Secondary cell

Patent metadata

Field	Value
Publication number	US-10651448-B2
Application number	US-201716337047-A
Country	US
Kind code	B2
Filing date	Sep 28, 2017
Priority date	Sep 29, 2016
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A secondary battery suppresses generation of wrinkle at the outer peripheral edge portion of a negative electrode plate due to expansion of a negative electrode active material layer with use. The secondary battery includes a positive electrode plate with a positive electrode active material layer disposed on a first current collector, and a negative electrode plate with a negative electrode active material layer having an area larger than an area of the positive electrode active material layer disposed on a second current collector. The negative electrode plate includes a facing portion facing the positive electrode active material layer and a non-facing portion. The negative electrode plate and a separator are bonded through a bonding layer. The bonding strength of a second bonding portion that bonds the non-facing portion to the separator is larger than the bonding strength of a first bonding portion that bonds the facing portion to the separator.

First claim

The invention claimed is:

1. A secondary battery comprising a power generating element, wherein a positive electrode plate, in which a positive electrode active material layer is disposed on at least one surface of a first current collector, and a negative electrode plate, in which a negative electrode active material layer having an area larger than an area of the positive electrode active material layer is disposed on at least one surface of a second current collector, are stacked with a separator holding an electrolyte interposed therebetween in a state in which the positive electrode active material layer and the negative electrode active material layer face each other,
the negative electrode plate comprises a facing portion facing the positive electrode active material layer with the separator interposed therebetween and a non-facing portion positioned at the outer periphery of the facing portion and not facing the positive electrode active material layer with the separator interposed therebetween,
the negative electrode plate and the separator are bonded through a bonding layer, and
in the bonding layer, bonding strength of a second bonding portion that bonds the non-facing portion to the separator is larger than bonding strength of a first bonding portion that bonds the facing portion to the separator.

2. The secondary battery according to claim 1 , wherein an average particle diameter of a material constituting the second bonding portion is smaller than an average particle diameter of a material constituting the first bonding portion.

3. The secondary battery according to claim 1 , wherein a basis weight of a material constituting the second bonding portion is larger than a basis weight of a material constituting the first bonding portion.

4. The secondary battery according to claim 1 , wherein a material constituting the first bonding portion and a material constituting the second bonding portion are different from each other.

5. The secondary battery according to claim 4 , wherein the second bonding portion has non-ionic permeability.

6. The secondary battery according to claim 1 , wherein the secondary battery is a lithium ion secondary battery, and
at least one kind of negative electrode active materials contained in the negative electrode active material layer is selected from a group consisting of silicon, a silicon alloy, and a silicon oxide.

Assignees

• Envision Aesc Japan Ltd

Inventors

• Honda Takashi
• Naruoka Yoshinori
• Yoshino Satoshi

Classifications

• H01M10/058

  Construction or manufacture · CPC title

• H01M4/483

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title

• H01M10/0585 Primary

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title

• H01M10/0525

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

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title