Battery separators, coated battery separators, batteries, and related methods

Patent metadata

Field	Value
Publication number	US-12412956-B2
Application number	US-201917054196-A
Country	US
Kind code	B2
Filing date	May 10, 2019
Priority date	May 10, 2018
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A new or improved microporous monolayer, bilayer, trilayer, or multilayer membrane, separator membrane, separator, or coated separator is disclosed. The membrane is preferably made up of at least one resin or polymer and at least one additive. The additive may comprise at least one material that improves adhesion of the microporous membrane to a coating, including a polyaramid-containing coating and a PCS coating, or to a different material such as a metallic surface, including an electrode surface. Improvements in adhesion are based on comparisons to similar microporous membranes without the at least one additive. In some preferred embodiments, the at least one additive may comprise, consist of, or consist essentially of a functionalized polymer or the combination of a functionalized polymer and an elastomer. In some embodiments, the functional group of the functionalized polymer may be maleic anhydride (MAH). Also disclosed is a battery separator or coated separator comprising the new or improved microporous membrane. The battery separator may comprise the microporous membrane coated with a polyaramid-containing coating. Also disclosed is a new or improved separator, composite, battery, secondary lithium ion battery, and/or vehicle or device comprising the separator, composite, or battery.

First claim

The invention claimed is:

1. A microporous membrane made from at least one polymer or resin and at least one additive in an amount of from 1 to 50 wt. %,
wherein at least one surface or layer of the microporous membrane exhibits an adhesion or adhesive strength with a coating comprising a polyaramid, a polymer coated separator (PCS) coating, and/or with a metallic surface such as an electrode that is higher when compared to the adhesion or adhesive strength between a microporous membrane that is made from just the at least one polymer, but does not contain the at least one additive, wherein
the higher adhesion is exhibited without pre-coating or pre-treating the microporous membrane to increase adhesion, and
the at least one additive comprises a functional polymer, and wherein the functional polymer is a mixture of maleic anhydride modified polypropylene (MA-PP) and a maleic anhydride modified high density polyethylene (MA-PE);
wherein, optionally, a coating comprising a polyaramid or a metallic surface is provided on the surface or layer of the microporous membrane; and
wherein additive achieves at least one of the following functions:
increases adhesion of at least one surface of the microporous membrane with a coating layer, including a polyaramid containing coating, a ceramic coating, a polymer coating, and the like;
increases adhesion of at least one surface of the microporous membrane with a metallic surface such as an electrode;
reduces pin removal on at least one surface of the microporous membrane;
increases wettability with electrolyte on at least one surface of the microporous membrane;
increases ion capture on at least one surface of the microporous membrane;
increases toughness or durability on at least one surface of the microporous membrane;
controls pore size on at least one surface of the microporous membrane;
reduces static on at least one surface of the microporous membrane;
increases puncture strength; and/or
increases ionic transport across the membrane.

2. The microporous membrane of claim 1 , wherein said coating alternatively comprising a polymer coated separator (PCS) coating.

3. The microporous membrane of claim 1 , wherein the additive further comprises an elastomer selected from styrene-ethylene-propylene-styrene (SEPS) and styrene-ethylene-butylene-styrene (SEBS).

4. The microporous membrane of claim 1 , wherein the additive is present in an amount of 1 to 25 wt. % based on the total weight of the membrane, 1 to 15 wt. % based on the total weight of the membrane, or 1 to 10 wt. % based on the total weight of the membrane.

5. The microporous membrane of claim 1 , wherein:
the membrane is a bilayer membrane, and at least one layer of the bilayer membrane comprises the additive;
the membrane is a bilayer membrane and both layers of the bilayer membrane comprise the additive;
the membrane is a bilayer membrane, and at least one layer of the bilayer membrane comprises the additive in an amount up to 50 wt. % based on the weight of the layer, up to 40 wt. % based on the weight of the layer, up to 30 wt. % based on the weight of the layer, up to 25 wt. % based on the weight of the layer, up to 20 wt. % based on the weight of the layer, based on 15 wt. % based on the weight of the layer, up to 10 wt. % based on the weight of the layer, or up to 5 wt. % based on the weight of the layer;
the membrane is a multilayer membrane, and at least one layer of the multilayer membrane comprises the additive;
the membrane is a multilayer membrane, and at least one outermost layer of the multilayer membrane comprises the additive;
the membrane is a multilayer membrane, and at least one layer of the multilayer membrane comprises the additive in an amount up to 50 wt. % based on the weight of the layer, up to 40 wt. % based on the weight of the layer, up to 30 wt. % based on the weight of the layer, up to 25 wt. % based on the weight of the layer, up to 20 wt. % based on the weight of the layer, based on 15 wt. % based on the weight of the layer, up to 10 wt. % based on the weight of the layer, or up to 5 wt. % based on the weight of the layer; or
the membrane is a multilayer membrane, and at least one outermost layer of the multilayer membrane comprises the additive in an amount up to 20 wt. % based on the weight of the layer, up to 15 wt. % based on the weight of the layer, up to 10 wt. % based on the weight of the layer, or up to 5 wt. % based on the weight of the layer.

6. The microporous membrane of claim 1 , wherein at least one surface of the microporous membrane exhibits at least one of reduced pin removal force, more controlled pore size, improved wetting with electrolyte, improved ion capture, increased toughness, and combinations thereof compared to a microporous membrane that is made from the at least one polymer, but does not contain any additives.

7. The microporous membrane of claim 6 , wherein:
at least one surface of the microporous membrane exhibits reduced pin removal force compared to a microporous membrane that is made from the at least one polymer, but does not contain any additives;
at least one surface of the microporous membrane exhibits reduced pin removal force compared to a microporous membrane that is made from the at least one polymer, but does not contain any additives, and the at least one surface that exhibits reduced pin removal force is not the same as the at least one surface that exhibits improved adhesion;
at least one surface of the microporous membrane exhibits reduced pin removal force compared to a microporous membrane that is made from the at least one polymer, but does not contain any additives, and the microporous membrane comprises the at least one additive comprises at least one lubricating agent;
at least one surface of the microporous membrane exhibits reduced pin removal force compared to a microporous membrane that is made from the at least one polymer, but does not contain any additives, and the microporous membrane comprises the at least one additive comprises at least one lubricating agent, wherein the lubricating agent is amphiphilic;
at least one surface of the microporous membrane exhibits reduced pin removal force compared to a microporous membrane that is made from the at least one polymer, but does not contain any additives, and the microporous membrane comprises the at least one additive comprises at least one lubricating agent, wherein the lubricating agent is a fatty acid salt;
at least one surface of the microporous membrane exhibits reduced pin removal force compared to a microporous membrane that is made from the at least one polymer, but does not contain any additives, and the microporous membrane comprises the at least one additive comprises at least one lubricating agent, wherein the lubricating agent is a fatty acid salt selected from lithium stearate, sodium stearate, potassium stearate, and combinations thereof;
at least one surface of the microporous membrane exhibits reduced pin removal force compared to a microporous membrane that is made from the at least one polymer, but does not contain any additives, and the microporous membrane comprises the at least one additive comprises at least one lubricating agent, wherein the lubricating agent is a compound comprising one or more siloxy functional groups, including a siloxane or polysiloxane;
at least one surface of the microporous membrane exhibits reduced pin removal force compared to a microporous membrane that is made from the at least one polymer, but does not contain any additives, and the microporous membrane comprises the at least one additive comprises at least one lubricating agent, wherein the lubricating agent is an ultra-high molecular weight polysiloxane;
at least one surface of the microporous membrane exhibits

Assignees

• Celgard Llc

Inventors

• Xiao Kang Karen
• Donn Allen M
• Reinartz Stefan
• Adams Changqing Wang
• Okada Masaaki
• Stepp Brian R
• White Eric Robert
• Chemelewski Katharine

Classifications

• H01M50/491

  Porosity · CPC title

• H01M10/0525 Primary

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

• H01M50/449

  having a layered structure · CPC title

• H01M50/46

  Separators, membranes or diaphragms characterised by their combination with electrodes · CPC title

• H01M50/423 Primary

  Polyamide resins · CPC title