Positive electrode plate and electrochemical battery

Patent metadata

Field	Value
Publication number	US-10892473-B2
Application number	US-201816152199-A
Country	US
Kind code	B2
Filing date	Oct 4, 2018
Priority date	Dec 19, 2017
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

The present disclosure provides a positive electrode plate and an electrochemical battery. The positive electrode plate comprises a positive electrode current collector and a positive electrode film. The positive electrode film is provided on the positive electrode current collector and comprises a positive electrode active material and a binder. The positive electrode active material comprises a prussian blue analogue material, the binder is an oil-soluble binder, an area density of the positive electrode film is 5 mg/cm2˜30 mg/cm2. In the positive electrode film of the present disclosure, the prussian blue analogue material is used together with the oil-soluble binder, and the area density of the positive electrode film is controlled within a certain range, so that introduction of the water molecule can be reduced during the preparation process and coating process of a positive electrode slurry, and cycle performance of the electrochemical battery can be improved.

First claim

What is claimed is:

1. A positive electrode plate, comprising:
a positive electrode current collector; and
a positive electrode film, the positive electrode film being provided on the positive electrode current collector and comprising a positive electrode active material and a binder;
wherein,
the positive electrode active material comprises a prussian blue analogue material, a molecular formula of the prussian blue analogue material is A x M y [M′(CN) 6 ] z ·nH 2 O, where, A is one or more selected from a group consisting of alkali metal cation, alkaline-earth metal cation, Zn 2+ and Al 3+ , M is a transition metal, M′ is a transition metal, 0<x≤2, 0<y≤1, 0<z≤1, 0<n≤20;
the binder is an oil-soluble binder;
an area density of the positive electrode film is 5 mg/cm 2 ˜30 mg/cm 2 ; and
a water content of the positive electrode film is 300 μg/g˜3000 μg/g.

2. The positive electrode plate according to claim 1 , wherein the oil-soluble binder is one or more selected from a group consisting of polyvinylidene fluoride-type polymer, polybutadiene diacrylate, acrylonitrile-butadiene rubber, polyvinylpyrrolidone, styrenic block copolymer, hydrogenated styrene-butadiene block copolymer and polyacrylonitrile.

3. The positive electrode plate according to claim 2 , wherein the oil-soluble binder is selected from polyvinylidene fluoride-type polymer.

4. The positive electrode plate according to claim 2 , wherein
the polyvinylidene fluoride-type polymer is one or more selected from a group consisting of vinylidene fluoride monomer homopolymer, vinylidene fluoride monomer and fluorovinylidene monomer copolymer;
the vinylidene fluoride monomer and fluorovinylidene monomer copolymer is one or more selected from a group consisting of vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, vinylidene fluoride-tetrafluoro ethylene copolymer, vinylidene fluoride-trifluoroethylene-chlorofluoroethylene copolymer and tetrafluoro ethylene-hexafluoropropylene-vinylidene fluoride copolymer.

5. The positive electrode plate according to claim 1 , wherein the area density of the positive electrode film is 8 mg/cm 2 ˜16 mg/cm 2 .

6. The positive electrode plate according to claim 1 , wherein a thickness of the positive electrode film is 30 μm˜200 μm.

7. The positive electrode plate according to claim 6 , wherein the thickness of the positive electrode film is 50 μm˜150 μm.

8. The positive electrode plate according to claim 1 , wherein the water content of the positive electrode film is 500 μg/g˜2000 μg/g.

9. The positive electrode plate according to claim 1 , wherein a weight percentage of the binder of the positive electrode film is 1%˜30%.

10. The positive electrode plate according to claim 9 , wherein the weight percentage of the binder of the positive electrode film is 5%˜20%.

11. The positive electrode plate according to claim 1 , wherein the positive electrode film further comprises a conductive agent, the conductive agent is one or more selected from a group consisting of conductive carbon black, conductive graphite, carbon nanotube and carbon nanofiber.

12. The positive electrode plate according to claim 11 , wherein a weight percentage of the conductive agent of the positive electrode film is 0.5%˜30%.

13. The positive electrode plate according to claim 12 , wherein the weight percentage of the conductive agent of the positive electrode film is 5%˜20%.

14. An electrochemical battery, comprising a positive electrode plate, the positive electrode plate comprising a positive electrode current collector and a positive electrode film, the positive electrode film being provided on the positive electrode current collector and comprising a positive electrode active material and a binder;
wherein,
the positive electrode active material comprises a prussian blue analogue material, a molecular formula of the prussian blue analogue material is A x M y [M′(CN) 6 ] z ·nH 2 O, where, A is one or more selected from a group consisting of alkali metal cation, alkaline-earth metal cation, Zn 2+ and Al 3+ , M is a transition metal, M′ is a transition metal, 0<x≤2, 0<y≤1, 0<z≤1, 0<n≤20;
the binder is an oil-soluble binder;
an area density of the positive electrode film is 5 mg/cm 2 ˜30 mg/cm 2 ; and
a water content of the positive electrode film is 300 μg/g˜3000 μg/g.

15. The electrochemical battery according to claim 14 , wherein the oil-soluble binder is one or more selected from a group consisting of polyvinylidene fluoride-type polymer, polybutadiene diacrylate, acrylonitrile-butadiene rubber, polyvinylpyrrolidone, styrenic block copolymer, hydrogenated styrene-butadiene block copolymer and polyacrylonitrile.

16. The electrochemical battery according to claim 14 , wherein the area density of the positive electrode film is 8 mg/cm 2 ˜16 mg/cm 2 .

17. The electrochemical battery according to claim 14 , wherein a thickness of the positive electrode film is 30 μm˜200 μm.

18. The electrochemical battery according to claim 14 , wherein a weight percentage of the binder of the positive electrode film is 1%˜30%.

Assignees

• Contemporary Amperex Technology Co Ltd

Inventors

• Wang Ying
• Guo Yongsheng
• Liang Chengdu
• Wang Xiqing
• Su Shuojian
• Liu Qian

Classifications

• H01M10/054

  Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium · CPC title

• H01M4/622

  being polymers · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M2004/021

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

• H01M4/136 Primary

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title