Secondary battery of improved lithium ion mobility and cell capacity

Patent metadata

Field	Value
Publication number	US-9276259-B2
Application number	US-201414228879-A
Country	US
Kind code	B2
Filing date	Mar 28, 2014
Priority date	Feb 23, 2005
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

Provided is a lithium secondary battery having improved discharge characteristics in a range of high-rate discharge while minimizing a dead volume and at the same time, having increased cell capacity via increased electrode density and electrode loading amounts, by inclusion of two or more active materials having different redox levels so as to exert superior discharge characteristics in the range of high-rate discharge via sequential action of cathode active materials in a discharge process, and preferably having different particle diameters.

First claim

What is claimed is:

1. A cathode active material for a lithium secondary battery, comprising:
a first active material; and
a second active material,
wherein the first and the second active materials have different redox levels,
wherein a redox potential difference between the redox levels of the first and the second active materials ranges from 0.29 V to 1.0 V,
wherein an average particle diameter of the first active material is less than 50% of an average particle diameter of the second active material,
wherein the average particle diameter of the first active material ranges from 12 μm to 15μm,
wherein the first active material is contained in an amount of 15 percent to 35percent by weight, based on the total weight of the cathode active material, and
wherein the first active material is LiNi 1/3 Mn 1/3 Co 1/3 O 2 , and wherein the second active materials is represented by Formula IV:
Li 1+x ,Mn 2−y M y O 4 A a   (IV)

wherein −0.2<x<0.2; 0≦y≦0.4; 0<a<0.05; M is a first row transition metal selected from the group consisting of Ni, Mn, Fe, Cr, Ti, Zn, V, Al, and Mg; and A is an element of Group 6A or Group 7A selected from the group consisting of S, Se, F, Cl and I; and
wherein the materials of Formula IV are active materials having electrochemical characteristics of Mn 3+ Mn 4+ oxidation-reduction in spinel structures thereof.

2. The cathode active material according to claim 1 , wherein the redox level of the first and the second active materials is in the range of 3.5 to 4.5V.

3. The cathode active material according to claim 1 , wherein the average particle diameter of the first active material is in the range of 10 to 35% of an average particle diameter of the second active material.

4. The cathode active material according to claim 1 , wherein the content of the first active material is in the range of 20 to 35% by weight, based on the total weight of the cathode active material.

5. The cathode active material accordingly to claim 1 , wherein M in Formula IV is Al.

6. The cathode active material according to claim 1 , wherein a redox potential difference between the redox levels of the first and the second active materials ranges from 0.32 V to 1.0 V.

Assignees

• Lg Chemical Ltd

Inventors

• Chang Sung Kyun
• Lee Seo-Jae
• Choy Sanghoon
• Bang Euiyong
• Jang Minchul
• Lee Ki-Young

Classifications

• H05B1/02

  Automatic switching arrangements specially adapted to apparatus {; Control of heating devices} (thermally-actuated switches H01H37/00) · CPC title

• H05B3/20

  Heating elements having extended surface area substantially in a two-dimensional [2D] plane, e.g. plate-heater (H05B3/62, H05B3/68, H05B3/78, H05B3/84 take precedence) · CPC title

• A47C21/048 Primary

  for heating · CPC title

• H01M4/131

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

• H01M4/364 Primary

  as mixtures · CPC title