LITHIUM ION BATTERY

• US 20100092869A1
• Filed: 09/02/2009
• Published: 04/15/2010
• Est. Priority Date: 10/14/2008
• Status: Abandoned Application

• Current Assignee: NEC Energy Devices, Ltd. (Envision Group /TX/)
• Original Assignee: NEC Tokin Corporation (Yageo Corporation)
• Inventors: KONO, Yasutaka, KANEKO, Shinako, KOBAYASHI, Hiroshi, ISHIKAWA, Hitoshi, HASHIZUME, Yoko
• Application Number:
  US12/552,449
• Publication Number:
  US 20100092869A1
• Time in Patent Office: Days
• US Class Current: 429/303
• 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 10/0569 characterised by the solvents
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 2300/0022 Room temperature molten salts
• CPC Class Codes: H01M 2300/0045 Room temperature molten salts comprising at least one organic ion
• CPC Class Codes: H01M 2300/0085 Immobilising or gelification of electrolyte
• CPC Class Codes: H01M 4/1393 of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/362 Composites
• 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

To provide high energy density, good cycle properties and rate characteristics and long-term safety of a lithium ion battery containing at least an ionic liquid and a lithium salt. The above problems are solved by suppressing reduction and decomposition of the ionic liquid on an anode by using a graphite coated with an amorphous carbon or onto which an amorphous carbon is deposited as an anode active material.

Claims

1. A lithium ion battery comprising an electrolyte containing at least an ionic liquid composed of a bis(fluorosulfonyl)imide anion and a lithium salt, a cathode and an anode, wherein an anode active material is formed by coating the surface of graphite particles with an amorphous carbon or depositing an amorphous carbon thereonto.

2. The lithium ion battery according to claim 1, wherein the amorphous carbon with which the surface of the graphite particles is coated or which is deposited thereonto has an amount of 1% by mass or more to 30% by mass or less based on the anode active material.

3. The lithium ion battery according to claim 1, wherein the graphite particles have an interlayer distance between (002) planes of 0.335 to 0.337 nm.

4. The lithium ion battery according to claim 1, wherein the graphite particles are of natural graphite.

5. The lithium ion battery according to claim 1, wherein the anode active material has a specific surface area of 1.0 to 1.8 m²/g.

6. The lithium ion battery according to claim 1, wherein the electrolyte comprises disulfonic acid ester.

7. The lithium ion battery according to claim 6, wherein the electrolyte further comprises vinylene carbonate or a derivative thereof.

8. The lithium ion battery according to claim 1, wherein the electrolyte is gelled by a polymer.