Cathode additive, preparation method thereof, and cathode and lithium secondary battery comprising the same

Patent metadata

Field	Value
Publication number	US-11329287-B2
Application number	US-201816605755-A
Country	US
Kind code	B2
Filing date	Nov 15, 2018
Priority date	Nov 30, 2017
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

The present invention relates to a cathode additive, a method for preparing the same, and a cathode and a lithium secondary battery including the same. More specifically, one embodiment of the present invention provides a cathode additive that can offset an irreversible capacity imbalance, increase the initial charge capacity of a cathode, and simultaneously inhibit the generation of gas in a battery.

First claim

The invention claimed is:

1. A cathode additive composition represented by the following Chemical Formula 1:
{ x (Li 2+a Ni b M 1−b O 2+c )}.{ y (NiO)}.{ z (Li 2 O)}.{ w Li 5 MO 4 }  [Chemical Formula 1]

wherein, in Chemical Formula 1,
M is one or more metal atoms forming a divalent cation or a trivalent cation,
−0.2≤a≤0.2, 0.5≤b≤1.0, −0.2≤c≤0.2,

0.6≤x≤1.0, 0<y≤0.15, 0<z≤0.15, 0≤w≤0.1, x+y+z+w=1,

provided that when b=1.0, 0<w≤0.1, and when w=0, 0.5≤b<1.0,
wherein a structure of the cathode additive composition includes a core including the (Li 2+a Ni b M 1−b O 2+c ), (NiO) and (Li 2 O), and a coating layer including the Li 5 MO 4 .

2. The cathode additive according to claim 1 , wherein M includes Al.

3. The cathode additive according to claim 2 , wherein a peak by Li 5 AlO 4 is detected in at least one of a range in which 2θ is 33 to 36°, or a range in which 2θ is 42 to 45°, by XRD (X-Ray Diffraction) measurement by Fe Kα X-ray (X-rα).

4. The cathode additive according to claim 2 , wherein the content of Li 5 AlO 4 in the total amount of the cathode additive (100 wt %) is greater than 0 wt % and equal to or less than 15 wt %.

5. The cathode additive according to claim 1 , wherein y=z.

6. The cathode additive according to claim 1 , wherein a peak by lithium oxide (Li 2 O) is detected in at least one of a range in which 2θ is 30 to 35°, a range in which 2θ is 35 to 40°, or a range in which 2θ is 55 to 60°, by XRD (X-Ray Diffraction) measurement by Fe Kα X-ray (X-rα).

7. The cathode additive according to claim 1 , wherein the content of lithium oxide (Li 2 O) in the total amount of the cathode additive (100 wt %) is greater than 0 wt % and equal to or less than 15 wt %.

8. The cathode additive according to claim 1 , wherein a peak by nickel oxide (N i O) is detected in at least one of a range in which 2θ is 35 to 40°, a range in which 2θ is 40 to 45°, or a range in which 2θ is 50 to 55°, by XRD (X-Ray Diffraction) measurement by Fe Kα X-ray (X-rα).

9. The cathode additive according to claim 1 , wherein the content of nickel oxide (N i O) in the total amount of the cathode additive (100 wt %) is greater than 0 wt % and equal to or less than 15 wt %.

10. A cathode mixture comprising:
the cathode additive of claim 1 ; and
a cathode active material.

11. The cathode mixture according to claim 10 , wherein the cathode additive is included in the content in an amount of 1 to 30 wt %, based on the total weight of the mixture (100 wt %).

12. The cathode mixture according to claim 10 , wherein the cathode active material includes one or more composite oxides of: a metal of cobalt, manganese, nickel, or a combination thereof; and lithium.

13. The cathode mixture according to claim 10 , further comprising a conductive material, a binder, or a mixture thereof.

14. A lithium secondary battery comprising:
a cathode comprising the cathode mixture of claim 10 ;
an electrolyte; and
an anode.

15. The lithium secondary battery according to claim 14 , wherein the anode includes one or more anode active materials selected from the group consisting of a carbon-based anode active material, a lithium metal, a lithium alloy, Si, SiO x (0<x<2), a Si—C composite, a Si-Q alloy (wherein Q is an alkali metal, an alkali earth metal, an atom of Groups 13 to 16, a transition metal, a rare earth atom, or a combination thereof, provided that it is not Si), Sn, SnO 2 , a Sn—C composite, and Sn—R (R is an alkali metal, an alkali earth metal, an atom of Groups 13 to 16, a transition metal, a rare earth metal, or a combination thereof, provided that it is not Sn).

Assignees

• Lg Chemical Ltd
• Lg Energy Solution Ltd

Inventors

• Han Jungmin
• Park Byungchun
• Kim Ji Hye
• Jung Wang Mo

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• 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

• C01G53/04

  Oxides · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title