Slurry for lithium ion secondary battery porous film, production method therefor, separator for lithium ion secondary battery, and lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-2016013465-A1
Application number	US-201414772036-A
Country	US
Kind code	A1
Filing date	Mar 19, 2014
Priority date	Mar 21, 2013
Publication date	Jan 14, 2016
Grant date	—

Abstract

A slurry for a lithium ion secondary battery porous membrane, including non-conductive particles, a water-soluble polymer containing an acidic group-containing monomer unit, and a particulate polymer, wherein: an amount of the water-soluble polymer is 0.05 parts by weight to 2 parts by weight relative to 100 parts by weight of the non-conductive particles; and a BET specific surface area of the non-conductive particles is 5 m 2 /g to 10 m 2 /g.

First claim

1 . A slurry for a lithium ion secondary battery porous membrane, comprising non-conductive particles, a water-soluble polymer containing an acidic group-containing monomer unit, and a particulate polymer, wherein:
an amount of the water-soluble polymer is 0.05 parts by weight to 2 parts by weight relative to 100 parts by weight of the non-conductive particles; and a BET specific surface area of the non-conductive particles is 5 m 2 /g to 10 m 2 /g.

2 . The slurry for a lithium ion secondary battery porous membrane according to claim 1 , wherein, in an accumulated particle size distribution of the non-conductive particles, a particle diameter D1 that is a cumulative volume of particle of 10% from a small diameter side, a particle diameter D50 that is a cumulative volume of particle of 50% from the small diameter side, and a particle diameter D90 that is a cumulative volume of particle of 90% from the small diameter side are as follows:
D10 is 0.2 μm to 0.4 μm; D50 is 0.5 μm to 0.9 μm; and D90 is 1.0 μm to 3.0 μm.

3 . The slurry for a lithium ion secondary battery porous membrane according to claim 1 having an iron ion concentration of 5 ppm to 500 ppm.

4 . The slurry for a lithium ion secondary battery porous membrane according to claim 1 , wherein the particulate polymer is a particulate acrylic polymer.

5 . The slurry for a lithium ion secondary battery porous membrane according to claim 1 having a solid content concentration of 35% by weight to 50% by weight.

6 . A method for producing the slurry for a lithium ion secondary battery porous membrane according to claim 1 , comprising the steps of:
mixing the non-conductive particles, the water-soluble polymer containing the acidic group-containing monomer unit, and water having an electrical conductivity of 0.5 μS/cm to 30 μS/cm to obtain a dispersion of the non-conductive particles having a solid content concentration of 40% by weight to 60% by weight; dispersing the dispersion of the non-conductive particles under a condition of 2 Wh/kg to 8 Wh/kg; and mixing the dispersion of the non-conductive particles with the particulate polymer.

7 . A separator for a lithium ion secondary battery, comprising: an organic separator layer; and a porous membrane obtained by applying onto the organic separator layer the slurry for a lithium ion secondary battery porous membrane according to claim 1 and drying the slurry.

8 . A lithium ion secondary battery comprising:
a positive electrode, a negative electrode, the separator for a lithium ion secondary battery according to claim 7 , a nd an electrolytic solution.

Assignees

• Zeon Corp

Inventors

• Akiike Junnosuke

Classifications

• C08L33/00 Primary

  Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/457

  comprising three or more layers · CPC title

• H01M50/489

  Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties · CPC title

• H01M50/423

  Polyamide resins · CPC title