ELECTROSPINNING OF PVDF-HFP: NOVEL COMPOSITE POLYMER ELECTROLYTES (CPES) WITH ENHANCED IONIC CONDUCTIVITIES FOR LITHIUM-SULFUR BATTERIES

• US 20200136113A1
• Filed: 07/09/2018
• Published: 04/30/2020
• Est. Priority Date: 07/07/2017
• Status: Active Grant

• Current Assignee: University of Pittsburgh of The Commonwealth System of Higher Education
• Original Assignee: University 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
• Granted Patent: US 11,728,543 B2
• Time in Patent Office: Days
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: D01D 5/003 the material being a polymer solution or dispersion D01D5/0053 takes precedence
• CPC Class Codes: D01F 1/09 for making electroconductive or anti-static filaments
• CPC Class Codes: D01F 1/10 Other agents for modifying properties
• CPC Class Codes: D01F 6/32 comprising halogenated hydrocarbons as the major constituent
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/056 characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 2300/0088 Composites
• CPC Class Codes: H01M 2300/0094 in the form of layered products, e.g. coatings
• CPC Class Codes: H01M 50/40 Separators; Membranes; Diaphragms; Spacing elements inside cells
• CPC Class Codes: H01M 50/403 Manufacturing processes of separators, membranes or diaphragms
• CPC Class Codes: H01M 50/426 Fluorocarbon polymers
• CPC Class Codes: H01M 50/431 Inorganic material
• CPC Class Codes: H01M 50/434 Ceramics
• CPC Class Codes: H01M 50/44 Fibrous material
• CPC Class Codes: H01M 50/489 Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
• CPC Class Codes: H01M 50/497 : Ionic conductivity
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries

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.

Claims

1. A lithium ion conducting composite polymer electrolyte separator, comprising:

a nanofiber mat, comprising;

electrospun nanofibers, comprising;

a polymer having one or more polar halogen groups;

a lithium-containing solid or liquid electrolyte; and

nanoparticle filler.

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 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 oxide is selected from the group consisting of SiO₂, Al₂O₃, B₂O₃, fumed SiO₂, TiO₂, V₂O₅, and mixtures and combinations thereof.

7. 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.

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

9. The composite polymer electrolyte separator of claim 8, wherein the doped nanoparticle filler is selected from the group consisting of Al₂O₃, B₂O₃, GeO₂, SnO₂, Bi₂O₃, Sb₂O₃ and mixtures thereof.

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

11. The composite polymer electrolyte separator of claim 1, wherein the nanofiber mat comprises multiple layers of the electrospun nanofibers.

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

m.

13. 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

nanoparticle filler;

electrospinning the solution;

forming electrospun nanofibers;

forming a nanofiber mat; and

activating the nanofiber mat.

14. The method of claim 13, wherein the activating step comprises soaking the nanofiber mat in an activation solution.

15. The method of claim 14, wherein the activation solution comprises a liquid electrolyte.