KR-20260064555-A - NONAQUEOUS ELECTROLYTE SECONDARY BATTERY LAMINATED BODY AND USE THEREOF

Abstract

The present disclosure provides a laminate for a non-aqueous electrolyte secondary battery having excellent ion permeability when pressurized. The laminate for a non-aqueous electrolyte secondary battery according to the present disclosure has a porous layer and a particle layer provided on at least one side of the porous layer, and satisfies the following formula (1). Ra/Sa≥0.80 … (1) (In Equation (1), Ra represents the arithmetic mean roughness [μm] measured by contact measurement of the surface having the particle layer, and Sa represents the arithmetic mean roughness [μm] measured by non-contact measurement of the surface having the particle layer.)

Inventors

• 이시이, 다이가
• 오제키, 도모아키
• 마츠미네, 리쿠
• 와타나베, 덴카이

Assignees

• 스미또모 가가꾸 가부시키가이샤

Dates

Publication Date

20260507

Application Date

20251024

Priority Date

20241031

Claims (8)

1. A laminate for a non-aqueous electrolyte secondary battery having a porous layer and a particle layer provided on at least one side of the porous layer, satisfying the following formula (1). Ra/Sa≥0.80 … (1) (In Equation (1), Ra represents the arithmetic mean roughness [μm] measured by contact measurement of the surface having the particle layer, and Sa represents the arithmetic mean roughness [μm] measured by non-contact measurement of the surface having the particle layer.)
2. A laminate for a non-aqueous electrolyte secondary battery that satisfies the following formula (2) in claim 1. Rq/Sq≥0.75 … (2) (In Equation (2), Rq represents the root mean square height [μm] measured by contact measurement of the surface having the particle layer, and Sq represents the root mean square height [μm] measured by non-contact measurement of the surface having the particle layer.)
3. A laminate for a non-aqueous electrolyte secondary battery according to claim 1, wherein the porous layer comprises at least one resin selected from the group consisting of acrylic resin, aromatic polyamide, polyimide, polyamideimide, and polyvinylidene fluoride.
4. A laminate for a non-aqueous electrolyte secondary battery, wherein the particle layer comprises an acrylic resin, in accordance with claim 1.
5. A laminate for a non-aqueous electrolyte secondary battery according to claim 1, wherein the average particle size of the particles included in the particle layer is 0.1㎛ or more and less than 3.0㎛.
6. Polyolefin porous film and, A laminated separator for a non-aqueous electrolyte secondary battery having a laminate for a non-aqueous electrolyte secondary battery described in any one of claims 1 to 5, laminated on at least one side of the above-mentioned polyolefin porous film.
7. A non-aqueous electrolyte secondary battery member having a positive electrode, a stacked separator for a non-aqueous electrolyte secondary battery described in claim 6, and a negative electrode stacked in this order.
8. A non-aqueous electrolyte secondary battery having a stacked separator for a non-aqueous electrolyte secondary battery as described in paragraph 6.

Description

Laminated body for non-aqueous electrolyte secondary battery and use thereof The present invention relates to a laminate for a non-aqueous electrolyte secondary battery, a laminated separator for a non-aqueous electrolyte secondary battery, a component 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 of their 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." [1. Laminate for Non-Aqueous Electrolyte Secondary Batteries] A laminate for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention has a porous layer and a particle layer provided on at least one side of the porous layer, and satisfies the following formula (1). Ra/Sa≥0.80 … (1) (In Equation (1), Ra represents the arithmetic mean roughness [μm] measured by contact measurement of the surface having the particle layer, and Sa represents the arithmetic mean roughness [μm] measured by non-contact measurement of the surface having the particle layer.) In the following, a laminate for a non-aqueous electrolyte secondary battery is also simply referred to as a laminate. The arithmetic mean roughness is specified in either ISO 25178 or JIS B 0601:2013 and corresponds to the standard deviation of height. Contact measurements can be performed, for example, using a stylus-type surface roughness meter. Non-contact measurements can be performed, for example, using a laser microscope. More specific measurement methods are described in the examples. During the charging and discharging of a non-aqueous electrolyte secondary battery, the electrode expands, and the separator may be compressed as a result. When a porous layer and a particle layer exist on the separator, there is a risk that the pores of the porous layer may be crushed by compression, and/or that the particles contained in the particle layer may be crushed by compression, thereby blocking the pores of the porous layer, which may increase the air permeability, i.e., worsen the ion permeability. The inventors, through repeated research, discovered that ion permeability in the pressurized case can be improved by controlling to satisfy the above-described equation (1). Improving ion permeability in the pressurized case means, for example, that the increase in permeability after pressurization is reduced. Ra/Sa is the ratio of the value obtained by contact measurement to the value obtained by non-contact measurement. In contact measurement, the surface of the laminate is physically scanned by a probe. At that time, if the porous layer is flexible, the probe is pushed into the surface of the porous layer, or particles of the particle layer settle on the surface of the porous layer. On the other hand, if the porous layer is rigid, this does not happen. Ra/Sa reflects the difference in probe behavior between the rigid and flexible regions of the porous layer. A value of Ra/Sa ≥ 0.80 indicates that the surface of the porous layer has appropriate hardness. Since the porous layer has appropriate hardness, it is prevented from uniformly collapsing or clogging the pores of the porous layer even when pressurized, so it is thought that ion permeability is unlikely to deteriorate. From the perspective of ion permeability after pressurization, Ra/Sa is preferably greater than 1.0, more preferably greater than 1.1, and even more preferably greater than 1.2. In additi