Laminated body

• US 10,461,297 B2
• Filed: 06/20/2017
• Issued: 10/29/2019
• Est. Priority Date: 06/21/2016
• Status: Active Grant

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Ogata, Toshihiko, Hashiwaki, Hiroki, Murakami, Chikara
• Primary Examiner(s): Fraser, Stewart A
• Application Number:
  US15/627,736
• Publication Number:
  US 20170365835A1
• Time in Patent Office: 861 Days
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 27/304 comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• CPC Class Codes: H01M 50/403 Manufacturing processes of separators, membranes or diaphragms
• CPC Class Codes: H01M 50/417 Polyolefins
• CPC Class Codes: H01M 50/426 Fluorocarbon polymers
• CPC Class Codes: H01M 50/449 having a layered structure
• CPC Class Codes: H01M 50/489 Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

To afford a laminated body that is usable as a nonaqueous electrolyte secondary battery separator and that is not easily curled, a laminated body includes: a porous base material containing a polyolefin-based resin as a main component; and a porous layer containing a polyvinylidene fluoride-based resin, the porous base material having a parameter X of not more than 20, the parameter X being calculated in accordance with a particular formula, the polyvinylidene fluoride-based resin containing 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.

Claims

1. A laminated body, comprising:

a porous base material containing a polyolefin-based resin as a main component; and

a porous layer on at least one surface of the porous base material, the porous layer containing a polyvinylidene fluoride-based resin,

the porous base material having a parameter X of not more than 20, the parameter X being calculated in accordance with a formula below, where MD tan δ

represents a tan δ

measured in a machine direction through a viscoelasticity measurement performed at a frequency of 10 Hz and a temperature of 90°

C., and TD tan δ

represents a tan δ

measured in a transverse direction through the viscoelasticity measurement,

X=100×

|MD tan δ

−

TD tan δ

|/{(MD tan δ

+TD tan δ

)/2}

the polyvinylidene fluoride-based resin containing 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,

where the amount of the crystal form α

is calculated from an absorption intensity at around 765 cm<sup>−

1</sup> 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<sup>−

1</sup> 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 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 polyvinylidene fluoride-based resin has a weight-average molecular weight of not less than 200,000 and not more than 3,000,000.

4. The laminated body according to claim 1,

wherein

the porous layer contains a filler.

5. The laminated body according to claim 4,

wherein

the filler has a volume-average particle size of not less than 0.01 μ

m and not more than 10 μ

m.

6. 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.

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