Laminated body

Patent metadata

Field	Value
Publication number	US-10476066-B2
Application number	US-201715627585-A
Country	US
Kind code	B2
Filing date	Jun 20, 2017
Priority date	Jun 21, 2016
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A nonaqueous electrolyte secondary battery separator having a laminated body which is not easily curled is provided. The laminated body includes a porous base material containing a polyolefin-based resin as a main component and a porous layer which is disposed on at least one surface of the porous base material and which contains a polyvinylidene fluoride-based resin. The porous base material has a piercing strength of not less than 26.0 gf/g/m2. The polyvinylidene fluoride-based resin contains crystal form α in an amount of not less than 36 mol % with respect to 100 mol % of a total amount of the crystal form α and crystal form β contained in the polyvinylidene fluoride-based resin.

First claim

The invention claimed is:

1. A laminated body, comprising:
a porous base material containing a polyolefin-based resin as a main component; and
a porous layer which is disposed on at least one surface of the porous base material and which contains a polyvinylidene fluoride-based resin,
the porous base material having a piercing strength of not less than 26.0 gf/g/m 2 , which piercing strength is measured with respect to a weight per unit area of the porous base material,
the polyvinylidene fluoride-based resin having a weight-average molecular weight of 500,000 to 1,500,000,
the porous base material having a value in a range of 0.00 to 0.54, which value is represented by the following Expression (1):
|1− T/M|   (1)

where (i) T represents a distance by which the porous base material moves in a traverse direction from a starting point of measurement to a point where a critical load is obtained in a scratch test under a constant load of 0.1 N and (ii) M represents a distance by which the porous base material moves in a machine direction from a starting point of measurement to a point where a critical load is obtained in a scratch test under a constant load of 0.1 N,
the polyvinylidene fluoride-based resin containing crystal form a in an amount of not less than 70 mol % with respect to 100 mol % of a total amount of the crystal form α and crystal form β contained in the polyvinylidene fluoride-based resin,
where the amount of the crystal form a is calculated from an absorption intensity at around 765 cm −1 in an IR spectrum of the porous layer, and an amount of the crystal form β is calculated from an absorption intensity at around 840 cm −1 in the IR spectrum of the porous layer.

2. The laminated body according to claim 1 , wherein the polyvinylidene fluoride-based resin contains (i) a homopolymer of vinylidene fluoride and/or (ii) a copolymer of 15 vinylidene fluoride and at least one monomer selected from the group consisting of hexafluoropropylene, tetrafluoroethylene, trifluoroethylene, trichloroethylene, and vinyl fluoride.

3. The laminated body according to claim 1 , wherein the porous layer contains a filler.

4. The laminated body according to claim 3 , wherein the filler has a volume-average particle size of 0.01 μm to 10 μm.

5. A nonaqueous electrolyte secondary battery member, comprising:
a cathode;
a laminated body according to claim 1 ; and
an anode,
the cathode, the laminated body, and the anode being arranged in this order.

6. A nonaqueous electrolyte secondary battery, comprising as a separator a laminated body according to claim 1 .

Assignees

• Sumitomo Chemical Co

Inventors

• Ogata Toshihiko
• Kurakane Kosuke
• Murakami Chikara

Classifications

• H01M10/0525 Primary

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• B32B27/32 Primary

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title

• B32B2307/558

  Impact strength, toughness · CPC title

• B32B2307/54

  Yield strength; Tensile strength · CPC title

• B05D1/42

  by non-rotary members · CPC title