Electrode active material, lithium secondary battery containing the electrode active material, and method of preparing the ode active material

Patent metadata

Field	Value
Publication number	US-2018205084-A1
Application number	US-201815873287-A
Country	US
Kind code	A1
Filing date	Jan 17, 2018
Priority date	Jan 17, 2017
Publication date	Jul 19, 2018
Grant date	—

Abstract

An electrode active material includes: a core active material having a layered structure and capable of reversibly incorporating and deincorporating lithium; a dopant including boron and a first metal element, wherein the dopant is in the core active material; and a nanostructure disposed on a surface of the core active material and including a metal borate compound including a second metal element, wherein the second metal element is the same as the first metal element.

First claim

What is claimed is:

1 . An electrode active material comprising:
a core active material having a layered structure and capable of reversibly incorporating and deincorporating lithium; a dopant comprising boron and a first metal element in the core active material; and a nanostructure disposed on a surface of the core active material and comprising a metal borate compound comprising a second metal element, wherein the second metal element is the same as the first metal element.

2 . The electrode active material of claim 1 , wherein the first metal element is intercalated in the layered structure of the core active material.

3 . The electrode active material of claim 1 , wherein the first metal element is configured to contract or expand the layered structure of the core active material, and comprises aluminum, zirconium, calcium, barium, bismuth, tin, zinc, silicon, strontium, titanium, vanadium, chromium, iron, copper, niobium, molybdenum, ruthenium, palladium, silver, cadmium, tantalum, tungsten, iridium, platinum, gold, or a combination thereof.

4 . The electrode active material of claim 3 , wherein the first metal element further comprises lithium.

5 . The electrode active material of claim 1 , wherein the boron and the first metal element are paired together in the layered structure of the core active material and are configured to contract or expand the layered structure of the core active material.

6 . The electrode active material of claim 1 , wherein a total amount of boron and the first metal element in the dopant, and boron and the second metal element contained in the metal borate compound is in a range of about 0.3 mole percent to about 10 mole percent based on 1 mole of the core active material.

7 . The electrode active material of claim 6 , wherein the total amount of the first metal element and the second metal element is about 0.25 mole percent or greater based on 1 mole of the core active material.

8 . The electrode active material of claim 1 , wherein a molar ratio of the total amount of the first metal element and the second metal element to the total amount of boron in the dopant and boron contained in the metal borate compound is in a range of about 1:10 to about 30:1.

9 . The electrode active material of claim 1 , wherein an aspect ratio of the nanostructure is in a range of about 1 to about 200.

10 . The electrode active material of claim 1 , wherein the nanostructure comprises a nanowire, a nanorod, a nanoplate, a nanobelt, a nanoribbon, or a combination thereof.

11 . The electrode active material of claim 1 , wherein the metal borate compound is represented by Formula 1:
M x B y O z   Formula 1
wherein, in Formula 1, M is a material configured to contract or expand the layered structure of the core active material and comprises aluminum, zirconium, calcium, barium, bismuth, tin, zinc, silicon, strontium, titanium, vanadium, chromium, iron, copper, niobium, molybdenum, ruthenium, palladium, silver, cadmium, tantalum, tungsten, iridium, platinum, gold, or a combination thereof; and x, y, and z satisfy 1≤x<30, 1≤y<10, and 1<z<40.

12 . The electrode active material of claim 1 , wherein the metal borate compound is a compound represented by Formula 2:
m MO β - n B 2 O 3   Formula 2
wherein, in Formula 2, M is a material capable of contracting or expanding the layered structure of the core active material and comprises aluminum, zirconium, calcium, barium, bismuth, tin, zinc, silicon, strontium, titanium, vanadium, chromium, iron, copper, niobium, molybdenum, ruthenium, palladium, silver, cadmium, tantalum, tungsten, iridium, platinum, gold, or a combination thereof; β is a number determined by an oxidation state of M; and m:n is in a range of 0.5:0.5 to 9:2.

13 . The electrode active material of claim 1 , wherein the metal borate compound comprises an aluminum borate compound, a zirconium borate compound, a Li-containing compound thereof, or a combination thereof.

14 . The electrode active material of claim 13 , wherein the aluminum borate compound comprises AlBO 3 , Al 4 B 2 O 9 , Al 5 BO 9 , Al 18 B 4 O 33 , a Li-containing compound thereof, or a combination thereof.

15 . The electrode active material of claim 13 , wherein the zirconium borate compound comprises ZrBO 3 , ZrB 2 O 5 , LiZrB 3 O 7 , Li 2 ZrB 4 O 9 , a Li-containing compound thereof, or a combination thereof.

16 . The electrode active material of claim 1 , wherein the dopant comprises AlB, Al 4 B 2 , Al 5 B, Al 18 B 4 , ZrB, ZrB 2 , ZrB 3 , ZrB 4 , a Li-containing compound thereof, or a combination thereof.

17 . The electrode active material of claim 1 , wherein an interlayer distance of the layered structure of the core active material with the dopant is increased as compared to an interlayer distance of the layered structure of the core active material without the dopant.

18 . The electrode active material of claim 1 comprising residual lithium in an amount in a range of about 100 parts per million to about 20,000 parts per million.

19 . The electrode active material of claim 1 , wherein the core active material is a compound represented by Formula 3 having a layered structure:
LiNi x M 1 1-x O 2-e M′ e   Formula 3
wherein, in Formula 3, M 1 is a Group 4 to a Group 14 element, or a combination thereof; M′ is an anion element comprising F, S, Cl, Br, or a combination thereof; and x and e satisfy 0.75≤x<1 and 0≤e<1.

20 . The electrode active material of claim 1 , wherein the core active material is a secondary particle comprising agglomerated primary particles, and the nanostructure comprising the metal borate is disposed on a surface of the primary particle, a grain boundary between the primary particles, a surface of the secondary particle, or a combination thereof.

21 . A lithium secondary battery comprising the electrode active material of claim 1 .

22 . A method of preparing the electrode active material of claim 1 , the method comprising:
dry-mixing a precursor material for the core active material, a metal element precursor, and a borate precursor to prepare a mixture; and heat-treating the mixture to prepare the electrode active material.

23 . The method of claim 22 , wherein the metal element of the metal element precursor is intercalated in the layered structure of the core active material and at the same time forms the nanostructure on the surface of the core active material.

24 . The method of claim 22 , wherein the precursor material for the core active material is in the form of a hydrate.

25 . The method of claim 22 , wherein the metal element precursor comprises an aluminum precursor, a zirconium precursor, a hydrate thereof, or a combination thereof;

26 . The method of claim 25 , wherein the aluminum precursor comprises Al(NO 3 ) 3 , Al 2 O 3 , AlPO 4 , Al(OH) 3 , Al(ClO 4 ) 3 , AlK(SO 4 ) 2 , Al 2 (SO 4 ) 3 , Al 2 S 3 , AlF 3 , a hydrate thereof, or a combination thereof;
the zirconium precursor comprises of Zr(NO 3 ) 4 , ZrO 2 , Zr(HPO 4 ) 2 , Zr(OH) 4 , Zr(ClO 4 ) 4 , Zr(SO 4 ) 2 , (CH 3 CO 2 ) x Zr(OH) y wherein x+y=4, ZrCl 4 , ZrF 4 , a hydrate thereof, or a combination thereof; and the borate precursor comprises H 2 BH 3 , LiBH 4 , NaBO 4 , KBH 4 , Mg(BH 4 ) 2 , Ca(BH 4 ) 2 , Sr(BH 4 ) 2 , NH 3 BH 3 , Al(BH 4 ) 3 , or a combination thereof.

27 . The method of claim 22 , wherei

Assignees

• Samsung Electronics Co Ltd
• Samsung Sdi Co Ltd

Inventors

• Ham Dongjin
• Song Jayhyok
• Yeon Donghee
• Park Jinhwan
• Yoo Daechul

Classifications

• H01M2004/028

  Positive electrodes · 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

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/5825 Primary

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M4/8657

  layered · CPC title