygen atom.

[0215]

[0216] As is clear from Table 7, the viscosity stability of the slurry composition can be effectively improved by keeping the weight-average molecular weight of polymer X within a predetermined range.

[0217] The present invention provides a binder composition for non-aqueous secondary battery electrodes that can improve the viscosity stability of the slurry composition. Furthermore, the present invention provides a slurry composition for non-aqueous secondary battery electrodes that exhibits excellent viscosity stability. Furthermore, the present invention provides an electrode for a non-aqueous secondary battery comprising an electrode composite layer formed using the above-mentioned slurry composition for non-aqueous secondary battery electrodes. Furthermore, the present invention provides a non-aqueous secondary battery comprising the above-mentioned electrode for non-aqueous secondary battery.

Claims

1. A binder composition for non-aqueous secondary battery electrodes comprising polymer X and water, wherein polymer X is water-soluble and contains conjugated diene monomer units and / or alkylene structural units and hydroxyl group-containing (meth)acrylic acid ester monomer units, the total proportion of the conjugated diene monomer units and the alkylene structural units in polymer X is 30.0% by mass or more and 55.0% by mass or less, and the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer units in polymer X is 27.0% by mass or more and 40.0% by mass or less.

2. The binder composition for non-aqueous secondary battery electrodes according to claim 1, wherein the hydroxyl group-containing (meth)acrylic acid ester monomer unit comprises a hydroxyl group-containing hydrocarbon unit A having 2 to 3 carbon atoms bonded to a non-carbonyl oxygen atom, and a hydroxyl group-containing (meth)acrylic acid ester monomer unit B having 4 or more carbon atoms bonded to a non-carbonyl oxygen atom, wherein the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer unit A in the polymer X is 2.0% by mass or more and 20.0% by mass or less, and the proportion of the hydroxyl group-containing (meth)acrylic acid ester monomer unit B in the polymer X is 15.0% by mass or more and 35.0% by mass or less.

3. The binder composition for non-aqueous secondary battery electrodes according to claim 1 or 2, wherein the polymer X further contains an acidic group-containing monomer unit.

4. The binder composition for non-aqueous secondary battery electrodes according to any one of claims 1 to 3, wherein the polymer X further contains hydroxyl group-free (meth)acrylic acid ester monomer units.

5. A binder composition for non-aqueous secondary battery electrodes according to any one of claims 1 to 4, wherein the weight-average molecular weight of the polymer X is 10,000 or more and 100,000 or less.

6. A slurry composition for a non-aqueous secondary battery electrode, comprising an electrode active material and a binder composition for a non-aqueous secondary battery electrode according to any one of claims 1 to 5.

7. The slurry composition for non-aqueous secondary battery electrodes according to claim 6, further comprising a particulate polymer Y containing a hydrophilic group.

8. The non-aqueous secondary battery electrode slurry composition according to claim 7, wherein the content of the particulate polymer Y is 0.1% by mass or more and 5.0% by mass or less, when the total solid content contained in the non-aqueous secondary battery electrode slurry composition is taken as 100% by mass.

9. The slurry composition for non-aqueous secondary battery electrodes according to any one of claims 6 to 8, wherein the electrode active material contains a lithium-containing composite metal oxide having an olivine-type structure.

10. A slurry composition for non-aqueous secondary battery electrodes according to any one of claims 6 to 9, further comprising a conductive material containing at least one of particulate conductive material and carbon nanotubes.

11. An electrode for a non-aqueous secondary battery comprising an electrode composite layer formed using the slurry composition for non-aqueous secondary battery electrodes described in any one of claims 6 to 10.

12. A non-aqueous secondary battery comprising an electrode for a non-aqueous secondary battery as described in claim 11.

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