Separator and energy storage device

Patent metadata

Field	Value
Publication number	US-11870029-B2
Application number	US-202117204739-A
Country	US
Kind code	B2
Filing date	Mar 17, 2021
Priority date	Apr 11, 2018
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

A separator includes: a first porous substrate; and a second porous substrate arranged on at least one surface of the first porous substrate; wherein the elongation at break of the second porous substrate is greater than the elongation at break of the first porous substrate in at least one of the machine and transverse directions of the separator. The separator has a high tensile strength and an elongation at break and good heat resistance, and may improve the safety performance of the energy storage device when the separator is applied to the energy storage device.

First claim

What is claimed is:

1. A battery separator, comprising:
a first porous substrate; and
a second porous substrate arranged on at least one surface of the first porous substrate; wherein,
an elongation at a break of the second porous substrate is greater than an elongation at a break of the first porous substrate in at least one of a machine direction or a transverse direction of the battery separator; and
the first porous substrate comprises one or more selected from the group consisting of polypropylene, polyethylene, polyethylene terephthalate, polyimide, and polyphthalaldehyde phenyl diamine.

2. The battery separator according to claim 1 , wherein the elongation at the break of the second porous substrate is 105% to 800% in the machine direction and the transverse direction.

3. The battery separator according to claim 1 , wherein a ratio of thickness of the first porous substrate to the second porous substrate is 1:2 to 3:2.

4. The battery separator according to claim 1 , wherein the second porous substrate has a tensile strength ranging from 150 kgf/cm 2 to 800 kgf/cm 2 in each of the machine direction and the transverse direction.

5. The battery separator according to claim 1 , wherein the second porous substrate comprises one or more selected from the group consisting of polyvinylidene fluoride, polytetrafluoroethylene, and polyurethane.

6. The battery separator according to claim 1 , wherein the second porous substrate further comprises an inorganic particle, and the inorganic particle is one or more selected from the group consisting of alumina, silica, magnesia, titania, hafnium dioxide, tin oxide, cerium oxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and barium sulfate.

7. The battery separator according to claim 1 , further comprising a binder layer disposed between the first porous substrate and the second porous substrate.

8. The battery separator according to claim 7 , wherein the binder layer comprises a binder selected from one or more of polyvinylidene fluoride, polytetrafluoroethylene, polyacrylate, carboxymethyl cellulose sodium, styrene butadiene rubber, or polyurethane.

9. The battery separator according to claim 7 , wherein the binder layer comprises a hot melt adhesive selected from one or more of a TPU hot melt adhesive, an EVA hot melt adhesive, or a butyl sealant.

10. The battery separator according to claim 1 , wherein a peeling force between the first porous substrate and the second porous substrate is 0.1 N/m to 20 N/m.

11. An energy storage device, comprising a battery separator, wherein the battery separator comprises:
a first porous substrate; and
a second porous substrate arranged on at least one surface of the first porous substrate; wherein,
an elongation at a break of the second porous substrate is greater than an elongation at a break of the first porous substrate in at least one of a machine direction or a transverse direction of the battery separator; and
the first porous substrate comprises one or more selected from the group consisting of polypropylene, polyethylene, polyethylene terephthalate, polyimide, and polyphthalaldehyde phenyl diamine.

12. The energy storage device according to claim 11 , wherein the elongation at the break of the second porous substrate is 105% to 800% in the machine direction and the transverse direction.

13. The energy storage device according to claim 11 , wherein a ratio of thickness of the first porous substrate to the second porous substrate is 1:2 to 3:2.

14. The energy storage device according to claim 11 , wherein the second porous substrate has a tensile strength ranging from 150 kgf/cm 2 to 800 kgf/cm 2 in each of the machine direction and the transverse direction.

15. The energy storage device according to claim 11 , wherein the the second porous substrate comprises one or more selected from the group consisting of polyvinylidene fluoride, polytetrafluoroethylene, and polyurethane, the second porous substrate further comprises an inorganic particle, and the inorganic particle is one or more selected from the group consisting of alumina, silica, magnesia, titania, hafnium dioxide, tin oxide, cerium oxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and barium sulfate.

16. The energy storage device according to claim 11 , further comprising a binder layer disposed between the first porous substrate and the second porous substrate, the binder layer comprises a binder selected from one or more of polyvinylidene fluoride, polytetrafluoroethylene, polyacrylate, carboxymethyl cellulose sodium, styrene butadiene rubber, or polyurethane.

17. The energy storage device according to claim 11 , further comprising a binder layer disposed between the first porous substrate and the second porous substrate, the binder layer comprises a hot melt adhesive selected from one or more of a TPU hot melt adhesive, an EVA hot melt adhesive, or a butyl sealant.

18. The energy storage device according to claim 11 , wherein a peeling force between the first porous substrate and the second porous substrate is 0.1 N/m to 20 N/m.

19. The energy storage device according to claim 11 , wherein the energy storage device comprises a lithium ion battery.

Assignees

• Ningde Amperex Technology Ltd

Inventors

• Cui Wei
• Tao Xinghua
• Cheng Cong

Classifications

• H01M10/0525 Primary

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

• H01M50/414

  Synthetic resins, e.g. thermoplastics or thermosetting resins · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/42

  Acrylic resins · CPC title

• H01M50/423

  Polyamide resins · CPC title