Electrode for lithium-ion cell, lithium-ion cell, and method for manufacturing electrode for lithium-ion cell

Patent metadata

Field	Value
Publication number	US-10727476-B2
Application number	US-201815951647-A
Country	US
Kind code	B2
Filing date	Apr 12, 2018
Priority date	Dec 20, 2013
Publication date	Jul 28, 2020
Grant date	Jul 28, 2020

Abstract

The present invention aims to provide an electrode for lithium ion batteries which exhibits excellent electrical conductivity even if its thickness is large. The electrode for lithium ion batteries of the present invention includes a first main surface to be located adjacent to a separator of a lithium ion battery and a second main surface to be located adjacent to a current collector of the lithium ion battery. The electrode has a thickness of 150 to 5000 μm. The electrode contains, between the first main surface and the second main surface, a conductive member (A) made of an electronically conductive material and a large number of active material particles (B). At least part of the conductive member (A) forms a conductive path that electrically connects the first main surface to the second main surface. The conductive path is in contact with the active material particles (B) around the conductive path.

First claim

The invention claimed is:

1. A method of producing an electrode for lithium ion batteries,
the electrode comprising:
a first main surface to be located adjacent to a separator of a lithium ion battery; and
a second main surface to be located adjacent to a current collector of the lithium ion battery,
wherein
the electrode has a thickness of 150 to 5000 μm,
the electrode contains, between the first main surface and the second main surface, a conductive member (A) made of an electronically conductive material and a large number of active material particles (B),
the electrode is free of a binder,
the conductive member (A) comprises conductive fibers dispersed between the first main surface and the second main surface,
the conductive fibers have an electrical conductivity of 50 ms/cm or more,
at least part of the conductive member (A) forms a conductive path that electrically connects the first main surface to the second main surface,
the conductive path is in contact with the active material particles (B) around the conductive path, and
the active material particles (B) comprise coated active material particles whose surface is at least partially coated with a coating agent containing a coating resin and a conductive additive,
wherein the coating resin is selected from the group consisting of vinyl resins, urethane resins, polyester resins, polyamide resins, epoxy resins, polyimide resins, silicone resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonates,
the method comprising:
step (Q1) of applying a slurry (Y) containing the conductive member (A) and the active material particles (B) to a film (E); and
step (Q2) of fixing the active material particles (B) and the conductive member (A) onto the film (E) by pressurization or depressurization.

2. The method of producing the electrode for lithium ion batteries according to claim 1 ,
wherein the slurry (Y) is an electrolyte solution slurry (Y1) containing an electrolyte solution (D),
the film (E) is impermeable to the active material particles (B) but permeable to the electrolyte solution (D), and
in step (Q2), the electrolyte solution (D) is allowed to permeate the film (E) by pressurization or depressurization so as to be removed.

3. The method of producing the electrode for lithium ion batteries according to claim 1 ,
wherein a press step (Q3) of pressurizing the slurry (Y) at a higher pressure is performed after step (Q2).

4. The method of producing the electrode for lithium ion batteries according to claim 1 ,
wherein the film (E) has an electrical conductivity of 100 mS/cm or more.

5. The method of producing the electrode for lithium ion batteries according to claim 1 , further comprising step (Q4) of transferring the electrode for lithium ion batteries fixed onto the film (E) to a main surface of a current collector or a separator to produce an electrode for lithium ion batteries having a first main surface thereof on the main surface of the separator, or to produce an electrode for lithium ion batteries having a second main surface thereof on the main surface of the current collector.

Assignees

• Sanyo Chemical Ind Ltd
• Nissan Motor

Inventors

• Mizuno Yusuke
• Shindo Yasuhiro
• Tsudo Yasuhiro
• Kawakita Kenichi
• Kusachi Yuki
• Ohsawa Yasuhiko
• Satou Hajime
• Akama Hiroshi
• Horie Hideaki

Classifications

• H01M4/626

  Metals · CPC title

• H01M4/043

  involving compressing or compaction · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/13 Primary

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M2004/021

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