Lithium ion secondary battery and a method for manufacturing the same

• US 20040106046A1
• Filed: 11/18/2003
• Published: 06/03/2004
• Est. Priority Date: 11/29/2002
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Ohara
• Original Assignee: Kabushiki Kaisha Ohara
• Inventors: Inda, Yasushi
• Application Number:
  US10/716,117
• Publication Number:
  US 20040106046A1
• Time in Patent Office: Days
• US Class Current: 429/322
• CPC Class Codes: H01M 10/0436 Small-sized flat cells or batteries for portable equipment
• 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 10/0562 Solid materials
• CPC Class Codes: H01M 10/058 Construction or manufacture
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 2300/0091 in the form of mixtures
• 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 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• 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: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

A lithium ion secondary battery includes a positive electrode, a negative electrode and a thin film solid electrolyte including lithium ion conductive inorganic substance. The thin film solid electrolyte has thickness of 20 μm or below and is formed directly on an electrode material or materials for the positive electrode and/or the negative electrode. The thin film solid electrolyte has lithium ion conductivity of 10⁻⁵ Scm⁻¹ or over and contains lithium ion conductive inorganic substance powder in an amount of 40 weight % or over in a polymer medium. The average particle diameter of the inorganic substance powder is 0.5 μm or below. According to a method for manufacturing the lithium ion secondary battery, the thin film solid electrolyte is formed by coating the lithium ion conductive inorganic substance directly on the electrode material or materials for the positive electrode and/or the negative electrode.

Claims

1. A lithium ion secondary battery comprising a positive electrode, a negative electrode and a solid electrolyte, said solid electrolyte being made in the form of a thin film comprising a lithium ion conductive inorganic substance.

2. A lithium ion secondary battery as defined in claim 1 wherein said thin film solid electrolyte has thickness of 20 μ

m or below.

3. A lithium ion secondary battery as defined in claim 1 wherein said thin film solid electrolyte is formed directly on an electrode material or materials for the positive electrode and/or the negative electrode.

4. A lithium ion secondary battery as defined in claim 1 wherein said thin film solid electrolyte has lithium ion conductivity of 10⁻

5 Scm<sup>−

1</sup> or over.

5. A lithium ion secondary battery as defined in claim 1 wherein said thin film solid electrolyte comprises the inorganic substance in an amount of 40 weight % or over.

6. A lithium ion secondary battery as defined in claim 1 wherein said inorganic substance is a lithium ion conductive crystal.

7. A lithium ion secondary battery as defined in claim 1 wherein said inorganic substance is a lithium ion conductive glass.

8. A lithium ion secondary battery as defined in claim 1 wherein said inorganic substance is a lithium ion conductive glass-ceramic.

9. A lithium ion secondary battery as defined in claim 1 wherein said inorganic substance is powder of the inorganic substance.

10. A lithium ion secondary battery as defined in claim 9 wherein said inorganic substance powder is powder of a lithium ion conductive glass-ceramic.

11. A lithium ion secondary battery as defined in claim 9 wherein an average particle diameter of the inorganic substance powder is 1.0 μ

m or below.

12. A lithium ion secondary battery as defined in claim 9 wherein said thin film solid electrolyte comprises a lithium ion conductive inorganic substance powder in a polymer medium.

13. A lithium ion secondary battery as defined in claim 9 wherein said thin film solid electrolyte comprises a lithium inorganic salt and lithium ion conductive glass-ceramic powder in a polymer medium.

14. A lithium ion secondary battery as defined in claim 3 wherein said thin film solid electrolyte is formed by direct coating on an electrode material or materials for the positive electrode and/or the negative electrode.

15. A lithium ion secondary battery as defined in claim 3 wherein said thin film solid electrolyte is formed by crystallizing an amorphous layer which is formed by direct coating on an electrode material or materials for the positive electrode and/or the negative electrode.

16. A lithium ion secondary battery as defined in claim 1 comprising a positive electrode, a negative electrode and a solid electrolyte wherein said positive and/or negative electrode comprises lithium ion conductive inorganic substance powder.

17. A lithium ion secondary battery as defined in claim 16 wherein said inorganic substance powder in the positive and/or negative electrode has an average particle diameter of 3 μ

m or below.

18. A method for manufacturing a lithium ion secondary battery having a thin film solid electrolyte comprising a lithium ion conductive inorganic substance comprising a step of forming the thin film solid electrolyte by coating the lithium ion conductive inorganic substance directly on an electrode material or materials for the positive and/or negative electrode.

19. A method for manufacturing a lithium ion secondary battery as defined in claim 18 comprising a step of preparing slurry comprising the lithium ion conductive inorganic substance, and a step of forming the thin film solid electrolyte by coating the slurry directly on the electrode material or materials for the positive and/or negative electrode.

20. A method for manufacturing a lithium ion secondary battery as defined in claim 18 comprising a step of coating the lithium ion conductive inorganic substance directly on the electrode material or materials for the positive and/or negative electrode to form an amorphous layer, and a step of forming the thin film solid electrolyte by crystallizing the amorphous layer.