Lithium secondary battery

Patent metadata

Field	Value
Publication number	US-10476079-B2
Application number	US-201514947654-A
Country	US
Kind code	B2
Filing date	Nov 20, 2015
Priority date	Nov 21, 2014
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A lithium secondary battery comprises a cathode, an anode and a non-aqueous electrolyte. The cathode includes a cathode active material containing lithium-metal oxide of which at least one of metals has a continuous concentration gradient from a core part to a surface part thereof, and is doped with transitional metal. The lithium-metal oxide includes elements M1, M2 and M3. One of M1, M2 and M3 has a concentration gradient range in which a concentration increases from the core part to the surface part.

First claim

What is claimed is:

1. A lithium secondary battery, comprising a cathode, an anode and a non-aqueous electrolyte,
wherein the cathode includes a cathode active material consisting of one or more lithium-metal oxides containing Ni, Co, and Mn,
and wherein at least one of the lithium-metal oxides includes a compound represented by Formula 1 below which is doped with a dopant element,
Li x M1 a M2 b M3 c O y   Formula 1

0<x≤1.1, 2≤y≤2.02, 0<a<1, 0<b<1, 0<c<1, and 0<a+b+c≤1,
wherein M3 is Mn and has a concentration gradient range in which a concentration increases continuously throughout the cathode active material from a center of the cathode active material to a surface of the cathode active material,
wherein M1 is Ni and has a concentration gradient range in which a concentration decreases continuously from the center of the cathode active material to the surface of the cathode active material,
wherein M2 is Co and has a constant concentration from the center of the cathode active material to the surface of the cathode active material,
wherein the dopant element is in a concentration of 1,000 to 5,000 ppm relative to the compound of Formula 1 having the concentration gradient range, and
wherein a of Formula 1 is 0.7797 or more throughout an entire region of the cathode active material.

2. The lithium secondary battery according to claim 1 , wherein the dopant element is at least one selected from a group consisting of Ti, Zr, Mg, Al, V, B, Na, Ca, Cr, Cu, Zn, Ge, Sr, Ba, Nb and Ga.

3. The lithium secondary battery according to claim 1 , wherein the dopant element is doped in a concentration of 1000 to 3,000 ppm.

4. The lithium secondary battery according to claim 1 , wherein the at least one of the lithium-metal oxides further includes a coating layer on a surface thereof, which is made of Al, Ti, Ba, Zr, Si, B, Mg and P, and alloys or oxides thereof.

5. The lithium secondary battery according to claim 1 , wherein the concentration of Ni is within a range from 0.7797 to 0.9 throughout the entire region of the cathode active material.

6. The lithium secondary battery according to claim 1 , wherein the at least one of the one or more lithium-metal oxides has a first particle of a rod-type shape.

7. The lithium secondary battery according to claim 1 , wherein the dopant element is doped in a concentration of 1000 to 3,000 ppm.

8. The lithium secondary battery according to claim 1 , wherein the at least one of the lithium-metal oxides further includes a coating layer on a surface thereof, which is made of Al, Ti, Ba, Zr, Si, B, Mg and P, and alloys or oxides thereof.

9. A lithium secondary battery, comprising a cathode, an anode and a non-aqueous electrolyte,
wherein the cathode includes a cathode active material consisting of one or more lithium-metal oxides containing Ni, Co, and Mn,
and wherein, at least one of the lithium-metal oxides includes a compound represented by Formula 1 below which is doped with a dopant element,
Li x M1 a M2 b M3 c O y   Formula 1

0<x≤1.1, 2≤y≤2.02, 0<a<1, 0<b<1, 0<c<1, and 0<a+b+c≤1,
wherein M3 is Mn, and has a concentration gradient range in which a concentration increases continuously throughout the cathode active material frog a center of the cathode active material to a surface of the cathode active material,
wherein M1 is Ni and has a concentration gradient range in which a concentration decreases continuously from the center of the cathode active material to the surface of the cathode active material,
wherein M2 is Co and has a constant concentration from the center of the cathode active material to the surface of the cathode active material, and
wherein the dopant element is in a concentration of 1,000 to 5,000 ppm relative to the compound of formula I having the concentration gradient range,
wherein a capacity of 0.5 C charging at −20° C. is 65% or more of that at room temperature, and a capacity of 0.5 discharging at −20° C. is 78% or more of that at room temperature, and
wherein a of Formula 1 is 0.7797 or more throughout an entire region of the cathode active material.

10. The lithium secondary, battery according to claim 9 , wherein the dopant element is at least one selected from a group consisting of Ti, Zr, Mg, Al, V, B, Na, Ca, Cr, Cu, Zn, Ge, Sr, Ba, Nb and Ga.

11. The lithium secondary battery according to claim 9 , wherein a discharge power at −20° C. is −20% or more of that at room temperature.

12. A lithium secondary battery, comprising a cathode, an anode and a non-aqueous electrolyte, the cathode including a cathode active material, wherein the cathode active material includes a lithium-metal oxide containing Ni, Co, and Mn, represented by Formula 1 below,
Li x M1 a M2 b M3 c O y   Formula 1

0<x≤1.1, 2≤y≤2.02, 0<a<1, 0<b<1, 0<c<1, and 0<a+b+c≤1,
wherein M3 is Mn and has a concentration gradient range in which a concentration increases continuously throughout the cathode active material from a center of the cathode active material to a surface of the cathode active material,
wherein M1 is Ni and has a concentration gradient range in which a concentration decreases continuously from the center of the cathode active material to the surface of the cathode active material,
wherein M2 is Co and has a constant concentration from the center of the cathode active material to the surface of the cathode active material,
wherein the lithium-metal oxide includes a dopant element in a concentration of 1,000 to 5,000 ppm relative to the compound of Formula 1 having the concentration gradient range,
wherein the concentration of Ni is 0.7 or more throughout an entire region of the cathode active material,
wherein the cathode does not include a cathode active material containing a lithium-metal oxide having which has only one or two of the Ni, Co, or Mn, and
wherein a of Formula 1 is 0.7797 or more throughout an entire region of the cathode active material.

13. The lithium secondary battery of claim 12 , wherein the concentration of Ni is within a range of from 0.7797 to 0.9 throughout the entire region, of the cathode active material.

Assignees

• Sk Innovation Co Ltd

Inventors

• Yoo Kyung-Bin
• Hwang Duck-Chul
• Lim Jin-Sub
• Han Kook-Hyun

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/525 Primary

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

• H01M10/0525

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

• H01M4/505 Primary

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