Lithium ion battery and positive active material thereof

Patent metadata

Field	Value
Publication number	US-2019036117-A1
Application number	US-201816045723-A
Country	US
Kind code	A1
Filing date	Jul 25, 2018
Priority date	Jul 26, 2017
Publication date	Jan 31, 2019
Grant date	—

Abstract

The present invention provides a positive electrode active material includes a first lithium transition metal oxide represented by formula Li a (Ni b Co c Mn d ) 1-e M e O 2 or Li a (Ni b Co c Al d ) 1-e M′ e O 2 , wherein 0.9<a<1.1, 0.6≤b<0.9, 0.1≤c<0.4, 0.05≤d<0.4, 0≤e≤0.1, b+c+d=1, M is at least one of Al, Mg, Ti, Zr, M′ is at least one of Mg, Ti, Zr, and a second lithium transition metal oxide represented by formula Li x Ni y Co z M″ s O 2 , wherein 0.9<x<1.1, 0.4≤y<0.6, 0.2≤z<0.5, 0.2≤s<0.5, y+z+s=1, M″ is at least one of Mn, Al, Mg, Ti, Zr, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Nb, Mo, Sr, Sb, W, Bi. The positive electrode active material for a lithium ion battery of the present invention shows a high compacted density. The present invention also provides a lithium ion battery using the positive electrode active material of the present invention. The lithium ion battery has high gram capacity, high energy density, good storage performance, and good cycle stability.

First claim

What is claimed is:

1 . A positive active material for a lithium ion battery, comprising a first lithium transition metal oxide represented by formula Li a (Ni b Co c Mn d ) 1-e M e O 2 or Li a (Ni b Co c Al d ) 1-e M′ e O 2 , wherein 0.9<a<1.1, 0.6≤b<0.9, 0.1≤c<0.4, 0.05≤d<0.4, 0≤e≤0.1, b+c+d=1, M is at least one of Al, Mg, Ti, Zr, M′ is at least one of Mg, Ti, Zr, and
a second lithium transition metal oxide represented by formula Li x Ni y Co z M″ s O 2 , wherein 0.9<x<1.1, 0.4≤y<0.6, 0.2≤z<0.5, 0.2≤s<0.5, y+z+s=1, M″ is at least one of Mn, Al, Mg, Ti, Zr, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Nb, Mo, Sr, Sb, W, Bi.

2 . The positive active material of claim 1 , wherein a weight ratio of the first lithium transition metal oxide to the second lithium transition metal oxide is 50:50 to 90:10.

3 . The positive active material of claim 1 , wherein a weight ratio of the first lithium transition metal oxide to the second lithium transition metal oxide is 50:50 to 80:20.

4 . The positive active material of claim 1 , wherein the first lithium transition metal oxide has a median particle size of 10 μm<D50≤20 μm, and the second lithium transition metal oxide has a median particle size of 6 μm<D50≤10 μm.

5 . The positive active material of claim 1 , wherein a compacted density of the positive electrode active material is more than 3.4 g/cm 3 .

6 . The positive active material of claim 1 , wherein a particle of the second lithium transition metal oxide represented by formula Li x Ni y Co z M″ s O 2 is a single crystalline particle.

7 . The positive active material of claim 1 , wherein in the second lithium transition metal oxide represented by formula Li x Ni y Co z M″ s O 2 , 0.9<x<1.1, 0.5≤y≤0.55, 0.2≤z<0.5, 0.2≤s<0.5, y+z+s=1, M″ is Mn and/or Al.

8 . A lithium ion battery, comprising a positive electrode plate containing a positive active material, a negative electrode plate containing a negative active material, a separator interposed between the positive electrode plate and the negative electrode plate, and an electrolyte, wherein the positive active material is the positive active material of claim 1 .

9 . The lithium ion battery of claim 8 , wherein the electrolyte comprises a lithium salt, and the lithium salt is selected from at least one of LiN(C p F 2p+1 SO 2 )(C q F 2q+1 SO 2 ), LiPF 6 , LiBF 4 , LiBOB, LiAsF 6 , LiCF 3 SO 3 , LiClO 4 , wherein p, q is a natural number.

10 . The lithium ion battery of claim 8 , wherein the negative active material is selected from at least one of soft carbon, hard carbon, artificial graphite, natural graphite, silicon, silicon oxide compound, silicon carbon composite, lithium titanate, and a metal that can form an alloy with lithium.

Assignees

• Contemporary Amperex Technology Co Ltd

Inventors

• Liu Hui

Classifications

• 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

• H01M4/505 Primary

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

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M10/0525

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

• H01M4/386

  Silicon or alloys based on silicon · CPC title