Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-10957941-B2
Application number	US-201816225015-A
Country	US
Kind code	B2
Filing date	Dec 19, 2018
Priority date	Dec 19, 2017
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A nonaqueous electrolyte secondary battery which satisfies four requirements is provided. A porous layer contains 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 (i) the α-form polyvinylidene fluoride-based resin and (ii) β-form polyvinylidene fluoride-based resin. A porous film has a temperature rise ending period of 2.9 sec·m2/g to 5.7 sec·m2/g with respect to an amount of a resin per unit area when the porous film is impregnated with N-methylpyrrolidone containing water in an amount of 3% by weight and then (ii) irradiated, at an output of 1,800 W, with a microwave having a frequency of 2,455 MHz. A positive electrode plate has a capacitance of 1 nF to 1000 nF per measurement area of 900 mm2. A negative electrode plate has a capacitance of 4 nF to 8500 nF per measurement area of 900 mm2.

First claim

The invention claimed is:

1. A nonaqueous electrolyte secondary battery comprising:
a nonaqueous electrolyte secondary battery separator containing a polyolefin porous film;
a porous layer containing a polyvinylidene fluoride-based resin;
a positive electrode plate having a capacitance of 1 nF to 1000 nF per measurement area of 900 mm 2 ; and
a negative electrode plate having a capacitance of 4 nF to 8500 nF per measurement area of 900 mm 2 ,
the polyolefin porous film having a temperature rise ending period of 2.9 sec·m 2 /g to 5.7 sec·m 2 /g with respect to an amount of a resin per unit area in a case where the polyolefin porous film is (i) impregnated with N-methylpyrrolidone containing water in an amount of 3% by weight and then (ii) irradiated, at an output of 1,800 W, with a microwave having a frequency of 2,455 MHz,
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 (i) the α-form polyvinylidene fluoride-based resin and (ii) 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 (i) waveform separation of (α/2) observed at around −78 ppm in a 19 F-NMR spectrum obtained from the porous layer and (ii) waveform separation of {(α/2)+β} observed at around −95 ppm in the 19 F-NMR 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, a meth acrylate-based resin, an 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

• Arise Ichiro
• Ogata Toshihiko
• Yoshimaru Chikae
• Murakami Chikara

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

• H01M50/443

  Particulate material · CPC title

• H01M50/409

  Separators, membranes or diaphragms characterised by the material · CPC title

• H01M10/0525

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

• H01M4/483 Primary

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title