Non-aqueous electrolyte secondary cell

• US 6,677,080 B2
• Filed: 08/09/2001
• Issued: 01/13/2004
• Est. Priority Date: 08/14/2000
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Omaru, Atsuo, Tanizaki, Hiroaki
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US09/925,669
• Publication Number:
  US 20020076612A1
• Time in Patent Office: 887 Days
• Field of Search: 429/231.9, 429/231.95, 429/231.8, 429/223, 429/224
• US Class Current: 429/223
• 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 10/0567 characterised by the additives
• 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 2004/021 Physical characteristics, e.g. porosity, surface area
• 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 4/364 as mixtures
• 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: H01M 4/661 Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• 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

The present invention provides a non-aqueous electrolyte secondary cell including: a lithium-nickel composite oxide as a cathode active material and a material having a specific surface in the range from 0.05 m²/g to 2 m²/g as an anode active material. When A is assumed to be the weight of the lithium-nickel composite oxide and B is assumed to be the weight of the cathode active material other than the lithium-nickel composite oxide, the mixture ratio R expressed A/(A+B) is in the range from 0.2 to 1. This combination of the cathode active material and the anode active material enables to obtain an improved anti-over discharge characteristic even when an anode current collector contains Cu.

Claims

1. A non-aqueous electrolyte secondary cell comprising:

a cathode containing a lithium compound as a cathode active material; and

an anode having an anode current collector containing Cu, and a material capable of doping/dedoping lithium as an anode active material; and

a non-aqueous electrolyte;

the cathode active material containing a lithium-nickel composite oxide with a mixture ratio A/(A+B) in the range from 0.2 to 1 wherein A is assumed to be the weight of the lithium-nickel composite oxide and B is assumed to be the total weight of the cathode active material other than the lithium-nickel composite oxide, and

the anode active material having a specific surface in the range from 0.05 m²/g to 2 m²/g.

2. A non-aqueous electrolyte secondary cell as claimed in claim 1, wherein the cathode active material contains a lithium-nickel composite oxide and a lithium-manganese composite oxide.

3. A non-aqueous electrolyte secondary cell as claimed in claim 2, wherein the lithium-nickel composite oxide contains a compound expressed by a general formula LiNi_1-xM_xO₂ (wherein x is in the range from 0.01 to 0.5;

and M represents at least one of Fe, Co, Mn, Cu, Zn, Al, Sn, B, Ga, Cr, V, Ti, Mg, Ca, and Sr).

4. A non-aqueous electrolyte secondary cell as claimed in claim 3, wherein the lithium-nickel composite oxide contains LiNi_0.8Co_0.2O₂.

5. Anon-aqueous electrolyte secondary cell as claimed in claim 2, wherein the lithium-manganese composite oxide contains a compound expressed by a general formula Li_yMn_2-zM′

_zO₄ (wherein y is in the range from 0.9 to 1.2;

z is in the range from 0.01 to 0.5; and

M′

represents at least one of Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, and Sr).

6. Anon-aqueous electrolyte secondary cell as claimed in claim 5, wherein the lithium-manganese composite oxide contains LiMn_1.8Cr_0.2O₄.

7. A non-aqueous electrolyte secondary cell as claimed in claim 1, wherein the electrolyte contains an unsaturated carbonate.

8. A non-aqueous electrolyte secondary cell as claimed in claim 7, wherein the unsaturated carbonate is contained in the electrolyte in the from 0.05 wt % to 5 wt %.

9. Anon-aqueous electrolyte secondary cell as claimed in claim 7, wherein the unsaturated carbonate is vinylene carbonate.

10. Anon-aqueous electrolyte secondary cell as claimed in claim 1, wherein the anode active material uses at least one material selected from a carbon material, a metal capable of being alloyed with lithium, or an alloy thereof.

11. A non-aqueous electrolyte secondary cell as claimed in claim 1, wherein the anode active material is graphite.

12. Anon-aqueous electrolyte secondary cell as claimed in claim 1, wherein the cathode and the anode are coiled multiple times through a separator to become a spirally type electrode body.

13. A non-aqueous electrolyte secondary cell as claimed in claim 1, wherein the electrolyte is selected from a non-aqueous electrolyte solution prepared by dissolving an electrolyte salt in a non-aqueous solvent, a solid electrolyte containing an electrolyte salt, or a polymer gel electrolyte prepared by dissolving an electrolyte salt in a non-aqueous solvent which is sustained in a polymer matrix.

14. A non-aqueous electrolyte secondary cell as claimed in claim 13, wherein the non-aqueous solvent comprises at least one material selected from propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, 1,2-diethoxyethane, diethyl carbonate, dimethyl carbonate, γ

-butyrol actone, tetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, diethyl ether, sulfolane, methyl sulfolane, acetonitrile, and propiononitrile.

15. A non-aqueous electrolyte secondary cell as claimed in claim 13, wherein the electrolyte salt comprises at least one material selected from LiClO₄, LiAsF₆, LiPF₆, LiBF₄, LiB(C₆H₅)₄, LiCl, LiBr, CH₃SO₃Li, and CF₃SO₃Li.