Positive electrode active material, lithium ion secondary battery and method for manufacturing positive electrode active material

Patent metadata

Field	Value
Publication number	US-2025309260-A1
Application number	US-202519051551-A
Country	US
Kind code	A1
Filing date	Feb 12, 2025
Priority date	Mar 29, 2024
Publication date	Oct 2, 2025
Grant date	—

Abstract

There is provided a positive electrode active material containing a lithium-iron composite fluoride as a principal component, wherein the lithium-iron composite fluoride is represented by the following formula (1):LixFeF(3+x)  (1)where, in formula (1), x is a number satisfying 0.4≤x<1.5.

First claim

What is claimed is:

1 . A positive electrode active material comprising a lithium-iron composite fluoride as a principal component, wherein
the lithium-iron composite fluoride is represented by the following formula (1):
Li x FeF (3+x)   (1)

where, in formula (1), x is a number satisfying 0.4≤x<1.5.

2 . The positive electrode active material according to claim 1 , wherein in the above formula (1), x satisfies 0.4≤x<1.0.

3 . The positive electrode active material according to claim 1 , having peaks in a range of 20°≤2θ<25° and a range of 25°≤2θ≤30° in an X-ray diffraction pattern.

4 . The positive electrode active material according to claim 2 , having peaks in a range of 20°≤2θ<25° and a range of 25°≤2θ≤30° in an X-ray diffraction pattern, wherein
a diffraction intensity ratio (I LFF/FeF3 ) represented by a maximum peak intensity in the range of 25°≤2θ≤30° to a maximum peak intensity in the range of 20°≤2θ<25° satisfies a relationship of the following formula (3):
I LFF/FeF3 =0.74 x+b   (3)

where, in formula (3), x represents a number satisfying 0.4≤x<1.0 in the above formula (1), and b represents a number satisfying b>0.46.

5 . A lithium ion secondary battery comprising a positive electrode, a negative electrode, and an electrolyte, wherein the positive electrode contains the positive electrode active material according to claim 1 .

6 . The lithium ion secondary battery according to claim 5 , wherein a dQ/dV plot during discharge in a charge-discharge cycle has a peak in a range of 3.77 to 4.0 V.

7 . The lithium ion secondary battery according to claim 5 , having an average discharge voltage of 3.8 to 4.0 V.

8 . The lithium ion secondary battery according to claim 5 , wherein the electrolyte is a liquid electrolyte, a solid electrolyte, or a semi-solid electrolyte.

9 . The lithium ion secondary battery according to claim 5 , wherein the negative electrode is formed of metallic lithium or graphite.

10 . A method for manufacturing the positive electrode active material according to claim 1 , the method comprising a step of mixing a lithium source and an iron source, and subjecting the mixture to a mechanical treatment to obtain a lithium-iron composite fluoride.

11 . The method for manufacturing the positive electrode active material according to claim 10 , further comprising a step of subjecting the lithium-iron composite fluoride to a heat treatment.

Assignees

• Honda Motor Co Ltd

Inventors

• Hakari Takashi
• Sakatsume Kazumasa
• Chiba Kazuki
• Tanaka Akihisa
• Morita Yoshiyuki

Classifications

• H01M4/5825

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

• H01M4/582 Primary

  Halogenides · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• C01G49/10

  Halides {(C01G49/0018 takes precedence)} · CPC title

• H01M10/0525 Primary

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