Non-aqueous electrolyte secondary battery and method for manufacturing negative electrode for secondary battery

Patent metadata

Field	Value
Publication number	US-9911972-B2
Application number	US-201114364839-A
Country	US
Kind code	B2
Filing date	Dec 14, 2011
Priority date	Dec 14, 2011
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

The non-aqueous electrolyte secondary battery 10 provided by the present invention comprises a positive electrode 30 , a negative electrode 50 and a non-aqueous electrolyte. The negative electrode 50 includes a negative electrode current collector 52 and a negative electrode active material layer 54 formed on the current collector 52 , the negative electrode active material layer 54 containing a negative electrode active material 55 capable of storing and releasing charge carriers and having shape anisotropy so that the charge carriers are stored and released along a predefined direction. The negative electrode active material layer 54 includes, at a bottom thereof contacting the current collector 52 , a minute conductive material 57 with granular shape and/or minute conductive material 57 with fibrous shape having an average particle diameter that is smaller than that of the negative electrode active material 55 , and includes, at the bottom thereof; a part of the negative electrode active material 55 . At least 50% by number of the total amount of the negative electrode active material 55 is oriented so that the direction of storage and release of the charge carriers is at an angle of 45° or more and 90° or less relative to the surface of the current collector 52.

First claim

The invention claimed is:

1. A non-aqueous electrolyte secondary battery, comprising:
a positive electrode, a negative electrode and a non-aqueous electrolyte,
the negative electrode including a negative electrode current collector, and a negative electrode active material layer formed on the current collector,
the negative electrode active material layer containing a negative electrode active material capable of storing and releasing charge carriers and having shape anisotropy so that the charge carriers are stored and released along a predefined direction, wherein
the negative electrode active material layer comprises a conductive base accumulated layer at a bottom of the negative electrode active material layer contacting the current collector,
the conductive base accumulated layer has more conductive material with at least one of granular shape and fibrous shape having an average particle diameter that is smaller than an average particle diameter of the negative electrode active material accumulated than other regions of the negative electrode active material layer,
at least 50% by number of a total amount of the negative electrode active material is oriented so that a direction of storage and release of the charge carriers is at an angle of 45° or more and 90° or less relative to a surface of the current collector, and
a lower end of a part of the negative electrode active material enters into the conductive base accumulated layer and is supported by the conductive base accumulated layer so as to maintain its orientation.

2. The non-aqueous electrolyte secondary battery according to claim 1 , wherein
the conductive material is at least one of a fibrous carbon material having an average fibre diameter of 1 μm or less and a granular carbon material having an average particle diameter of 1 μm or less.

3. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the negative electrode active material is a graphite material with flake shape or a graphite material with fibrous shape and at least 50% by number of the graphite material in the negative electrode active material layer is oriented so that an angle of the (004) plane thereof relative to the surface of the current collector is 45° or more and 90° or less.

4. The non-aqueous electrolyte secondary battery according to claim 3 , wherein the negative electrode active material layer has a ratio I(110)/I(004) of a diffraction intensity of the (110) plane relative to a diffraction intensity of the (004) plane in X-ray diffraction of the surface thereof, of 0.6 or more and 1.0 or less.

5. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the negative electrode active material layer has a density of at least 1.5 g/cm 3 .

6. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the negative electrode active material layer contains a binder at 1.0 part by mass or less relative to 100 parts by mass of the negative electrode active material.

7. A vehicle comprising the secondary battery according to claim 1 .

8. A method for producing a negative electrode for a secondary battery comprising a negative electrode active material layer formed on a negative electrode current collector, the method comprising:
preparing a composition for forming a negative electrode active material layer containing a negative electrode active material capable of storing and releasing charge carriers and having shape anisotropy so that the charge carriers are stored and released along a predefined direction;
preparing a composition for forming a conductive base accumulated layer containing at least one of a granular conductive material and a conductive material with fibrous shape having an average particle diameter that is smaller than an average particle diameter of the negative electrode active material;
applying the composition for forming a conductive base accumulated layer on a given negative electrode current collector;
applying, before the composition for forming a conductive base accumulated layer applied on the current collector is dried, the composition for forming a negative electrode active material layer on the applied composition for forming a conductive base accumulated layer to form the negative electrode active material layer; and
applying, to the negative electrode active material layer, a magnetic field having magnetic force lines aligned in a direction orthogonal to the surface of the current collector in order to orient the negative electrode active material,
wherein:
at least 50% by number of the total amount of the negative electrode active material is oriented so that a direction of storage and release of the charge carriers is at an angle of 450 or more and 900 or less relative to the surface of the current collector,
the conductive base accumulated layer has more conductive material with at least one of granular shape and fibrous shape having an average particle diameter that is smaller than an average particle diameter of the negative electrode active material accumulated than other regions of the negative electrode active material layer, and
a lower end of a part of the negative electrode active material enters into the conductive base accumulated layer and is supported by the conductive base accumulated layer so as to maintain its orientation.

9. The method according to claim 8 , wherein at least one of a fibrous carbon material having an average fibre diameter of 1 μm or less and a granular carbon material having an average particle diameter of 1 μm or less is used as the conductive material.

10. The method according to claim 8 , wherein: a graphite material with flake shape or a graphite material with fibrous shape is used as the negative electrode active material, and the graphite material is oriented in the step of orientation so that an angle of the (004) plane of at least 50% by number of the graphite material in the negative electrode active material layer is 45° or more and 90° or less relative to the surface of the current collector.

11. The method according to claim 10 , wherein the negative electrode active material are oriented in the step of orientation so that the negative electrode active material layer has a ratio I(110)/I(004) of a diffraction intensity of the (110) plane relative to a diffraction intensity of the (004) plane in X-ray diffraction of the surface thereof, of 0.6 or more and 1.0 or less.

12. The method according to claim 8 , wherein the magnetic field applied in the step of orientation has an intensity of 0.5 T or more.

13. The method according to claim 8 , further comprising: pressing the negative electrode active material layer obtained after the step of orientation so that the negative electrode active material layer has a density of at least 1.5 g/cm 3 .

14. The method according to claim 8 , wherein the composition for forming a negative electrode active material layer contains a binder at 1.0 part by mass or less relative to 100 parts by weight of the negative electrode active material.

15. A method for producing a non-aqueous electrolyte secondary battery, comprising: preparing a positive electrode, a negative electrode and a non-aqueous electrolyte and assembling a non-aqueous electrolyte secondary battery by using the positive electrode, the negative electrode and the non-aqueous electrolyte, wherein the negative electrode is produced by the method according to claim 8 .

Assignees

• Takahata Koji
• Hashimoto Tatsuya
• Ozaki Yoshiyuki
• Okada Yukihiro
• Tsuchiya Kenji
• Kitayoshi Masanori
• Wada Naoyuki
• Toyota Motor Co Ltd

Inventors

• Takahata Koji
• Hashimoto Tatsuya
• Ozaki Yoshiyuki
• Okada Yukihiro
• Tsuchiya Kenji
• Kitayoshi Masanori
• Wada Naoyuki

Classifications

• H01M4/133 Primary

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/0416

  involving impregnation with a solution, dispersion, paste or dry powder (H01M4/0438 takes precedence) · CPC title

• H01M10/058

  Construction or manufacture · CPC title

• H01M4/0402

  Methods of deposition of the material · CPC title

• Y02T10/7011

  Cross-Sectional Technologies · mapped topic