KR-20260064557-A - NONAQUEOUS ELECTROLYTE SECONDARY BATTERY LAMINATED SEPARATOR AND USE THEREOF

KR20260064557AKR 20260064557 AKR20260064557 AKR 20260064557AKR-20260064557-A

Abstract

The present invention provides a laminated separator for a non-aqueous electrolyte secondary battery having excellent stability of high-rate characteristics when pressurized. The laminated separator for a non-aqueous electrolyte secondary battery of the present disclosure comprises a polyolefin porous film and a porous layer provided on one or both sides of the polyolefin porous film. The laminated separator for a non-aqueous electrolyte secondary battery further comprises a particle layer on at least one side. The laminated separator for a non-aqueous electrolyte secondary battery satisfies the condition that the coefficient of variation of the compression amount at 5 MPa compression ÷ the coefficient of variation of the compression amount at 1 MPa compression ≤ 0.9.

Inventors

야마시타, 마스미
이시이, 다이가
마츠미네, 리쿠

Assignees

스미또모 가가꾸 가부시키가이샤

Dates

Publication Date: 20260507
Application Date: 20251024
Priority Date: 20241031

Claims (6)

A laminated separator for a non-aqueous electrolyte secondary battery, comprising a polyolefin porous film and a porous layer provided on one or both sides of the polyolefin porous film, The above-described laminated separator for a non-aqueous electrolyte secondary battery further comprises a particle layer on at least one side, and The above-described stacked separator for a non-aqueous electrolyte secondary battery satisfies the following formula, Stacked separator for non-aqueous electrolyte secondary batteries: Coefficient of variation of compression amount at 5 MPa compression ÷ Coefficient of variation of compression amount at 1 MPa compression ≤ 0.9.
In claim 1, the porous layer comprises one or more resins selected from the group consisting of acrylic resin, aromatic polyamide, polyimide, polyamideimide, and polyvinylidene fluoride. Stacked separator for non-aqueous electrolyte secondary battery.
In claim 1, the particle layer comprises acrylic resin, Stacked separator for non-aqueous electrolyte secondary battery.
In claim 1, the average particle size of the particles included in the particle layer is 0.1㎛ or more and less than 3.0㎛, Stacked separator for non-aqueous electrolyte secondary battery.
A positive electrode, a stacked separator for a non-aqueous electrolyte secondary battery described in any one of claims 1 to 4, and a negative electrode are stacked in this order. A component for a non-aqueous electrolyte secondary battery.
A stacked separator for a non-aqueous electrolyte secondary battery having a stacked separator as described in any one of claims 1 to 4, Non-aqueous electrolyte secondary battery.

Description

Laminated Separator for Non-Aqueous Electrolyte Secondary Battery and Use Thereof The present invention relates to a stacked separator for a non-aqueous electrolyte secondary battery, a member for a non-aqueous electrolyte secondary battery, and a non-aqueous electrolyte secondary battery. Non-aqueous electrolyte secondary batteries, especially lithium-ion secondary batteries, are widely used as batteries for personal computers, mobile phones, portable information terminals, and vehicles because they have a high energy density. Lithium-ion secondary batteries generally have a separator between a positive electrode and a negative electrode. For example, Patent Document 1 discloses a separator for a non-aqueous secondary battery comprising a heat-resistant porous layer containing an aromatic resin and inorganic particles, and an adhesive layer containing adhesive resin particles containing a phenyl group-containing acrylic resin. FIG. 1 is a schematic diagram illustrating the schematic structure of a stacked separator for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention. FIG. 2 is a schematic diagram illustrating the schematic structure of a stacked separator for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention. FIG. 3 is a schematic diagram illustrating the schematic structure of a stacked separator for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention. FIG. 4 is a schematic diagram illustrating the schematic structure of a stacked separator for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention. One embodiment of the present invention is described below, but the present invention is not limited thereto. Furthermore, unless otherwise specified in this specification, "A to B" indicating a numerical range means "A or more, B or less." In this specification, a laminated separator for a non-aqueous electrolyte secondary battery is also simply referred to as a "laminated separator." In this specification, a polyolefin porous film is also simply referred to as a "porous film." [1. Stacked Separator for Non-Aqueous Electrolyte Secondary Batteries] A laminated separator for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention comprises a polyolefin porous film, a porous layer, and a particle layer. The porous layer is provided on one or both sides of the porous film. The particle layer is provided on at least one side of the laminated separator. The stacked separator satisfies the relationship ÷ coefficient of variation of the compression amount at 5 MPa compression ÷ coefficient of variation of the compression amount at 1 MPa compression ≤ 0.9. This value may be 0.85 or less, 0.8 or less, 0.75 or less, 0.74 or less, 0.73 or less, 0.72 or less, or 0.71 or less. The lower limit of this value may be 0.00 or more, or 0.01 or more. The amount of compression during compression is determined from a curve in which the position of the indenter is plotted on the horizontal axis and the indentation pressure on the vertical axis. The difference between the position of the indenter at the point where the indentation pressure is 1 MPa and the position of the indenter when contact between the indenter and the sample begins is the amount of compression during 1 MPa compression. The difference between the position of the indenter at the point where the indentation pressure is 5 MPa and the position of the indenter when contact between the indenter and the sample begins is the amount of compression during 5 MPa compression. The difference between the position of the indenter at the point where the indentation pressure is 10 MPa and the position of the indenter when contact between the indenter and the sample begins is the amount of compression during 10 MPa compression. The coefficient of variation of the compression amount is obtained by measuring the compression amount during compression at 15 different locations on the same stacked separator. The value obtained by dividing the standard deviation of the 15 obtained data points by the average of the 15 data points is the coefficient of variation of the compression amount during compression. Compression at 1 MPa is approximately equivalent to the pressure used when manufacturing a component for a non-aqueous electrolyte secondary battery by pressing a multilayer separator and an electrode plate. Therefore, it is believed that the coefficient of variation of the amount of compression at 1 MPa depends on the characteristics of the particle layer and the porous layer. Specifically, it is believed that the coefficient of variation depends on how uniformly the particle layer is compressed and how much unevenness there is on the surface of the porous layer when pressed to manufacture a component for a non-aqueous electrolyte secondary battery. Compression at 5