Non-aqueous electrolyte secondary battery and method for charging the same

• US 20030228519A1
• Filed: 05/28/2003
• Published: 12/11/2003
• Est. Priority Date: 05/30/2002
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Nakura, Kensuke, Okamura, Kazuhiro, Tsutsumi, Shuji, Takeno, Mitsuhiro, Oura, Takafumi
• Granted Patent: US 7,674,556 B2
• Time in Patent Office: Days
• 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 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2300/0051 Carbonates
• 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 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A non-aqueous electrolyte secondary battery comprises a negative electrode including a negative electrode active material, a positive electrode including a positive electrode active material, and a non-aqueous electrolyte; the positive electrode active material is LiNi_1-y-zMn_yCo_zO₂, wherein y and z satisfy 0<y≦0.5, 0≦z≦0.5, and 0<y+z≦0.75; and an upper limit voltage for charging the non-aqueous electrolyte secondary battery is 4.25 to 4.70 V.

It is possible to obtain a non-aqueous electrolyte secondary with high capacity, high reliability, and long life by properly setting the composition of a composite oxide of lithium which is a positive electrode active material and the charging conditions of the battery using this composite oxide of lithium as a positive electrode active material as described above.

Claims

1. A non-aqueous electrolyte secondary battery comprising a negative electrode including a negative electrode active material, a positive electrode including a positive electrode active material, and a non-aqueous electrolyte,

characterized in that said positive electrode active material is LiNi_1-y-zMn_yCo_zO₂, wherein y and z satisfy 0<

y≦

0.5, 0≦

z≦

0.5, and 0<

y+z≦

0.75, and an upper limit voltage for charging said non-aqueous electrolyte secondary battery is 4.25 to 4.70 V.

2. The non-aqueous electrolyte secondary battery in accordance with claim 1, wherein said negative electrode active material is graphite;

said non-aqueous electrolyte comprises a mixture solvent containing ethylene carbonate and ethyl methyl carbonate, and a salt comprising LiPF₆;

said positive electrode active material is LiNi_1-y-zMn_yCo_zO₂, wherein y and z satisfy 0.25≦

y≦

0.5, 0.25≦

z≦

0.5, and 0<

y+z≦

0.75; and

said upper limit voltage is 4.30 to 4.50 V.

3. A method for charging a non-aqueous electrolyte secondary battery, comprising:

(1) a first step of charging a non-aqueous electrolyte secondary battery at a constant current until the battery voltage reaches an upper limit voltage of 4.25 to 4.70 V, said non-aqueous electrolyte secondary battery comprising a negative electrode including a negative electrode active material, a positive electrode including LiNi_1-y-zMn_yCo_zO₂, wherein y and z satisfy 0<

y≦

0.5, 0≦

z≦

0.5, and 0<

y+z≦

0.75, as a positive electrode active material, and a non-aqueous electrolyte; and

(2) a second step of charging said non-aqueous electrolyte secondary battery at a constant voltage of said upper limit voltage, following said first step (1).

4. The method for charging a non-aqueous electrolyte secondary battery, in accordance with claim 3, wherein said negative electrode active material is graphite;

said non-aqueous electrolyte comprises a mixture solvent containing ethylene carbonate and ethyl methyl carbonate, and a salt comprising LiPF₆;

said positive electrode active material is LiNi_1-y-zMn_yCo_zO₂, wherein y and z satisfy 0.25≦

y≦

0.5, 0.25≦

z≦

0.5, and 0<

y+z≦

0.75; and

said upper limit voltage is 4.30 to 4.50 V.

5. A method for charging a non-aqueous electrolyte secondary battery, comprising:

(1) a first step of charging a non-aqueous electrolyte secondary battery at a constant current until the battery voltage reaches an upper limit voltage of 4.25 to 4.70 V, said non-aqueous electrolyte secondary battery comprising a negative electrode including a negative electrode active material, a positive electrode including LiNi_1-y-zMn_yCo_zO₂, wherein y and z satisfy 0<

y≦

0.5, 0≦

z≦

0.5, and 0<

y+z≦

0.75, as a positive electrode active material, and a non-aqueous electrolyte; and

(2) a second step of pulse charging said non-aqueous electrolyte secondary battery below said upper limit voltage, following said first step (1).

6. The method for charging a non-aqueous electrolyte secondary battery, in accordance with claim 5, wherein said negative electrode active material is graphite;

said non-aqueous electrolyte comprises a mixture solvent containing ethylene carbonate and ethyl methyl carbonate, and a salt comprising LiPF₆;

said positive electrode active material is LiNi_1-y-zMn_yCo_zO₂, wherein y and z satisfy 0.25≦

y≦

0.5, 0.25≦

z≦

0.5, and 0<

y+z≦

0.75; and

said upper limit voltage is 4.30 to 4.50 V.