Electrode binder for lithium secondary batteries, negative electrode for lithium secondary batteries using same, lithium secondary battery, automobile, method for producing electrode binder for lithium secondary batteries, and method for manufacturing lithium secondary battery

Patent metadata

Field	Value
Publication number	US-9991506-B2
Application number	US-201214114954-A
Country	US
Kind code	B2
Filing date	Jun 1, 2012
Priority date	Jun 3, 2011
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

Provided are an electrode binder for lithium secondary batteries, which is suppressed in deterioration in adhesive power, strength and stretchability caused by decomposition of imide groups by hydrolysis, said imide groups being contained in a polyamide-imide that is used as a binder for an electrode active material, and which is capable of prolonging the service life of a lithium secondary battery by suppressing deterioration of an electrode even in cases where water is generated due to repeated charging and discharging; a negative electrode for lithium secondary batteries; a lithium secondary battery; a method for manufacturing a lithium secondary battery having long service life, said lithium secondary battery being suppressed in deterioration of an electrode even in cases where water is generated due to repeated charging and discharging; a method for producing an electrode binder for lithium secondary batteries; and an automobile. This electrode binder for lithium secondary batteries contains a polyamideimide and a carbodiimide. A lithium secondary battery is manufactured by forming an electrode layer using a coating liquid that contains an electrode active material, a polyamideimide, a carbodiimide and a solvent.

First claim

The invention claimed is:

1. A negative electrode for lithium secondary batteries comprising a negative electrode active material layer comprising a binder for lithium secondary batteries comprising a polyamideimide and a carbodiimide and a negative electrode active material comprising a silicon oxide, wherein the carbodiimide has the number average molecular weight not less than 3,000 and not more than 50,000 and the polyamideimide has the number average molecular weight not less than 5,000 and not more than 100,000.

2. A lithium secondary battery having an electrode active material layer comprising a binder for a lithium secondary batteries comprising a polyamideimide and a carbodiimide and an electrode active material, wherein the carbodiimide has the number average molecular weight not less than 3,000 and not more than 50,000 and the polyamideimide has the number average molecular weight not less than 5,000 and not more than 100,000.

3. An automobile having a lithium secondary battery according to claim 2 .

4. A negative electrode for lithium secondary batteries comprising a negative electrode active material layer comprising a negative electrode active material and a binder comprising a polyamideimide and a carbodiimide, wherein a content of the carbodiimide is not less than 0.5 wt % and not more than 20 wt % with respect to the polyamideimide, and wherein the carbodiimide has the number average molecular weight not less than 3,000 and not more than 50,000.

5. The negative electrode for lithium secondary batteries according to claim 4 , wherein functional groups of the polyamideimide are blocked by a blocking agent.

6. The negative electrode for lithium secondary batteries according to claim 5 , wherein as the blocking agent, one or more selected from a monoamine, a monoalcohol, a monocarboxylic acid and monoisocyanate be used.

7. The negative electrode for lithium secondary batteries according to claim 4 , wherein the polyamideimide is able to dissolve or disperse in a solvent.

8. A method for producing the negative electrode for lithium secondary batteries according to claim 4 , comprising mixing a polyamideimide, a carbodiimide and a solvent.

9. The negative electrode for lithium secondary batteries according to claim 4 , wherein the negative electrode active material comprises a silicon oxide.

10. The negative electrode for lithium secondary batteries according to claim 9 , wherein a content of the negative electrode active material is not less than 70 wt % and not more than 99 wt %.

11. A lithium secondary battery having the negative electrode according to claim 4 .

12. A method for producing a lithium secondary battery according to claim 11 , comprising a negative electrode active material layer using a coating liquid comprising an electrode active material, a polyamideimide, a carbodiimide and a solvent, wherein a content of the carbodiimide is not less than 0.5 wt % and not more than 20 wt % with respect to the polyamideimide.

13. An automobile having a lithium secondary battery according to claim 11 .

14. A negative electrode for lithium secondary batteries comprising a negative electrode active material layer comprising a binder for lithium secondary batteries comprising a polyamideimide and a carbodiimide, and a negative electrode active material, wherein the carbodiimide has the number average molecular weight not less than 3,000 and not more than 50,000 and the polyamideimide has the number average molecular weight not less than 5,000 and not more than 100,000.

Assignees

• Inoue Kazuhiko
• Nec Corp

Inventors

• Inoue Kazuhiko

Classifications

• H01M4/622

  being polymers · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/364 Primary

  as mixtures · CPC title

• H01M4/621 Primary

  Binders · CPC title

• H01M4/0404

  by coating on electrode collectors · CPC title