High voltage positive active material and lithium secondary battery comprising the same

Patent metadata

Field	Value
Publication number	US-9799878-B2
Application number	US-201414548747-A
Country	US
Kind code	B2
Filing date	Nov 20, 2014
Priority date	Jul 9, 2012
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

Disclosed are a cathode active material for high voltage and a lithium secondary battery including the same. More particularly, a cathode active material including spinel-type compound particles having a composition represented by Formula 1 below;

Li 1+a M x Mn 2−x O 4−z A z   (1)

where a, x and z are defined in a specification of the present invention, and metal oxides or metal hydroxides present on surfaces of the spinel-type compound particles, and a lithium secondary battery including the same.

First claim

The invention claimed is:

1. A cathode active material comprising spinel-type compound particles having a composition represented by Formula 1:
Li 1+a M x Mn 2−x O 4−z A z   (1)

wherein M is at least one selected form the group consisting of Ni, Ti, Co, Al, Cu, Fe, Mg, B, Cr, Zr, and Zn;
A is a monovalent anion or divalent anion; and
−0.1≦a≦0.1, 0.3≦x≦0.8, and 0≦z≦0.1; and
wherein the spinel-type compound particles have a surface layer of metal oxides or metal hydroxides, the metal oxides or the metal hydroxides are oxides or hydroxides of at least one metal selected from the group consisting of Al, Mg, Ni, Co, Ti, Cr, Mo, Bi, Zn, Zr, Ru and W, and
wherein the metal oxides or the metal hydroxides adhere to surfaces of spinel-type compound particles in a particle form and wherein the metal oxides or the metal hydroxides cover from about 50% to about 80% of an overall surface of a spinel-type compound represented by Formula 1.

2. The cathode active material according to claim 1 , wherein the spinel-type compound is a compound represented by Formula 2 below:
Li 1+a Ni b M c Mn 2 −(b+c)O 4+z A z   (2)

wherein M is at least one selected from the group consisting of Ti, Co, Al, Cu, Fe, Mg, B, Cr, Zr, and Zn;
A is a monovalent anion or divalent anion; and
−0.1≦a≦0.1, 0.3≦b≦0.6, 0≦c≦0.2, and 0≦z≦0.1.

3. The cathode active material according to claim 1 , wherein A independently is at least one selected from the group consisting of a halogen such as F, Cl, Br, I and the like, S, and N.

4. A cathode active material comprising spinel-type compound particles having a composition represented by Formula 1:
Li 1+a M x Mn 2 −x O 4−z A z   (1)

wherein M is at least one selected form the group consisting of Ni, Ti, Co, Al, Cu, Fe, Mg, B, Cr, Zr, Zn and Period II transition metals;
A is a monovalent anion or divalent anion; and
−0.1≦a≦0.1, 0.3≦x≦0.8, and 0≦z≦0.1; and
wherein a metal oxide film or a metal hydroxide film is formed on the surfaces of spinel-type compound particles, the metal oxides or the metal hydroxides are oxides or hydroxides of at least one metal selected from the group consisting of Al, Mg, Ni, Co, Ti, Cr, Mo, Bi, Zn, Zr, Ru and W, wherein the metal oxide film or the metal hydroxide film is formed on entire surfaces of the spinel-type compound particles to form a core-shell structure.

5. The cathode active material according to claim 1 , wherein the metal oxide or the metal hydroxide physically and/or chemically combines with a surface of the spinel-type compound.

6. The cathode active material according to claim 1 , wherein an average diameter (D50) of the metal oxides or the metal hydroxide particles is 20 nm to 1000 nm.

7. The cathode active material according to claim 4 , wherein the metal oxide or the metal hydroxide film has a thickness of 50 nm to 500 nm.

8. The cathode active material according to claim 1 , wherein the cathode active material is prepared by wet-mixing and drying a spinel-type compound having a composition represented by Formula 1 and a metal oxide precursor or a metal hydroxide precursor.

9. The cathode active material according to claim 1 , wherein the cathode active material is prepared by dry-mixing and heat-treating a spinel-type compound having a composition represented by Formula 1 and a metal oxide precursor or a metal hydroxide precursor.

10. A lithium secondary battery comprising the cathode active material according to claim 1 .

11. The lithium secondary battery according to claim 10 , wherein initial charge and discharge efficiency measured after charging and discharging once at a current of 0.1 C in a voltage range of 3.5 to 4.9 V is 95% or more.

12. The lithium secondary battery according to claim 10 , wherein high speed charge efficiency measured by charging at a current of 5.0 C after charging and discharging at a current of 0.1 C is 86% or more.

13. The lithium secondary battery according to claim 12 , wherein the high speed charge efficiency is 90% or more.

14. The lithium secondary battery according to claim 10 , wherein lifespan characteristics measured by charging and discharging one hundred times at a current of 1.0 C are 92% or more.

15. The lithium secondary battery according to claim 10 , wherein, after decomposing a battery by charging to 4.9 V at a current of 0.1 C after charging and discharging once at a current of 0.1 C in a voltage range of 3.5 to 4.9 V, and then soaking a cathode obtained from the decomposed battery in a container containing 15 ml of a liquid electrolyte comprising 1 M LiPF 6 dissolved in a solvent in which ethylene carbonate, dimethyl carbonate and diethyl carbonate were mixed in a ratio of 1:2:1 and storing in a 80° C. constant-temperature bath for two weeks, an amount of manganese eluted in an electrolyte measured with an inductively coupled plasma optical emission spectrometer is 60 ppm or more and less than 280 ppm.

16. The lithium secondary battery according to claim 15 , wherein the amount of manganese is 80 ppm or more and less than 250 ppm.

17. The lithium secondary battery according to claim 16 , wherein the amount of manganese is 90 ppm or more and less than 200 ppm.

18. A battery pack comprising the lithium secondary battery according to claim 7 .

19. An electric vehicle comprising the battery pack according to claim 18 as a power source.

Assignees

• Lg Chemical Ltd

Inventors

• Kang Minsuk
• Kang Seong Hoon
• Shin Ho Suk
• Park Byung Chun
• Park Sang Min
• Min Geungi

Classifications

• H01M4/131 Primary

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

• H01M4/1391

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

• B60L2240/547

  Voltage · CPC title

• B60L50/64

  Constructional details of batteries specially adapted for electric vehicles · 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