Nanoporous composite separators with increased thermal conductivity

Patent metadata

Field	Value
Publication number	US-12567651-B2
Application number	US-202217861535-A
Country	US
Kind code	B2
Filing date	Jul 11, 2022
Priority date	Apr 29, 2013
Publication date	Mar 3, 2026
Grant date	Mar 3, 2026

Abstract

Nanoporous composite separators are disclosed for use in batteries and capacitors comprising a nanoporous inorganic material and an organic polymer material. The inorganic material may comprise Al 2 O 3 , AlO(OH) or boehmite, AlN, BN, SiN, ZnO, ZrO 2 , SiO 2 , or combinations thereof. The nanoporous composite separator may have a porosity of between 35-50%. The average pore size of the nanoporous composite separator may be between 10-90 nm. The separator may be formed by coating a substrate with a dispersion including the inorganic material, organic material, and a solvent. Once dried, the coating may be removed from the substrate, thus forming the nanoporous composite separator. A nanoporous composite separator may provide increased thermal conductivity and dimensional stability at temperatures above 200° C. compared to polyolefin separators.

First claim

What is claimed is:

1 . A porous composite battery separator, comprising:
a polymeric binder which comprises at least one of a polyvinylidene difluoride (PVdF) or a copolymer thereof; and modified hydrated aluminum oxide particles dispersed in the polymeric binder, the modified hydrated aluminum oxide particles having a bimodal particle size distribution in a range from about 0.15 μm to about 0.19 μm and from about 2 μm to about 11 μm, the porous composite battery separator having thermal conductivity of at least 0.6 W/m-K at 25° C. when measured by an ASTM E1461 method, and the porous composite battery separator not comprising an additional polymeric separator layer.

2 . The porous composite battery separator of claim 1 which exhibits less than 1% shrinkage when exposed to a temperature of 200° C. or 220° C. for one hour.

3 . The porous composite battery separator of claim 1 , wherein the thermal conductivity of the porous composite battery separator is higher at 50° C. than at 25° C.

4 . The porous composite battery separator of claim 1 , having an average pore size from 10 nm to 50 nm.

5 . The porous composite battery separator of claim 1 , having a porosity of from 35% to 50%.

6 . The porous composite battery separator of claim 1 , wherein the PVdF has a molecular weight of equal to or greater than 1,000,000 Da.

7 . The porous composite battery separator of claim 1 , wherein the copolymer is selected from the group consisting of polyvinyl ethers, urethanes, acrylics, cellulosics, styrene-butadiene copolymers, natural rubbers, chitosan, nitrile rubbers, silicone elastomers, PEO or PEO copolymers, and polyphosphazenes.

8 . The porous composite battery separator of claim 1 , wherein a dimensional stability of the porous composite battery separator is substantially constant at temperatures from 50° C. to 250° C.

9 . The porous composite battery separator of claim 1 , wherein the modified hydrated aluminum oxide particles comprise a boehmite.

10 . An electrochemical cell comprising:
an anode; a cathode; an organic electrolyte comprising a lithium salt; and a porous composite battery separator, comprising:
a polymeric binder which comprises at least one of a polyvinylidene difluoride (PVdF) or a copolymer thereof; and
modified hydrated aluminum oxide particles dispersed in the polymeric binder, the modified hydrated aluminum oxide particles having a bimodal particle size distribution in a range from about 0.15 μm to about 0.19 μm and from about 2 μm to about 11 μm,
the porous composite battery separator having a thermal conductivity of at least 0.6 W/m-K at 25° C. when measured by an ASTM E1461, and the porous composite battery separator not comprising an additional polymeric separator layer.

11 . The electrochemical cell of claim 10 which exhibits less than 1% shrinkage when exposed to a temperature of 200° C. or 220° C. for one hour.

12 . The electrochemical cell of claim 10 , wherein the thermal conductivity of the porous composite battery separator is higher at 50° C. than at 25° C.

13 . The electrochemical cell of claim 10 , having an average pore size of 10 nm to 50 nm.

14 . The electrochemical cell of claim 10 , having a porosity of 35% to 50%.

15 . The electrochemical cell of claim 10 , wherein the PVdF has a molecular weight of equal to or greater than 1,000,000 Da.

16 . The electrochemical cell of claim 10 , wherein the copolymer selected from the group consisting of polyvinyl ethers, urethanes, acrylics, cellulosics, styrene-butadiene copolymers, natural rubbers, chitosan, nitrile rubbers, silicone elastomers, PEO or PEO copolymers, and polyphosphazenes.

17 . The electrochemical cell of claim 10 , wherein a dimensional stability of the porous composite battery separator is substantially constant at temperatures from 50° C. to 250° C.

18 . The electrochemical cell of claim 10 , wherein the modified hydrated aluminum oxide particles comprise a boehmite.

Assignees

• 24M Tech Inc

Inventors

• Avison David W
• Shingi Shreyans
• Patel Chandrakant C
• Comeau Jr Charles R
• Lim Samuel

Classifications

• C09K5/08

  Materials not undergoing a change of physical state when used (C09K5/16, C09K5/20 take precedence) · CPC title

• B29L2031/3468

  Batteries, accumulators or fuel cells (battery cases B29L2031/7146) · CPC title

• B29K2715/003

  Cellular or porous · CPC title

• B29K2709/02

  Ceramics · CPC title

• B29K2105/20

  Inserts · CPC title