Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-11094997-B2
Application number	US-201815989901-A
Country	US
Kind code	B2
Filing date	May 25, 2018
Priority date	May 29, 2017
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

The present invention provides a nonaqueous electrolyte secondary battery having excellent battery characteristics, including a battery separator containing a polyolefin porous film; a positive electrode plate; and a negative electrode plate. The polyolefin porous film has a puncture strength of at least 26.0 gf/g/m2 and satisfies Formula (A), and the positive and negative electrode plates satisfy Formula (B).0.00≤|1−T/M|≤0.54  (A)0.00≤|1−T/M|≤0.50  (B)T represents a distance by which the polyolefin porous film or positive or negative electrode plate moves in a traverse direction from a starting point to a point where a critical load is obtained in a scratch test under a constant load of 0.1 N, and M represents a distance by which the porous film or positive or negative electrode plate moves in a machine direction from the starting point to the point where the critical load is obtained.

First claim

The invention claimed is:

1. A nonaqueous electrolyte secondary battery comprising:
a positive electrode plate;
a nonaqueous electrolyte secondary battery separator containing a polyolefin porous film; and
a negative electrode plate,
wherein the polyolefin porous film contains a polyethylene having a weight-average molecular weight of 5×10 5 to 15×10 6 in an amount of not less than 68% by weight relative to the total weight of the polyolefin porous film,
wherein the polyolefin porous film has a puncture strength of equal to or greater than 26.0 gf/g/m 2 , which puncture strength is measured with respect to a weight per unit area of the polyolefin porous film, and
wherein the polyolefin porous film has a value in a range of 0.00 to 0.54, the positive electrode plate has a value in a range of 0.00 to 0.50, and the negative electrode plate has a value in a range of 0.00 to 0.50, where each of the values is represented by the following Formula (1):
|1− T/M|   (1)

where T represents a distance by which the polyolefin porous film, the positive electrode plate, or the negative electrode plate 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 M represents a distance by which the polyolefin porous film, the positive electrode plate, or the negative electrode plate 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.

2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the positive electrode plate contains a transition metal oxide.

3. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the negative electrode plate contains graphite.

4. A nonaqueous electrolyte secondary battery member comprising:
a positive electrode plate;
a nonaqueous electrolyte secondary battery separator containing a polyolefin porous film; and
a negative electrode plate,
the positive electrode plate, the nonaqueous electrolyte secondary battery separator, and the negative electrode plate being arranged in this order,
wherein the polyolefin porous film contains a polyethylene having a weight-average molecular weight of 5×10 5 to 15×10 6 in an amount of not less than 68% by weight relative to the total weight of the polyolefin porous film,
wherein the polyolefin porous film has a puncture strength of equal to or greater than 26.0 gf/g/m 2 , which puncture strength is measured with respect to a weight per unit area of the polyolefin porous film, and
wherein the polyolefin porous film has a value in a range of 0.00 to 0.54, the positive electrode plate has a value in a range of 0.00 to 0.50, and the negative electrode plate has a value in a range of 0.00 to 0.50, where each of the values is represented by the following Formula (1):
|1− T/M|   (1)

where T represents a distance by which the polyolefin porous film, the positive electrode plate, or the negative electrode plate 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 M represents a distance by which the polyolefin porous film, the positive electrode plate, or the negative electrode plate 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.

Assignees

• Sumitomo Chemical Co

Inventors

• Kurakane Kosuke

Classifications

• H01M50/489 Primary

  Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M10/0525 Primary

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

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title