Separator for non-aqueous electrolyte secondary battery and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-2016308185-A1
Application number	US-201615095592-A
Country	US
Kind code	A1
Filing date	Apr 11, 2016
Priority date	Apr 14, 2015
Publication date	Oct 20, 2016
Grant date	—

Abstract

A separator includes a substrate layer made of a resin and a heat resistance layer. The heat resistance layer contains heat-resistant fine particles and a binder. An amount of the binder contained per unit volume in the heat resistance layer positioned at an end portion in a width direction perpendicular to a longitudinal direction of the separator is higher than the amount of the binder contained per unit volume in the heat resistance layer ( 84 ) positioned at a center portion which includes the center in the width direction of the separator. In the heat resistance layer at the end portion, the amount of the binder contained per unit volume in a substrate layer side region is higher than the amount of the binder contained per unit volume in a surface region which includes a surface of the heat resistance layer.

First claim

What is claimed is:

1 . A manufacturing method of a separator for a non-aqueous electrolyte secondary battery, the separator including a substrate layer made of a resin and a heat resistance layer formed on a surface of the substrate layer and having a long sheet shape, the manufacturing method comprising processes of:
applying a heat resistance layer formation composition containing heat-resistant fine particles, a binder, and a solvent onto the substrate layer; and heating the heat resistance layer formation composition applied to an end portion in a width direction perpendicular to a longitudinal direction of the substrate layer in the heat resistance layer formation composition applied onto the substrate layer, from a substrate layer side, thereby forming the heat resistance layer, in which an amount of the binder contained per unit volume in a substrate layer side region is higher than the amount of the binder contained per unit volume in a surface side region which includes a surface of the heat resistance layer, at the end portion in the width direction of the heat resistance layer.

2 . The manufacturing method according to claim 1 , wherein
the end portion in the width direction of the heat resistance layer is heated at a temperature of 80° C. or higher.

3 . The manufacturing method according to claim 1 , wherein
a length in the width direction of the end portion is 1.5% or more and 10% or less of a length in the width direction of the substrate layer for each end portion in the width direction.

4 . A separator for a non-aqueous electrolyte secondary battery, comprising:
a substrate layer made of a resin; and a heat resistance layer provided on one surface of the substrate layer, the separator having a long sheet shape, wherein the heat resistance layer contains heat-resistant fine particles and a binder, an amount of the binder contained per unit volume in the heat resistance layer positioned at an end portion in a width direction perpendicular to a longitudinal direction of the separator is higher than the amount of the binder contained per unit volume in the heat resistance layer positioned at a center portion which includes the center in the width direction of the separator, and in the heat resistance layer at the end portion, the amount of the binder contained per unit volume in a substrate layer side region is higher than the amount of the binder contained per unit volume in a surface side region which includes a surface of the heat resistance layer.

5 . The separator according to claim 4 , wherein
a peel strength between the substrate layer and the heat resistance layer at the end portion is 20 N/m or higher and 50 N/m or lower.

6 . The separator according to claim 4 , wherein
a length in the width direction of the end portion is 1.5% or more and 10% or less of a length in the width direction of the separator for each end portion in the width direction.

7 . A non-aqueous electrolyte secondary battery comprising:
an electrode body which includes a positive electrode and a negative electrode laminated with the separator according to claim 4 interposed therebetween; and a non-aqueous electrolyte.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kondo Shinpei
• Oyama Yutaka
• Ochiai Akihiro

Classifications

• H01M10/4235 Primary

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M10/05

  Accumulators with non-aqueous electrolyte (H01M10/39 takes precedence) · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M10/0525

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

• H01M50/443

  Particulate material · CPC title