Secondary battery with improved life characteristics

Patent metadata

Field	Value
Publication number	US-9887407-B2
Application number	US-201414646598-A
Country	US
Kind code	B2
Filing date	Oct 2, 2014
Priority date	Apr 4, 2014
Publication date	Feb 6, 2018
Grant date	Feb 6, 2018

Abstract

The present disclosure refers to a secondary battery which comprises a high-voltage cathode active material and a separator whose pores are not obstructed even though being used together with the high-voltage cathode active material, thereby preventing the obstruction of pores in the separator and the formation of a dendrite in the anode and eventually providing good battery life performance.

First claim

What is claimed is:

1. An electrode assembly comprising a cathode, an anode, and a separator interposed between the cathode and the anode,
wherein the cathode comprises a cathode active material capable of being applied at a high voltage, and
the separator comprises a porous substrate and a porous coating layer formed on only one surface of the porous substrate and comprising inorganic particles and an organic binder polymer, and has pores whose longest diameter ranges from 10 nm to 5 μm,
wherein the porous coating layer is formed in a thickness of 0.5 to 20 μm, and
wherein the porous coating layer is disposed to be faced with the anode.

2. The electrode assembly of claim 1 , wherein the cathode active material is any one selected from lithium oxides of formula (I) to (IV) and a mixture thereof:
Li x [Ni a Co b Mn c ]O 2   (I)

(0.95≦x≦1.05, 0≦a, b, c≦1, a+b+c=1, and a and c are not simultaneously 0),
Li[Li x Ni a Co b Mn c ]O 2   (II)

(0.05≦x≦0.6, and x+a+b+c=1),
Li x [Ni a Co b Mn c ]O 2   (III)

(0.95≦x≦1.05, 0<a, b, c≦1, a+b+c=1, and 0.4<c<1),
LiMn 2-x M x O 4   (IV)

(M is at least one element selected from the group consisting of Ni, Co, Fe and Al, and 0≦x≦2).

3. The electrode assembly of claim 1 , wherein the longest diameter of pores ranges from 50 to 500 nm.

4. The electrode assembly of claim 1 , wherein the separator has a Gurley value of 1 to 3000 sec/100 cc.

5. The electrode assembly of claim 1 , wherein the separator has a Gurley value of 50 to 2000 sec/100 cc.

6. The electrode assembly of claim 1 , wherein the porous substrate is a porous membrane obtained from a polyethylene resin, a polypropylene/polyethylene/polypropylene resin, or a polypropylene resin.

7. The electrode assembly of claim 1 , wherein the porous substrate is a non-woven fabric.

8. A secondary battery comprising the electrode assembly of claim 1 .

9. The secondary battery of claim 8 , which has an upper voltage of 4.3 to 5.0 V.

Assignees

• Lg Chemical Ltd
• Toray Industries

Inventors

• Yu Sung Hoon
• Suk Jung Don
• Kim Seok Koo
• Yang Doo Kyung
• Kang Yoo Sun
• Lee Kyung Mi
• Park Jin Hyun

Classifications

• H01M4/505 Primary

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M50/451

  comprising layers of only organic material and layers containing inorganic material · CPC title

• H01M50/454

  comprising a non-fibrous layer and a fibrous layer superimposed on one another · CPC title

• H01M50/42

  Acrylic resins · CPC title

• H01M50/417

  Polyolefins · CPC title