Positive electrode for secondary battery, and secondary battery

Patent metadata

Field	Value
Publication number	US-12362359-B2
Application number	US-202217970312-A
Country	US
Kind code	B2
Filing date	Oct 20, 2022
Priority date	Apr 28, 2020
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a positive electrode active material layer. The positive electrode active material layer includes a lithium-nickel composite oxide of a layered rock-salt type.

First claim

The invention claimed is:

1. A secondary battery comprising:
a positive electrode including a positive electrode active material layer;
a negative electrode; and
an electrolytic solution, wherein
the positive electrode active material layer includes a lithium-nickel composite oxide of a layered rock-salt type represented by Formula (1) below,
according to an analysis of the positive electrode active material layer performed at a surface of the positive electrode active material layer by X-ray photoelectron spectroscopy, a ratio X of an atomic concentration of Al to an atomic concentration of Ni satisfies a condition represented by Expression (2) below,
according to an analysis of the positive electrode active material layer performed at an inner part at a depth of 100 nanometers of the positive electrode active material layer by the X-ray photoelectron spectroscopy, a ratio Y of the atomic concentration of Al to the atomic concentration of Ni satisfies a condition represented by Expression (3) below,
a ratio Z of the ratio X to the ratio Y satisfies a condition represented by Expression (4) below,
a B1s spectrum, an S2p spectrum, an F1s spectrum, and an Ni3p spectrum are detectable by a surface analysis of the positive electrode by the X-ray photoelectron spectroscopy,
a ratio IBN of an intensity of the B1s spectrum to an intensity of the Ni3p spectrum satisfies a condition represented by Expression (5) below,
a ratio ISN of an intensity of the S2p spectrum to the intensity of the Ni3p spectrum satisfies a condition represented by Expression (6) below, and
a ratio IFN of an intensity of the F1s spectrum to the intensity of the Ni3p spectrum satisfies a condition represented by Expression (7) below,
Li a Ni 1-b-c-d CO b Al c M d O e   (1)

where
M is at least one of Fe, Mn, Cu, Zn, Cr, V, Ti, Mg, or Zr; and
a, b, c, d, and e satisfy 0.8<a<1.2, 0.06≤b≤0.18, 0.015≤c≤0.05, 0≤d≤0.08, 0<e<3, 0.1≤(b+c+d)≤0.22, and 4.33≤(1−b−c−d)/b≤15.0,
0.30≤ X≤ 0.70  (2)

0.16≤ Y≤ 0.37  (3)

1.30≤ Z≤ 2.52  (4)

0.9≤ IBN≤ 1.8  (5)

0.4≤ ISN≤ 1.2  (6)

8≤ IFN≤ 13  (7).

2. The secondary battery according to claim 1 , wherein din Formula (1) above satisfies d>0.

3. The secondary battery according to claim 1 , further comprising an outer package member having flexibility and containing the positive electrode, the negative electrode, and the electrolytic solution.

4. The secondary battery according to claim 1 , wherein
the positive electrode further includes a film covering the surface of the positive electrode active material layer,
the film includes boron, sulfur, and fluorine as constituent elements, and
the surface analysis of the positive electrode by the X-ray photoelectron spectroscopy comprises an analysis of the film.

5. The secondary battery according to claim 1 , wherein the electrolytic solution includes a boron-containing compound, a sulfur-containing compound, and a fluorine-containing compound.

6. The secondary battery according to claim 5 , wherein
the boron-containing compound includes a boron-containing lithium salt,
the sulfur-containing compound includes a cyclic disulfonic acid anhydride, an alkynyl sulfonic acid, or both, and
the fluorine-containing compound includes a fluorine-containing lithium salt.

7. The secondary battery according to claim 1 , wherein the secondary battery comprises a lithium-ion secondary battery.

8. A positive electrode for a secondary battery, the positive electrode comprising
a positive electrode active material layer, wherein
the positive electrode active material layer includes a lithium-nickel composite oxide of a layered rock-salt type represented by Formula (1) below,
according to an analysis of the positive electrode active material layer performed at a surface of the positive electrode active material layer by X-ray photoelectron spectroscopy, a ratio X of an atomic concentration of Al to an atomic concentration of Ni satisfies a condition represented by Expression (2) below,
according to an analysis of the positive electrode active material layer performed at an inner part at a depth of 100 nanometers of the positive electrode active material layer by the X-ray photoelectron spectroscopy, a ratio Y of the atomic concentration of Al to the atomic concentration of Ni satisfies a condition represented by Expression (3) below,
a ratio Z of the ratio X to the ratio Y satisfies a condition represented by Expression (4) below,
a B1s spectrum, an S2p spectrum, an F1s spectrum, and an Ni3p spectrum are detectable by a surface analysis of the positive electrode by the X-ray photoelectron spectroscopy,
a ratio IBN of an intensity of the B1s spectrum to an intensity of the Ni3p spectrum satisfies a condition represented by Expression (5) below,
a ratio ISN of an intensity of the S2p spectrum to the intensity of the Ni3p spectrum satisfies a condition represented by Expression (6) below, and
a ratio IFN of an intensity of the F1s spectrum to the intensity of the Ni3p spectrum satisfies a condition represented by Expression (7) below,
Li a Ni 1-b-c-d CO b Al c M d O e   (1)

where
M is at least one of Fe, Mn, Cu, Zn, Cr, V, Ti, Mg, or Zr; and

a, b, c, d, and e satisfy 0.8<a<1.2, 0.06≤b≤0.18, 0.015≤c≤0.05, 0≤d≤0.08, 0<e<3, 0.1≤(b+c+d)≤0.22, and 4.33≤(1−b−c−d)/b≤15.0,
0.30≤ X≤ 0.70  (2)

0.16≤ Y≤ 0.37  (3)

1.30≤ Z≤ 2.52  (4)

0.9≤ IBN≤ 1.8  (5)

0.4≤ ISN≤ 1.2  (6)

8≤ IFN≤ 13  (7).

Assignees

• Murata Manufacturing Co

Inventors

• Fukuda Masumi
• Ouki Atsushi
• Nemoto Atsushi
• Ono Takamasa
• Kuratsuka Masaki
• Fujikawa Takashige
• Soeda Ryuji
• Takahashi Sho
• Akiyama Yoshihito
• Kono Yosuke
• Nishiyama Shoichi
• Asanuma Takeo
• Hayazaki Shinji

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/021

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

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0525

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

• H01M4/505

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