Non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-10777799-B2
Application number	US-201013989428-A
Country	US
Kind code	B2
Filing date	Nov 26, 2010
Priority date	Nov 26, 2010
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

The present invention provides an optimal non-aqueous electrolyte secondary battery having high durability against high rate charging and discharging and excellent safety. The non-aqueous electrolyte secondary battery 100 according to the present invention comprises a positive electrode 10, a negative electrode 20 and a separator 30 which is interposed between the positive electrode 10 and the negative electrode 20. The separator 30 has a two-layer structure which is composed of a porous polyethylene layer 34 mainly composed of polyethylene, and a porous polymer layer 32 mainly composed of a polymer having higher oxidation resistance than that of the polyethylene, and an inorganic filler layer 40 including an inorganic filler and a binder is formed on the surface of the polyethylene layer 34 on which the porous polymer layer 32 is not formed.

First claim

The invention claimed is:

1. A non-aqueous electrolyte secondary battery comprising:
a positive electrode;
a negative electrode;
an inorganic filer layer-containing separator interposed between the positive electrode and negative electrode, the inorganic filler layer-containing separator comprising
a resin separator component comprising a two-layer structure consisting of
a porous polyethylene layer mainly composed of polyethylene, and
a porous polymer layer mainly composed of polytetrafluoroethylene, a polyamide, a polyimide, an aramid, polyvinylidene fluoride, polyacrylonitrile, or a polyamide-imide, the thickness of the porous polymer layer being 30 to 45 relative to a total separator thickness of the resin separator component being 100, and

an inorganic filler layer including an inorganic filler and a binder, formed on and directly bound with, by means of the binder, a surface of the polyethylene layer being not provided with the porous polymer layer, wherein
the inorganic filler layer is disposed on a side facing the negative electrode,
the inorganic filler is metal oxides having a high melting point of 1000° C. or higher,
the proportion of the inorganic filler is 90 mass % or more and 99 mass % or less with respect to the whole inorganic filler layer.

2. The non-aqueous electrolyte secondary battery according to claim 1 , wherein
the inorganic filler is at least one type of metal oxide selected from the group consisting of alumina, magnesia and zirconia.

3. The non-aqueous electrolyte secondary battery according to claim 1 , wherein
the positive electrode has, as a positive electrode active material, a lithium-transition metal composite oxide containing at least one type of metallic element selected from the group consisting of nickel, cobalt and manganese.

4. The non-aqueous electrolyte secondary battery according to claim 3 , wherein the lithium-transition metal composite oxide is a lithium-nickel-cobalt-manganese composite oxide.

5. The non-aqueous electrolyte secondary battery according to claim 1 , wherein
the positive electrode is a positive electrode sheet having a positive electrode mixture layer on a long sheet-like positive electrode current collector,
the negative electrode is a negative electrode sheet having a negative electrode mixture layer on a long sheet-like negative electrode current collector,
the separator is a long sheet-like separator, and
the non-aqueous electrolyte secondary battery has a wound electrode body constructed by winding the positive electrode sheet and the negative electrode sheet in a longitudinal direction via the separator.

6. A vehicle provided with non-aqueous electrolyte secondary battery according to claim 1 .

7. The non-aqueous electrolyte secondary battery according to claim 1 , wherein
the porous polyethylene layer has a porosity of 45% to 55%, and
the porous polymer layer has a porosity of 40% to 50%.

Assignees

• Ueki Tomoyoshi
• Wada Naoyuki
• Ozaki Yoshiyuki
• Toyota Motor Co Ltd

Inventors

• Ueki Tomoyoshi
• Wada Naoyuki
• Ozaki Yoshiyuki

Classifications

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M50/443

  Particulate material · CPC title

• H01M50/457

  comprising three or more layers · CPC title

• H01M50/423

  Polyamide resins · CPC title

• H01M50/42

  Acrylic resins · CPC title