KR-20260062962-A - Binder composition for capacitor devices, slurry for capacitor device electrodes, capacitor device electrodes, and capacitor devices

Abstract

The present invention provides a binder composition for a capacitor device that can produce capacitor device electrodes with excellent surface condition, adhesion, and ion conductivity, and can also improve the cycle life characteristics of the capacitor device. A binder composition for a capacitor device according to the present invention comprises a polymer (A), a nonionic surfactant (B), and a liquid medium (C), wherein, when the total number of repeating units included in the polymer (A) is 100 mass%, the polymer (A) contains 1 to 50 mass% of repeating units (a1) derived from an α,β-unsaturated nitrile compound and 40 to 80 mass% of repeating units (a2) derived from an unsaturated carboxylic acid ester, the content ratio of the nonionic surfactant (B) is 0.1 to 10 mass parts per 100 mass parts of the polymer (A), and the liquid medium (C) is selected from the group consisting of aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ketones, esters, ethers, glycol ethers, lactams, lactones, and amides. There is at least one type.

Inventors

• 나카야마, 다쿠야
• 미야베, 도시타카
• 오타, 준야
• 마스다, 가나
• 모리, 가즈마사

Assignees

• 가부시키가이샤 에네오스 마테리아루

Dates

Publication Date

20260507

Application Date

20240828

Priority Date

20230901

Claims (11)

1. Containing a polymer (A), a nonionic surfactant (B), and a liquid medium (C), When the total sum of the repeating units included in the above polymer (A) is set to 100 mass%, the above polymer (A) 1 to 50 mass% of repeating units (a1) derived from an α,β-unsaturated nitrile compound, and Repeating unit (a2) derived from an unsaturated carboxylic acid ester, 40 to 80 mass% Contains, The content ratio of the above nonionic surfactant (B) is 0.1 to 10 parts by mass per 100 parts by mass of the polymer (A), and A binder composition for a capacitor device, wherein the above liquid medium (C) is at least one selected from the group consisting of aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ketones, esters, ethers, glycol ethers, lactams, lactones, and amides.
2. In claim 1, the polymer (A) is a polymer particle, and A binder composition for a capacitor device, wherein the number average particle size of the polymer particles is 50 nm or more and 1,000 nm or less.
3. A binder composition for a capacitor device according to claim 1 or 2, wherein the polymer (A) further contains 0.1 to 10 mass% of repeating units (a3) derived from an unsaturated carboxylic acid.
4. A binder composition for a capacitor device according to claim 1 or 2, wherein the polymer (A) further contains 0.1 to 10 mass% of repeating units (a6) derived from (meth)acrylamide.
5. A binder composition for a capacitor device according to claim 1 or 2, wherein the polymer (A) further contains 0.1 to 10 mass% of repeating units (a7) derived from a compound having a sulfonic acid group.
6. A binder composition for a capacitor device described in claim 1 or 2, and a slurry for a capacitor device electrode containing an active material.
7. A slurry for an electrode of a capacitor device, further containing a thickening agent in claim 6.
8. A slurry for an electrode of a capacitor device according to claim 6, wherein the active material is a positive electrode active material.
9. A slurry for an electrode of a capacitor device according to claim 8, wherein the positive electrode active material contains at least one selected from the group consisting of lithium cobaltate, lithium nickelate, lithium manganate, ternary nickel-cobalt-manganate, and olivine-type lithium-containing phosphate compounds.
10. A capacitor electrode comprising a current collector and an active material layer formed by applying and drying a slurry for a capacitor electrode described in claim 6 on the surface of the current collector.
11. A capacitor device having the capacitor device electrode described in paragraph 10.

Description

Binder composition for capacitor devices, slurry for capacitor device electrodes, capacitor device electrodes, and capacitor devices The present invention relates to a binder composition for a capacitor device, a slurry for a capacitor device electrode, a capacitor device electrode, and a capacitor device. In recent years, there has been a demand for energy storage devices with high voltage and high energy density as power sources for driving electronic devices. Lithium-ion batteries and lithium-ion capacitors are expected to serve as such storage devices. The electrode used in such a capacitor device is manufactured by applying and drying a composition (slurry for capacitor device electrodes) containing an active material and a polymer that functions as a binder onto the surface of a current collector. The characteristics required for the polymer used as a binder include the ability to bond between active materials and the ability to adhere between the active material and the current collector. Additionally, when cutting the coated and dried composition film (hereinafter also referred to as the "active material layer"), characteristics such as powder drop resistance, which prevents fine particles of the active material from falling off from the active material layer, may be required. By allowing such a binder material to exhibit good adhesion and thereby reducing the internal resistance of the battery caused by the binder material, good charge and discharge characteristics can be imparted to the capacitor device. Furthermore, it has been empirically established that the bonding ability between the active materials, the adhesion ability between the active material and the current collector, and the resistance to powder drop are in a nearly proportional relationship. Therefore, in this specification, the term "adhesion" may be used to encompass these aspects. Recently, in order to fabricate electrochemical devices with excellent capacity and charge/discharge cycle characteristics, the use of positive electrode active materials with high reactivity with water is being considered. Furthermore, polyvinylidene fluoride (PVdF) is the most widely used binder for electrodes of organic solvent-based capacitor devices. Although PVdF possesses good binding properties and oxidation resistance, it has a high environmental burden due to the presence of fluorine atoms, and the instability of raw material supply is also becoming a reality (see, for example, Patent Document 1). Against this backdrop, various binder materials have been proposed to solve various problems of positive electrode slurries (see, for example, Patent Documents 1 and 2). Suitable embodiments of the present invention will be described in detail below. Furthermore, it should be understood that the present invention is not limited to the embodiments described below, but includes various modifications implemented within the scope that do not alter the essence of the invention. In this specification, “(meth)acrylic acid~” represents “acrylic acid~” or “methacrylic acid~”, “~(meth)acrylate” represents “~acrylate” or “~methacrylate”, and “(meth)acrylamide” represents “acrylamide” or “methacrylamide”. In this specification, a numerical range described as “X to Y” is interpreted as including the numerical value X as a lower limit and also including the numerical value Y as an upper limit. 1. Binder composition for capacitor devices A binder composition for a capacitor device according to one embodiment of the present invention comprises a polymer (A), a nonionic surfactant (B), and a liquid medium (C). The polymer (A) contains 1 to 50 mass% of repeating units (a1) derived from an α,β-unsaturated nitrile compound and 40 to 80 mass% of repeating units (a2) derived from an unsaturated carboxylic acid ester, when the total number of repeating units contained in the polymer (A) is 100 mass%. Additionally, the content ratio of the nonionic surfactant (B) is 0.1 to 10 mass parts per 100 mass parts of the polymer (A). In addition, the liquid medium (C) is at least one selected from the group consisting of aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ketones, esters, ethers, glycol ethers, lactams, lactones, and amides. Hereinafter, the components included in the binder composition for a capacitor device according to the present embodiment will be described in detail. 1.1. Polymer (A) The binder composition for a capacitor device according to the present embodiment contains a polymer (A). It is preferable that the polymer (A) be dispersed in a particulate form in a liquid medium (C) described below. It is desirable that the polymer (A) be dispersed in a particulate form in the liquid medium (C) so that the stability of the composition (hereinafter also referred to as "slurry") produced by mixing with the active material is improved, and the coating properties of the slurry on the current collector are improved. In addition, the presence of a