Electrospinning of PVdF-HFP: novel composite polymer electrolytes (CPES) with enhanced ionic conductivities for lithium-sulfur batteries

Patent metadata

Field	Value
Publication number	US-11728543-B2
Application number	US-201816628837-A
Country	US
Kind code	B2
Filing date	Jul 9, 2018
Priority date	Jul 7, 2017
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

The invention relates to lithium ion batteries and, more particularly, to lithium ion conducting composite polymer electrolyte separators. The separators include a nanofiber mat composed of electrospun nanofibers. The nanofibers include a polymer having one or more polar halogen groups, a lithium-containing solid or liquid electrolyte and nanoparticle filler. The polymer, electrolyte and filler are combined to form a solution that is subjected to the electro-spinning process to produce electrospun nanofibers in the form of the mat.

First claim

The invention claimed is:

1. A lithium ion conducting composite polymer electrolyte separator, comprising:
an activated nanofiber mat, comprising:
a nanofiber mat, comprising:
multiple layers of electrospun nanofibers, comprising:
a polymer having one or more polar halogen groups;
a lithium-containing solid or liquid electrolyte; and
from 10 to 20 weight percent of nanoparticle filler based on total weight of the lithium ion conducting composite polymer electrolyte separator, comprising fumed silica, nanoparticle silicon dioxide, and one or more of nanoparticle titanium dioxide, nanoparticle vanadium oxide, and nanoparticle boron trioxide; and

an activation solution comprising a liquid electrolyte, soaked in the nanofiber mat.

2. The composite polymer electrolyte separator of claim 1 , wherein the polymer comprises poly(vinylidene fluoride-co-hexafluoro propylene).

3. The composite polymer electrolyte separator of claim 1 , wherein the electrolyte comprises bis(trifluoromethane)sulfonimide lithium salt.

4. The composite polymer electrolyte separator of claim 1 , wherein the lithium-containing solid or liquid electrolyte comprises an element selected from the group consisting of magnesium, sodium and mixtures and combinations thereof.

5. The composite polymer electrolyte separator of claim 1 , wherein the nanoparticle filler comprises nanoparticles selected from the group consisting of transition metal, metal oxide and metal non-oxide selected from Group III, Group IV and Group V of the Periodic Table.

6. The composite polymer electrolyte separator of claim 5 , wherein the metal non-oxide is selected from the group consisting of nitride, carbide, boride, sulfide, selenide, telluride, phosphide, antimonide, arsenide, bismuthide, and mixtures and combinations thereof.

7. The composite polymer electrolyte separator of claim 1 , wherein the nanoparticle filler comprises a dopant to form a doped nanoparticle filler.

8. The composite polymer electrolyte separator of claim 7 , wherein the doped nanoparticle filler is selected from the group consisting of Al 2 O 3 , B 2 O 3 , GeO 2 , SnO 2 , Bi 2 O 3 , Sb 2 O 3 and mixtures thereof.

9. The composite polymer electrolyte separator of claim 1 , wherein the composite is a membrane.

10. The composite polymer electrolyte separator of claim 1 , wherein the electrospun nanofibers have a diameter from 1-5 μm.

11. A method of preparing a lithium ion conducting composite polymer electrolyte separator, comprising:
preparing a solution, comprising:
a polymer having one or more polar halogen groups;
a lithium-containing solid or liquid electrolyte; and
from 10 to 20 weight percent of nanoparticle filler based on total weight of the lithium ion conducting composite polymer electrolyte separator, comprising fumed silica, nanoparticle silicon dioxide, and one or more of nanoparticle titanium dioxide, nanoparticle vanadium oxide, and nanoparticle boron trioxide;

electrospinning the solution;
forming electrospun nanofibers;
forming a nanofiber mat comprising multiple layers of the electrospun nanofibers; and
activating the nanofiber mat comprising soaking the nanofiber mat in an activation solution comprising a liquid electrolyte.

Assignees

• Univ Of Pittsburgh—Of The Commonwealth System Of Higher Education

Inventors

• Kumta Prashant N
• Gattu Bharat
• Datta Moni Kanchan
• Velikokhatnyi Oleg
• Shanthi Pavithra Murugavel
• Jampani Hanumantha Prashanth

Classifications

• H01M50/44 Primary

  Fibrous material · CPC title

• D01D5/003

  the material being a polymer solution or dispersion (D01D5/0053 takes precedence) · CPC title

• D01F1/10

  Other agents for modifying properties · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M10/0565

  Polymeric materials, e.g. gel-type or solid-type · CPC title