Separator, electrode group, secondary battery, battery pack, vehicle, and stationary power supply

Patent metadata

Field	Value
Publication number	US-11811088-B2
Application number	US-202016883331-A
Country	US
Kind code	B2
Filing date	May 26, 2020
Priority date	Sep 19, 2019
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

Abstract

A separator includes an inorganic particle layer including an inorganic particle, a polymeric binder and a fiber substance. A mass ratio of the fiber substance with respect to a total mass of the inorganic particle, the polymeric binder and the fiber substance is 0.1 mass % or more and 40 mass % or less.

First claim

What is claimed is:

1. A secondary battery comprising:
a positive electrode containing a positive electrode active material;
a negative electrode containing a negative electrode active material;
a separator disposed at least between the positive electrode and the negative electrode; and
an aqueous electrolyte, wherein
the separator comprises an inorganic particle layer including an inorganic particle, a polymeric binder and a fiber substance,
the fiber substance is hydrophilic and a mass ratio of the fiber substance with respect to a total mass of the inorganic particle, the polymeric binder and the fiber substance is 0.1 mass % or more and 40 mass % or less, and
a mass ratio of the polymeric binder with respect to a total mass of the inorganic particle, the polymeric binder and the fiber substance is 5 mass % or more and 30 mass % or less.

2. The secondary battery according to claim 1 , wherein the mass ratio of the fiber substance is 0.5 mass % or more and 30 mass % or less.

3. The secondary battery according to claim 1 , wherein an average fiber diameter of the fiber substance is 1 nm or more and 100 nm or less.

4. The secondary battery according to claim 1 , wherein the separator further comprises a porous free-standing film disposed on a main surface of the inorganic particle layer.

5. The secondary battery according to claim 1 , wherein the inorganic particle include at least one of NASICON type LATP (Li 1+x Al x Ti 2−x (PO 4 ) 3 ), Li 1+x Al x Ge 2−x (PO 4 ) 3 , Li 1+x Al x Zr 2−x (PO 4 ) 3 (0.1≤x≤0.5), amorphous LIPON (Li 2.9 PO 3.3 N 0.46 ), or garnet type LLZ (Li 7 La 3 Zr 2 O 12 ).

6. The secondary battery according to claim 1 , wherein the polymeric binder includes a part composed of a monomer unit comprising a hydrocarbon having a functional group containing at least one element selected from the group consisting of oxygen (O), sulfur (S), nitrogen (N), and fluorine (F), and a ratio of the part composed of the monomer unit is 70 mol % or more.

7. The secondary battery according to claim 1 , wherein the negative electrode active material includes a compound having a lithium ion adsorption/desorption potential of 1 V or more and 3 V or less (vs. Li/Li + ) as a potential based on metal lithium.

8. The secondary battery according to claim 1 , wherein the positive electrode active material includes a compound having a lithium ion adsorption/desorption potential of 2.5 V or more and 5.5 V or less (vs. Li/Li + ) as a potential based on metal lithium.

9. A battery pack comprising the secondary battery according to claim 1 .

10. The battery pack according to claim 9 , further comprising an external terminal for energization and a protection circuit.

11. The battery pack according to claim 9 , comprising a plurality of the secondary batteries, wherein the plurality of secondary batteries are electrically connected in series, in parallel, or in combination of series and parallel.

12. A vehicle comprising the battery pack according to claim 9 .

13. A stationary power supply comprising the battery pack according to claim 9 .

14. The secondary battery according to claim 1 , wherein the fiber substance is selected from the group consisting of cellulose fibers, polysaccharides, and polyvinyl alcohol.

Assignees

• Toshiba Kk

Inventors

• Uno Wataru
• Hotta Yasuyuki
• Matsuno Shinsuke
• Takami Norio

Classifications

• H01M50/446 Primary

  Composite material consisting of a mixture of organic and inorganic materials · CPC title

• H01M50/449

  having a layered structure · CPC title

• H01M50/443

  Particulate material · CPC title

• H01M50/44

  Fibrous material · CPC title

• H01M50/497

  Ionic conductivity · CPC title