Non-woven fabric base material for lithium ion secondary battery separator and lithium ion secondary battery separator

Patent metadata

Field	Value
Publication number	US-9768430-B2
Application number	US-201414763967-A
Country	US
Kind code	B2
Filing date	Jan 28, 2014
Priority date	Feb 5, 2013
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A non-woven fabric base material for a lithium ion secondary battery separator composed mainly of a polyethylene terephthalate fiber, characterized in that the non-woven fabric base material comprises a polyethylene terephthalate binder fiber and a crystallized polyethylene terephthalate fiber, and the content of a polyethylene terephthalate binder fiber having a fiber length of 2.5 mm or less is 10 to 60 mass %.

First claim

What is claimed is:

1. A non-woven fabric base material for a lithium ion secondary battery separator composed mainly of a polyethylene terephthalate fiber, characterized in that:
the non-woven fabric base material comprises a polyethylene terephthalate binder fiber staple and a crystallized polyethylene terephthalate fiber, and the content of a polyethylene terephthalate binder fiber staple having an average fiber diameter of 1.5 to 10.0 μm and a fiber length of 2.5 mm or less is 10 to 35 mass %.

2. The non-woven fabric base material for a lithium ion secondary battery separator recited in claim 1 , wherein the content of a polyethylene terephthalate binder staple fiber having an average fiber diameter of 2.0 to 10.0 μm and a fiber length of 0.5 to 2.5 mm is 25 to 35 mass %.

3. A lithium ion secondary battery separator, comprising the non-woven fabric base material for a lithium ion secondary battery separator recited in claim 2 , wherein the non-woven fabric base material for a lithium ion secondary battery separator has been subjected to at least one treatment selected from the group consisting of:
a treatment in which a coating liquid containing an inorganic pigment is coated;
a treatment in which a coating liquid containing an organic particle is coated;
a treatment in which a microporous resin film is laminated;
a treatment in which a fine fiber layer is formed by an electrospinning method; and
a treatment in which a solid electrolyte or a gel-like electrolyte is coated.

4. The non-woven fabric base material for a lithium ion secondary battery separator recited in claim 1 ,
wherein the content of a polyethylene terephthalate binder fiber staple having an average fiber diameter of 1.5 to 2.8 μm and a fiber length of 1.0 to 2.5 mm is 10 to 30 mass %;
the total content of the polyethylene terephthalate binder fiber staple and the crystallized polyethylene terephthalate fiber is 80 to 100 mass %; and
the average fiber diameter of crystallized polyethylene terephthalate fiber is 2.0 to 4.0 μm.

5. A lithium ion secondary battery separator, comprising the non-woven fabric base material for a lithium ion secondary battery separator recited in claim 4 , wherein the non-woven fabric base material for a lithium ion secondary battery separator has been subjected to at least one treatment selected from the group consisting of:
a treatment in which a coating liquid containing an inorganic pigment is coated;
a treatment in which a coating liquid containing an organic particle is coated;
a treatment in which a microporous resin film is laminated;
a treatment in which a fine fiber layer is formed by an electrospinning method; and
a treatment in which a solid electrolyte or a gel-like electrolyte is coated.

6. The non-woven fabric base material for a lithium ion secondary battery separator recited in claim 1 :
wherein the non-woven fabric base material comprises a polyethylene terephthalate binder fiber staple containing 3,5-dicarbomethoxy benzene sulfonic acid as a copolymer component.

7. A lithium ion secondary battery separator, comprising the non-woven fabric base material for a lithium ion secondary battery separator recited in claim 6 , wherein the non-woven fabric base material for a lithium ion secondary battery separator has been subjected to at least one treatment selected from the group consisting of:
a treatment in which a coating liquid containing an inorganic pigment is coated;
a treatment in which a coating liquid containing an organic particle is coated;
a treatment in which a microporous resin film is laminated;
a treatment in which a fine fiber layer is formed by an electrospinning method; and
a treatment in which a solid electrolyte or a gel-like electrolyte is coated.

8. A lithium ion secondary battery separator, comprising the non-woven fabric base material for a lithium ion secondary battery separator recited in claim 1 , wherein the non-woven fabric base material for a lithium ion secondary battery separator has been subjected to at least one treatment selected from the group consisting of:
a treatment in which a coating liquid containing an inorganic pigment is coated;
a treatment in which a coating liquid containing an organic particle is coated;
a treatment in which a microporous resin film is laminated;
a treatment in which a fine fiber layer is formed by an electrospinning method; and
a treatment in which a solid electrolyte or a gel-like electrolyte is coated.

Assignees

• Mitsubishi Paper Mills Ltd

Inventors

• Sato Tomohiro
• Shigematsu Toshihiro
• Kato Makoto
• Hyodo Kenji
• Aizawa Wakana

Classifications

• H01M10/052

  Li-accumulators · CPC title

• D04H1/55 Primary

  Polyesters · CPC title

• H01M10/0525

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

• H01M50/494

  Tensile strength · 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