Secondary battery

Patent metadata

Field	Value
Publication number	US-2019036094-A1
Application number	US-201616072801-A
Country	US
Kind code	A1
Filing date	Nov 30, 2016
Priority date	Jan 25, 2016
Publication date	Jan 31, 2019
Grant date	—

Abstract

The secondary battery of the present invention is a secondary battery comprising: a negative electrode; a positive electrode; a separator disposed between the electrodes; and an electrolytic solution, wherein the separator is a porous film, or a porous film laminate having a porous film integrated with a support, a main component of the porous film is a polyetherimide-based resin, and in the configuration of the secondary battery described in this specification, an ion resistance value of the separator as determined by a measuring method described in this specification is 0.18 Ω or less. The secondary battery of the present invention is also a secondary battery comprising: a negative electrode; a positive electrode; a separator disposed between the electrodes; and an electrolytic solution, wherein the separator is a porous film, or a porous film laminate having a porous film integrated with a support, a main component of the porous film is a polyetherimide-based resin, and the separator has an electrolytic solution penetration rate value of 10 to 30 mm/30 minutes in an MD direction.

First claim

1 . A secondary battery comprising:
a negative electrode; a positive electrode; a separator disposed between the electrodes; and an electrolytic solution, wherein the separator is a porous film, or a porous film laminate having a porous film integrated with a support, a main component of the porous film is a polyetherimide-based resin, and in the following configuration of the secondary battery, an ion resistance value of the separator as determined by the following measuring method is 0.18Ω or less; Configuration of the secondary battery: the positive electrode and the negative electrode defined below are made to face each other through the separator, and inserted into an aluminum laminate outer packaging, an electrolytic solution (1M-LiPF 6 /3EC7MEC) is injected into the outer packaging, and after impregnation under reduced pressure, the outer packaging is vacuum-sealed; Positive electrode: a laminate formed by laminating a mixture of a ternary system positive-electrode active material (NCM):AB:PVdf=93:4:3 on an aluminum foil current collector, the laminate being 30 mm in width, 50 mm in length, and 80 μm in thickness; Negative electrode: a laminate formed by laminating a mixture of graphite:CMC:SBR=97.5:1:1.5 on a copper foil current collector, the laminate being 32 mm in width, 52 mm in length, and 70 μm in thickness; and Measuring method: measuring an alternating-current impedance of the secondary battery with an impedance analyzer under conditions of a scanning frequency of 0.1 Hz to 50000 Hz and a voltage amplitude of 10 mV, obtaining an X intercept of an obtained Nyquist plot as a direct-current resistance component of the secondary battery, and subtracting blank resistance from the X intercept to obtain an ion resistance value of the separator.

2 . A secondary battery comprising:
a negative electrode; a positive electrode; a separator disposed between the electrodes; and an electrolytic solution, wherein the separator is a porous film, or a porous film laminate having a porous film integrated with a support, a main component of the porous film is a polyetherimide-based resin, and the separator has an electrolytic solution penetration rate value of 10 to 30 mm/30 minutes in an MD direction.

3 . The secondary battery according to claim 2 , wherein the separator has an electrolytic solution penetration rate value of 12 to 30 mm/30 minutes in a TD direction.

4 . The secondary battery according to claim 1 , wherein
the porous film of the separator has a large number of micro-pores having communicating properties, the micro-pores having an average pore size of 0.01 to 10 μm, the porous film has an average aperture ratio of 30 to 80%, the separator has an air permeability value of 0.5 to 100 seconds, and the separator has a thickness of 10 to 60 μm.

5 . The secondary battery according to claim 1 , wherein the micro-pores of the porous film have an average pore size of 0.05 to 5 μm.

6 . The secondary battery according to claim 1 , wherein the porous film has an average aperture ratio of 40 to 80%.

7 . The secondary battery according to claim 1 , wherein the separator has an air permeability value of 0.5 to 50 seconds.

8 . The secondary battery according to claim 1 , wherein the separator has a thickness of 15 to 50 μm.

9 . The secondary battery according to claim 1 , wherein the current collector of the negative electrode is a copper foil or stainless steel.

10 . The secondary battery according to claim 1 , wherein the current collector of the positive electrode is aluminum foil or stainless steel.

11 . The secondary battery according to claim 1 , wherein a raw material of the porous film is a polymer solution comprising 8 to 25% by weight of a polyetherimide-based resin component, 5 to 50% by weight of a water-soluble polymer, 0 to 10% by weight of water, and 30 to 82% by weight of a water-soluble polar solvent.

12 . The secondary battery according to claim 11 , wherein a content of the water-soluble polymer is 5 to 40 parts by weight per 100 parts by weight in total of the polyetherimide-based resin component and the water-soluble polar solvent.

13 . The secondary battery according to claim 2 , wherein
the porous film of the separator has a large number of micro-pores having communicating properties, the micro-pores having an average pore size of 0.01 to 10 μm, the porous film has an average aperture ratio of 30 to 80%, the separator has an air permeability value of 0.5 to 100 seconds, and the separator has a thickness of 10 to 60 μm.

14 . The secondary battery according to claim 3 , wherein
the porous film of the separator has a large number of micro-pores having communicating properties, the micro-pores having an average pore size of 0.01 to 10 μm, the porous film has an average aperture ratio of 30 to 80%, the separator has an air permeability value of 0.5 to 100 seconds, and the separator has a thickness of 10 to 60 μm.

15 . The secondary battery according to claim 2 , wherein the micro-pores of the porous film have an average pore size of 0.05 to 5 μm.

16 . The secondary battery according to claim 3 , wherein the micro-pores of the porous film have an average pore size of 0.05 to 5 μm.

17 . The secondary battery according to claim 4 , wherein the micro-pores of the porous film have an average pore size of 0.05 to 5 μm.

18 . The secondary battery according to claim 2 , wherein the porous film has an average aperture ratio of 40 to 80%.

19 . The secondary battery according to claim 3 , wherein the porous film has an average aperture ratio of 40 to 80%.

20 . The secondary battery according to claim 4 , wherein the porous film has an average aperture ratio of 40 to 80%.

Assignees

• Daicel Corp

Inventors

• Yamato Yo
• Iwaya Masao

Classifications

• H01M4/66 Primary

  Selection of materials · CPC title

• H01M50/124

  having a layered structure · CPC title

• H01M50/491

  Porosity · CPC title

• H01M50/489

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

• H01M50/449

  having a layered structure · CPC title