Electrochemical device comprising aliphatic nitrile compound

• US 20050208371A1
• Filed: 01/14/2005
• Published: 09/22/2005
• Est. Priority Date: 01/15/2004
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Kim, Young Soo, Ahn, Soon Ho
• Granted Patent: US 8,372,550 B2
• Time in Patent Office: Days
• US Class Current: 429/137
• 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 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 2300/004 Three solvents
• CPC Class Codes: H01M 4/00 Electrodes
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• 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 4/366 as layered products
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• 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 29/49204 Contact or terminal manufacturing

Abstract

The present invention provides a cathode having a protection layer formed by a complex between the surface of a cathode active material and an aliphatic nitrile compound, as well as an electrochemical device comprising the cathode. Also, the present invention provides an electrochemical device comprising: (1) a cathode having a protection layer formed by a complex between the surface of a cathode active material and an aliphatic nitrile compound; (2) an anode having a passivation layer formed by a compound selected from the group consisting of vinylene carbonate, its derivative and an ether compound; and (3) an electrolyte solution containing a lithium salt and a solvent.

Claims

1. A cathode having a protection layer formed by a complex between the surface of a cathode active material and an aliphatic nitrile compound.

2. The cathode of claim 1, wherein the aliphatic nitrile compound is a compound represented by the following formula 1:

3. The cathode of claim 2, wherein the aliphatic nitrile compound is succinonitrile.

4. The cathode of claim 1, wherein the complex between the surface of the cathode active material and the aliphatic nitrile compound is formed by immersing the cathode having the cathode active material applied on a collector in an electrolyte solution containing the aliphatic nitrile compound and then treating the resultant cathode at high temperature.

5. The cathode of claim 4, wherein the high-temperature treatment is performed at 60-90°

C. before or after battery assembling.

6. An electrochemical device comprising:

a cathode having a protection layer formed by a complex between the surface of a cathode active material and an aliphatic nitrile compound;

an anode; and

an electrolyte solution containing a lithium salt and a solvent.

7. The electrochemical device of claim 6, wherein the anode has a passivation layer formed by a compound selected from the group consisting of vinylene carbonate represented by the following formula 2, its derivative and an ether compound:

8. The electrochemical device of claim 7, wherein the ether compound is benzyl methyl ether or tetraethylene glycol dimethyl ether.

9. The electrochemical device of claim 6, wherein the solvent is at least one cyclic carbonate selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC) and gamma-butyrolactone (GBL);

at least one linear carbonate selected from the group consisting of diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC) and methylpropyl carbonate (MPC);

or a combination of the cyclic carbonate and the linear carbonate.

10. The electrochemical device of claim 7, wherein the electrolyte solution contains, as additives, a compound selected from the group consisting of vinylene carbonate, its derivative and an ether compound, and an aliphatic nitrile compound.

11. The electrochemical device of claim 10, wherein the complex on the cathode or the passivation layer on the anode is formed by the additives contained in the electrolyte solution.

12. The electrochemical device of claim 10, wherein the additive for forming the complex on the cathode is contained in the electrolyte solution at an amount of 0.1-20% by weight, and the additive for forming the passivation layer on the anode is contained in the electrolyte solution at an amount of 0.1-5% by weight.

13. The electrochemical device of claim 6, wherein the aliphatic nitrile compound is a compound represented by the following formula 1:

14. The electrochemical device of claim 13, wherein the aliphatic nitrile compound is succinonitrile.

15. The electrochemical device of claim 6, wherein the complex between the surface of the cathode active material and the aliphatic nitrile compound is formed by immersing the cathode having the cathode active material applied on a collector in an electrolyte solution containing the aliphatic nitrile compound and then treating the resultant cathode at high temperature.

16. The electrochemical device of claim 15, wherein the high-temperature treatment is performed at 60-90°

C. before or after battery assembling.