Positive electrode for lithium secondary battery and lithium secondary battery having the same

Patent metadata

Field	Value
Publication number	US-9786904-B2
Application number	US-201414172879-A
Country	US
Kind code	B2
Filing date	Feb 4, 2014
Priority date	Apr 28, 2005
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A positive electrode for a lithium secondary battery includes a positive activation material mixture that intercalates and de-intercalates lithium ions, wherein a first positive activation material having an average particle diameter D50 of from 12.5 μm to 22 μm and a second positive activation material having an average particle diameter D50 of from 1 μm to 5 μm are mixed with a weight ratio of from 95:5 to 60:40.

First claim

What is claimed is:

1. A positive electrode for a lithium secondary battery, the positive electrode including a positive activation material mixture that intercalates and de-intercalates lithium ions, wherein the positive activation material mixture comprises a first positive activation material having an average particle diameter D 50 of from 12.5 μm to 22 μm and a second positive activation material having an average particle diameter D 50 of from 1 μm to 5 μm, and
wherein in a particle size distribution graph that plots a percentage of particles of the positive activation material mixture having a respective particle size based on a total volume of the particles as a y-axis and the respective particle size as an x-axis, as measured by a laser diffraction particle size analyzer, a minimum peak value is between a first highest peak value corresponding to the first positive activation material and a second highest peak value corresponding to the second positive activation material, a peak value Hb corresponds to a difference between the first highest peak value and the minimum peak value, and a peak value Hs corresponds to a difference between the second highest peak value and the minimum peak value, wherein a ratio of Hs/Hb is from 0.07:1 to 0.20:1.

2. The positive electrode according to claim 1 , wherein the first positive activation material has an average particle diameter D 50 of from 13 μm to 17 μm and the second positive activation material has an average particle diameter D 50 of from 2 μm to 4 μm.

3. The positive electrode according to claim 1 , wherein the first positive activation material and the second positive activation material have a same chemical composition.

4. A lithium secondary battery comprising:
a positive electrode including a positive activation material mixture that intercalates and de-intercalates lithium ions, wherein the positive activation material mixture comprises a first positive activation material having an average particle diameter D 50 of from 12.5 μm to 22 μm and a second positive activation material having an average particle diameter D 50 of from 1 μm to 5 μm;
a negative electrode including a negative activation material that intercalates and de-intercalates lithium ions; and
a non-aqueous electrolyte solution,
wherein in a particle size distribution graph that plots a percentage of particles of the positive activation material mixture having a respective particle size based on a total volume of the particles as a y-axis and the respective particle size as an x-axis, as measured by a laser diffraction particle size analyzer, a minimum peak value is between a first highest peak value corresponding to the first positive activation material and a second highest peak value corresponding to the second positive activation material, a peak value Hb corresponds to a difference between the first highest peak value and the minimum peak value, and a peak value Hs corresponds to a difference between the second highest peak value and the minimum peak value, wherein a ratio of Hs/Hb is from 0.07:1 to 0.20:1.

5. The lithium secondary battery according to claim 4 , wherein the first positive activation material has an average particle diameter D 50 of from 13 μm to 17 μm and the second positive activation material has an average particle diameter D 50 of from 2 μm to 4 μm.

6. The lithium secondary battery according to claim 4 , wherein the first positive activation material and the second positive activation material have a same chemical composition.

Assignees

• Samsung Sdi Co Ltd
• Samsung Sdi Co Ltd

Inventors

• Park Jung Joon
• Um Jae Chul
• Shin Myung Hyo

Classifications

• H01M4/1315

  containing halogen atoms, e.g. LiCoOxFy · CPC title

• H01M4/505

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

• H01M4/131 Primary

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

• H01M4/36 Primary

  Selection of substances as active materials, active masses, active liquids · CPC title

• H01M4/625

  Carbon or graphite · CPC title