Positive electrode for rechargeable lithium battery and rechargeable lithium battery

Patent metadata

Field	Value
Publication number	US-9419270-B2
Application number	US-201213610504-A
Country	US
Kind code	B2
Filing date	Sep 11, 2012
Priority date	Apr 30, 2012
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

Disclosed is a positive electrode according to one embodiment of the present invention that includes a current collector and a positive active material layer on the current collector, wherein the positive active material layer includes a positive active material and activated carbon coated with a fibrous carbon material.

First claim

What is claimed is:

1. A positive electrode for a rechargeable lithium battery, comprising:
a current collector; and
a positive active material layer on the current collector and comprising a positive active material mixed with activated carbon coated with a fibrous carbon material,
wherein the fibrous carbon material is present in the positive active material layer in an amount in a range of about 20 wt % to about 50 wt % based on 100 wt % of the activated carbon.

2. The positive electrode of claim 1 , wherein the fibrous carbon material has a larger specific surface area than that of the activated carbon.

3. The positive electrode of claim 1 , wherein the fibrous carbon material has a specific surface area in a range of about 500 m 2 /g to about 3000 m 2 /g.

4. The positive electrode of claim 1 , wherein the fibrous carbon material has a specific surface area in a range of about 300 m 2 /g to about 2000 m 2 /g.

5. The positive electrode of claim 1 , wherein the positive active material and activated carbon are mixed in a ratio in a range of about 98:2 wt % to about 60:40 wt %.

6. The positive electrode of claim 1 , further comprising an ionic conductive layer between the current collector and the positive active material layer.

7. The positive electrode of claim 6 , wherein the ionic conductive layer has a thickness in a range of about 3 μm to about 5 μm.

8. The positive electrode of claim 6 , wherein the ionic conductive layer comprises a conductive material and an ionic conductive polymer.

9. The positive electrode of claim 8 , wherein the conductive material and the ionic conductive polymer are mixed in a weight ratio in a range of 1:1 to 2:8.

10. The positive electrode of claim 8 , wherein the ionic conductive polymer comprises a polytetrafluoroethylene-hexafluoropropylene copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, a polyvinylidene difluoride-hexafluoropropylene copolymer, a vinylidene fluoride-hexafluoropropylene copolymer, polyethylene glycol, polypropyleneoxide, polyethylene oxide, polyacrylate ester, polymethacrylic acid ester, polysiloxane, polyphosphazene, or a combination thereof.

11. The positive electrode of claim 1 , wherein the fibrous carbon material comprises carbon nanotubes (CNT), carbon nanofiber (CNF), vapor grown carbon fiber (VGCF), or a combination thereof.

12. The positive electrode of claim 11 , wherein the fibrous carbon material comprises carbon nanotubes.

13. A rechargeable lithium battery, comprising
the positive electrode according to claim 1 ;
a negative electrode including a negative active material; and
an electrolyte including an organic solvent and a lithium salt.

14. The rechargeable lithium battery of claim 13 , wherein the negative active material is amorphous carbon.

Assignees

• An Jung-Woo
• Sheem Kyeu-Yoon
• Han Da-Woon
• Samsung Sdi Co Ltd

Inventors

• An Jung-Woo
• Sheem Kyeu-Yoon
• Han Da-Woon

Classifications

• H01M50/497

  Ionic conductivity · CPC title

• H01M4/625 Primary

  Carbon or graphite · CPC title

• H01M50/446

  Composite material consisting of a mixture of organic and inorganic materials · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title