Positive electrode slurry, positive electrode, secondary battery, and positive electrode manufacturing method

Patent metadata

Field	Value
Publication number	US-12438139-B2
Application number	US-201917415224-A
Country	US
Kind code	B2
Filing date	Nov 29, 2019
Priority date	Dec 28, 2018
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

A positive electrode slurry including a positive electrode material mixture and a dispersion medium for dispersing the positive electrode material mixture. The positive electrode material mixture contains a positive electrode active material, an electrically conductive agent, a binder, and an additive. The additive includes a compound intramolecularly having a polyether group and an acidic group.

First claim

The invention claimed is:

1. A positive electrode slurry, comprising:
a positive electrode material mixture; and an organic dispersion medium as a sole dispersion medium for dispersing the positive electrode material mixture, wherein the organic dispersion medium is an organic compound,
the positive electrode material mixture comprising: a lithium-containing composite oxide containing a transition metal element as a positive electrode active material; an electrically conductive agent; a binder; and an additive,
the additive including a compound intramolecularly having a polyether group and an acidic group and free of an amine, wherein
the acidic group includes at least a sulfonic acid group.

2. The positive electrode slurry according to claim 1 , wherein the polyether group includes a polyalkylene oxide group.

3. The positive electrode slurry according to claim 1 , wherein a content of the compound is 0.1 parts by mass or more per 100 parts by mass of the positive electrode active material.

4. A positive electrode, comprising:
a current collector sheet; and a positive electrode material mixture layer supported on the current collector sheet,
the positive electrode material mixture layer being formed using the positive electrode slurry according to claim 1 .

5. A secondary battery, comprising:
a positive electrode; a negative electrode; and an electrolyte,
the positive electrode being the positive electrode according to claim 4 .

6. A method for producing a positive electrode, the method comprising:
a first step of preparing the positive electrode slurry according to claim 1 ; and
a second step of applying the positive electrode slurry onto a surface of a current collector sheet, followed by drying, to form a positive electrode material mixture layer.

7. The method for producing a positive electrode according to claim 6 , wherein in the second step, while the current collector sheet having a belt-like shape is conveyed, the positive electrode slurry is intermittently applied onto the surface of the current collector sheet.

8. The positive electrode slurry according to claim 1 , wherein the organic dispersion medium consists essentially of N-methyl-2-pyrrolidone.

9. The positive electrode slurry according to claim 1 , wherein the polyether group includes at least one or both of polypropylene oxide (PPO), and a copolymer of ethylene oxide (EO) and propylene oxide (PO).

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Mino Shinji
• Sato Eisuke
• Sakai Yoshinori
• UTSUMIYA Kazutoshi

Classifications

• H01M4/0409

  by a doctor blade method, slip-casting or roller coating · CPC title

• H01M10/0525

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

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/364

  as mixtures · CPC title