Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-11038208-B2
Application number	US-201816224014-A
Country	US
Kind code	B2
Filing date	Dec 18, 2018
Priority date	Dec 19, 2017
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

A nonaqueous electrolyte secondary battery includes: a separator including a polyolefin porous film; a porous layer containing a polyvinylidene fluoride-based resin; a positive electrode plate having a capacitance falling within a specific range; and a negative electrode plate having a capacitance falling within a specific range. The polyolefin porous film has a given piercing strength, having a value of not less than 0.00 and not more than 0.54, the value being represented by the following expression: |1−T/M|, where T and M are distances at which a critical load is reached in a scratch test in which the polyolefin porous film is moved in transverse and machine directions, respectively, under a constant load of 0.1N. The polyvinylidene fluoride-based resin contains an α-form polyvinylidene fluoride-based resin in an amount of not less than 35.0 mol %.

First claim

The invention claimed is:

1. A nonaqueous electrolyte secondary battery comprising:
a nonaqueous electrolyte secondary battery separator including a polyolefin porous film;
a porous layer containing a polyvinylidene fluoride-based resin;
a positive electrode plate having a capacitance of not less than 1 nF and not more than 1000 nF per measurement area of 900 mm 2 ; and
a negative electrode plate having a capacitance of not less than 4 nF and not more than 8500 nF per measurement area of 900 mm 2 ,
the polyolefin porous film having a piercing strength of not less than 26.0 gf/g/m 2 , the piercing strength being measured with respect to a weight per unit area of the polyolefin porous film,
the polyolefin porous film having a value in a range of 0.00 to 0.54, the value being represented by the following Expression (1):
|1− T/M|   (1)

where T represents a distance at which a critical load is reached in a scratch test in which the polyolefin porous film is moved in a transverse direction under a constant load of 0.1 N, and M represents a distance at which a critical load is reached in a scratch test in which the polyolefin porous film is moved in a machine direction under a constant load of 0.1 N,
the porous layer being provided between the nonaqueous electrolyte secondary battery separator and at least one of the positive electrode plate and the negative electrode plate, and
the polyvinylidene fluoride-based resin containing an α-form polyvinylidene fluoride-based resin in an amount of not less than 35.0 mol % with respect to 100 mol % of a total amount of the α-form polyvinylidene fluoride-based resin and a β-form polyvinylidene fluoride-based resin contained in the polyvinylidene fluoride-based resin,
where the amount of the α-form polyvinylidene fluoride-based resin contained is calculated from waveform separation of (α/2) observed at around −78 ppm in a 19 F-NMR spectrum obtained from the porous layer, and waveform separation of {(α/2)+β} observed at around −95 ppm in the 19 F-MMR spectrum obtained from the porous layer.

2. The nonaqueous electrolyte secondary battery as set forth in claim 1 , wherein the positive electrode plate contains a transition metal oxide.

3. The nonaqueous electrolyte secondary battery as set forth in claim 1 , wherein the negative electrode plate contains graphite.

4. The nonaqueous electrolyte secondary battery as set forth in claim 1 , further comprising:
another porous layer which is provided between (i) the nonaqueous electrolyte secondary battery separator and (ii) at least one of the positive electrode plate and the negative electrode plate.

5. The nonaqueous electrolyte secondary battery as set forth in claim 4 , wherein the another porous layer contains at least one resin selected from the group consisting of a polyolefin, an acrylate-based resin, a meth acrylate-based resin, a fluorine-containing resin excluding a polyvinylidene fluoride-based resin, a polyamide-based resin, a polyester-based resin, and a water-soluble polymer.

6. The nonaqueous electrolyte secondary battery as set forth in claim 5 , wherein the polyamide-based resin is an aramid resin.

Assignees

• Sumitomo Chemical Co

Inventors

• Kashiwazaki Eiko
• Ogata Toshihiko
• Kurakane Kosuke
• Arise Ichiro

Classifications

• H01M10/48

  Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) · CPC title

• H01M50/451

  comprising layers of only organic material and layers containing inorganic material · CPC title

• H01M50/443

  Particulate material · CPC title

• H01M50/457

  comprising three or more layers · CPC title

• H01M50/491

  Porosity · CPC title