Composition for electricity storage devices, slurry for electricity storage device electrodes, electricity storage device electrode, and electricity storage device

Abstract

The present invention provides a composition for electricity storage devices, which is excellent in terms of flexibility, rubbing resistance and particle fall-off, and which is capable of producing anelectricity storage device electrode that exhibits good charge and discharge durability characteristics. A composition for electricity storage devices according to the present invention contains a polymer (A) and a liquid medium (B); and the polymer (A) contains 20-70 parts by mass of a repeating unit (a1) that is derived from a conjugated diene compound and 10-50 parts by mass of a repeating unit (a2) that is derived from an unsaturated carboxylic acid if the total of repeating units contained in the polymer (A) is taken as 100 parts by mass. With respect to the integral molecular weight distribution curve of the polymer (A) as determined by size exclusion chromatography (SEC) in accordance with JIS K7252, a copolymer fraction having a molecular weight of 1,000,000 or less is contained in an amount of 30% by mass or more relative to all copolymers.

Description

technical field [0001] The present invention relates to a composition for an electrical storage device, a slurry for an electrical storage device electrode containing the composition and an active material, an electrode for an electrical storage device formed by applying the slurry to a current collector and drying the electrode, and an electrode provided with the electrode power storage equipment. Background technique [0002] In recent years, power storage devices with high voltage and high energy density have been required as power sources for driving electronic devices. As such power storage devices, lithium ion batteries, lithium ion capacitors, and the like have been expected. [0003] An electrode used in such an electrical storage device is produced by applying a composition (slurry for electrode) containing an active material and a polymer functioning as a binder on the surface of a current collector and drying it. The properties required for polymers used as bind...

AI Technical Summary

Problems solved by technology

[0006] However, the active material using such a material with a large lithium storage capacity is accompanied by a large volume change due to the storage and release of lithium.

Therefore, if the conventionally used electrode binder is applied to such a material with a large lithium storage capacity, the volume change accompanying charge and discharge will not be tolerated, the structure of the active material layer will be destroyed, and the charge and discharge durability characteristics will be significantly deteriorated.

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