Positive Electrode Active Material for Secondary Battery and Lithium Secondary Battery Including the Same

Patent metadata

Field	Value
Publication number	US-2020028168-A1
Application number	US-201816485307-A
Country	US
Kind code	A1
Filing date	Sep 19, 2018
Priority date	Sep 19, 2017
Publication date	Jan 23, 2020
Grant date	—

Abstract

The present invention provides a positive electrode active material for a secondary battery which includes a lithium transition metal oxide, wherein the positive electrode active material has three peaks in a differential graph (ERC curve) obtained by differentiating a pH value against an amount of acid (HCl) added, which is obtained by pH titration of 10 g of the lithium transition metal oxide using 0.5 M HCl, wherein a y-axis (dpH/dml) value of a first peak at the smallest x-axis value among the three peaks is −1.0 or less.

First claim

1 . A positive electrode active material for a secondary battery, comprising:
a lithium transition metal oxide, wherein the positive electrode active material has three peaks in a differential graph (ERC curve) obtained by differentiating a pH value against an amount of HCl added, which is obtained by pH titration of 10 g of the lithium transition metal oxide using 0.5 M HCl, wherein a y-axis (dpH/dml) value of a first peak at a smallest x-axis value among the three peaks is −1.0 or less.

2 . The positive electrode active material for a secondary battery of claim 1 , wherein the y-axis (dpH/dml) value of the first peak is in a range of −1.5 to −2.5.

3 . The positive electrode active material for a secondary battery of claim 1 , wherein the lithium transition metal oxide has a coating portion comprising a boron lithium oxide on a surfaces of a particles of the lithium transition metal oxide.

4 . The positive electrode active material for a secondary battery of claim 3 , wherein the boron lithium oxide comprises LiBO 2 .

5 . The positive electrode active material for a secondary battery of claim 4 , wherein the coating portion comprises the LiBO 2 in an amount of 95 wt % or more.

6 . The positive electrode active material for a secondary battery of claim 4 , wherein the coating portion comprises the LiBO 2 in an amount of 95 wt % to 99 wt %.

7 . The positive electrode active material for a secondary battery of claim 3 , wherein the coating portion comprises elemental boron (B) in an amount of 500 ppm or more.

8 . The positive electrode active material for a secondary battery of claim 1 , wherein the lithium transition metal oxide comprises at least one transition metal cation selected from the group consisting of cobalt (Co), nickel (Ni), and manganese (Mn).

9 . The positive electrode active material for a secondary battery of claim 1 , wherein the lithium transition metal oxide comprises at least one of a lithium cobalt oxide, a lithium nickel oxide a lithium manganese oxide, a lithium iron phosphate compound, or a lithium transition metal composite oxide represented by Formula 1:
Li a Ni 1-x-y Co x Mn y M z O 2   [Formula 1]
wherein, in Formula 1, M is at least one element selected from the group consisting of aluminum (Al), zirconium (Zr), titanium (Ti), magnesium (Mg), tantalum (Ta), niobium (Nb), molybdenum (Mo), and chromium (Cr), 0.9≤a≤1.5, 0≤x≤0.5, 0≤y≤0.5, and 0≤z≤0.1.

10 . The positive electrode active material for a secondary battery of claim 9 , wherein the lithium transition metal composite oxide represented by Formula 1 comprises nickel (Ni) in an amount of 60 mol % or more based on an amount of total transition metals.

11 . A positive electrode for a secondary battery, the positive electrode comprising: the positive electrode active material of claim 1 , a conductive agent, a binder, and a positive electrode collector.

12 . A lithium secondary battery comprising: the positive electrode of claim 11 , a negative electrode disposed to face the positive electrode, and a separator disposed between the positive electrode and the negative electrode.

Assignees

• Lg Chemical Ltd

Inventors

• Ju In Seong
• Jung Wang Mo
• Park Byung Chun
• Jin Joo Hong
• Shin Ju Kyung
• Kim Ji Hye
• Baek So Ra
• Yoo Tae Gu

Classifications

• H01M4/505 Primary

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

• H01M10/052

  Li-accumulators · CPC title

• H01M4/5825

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

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title