Positive electrode for lithium ion battery, lithium ion battery and method of producing positive electrode for lithium ion battery

Patent metadata

Field	Value
Publication number	US-11664490-B2
Application number	US-202016876154-A
Country	US
Kind code	B2
Filing date	May 18, 2020
Priority date	Jun 24, 2019
Publication date	May 30, 2023
Grant date	May 30, 2023

Abstract

A positive electrode (21) includes a positive electrode current collector (21A), and a positive electrode mixture layer (21B) which is formed on the positive electrode current collector (21A) and contains a positive electrode active material. The positive electrode mixture layer (21B) includes a first positive electrode active material (21B-1) composed of LiVPO4F and a second positive electrode active material (21B-2) composed of LiVP2O7. In addition, a mixing ratio of the first positive electrode active material (21B-1) and the second positive electrode active material (21B-2) contained in the positive electrode mixture layer (21B) is represented by (1−x)LiVPO4F+xLiVP2O7 (x is a mass ratio, 0<x≤0.21).

First claim

What is claimed is:

1. A positive electrode for a lithium ion battery, comprising:
a positive electrode current collector and a positive electrode mixture layer formed on the positive electrode current collector,
wherein the positive electrode mixture layer contains a first positive electrode active material composed of LiVPO 4 F and a second positive electrode active material composed of LiVP 2 O 7 , and
wherein a mixing ratio of the first positive electrode active material and the second positive electrode active material contained in the positive electrode mixture layer is represented by (1−x)LiVPO 4 F+xLiVP 2 O 7 , wherein x is a mass ratio, and wherein 0.03<x≤0.21.

2. A lithium ion battery comprising the positive electrode for a lithium ion battery according to claim 1 .

3. A method of producing a positive electrode for a lithium ion battery, comprising
forming a positive electrode mixture layer, wherein the positive electrode mixture layer comprises a first positive electrode active material and a second positive electrode active material on a positive electrode current collector, wherein a mixing ratio of the first positive electrode active material composed of LiVPO 4 F and the second positive electrode active material composed of LiVP 2 O 7 is represented by (1−x)LiVPO 4 F+xLiVP 2 O 7 , wherein x is a mass ratio, and wherein 0.3<x≤0.21.

4. The method of producing a positive electrode for a lithium ion battery according to claim 3 ,
wherein the mixing ratio is determined by Rietveld analysis of XRD patterns is represented by (1−x)LiVPO 4 F+xLiVP 2 O 7 , wherein x is a mass ratio, and wherein 0.03<x≤0.21.

5. The method of producing a positive electrode for a lithium ion battery according to claim 3 , comprising:
a mixing process in which LiF, PTFE, stearic acid, a vanadium compound and an ammonium phosphate compound are mixed;
a drying process in which the mixture obtained in the mixing process is dried;
a pulverizing process in which the dried product obtained in the drying process is pulverized; and
a firing process in which the pulverized product obtained in the pulverizing process is fired to obtain a positive electrode active material composed of the first positive electrode active material and the second positive electrode active material.

6. The method of producing a positive electrode for a lithium ion battery according to claim 3 , comprising:
a mixing process (A) in which LiF, PTFE, stearic acid, vanadium oxide having a particle size distribution of less than 200 μm and an ammonium phosphate compound are mixed;
a drying process (B) in which the mixture obtained in the mixing process (A) is dried;
a pulverizing process (C) in which the dried product obtained in the drying process (B) is pulverized 120 times over 30 seconds;
a firing process (D) in which the pulverized product obtained in the pulverizing process (C) is fired to obtain the first positive electrode active material;
a mixing process (E) in which citric acid and phosphoric acid are mixed into a solution in which vanadium oxide is dissolved;
a drying process (F) in which the mixture obtained in the mixing process (E) is dried;
a firing process (G) in which the dried product obtained in the drying process (F) is fired;
a pulverizing process (H) in which lithium carbonate and citric acid are added to the fired product obtained in the firing process (G) and the mixture is pulverized and mixed;
a pre-firing process (I) in which the pulverized product obtained in the pulverizing process (H) is pre-fired;
a main firing process (J) in which the fired product obtained in the pre-firing process (I) is main-fired to obtain a second positive electrode active material; and
a mixing process (K) in which the first positive electrode active material and the second positive electrode active material are mixed at the mixing ratio to obtain a positive electrode active material composed of the first positive electrode active material and the second positive electrode active material.

Assignees

• Honda Motor Co Ltd

Inventors

• Araki Kazuhiro
• Matsuzaka Taku

Classifications

• H01M4/5825

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

• H01M10/0525

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

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/136 Primary

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title