Positive electrode for rechargeable lithium battery and rechargeable lithium battery including same

Patent metadata

Field	Value
Publication number	US-10381126-B2
Application number	US-68486810-A
Country	US
Kind code	B2
Filing date	Jan 8, 2010
Priority date	Feb 13, 2009
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

A positive electrode for a rechargeable lithium battery and a rechargeable lithium battery including the same. The positive electrode includes a positive active material, a binder, and a conductive material, wherein a weight ratio of the binder and conductive material, and the positive active material, ranges from 3:97 to 5:95 wt %, and a weight ratio of the binder and the conductive material ranges from 1.5 to 3:1.

First claim

What is claimed is:

1. A positive electrode for a rechargeable lithium battery, comprising:
a positive active material;
a binder; and
a conductive material,
wherein a weight ratio of the binder and conductive material to the positive active material, ranges from 3:97 to 4:96, and
a weight ratio of the binder to the conductive material ranges from 1.6 to 2:1, and
wherein the positive active material satisfies the following:
Li x M y O 2−z

wherein M is Ni 1−a−b (Ni 1/2 Mn 1/2 ) a Co b , 0.65≤a+b≤0.85, and 0.1≤b≤0.4,
0.95≤x≤1.05,
x+y≈2, and
0≤z≤0.05.

2. The positive electrode of claim 1 , wherein the binder comprises a material selected from the group consisting of polyvinylalcohols, carboxylmethylcelluloses, hydroxypropylcelluloses, diacetylcelluloses, polyvinylchlorides, carboxylated polyvinylchlorides, polyvinylfluorides, ethylene oxide-containing polymers, polyvinylpyrrolidones, polyurethanes, polytetrafluoroethylenes, polyvinylidene fluorides, polyethylenes, polypropylenes, styrene-butadiene rubbers, acrylated styrene-butadiene rubbers, epoxy resins, nylons, and mixtures thereof.

3. The positive electrode of claim 1 , wherein the conductive material comprises a material selected from the group consisting of carbon-based materials, metal-based materials, conductive polymers, and mixtures thereof.

4. A rechargeable lithium battery comprising:
a positive electrode comprising a positive active material, a binder, and a conductive material, wherein a weight ratio of the binder and conductive material to the positive active material, ranges from 3:97 to 4:96, and a weight ratio of the binder to the conductive material ranges from 1.6 to 2:1;
a negative electrode comprising a negative active material; and
a non-aqueous electrolyte, and wherein the positive active material satisfies the following:
Li x M y O 2−z

wherein M is Ni 1−a−b (Ni 1/2 Mn 1/2 ) a Co b , 0.65≤a+b≤0.85, and 0.1≤b≤0.4,
0.95≤x≤1.05,
x+y≈2, and
0≤z≤0.05.

5. The rechargeable lithium battery of claim 4 , wherein the negative active material comprises a carbon-based material for reversibly intercalating and deintercalating lithium ions.

6. The rechargeable lithium battery of claim 4 , wherein the binder comprises a material selected from the group consisting of polyvinylalcohol, carboxylmethylcelluloses, hydroxypropylcelluloses, diacetylcelluloses, polyvinylchlorides, carboxylated polyvinylchlorides, polyvinylfluorides, ethylene oxide-containing polymers, polyvinylpyrrolidones, polyurethanes, polytetrafluoroethylenes, polyvinylidene fluorides, polyethylenes, polypropylenes, styrene-butadiene rubbers, acrylated styrene-butadiene rubbers, epoxy resins, nylons, and mixtures thereof.

7. The rechargeable lithium battery of claim 4 , wherein the conductive material comprises a material selected from the group consisting of carbon-based materials, metal-based materials, conductive polymers, and mixtures thereof.

8. A method of forming a positive electrode for a rechargeable lithium battery, the method comprising:
mixing a positive active material, a binder, and a conductive material in a solvent to form a positive active material slurry; and
coating the positive active material slurry on a metal-foil current collector to form the positive electrode,
wherein a weight ratio of the binder and conductive material, and the positive active material, ranges from 3:97 to 5:95 wt %, and
a weight ratio of the binder and the conductive material ranges from 1.5 to 3:1, and
wherein the positive active material satisfies the following:
Li x M y O 2−z

wherein M is Ni 1−a−b (Ni 1/2 Mn 1/2 ) a Co b , 0.65≤a+b≤0.85, and 0.1≤b≤0.4,
0.95≤x≤1.05,
x+y≈2, and
0≤z≤0.05.

9. The method of claim 8 , wherein the binder comprises a material selected from the group consisting of polyvinylalcohols, carboxylmethylcelluloses, hydroxypropylcelluloses, diacetylcelluloses, polyvinylchlorides, carboxylated polyvinylchlorides, polyvinylfluorides, ethylene oxide-containing polymers, polyvinylpyrrolidones, polyurethanes, polytetrafluoroethylenes, polyvinylidene fluorides, polyethylenes, polypropylenes, styrene-butadiene rubbers, acrylated styrene-butadiene rubbers, epoxy resins, nylons, and mixtures thereof.

10. The method of claim 8 , wherein the conductive material comprises a material selected from the group consisting of carbon-based materials, metal-based materials, conductive polymers, and mixtures thereof.

Assignees

• Kim Jin Bum
• Samsung Sdi Co Ltd

Inventors

• Kim Jin-Bum

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/621

  Binders · CPC title

• H01M4/624

  Electric conductive fillers · CPC title

• H01B1/24 Primary

  the conductive material comprising carbon-silicon compounds, carbon or silicon · CPC title