Separator for alkaline batteries, and alkaline battery using same

• US 10,461,294 B2
• Filed: 09/16/2016
• Issued: 10/29/2019
• Est. Priority Date: 03/25/2014
• Status: Active Grant

• Current Assignee: Kuraray Company Limited
• Original Assignee: Kuraray Company Limited
• Inventors: Hayakawa, Tomohiro, Kawai, Hiroyuki
• Primary Examiner(s): Jelsma, Jonathan G
• Assistant Examiner(s): Kekia, Omar M
• Application Number:
  US15/267,604
• Publication Number:
  US 20170005311A1
• Time in Patent Office: 1,138 Days
• Field of Search: 429246, 429247, 429249, 429255
• CPC Class Codes: H01M 50/417 Polyolefins
• CPC Class Codes: H01M 50/423 Polyamide resins
• CPC Class Codes: H01M 50/429 Natural polymers
• CPC Class Codes: H01M 50/4295 Natural cotton, cellulose or wood
• CPC Class Codes: H01M 50/44 Fibrous material
• CPC Class Codes: H01M 50/491 Porosity
• CPC Class Codes: H01M 50/494 Tensile strength
• CPC Class Codes: H01M 6/045 characterised by aqueous electrolyte

Abstract

Provided are an alkaline battery separator suitably used for an alkaline battery, and an alkaline battery using the separator. The separator includes a nonwoven fabric including subject fibers; at least a part of the subject fibers containing a chelate forming fiber having a chelate formable functional group being capable of forming a chelate with a metal ion. The alkaline battery includes a positive electrode, a negative electrode, the above-described separator placed therebetween, and an electrolyte.

Claims

1. An alkaline battery separator comprising a nonwoven fabric, wherein

the nonwoven fabric comprises subject fibers;

at least a part of the subject fibers comprise a chelate forming fiber;

the chelate forming fiber has a chelate formable functional group introduced into a fiber material and is capable of forming a chelate with a metal ion;

the subject fibers in the nonwoven fabric further comprise a shape retainable fiber; and

a mass ratio of the chelate forming fiber to the shape retainable fiber, chelate forming fiber/shape retainable fiber, is from 8/92 to 67/33.

2. The separator as claimed in claim 1, wherein the chelate formable functional group is an aminopolycarboxylic group.

3. The separator as claimed in claim 1, wherein the chelate forming fiber is a fiber having a chelate formable functional group introduced into a cellulosic fiber.

4. The separator as claimed in claim 1, wherein the subject fibers comprise a chelate forming fiber and an additional fiber other than the chelate forming fiber.

5. The separator as claimed in claim 1, wherein a proportion of the chelate forming fiber in the nonwoven fabric is from 1 to 30% by mass.

6. The separator as claimed in claim 1, wherein the subject fibers in the nonwoven fabric further comprise an alkaline-resistant fibrillated fiber.

7. The separator as claimed in claim 6, wherein the alkaline-resistant fibrillated fiber comprises a cellulosic fibrillated fiber.

8. The separator as claimed in claim 6, wherein the mass ratio of the chelate forming fiber to the alkaline-resistant fibrillated fiber, chelate forming fiber/alkaline-resistant fibrillated fiber, is from 2/98 to 60/40.

9. The separator as claimed in claim 1, wherein the shape retainable fiber comprises a polyvinyl alcohol fiber.

10. The separator as claimed in claim 1, wherein the separator has an impurity metal adsorption rate of 0.5 mg or higher per 1 g of the separator.

11. The separator of claim 10, wherein the impurity metal adsorption rate is a copper adsorption rate.

12. The separator as claimed in claim 1, wherein the separator has an air permeability of from 1 to 500 cc/cm²/sec.

13. The separator as claimed in claim 1, wherein the separator has a thickness of from 50 to 300 μ

m.

14. The separator of claim 1, wherein the metal ion is at least one selected from the group consisting of copper, nickel, cobalt, and lead.

15. The separator of claim 1, wherein the shape retainable fiber comprises at least one fiber selected from the group consisting of a polyvinyl alcohol fiber, an ethylene-vinyl alcohol copolymer fiber, a polyolefinic fiber, a polyamide fiber and a polyamide/modified-polyamide composite fiber.

16. An alkaline battery comprising a positive electrode, a negative electrode, a separator placed between the positive and negative electrodes, and an electrolyte, wherein the separator is the separator of claim 1.