Nonaqueous electrolyte secondary battery and separator

• US 9,356,273 B2
• Filed: 12/02/2010
• Issued: 05/31/2016
• Est. Priority Date: 12/04/2009
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sato, Hironori
• Primary Examiner(s): Stagg, Mariam
• Assistant Examiner(s): LYLES-IRVING, CARMEN V
• Application Number:
  US12/958,961
• Publication Number:
  US 20110135991A1
• Time in Patent Office: 2,007 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B01D 53/22 by diffusion manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0568 characterised by the solutes
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 10/0587 of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 2004/028 Positive electrodes
• CPC Class Codes: H01M 2200/106 PTC
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 2300/0037 Mixture of solvents
• CPC Class Codes: H01M 4/02 Electrodes composed of, or comprising, active material
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/1391 of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/1397 of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/387 Tin or alloys based on tin
• CPC Class Codes: H01M 4/525 : of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/58 : of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
• CPC Class Codes: H01M 4/623 : fluorinated polymers
• CPC Class Codes: H01M 4/625 : Carbon or graphite
• CPC Class Codes: H01M 4/661 : Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• CPC Class Codes: H01M 50/107 : having curved cross-section, e.g. round or elliptic H01M50/103, H01M50/109, H01M50/11 take precedence
• CPC Class Codes: H01M 50/124 : having a layered structure
• CPC Class Codes: H01M 50/417 : Polyolefins
• CPC Class Codes: H01M 50/426 : Fluorocarbon polymers
• CPC Class Codes: H01M 50/434 : Ceramics
• CPC Class Codes: H01M 50/446 : Composite material consisting of a mixture of organic and inorganic materials
• CPC Class Codes: H01M 50/449 : having a layered structure
• CPC Class Codes: H01M 50/491 : Porosity
• CPC Class Codes: H01M 50/581 : in response to temperature
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The separator includes a substrate layer and a surface layer formed on at least one principal plane of the substrate layer, the surface layer contains polyvinylidene fluoride and an inorganic material particle, and an amount of deformation against pressure of the surface layer is larger than that of the substrate layer.

Claims

1. A nonaqueous electrolyte secondary battery comprising:

a positive electrode;

a negative electrode; and

a separator disposed between the positive electrode and the negative electrode,

wherein the separator includes

a substrate layer, and

a surface layer formed on at least one principal plane of the substrate layer,

wherein the surface layer contains polyvinylidene fluoride and an inorganic material particle, the inorganic material composing at least 70 wt % of the surface layer,

wherein an amount of deformation against pressure of the surface layer is larger than that of the substrate layer,

wherein an average particle size of the inorganic material particle is not more than 50% relative to a thickness of the surface layer, and

wherein the surface layer has a three-dimensional network structure in which continuously connected fibrils made of the polyvinylidene fluoride have an average diameter of not more than 1.0 μ

m.

2. The nonaqueous electrolyte secondary battery according to claim 1, wherein

the negative electrode has a negative electrode active material containing at least one member selected from silicon and tin as a constituent element.

3. The nonaqueous electrolyte secondary battery according to claim 2, wherein

the negative electrode active material is a material containing

a first constituent element,

a second constituent element, and

a third constituent element;

the first constituent element is tin;

the second constituent element is at least one member selected from the group consisting of cobalt, iron, magnesium, titanium, vanadium, chromium, manganese, nickel, copper, zinc, gallium, zirconium, niobium, molybdenum, silver, indium, cerium, hafnium, tantalum, tungsten, bismuth and silicon; and

the third constituent element is at least one member selected from the group consisting of boron, carbon, aluminum and phosphorus.

4. The nonaqueous electrolyte secondary battery according to claim 1, wherein

a porosity of the surface layer is 20% or more and not more than 90%.

5. The nonaqueous electrolyte secondary battery according to claim 1, wherein

the inorganic material particle is an alumina (Al₂O₃) particle.

6. The nonaqueous electrolyte secondary battery according to claim 1, wherein

the substrate layer is a microporous polyolefin resin.

7. A separator comprising:

a substrate layer; and

a surface layer formed on at least one principal plane of the substrate layer,

wherein the surface layer contains polyvinylidene fluoride and an inorganic material particle, the inorganic material composing at least 70 wt % of the surface layer,

wherein an amount of deformation against pressure of the surface layer is larger than that of the substrate layer,

wherein an average particle size of the inorganic material particle is not more than 50% relative to a thickness of the surface layer, and

wherein the surface layer has a three-dimensional network structure in which continuously connected fibrils made of the polyvinylidene fluoride have an average diameter of not more than 1.0 μ

m.

8. The separator according to claim 7, wherein a porosity of the surface layer is 20% or more and not more than 90%.

9. The separator according to claim 7, wherein the inorganic material particle is an alumina (Al₂O₃) particle.

10. The separator according to claim 7, wherein the substrate layer is a microporous polyolefin resin.