Cathode and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-2017110733-A1
Application number	US-201515316925-A
Country	US
Kind code	A1
Filing date	Jul 9, 2015
Priority date	Jul 11, 2014
Publication date	Apr 20, 2017
Grant date	—

Abstract

The present application relates to a cathode, a method of manufacturing the same, and a battery including the same. The present application may provide a cathode and a method of manufacturing the same, wherein the cathode comprises an active material layer that contains an acrylic polymer and exhibits excellent resistance to an electrolyte, excellent dispersion of its components and great adhesion to a current collector.

First claim

What is claimed is:

1 . A cathode for a secondary battery, comprising:
a current collector; and an active material layer present on the current collector and comprising an acrylic polymer which forms a cross-linked structure with a polyfunctional cross-linker.

2 . The cathode of claim 1 , wherein the acrylic polymer comprises a polymerization unit of a (meth)acrylic acid ester compound and a polymerization unit of a monomer containing a cross-linkable functional group.

3 . The cathode of claim 2 , wherein the (meth)acrylic acid ester compound is an alkyl (meth)acrylate.

4 . The cathode of claim 2 , wherein the cross-linkable functional group comprises a hydroxyl group, an isocyanate group, a glycidyl group, an epoxy group, an amine group or a carboxyl group.

5 . The cathode of claim 1 , wherein the acrylic polymer further comprises a polymerization unit of a vinyl-based monomer except for a (meth)acrylic acid ester compound.

6 . The cathode of claim 1 , wherein the acrylic polymer further comprises a polymerization unit of a monomer containing a nitrogen-containing functional group, or a polymerization unit of a monomer containing an alkoxysilane group.

7 . The cathode of claim 6 , wherein the acrylic polymer comprises a gel content of 80% to 100%.

8 . The cathode of claim 1 , wherein the polyfunctional cross-linker is a polyfunctional compound comprising two or more functional groups that contain at least one functional group selected from the group consisting of an alkoxysilane group, a carboxyl group, an acid anhydride group, a vinyl ether group, an amine group, a carbonyl group, an isocyanate group, an epoxy group, an aziridinyl group, a carbodiimide group and an oxazoline group.

9 . The cathode of claim 1 , wherein the acrylic polymer is comprised in the active material layer at a ratio of 0.01 to 10 parts by weight with respect to 100 parts by weight of the active material layer.

10 . The cathode of claim 1 , wherein a particle diameter of the acrylic polymer is 10 nm or less.

11 . The cathode of claim 1 , wherein the active material layer further comprises a fluorine-based polymer.

12 . The cathode of claim 1 , wherein the active material layer further comprises a cathode active material.

13 . The cathode of claim 12 , wherein the cathode active material is comprised in the active material layer at a ratio of 80 to 99.5 parts by weight with respect to 100 parts by weight of the active material layer.

14 . The cathode of claim 1 , wherein a peel strength of the active material layer to the current collector is 20 gf or greater when measured at a peeling speed of 0.3 m/min and a peeling angle of 180 degrees at room temperature with an electrode specimen sized 15×150 mm 2 .

15 . The cathode of claim 1 , wherein the active material layer further comprises a conductive material.

16 . The cathode of claim 1 , wherein the current collector comprises aluminum.

17 . A method of manufacturing a cathode for a secondary battery, the method comprising cross-linking of an acrylic polymer in a state in which a layer of composition forming an active material layer comprising the acrylic polymer is previously formed on a current collector.

18 . The method of claim 17 , wherein the acrylic polymer is cross-linked in the range of 50° C. to 300° C.

19 . The method of claim 17 , wherein the acrylic polymer is prepared through solution polymerization using a mixture which comprises a (meth)acrylic acid ester compound, a monomer containing a cross-linkable functional group and a solvent.

20 . The method of claim 19 , wherein the mixture further comprises a monomer containing a nitrogen-containing functional group or a monomer containing an alkoxysilane group.

21 . The method of claim 17 , wherein a particle diameter of the acrylic polymer is 10 nm or less.

22 . A secondary battery comprising the cathode of claim 1 .

Assignees

• Lg Chemical Ltd

Inventors

• Yoon Jeong Ae
• Chi Han Na
• Yoon Sung Soo
• Kwon Su Jee

Classifications

• H01M4/505

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

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title