NON-AQUEOUS ELECTROLYTIC SOLUTION AND LITHIUM SECONDARY BATTERY

• US 20100079110A1
• Filed: 10/26/2009
• Published: 04/01/2010
• Est. Priority Date: 05/25/2000
• Status: Active Grant

• Current Assignee: Akira Ueki, Koji Abe, Toshikazu Hamamoto
• Original Assignee: Akira Ueki, Koji Abe, Toshikazu Hamamoto
• Inventors: Abe, Koji, Hamamoto, Toshikazu, Ueki, Akira
• Granted Patent: US 7,968,220 B2
• Time in Patent Office: Days
• US Class Current: 320/130
• 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 2300/0037 Mixture of solvents
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A non-aqueous electrolytic solution favorably employable for a lithium secondary battery employs a non-aqueous electrolytic solution which comprises a non-aqueous solvent and an electrolyte which further contains 0.001 to 0.8 weight % of a biphenyl derivative having the formula:

in which each of Y¹ and Y² represents hydroxyl, alkoxy, hydrocarbyl, hydrogen, acyloxy, alkoxycarbonyloxy, alkylsulfonyloxy, or halogen, and each of p and q is an integer of 1 to 3.

Claims

1-10. -10. (canceled)

11. A method for operating a lithium secondary battery comprising cyclically charging and discharging the battery in a voltage range having a maximum operating voltage exceeding 4.2 V, the battery comprising a positive electrode, a negative electrode comprising graphite, and a non-aqueous electrolytic solution comprising a cyclic carbonate, a linear chain carbonate and an electrolyte, the non-aqueous electrolytic solution further containing 0.03 to 0.5 weight % of biphenyl.

12. The method of claim 11, wherein the non-aqueous electrolytic solution contains the biphenyl in an amount of 0.05 to 0.5 weight %.

13. The method of claim 11, wherein the positive electrode comprises a complex oxide comprising lithium and at least one metal element selected from the group consisting of cobalt, nickel, manganese, chromium, vanadium and iron.

14. The method of claim 11, wherein the cyclic carbonate comprises at least one compound selected from the group consisting of ethylene carbonate, propylene carbonate and butylene carbonate.

15. The method of claim 11, wherein the linear chain carbonate comprises at least one compound selected from the group consisting of dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate.

16. The method of claim 11, wherein the lithium secondary battery is cyclically charged and discharged under such condition that 100 cycle retention is not less than 88.8%.