Water-soluble polyamic acid, method of preparing the same, binder composition for lithium battery including the same, and lithium battery manufactured using the binder composition

Patent metadata

Field	Value
Publication number	US-10186709-B2
Application number	US-201615356932-A
Country	US
Kind code	B2
Filing date	Nov 21, 2016
Priority date	Nov 26, 2015
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A water-soluble partially lithiated polyamic acid having an acid equivalent of less than 300 grams per equivalent and a degree of lithium ion substitution of from about 0.2 equivalents to about 1.0 equivalent with respect to carboxylic acid groups, which is a product of a polyamic acid and lithium hydroxide.

First claim

What is claimed is:

1. A water-soluble partially lithiated polyamic acid having an acid equivalent of less than 300 grams per equivalent and a degree of lithium ion substitution of from about 0.2 equivalents to about 1.0 equivalent with respect to carboxylic acid groups, which is a product of a polyamic acid and lithium hydroxide.

2. The water-soluble partially lithiated polyamic acid of claim 1 , wherein the acid equivalent of the polyamic acid is between about 50 grams per equivalent and about 250 grams per equivalent.

3. The water-soluble partially lithiated polyamic acid of claim 1 , wherein the water-soluble polyamic acid has a pH of from about 4 to about 7.

4. The water-soluble partially lithiated polyamic acid of claim 1 , wherein the water-soluble polyamic acid has an imidization ratio of from about 50% to about 90% at a curing temperature of 150° C. or less.

5. A binder composition for a lithium battery, comprising the water-soluble partially lithiated polyamic acid according to claim 1 and a solvent.

6. The binder composition of claim 5 , wherein the solvent is water, a polar organic solvent, or a combination thereof.

7. The binder composition of claim 6 , wherein the polar organic solvent is at least one solvent selected from N,N-dimethylformamide, N,N-dimethylacetamide, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, diethylene glycol dimethyl ether, toluene, and xylene.

8. The binder composition of claim 5 , wherein the solvent comprises water and a polar organic solvent, and the water and the polar organic solvent are combined in a volume ratio of from about 10:1 to about 1:10.

9. A method of preparing a water-soluble polyamic acid, the method comprising:
adding, to a polyamic acid having an acid equivalent of less than 300 grams per equivalent, lithium hydroxide in an amount of from about 0.2 equivalents to about 1.0 equivalent with respect to carboxylic acid group to lithiate the polyamic acid.

10. A method of manufacturing an electrode for a lithium battery, the method comprising:
providing an electrode slurry comprising an electrode active material and the binder composition according to claim 5 ; and
heat-treating the electrode slurry at a temperature of 150° C. or less to form the electrode for a lithium battery.

11. The method of claim 10 , wherein the electrode active material comprises at least one anode active material selected from a silicon active material, a tin active material, a silicon-tin alloy active material, and a silicon-carbon active material.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Bae Woojin
• Kwon Seunguk
• Yang Jeeeun

Classifications

• H01M4/362

  Composites · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• C08G73/105

  with oxygen only in the diamino moiety · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M4/139

  Processes of manufacture · CPC title